[PATCH v8 00/81] VM introspection

[PATCH v8 00/81] VM introspection

[Adalbert Lazăr]

VM introspection

The KVM introspection subsystem provides a facility for applications
running on the host or in a separate VM, to control the execution of
other VMs (pause, resume, shutdown), query the state of the vCPUs (GPRs,
MSRs etc.), alter the page access bits in the shadow page tables (only
for the hardware backed ones, eg. Intel's EPT) and receive notifications
when events of interest have taken place (shadow page table level faults,
key MSR writes, hypercalls etc.). Some notifications can be responded
to with an action (like preventing an MSR from being written), others
are mere informative (like breakpoint events which can be used for
execution tracing).  With few exceptions, all events are optional. An
application using this subsystem will explicitly register for them.

The use case that gave way for the creation of this subsystem is to
monitor the guest OS and as such the ABI/API is highly influenced by how
the guest software (kernel, applications) sees the world. For example,
some events provide information specific for the host CPU architecture
(eg. MSR_IA32_SYSENTER_EIP) merely because its leveraged by guest software
to implement a critical feature (fast system calls).

At the moment, the target audience for KVMI are security software authors
that wish to perform forensics on newly discovered threats (exploits)
or to implement another layer of security like preventing a large set
of kernel rootkits simply by "locking" the kernel image in the shadow
page tables (ie. enforce .text r-x, .rodata rw- etc.). It's the latter
case that made KVMI a separate subsystem, even though many of these
features are available in the device manager. The ability to build a
security application that does not interfere (in terms of performance)
with the guest software asks for a specialized interface that is designed
for minimum overhead.

This patch series is based on kvm/master,
commit 428b8f1d9f92 ("KVM: VMX: don't allow memory operands for inline asm that modifies SP").

The previous version (v7) can be read here:

	https://lore.kernel.org/kvm/20200207181636.1065-1-alazar@bitdefender.com/

Patches 1-37: make preparatory changes

Patches 38-79: add basic introspection capabilities

Patch 80: support introspection tools that write-protect guest page tables

Patch 81: notify the introspection tool even on emulation failures
          (when the read/write callbacks used by the emulator,
           kvm_page_preread/kvm_page_prewrite, are not invoked)

Changes since v7:
    - remove the RFC tag
    - KVMI_EVENT_SINGLESTEP and KVMI_EVENT_TRAP doesn't have to
      be enabled. These events are sent after a specific command
      (KVMI_VCPU_CONTROL_SINGLESTEP/KVMI_VCPU_INJECT_EXCEPTION), as it is
      the case with KVMI_VCPU_PAUSE/KVMI_EVENT_PAUSE.
    - add kvm_x86_ops.desc_ctrl_supported()
    - fix the descriptor-table and MSR events on AMD
    - drop KVMI_EVENT_REPLY (use KVMI_EVENT instead; as we do with the commands)
    - other small changes (code refactoring, message validation, etc.).

Adalbert Lazăr (20):
  sched/swait: add swait_event_killable_exclusive()
  KVM: add new error codes for VM introspection
  KVM: add kvm_vcpu_kick_and_wait()
  KVM: doc: fix the hypercall numbering
  KVM: x86: add .control_cr3_intercept() to struct kvm_x86_ops
  KVM: x86: add .desc_ctrl_supported()
  KVM: x86: add .control_desc_intercept()
  KVM: x86: intercept the write access on sidt and other emulated
    instructions
  KVM: introspection: add hook/unhook ioctls
  KVM: introspection: add permission access ioctls
  KVM: introspection: add the read/dispatch message function
  KVM: introspection: add KVMI_GET_VERSION
  KVM: introspection: add KVMI_VM_CHECK_COMMAND and KVMI_VM_CHECK_EVENT
  KVM: introspection: add KVMI_EVENT_UNHOOK
  KVM: introspection: add KVMI_VM_CONTROL_EVENTS
  KVM: introspection: add a jobs list to every introspected vCPU
  KVM: introspection: add KVMI_VCPU_PAUSE
  KVM: introspection: add KVMI_EVENT_PAUSE_VCPU
  KVM: introspection: extend KVMI_GET_VERSION with struct kvmi_features
  KVM: introspection: add KVMI_VCPU_TRANSLATE_GVA

Marian Rotariu (1):
  KVM: introspection: add KVMI_VCPU_GET_CPUID

Mathieu Tarral (1):
  export kill_pid_info()

Mihai Donțu (35):
  KVM: x86: add kvm_arch_vcpu_get_regs() and kvm_arch_vcpu_get_sregs()
  KVM: x86: avoid injecting #PF when emulate the VMCALL instruction
  KVM: x86: add .control_msr_intercept()
  KVM: x86: vmx: use a symbolic constant when checking the exit
    qualifications
  KVM: x86: save the error code during EPT/NPF exits handling
  KVM: x86: add .fault_gla()
  KVM: x86: add .spt_fault()
  KVM: x86: add .gpt_translation_fault()
  KVM: x86: extend kvm_mmu_gva_to_gpa_system() with the 'access'
    parameter
  KVM: x86: page track: provide all page tracking hooks with the guest
    virtual address
  KVM: x86: page track: add track_create_slot() callback
  KVM: x86: page_track: add support for preread, prewrite and preexec
  KVM: x86: wire in the preread/prewrite/preexec page trackers
  KVM: introduce VM introspection
  KVM: introspection: add KVMI_VM_GET_INFO
  KVM: introspection: add KVMI_VM_READ_PHYSICAL/KVMI_VM_WRITE_PHYSICAL
  KVM: introspection: handle vCPU introspection requests
  KVM: introspection: handle vCPU commands
  KVM: introspection: add KVMI_VCPU_GET_INFO
  KVM: introspection: add crash action handling on event reply
  KVM: introspection: add KVMI_VCPU_CONTROL_EVENTS
  KVM: introspection: add KVMI_VCPU_GET_REGISTERS
  KVM: introspection: add KVMI_VCPU_SET_REGISTERS
  KVM: introspection: add KVMI_EVENT_HYPERCALL
  KVM: introspection: add KVMI_EVENT_BREAKPOINT
  KVM: introspection: add KVMI_VCPU_CONTROL_CR and KVMI_EVENT_CR
  KVM: introspection: add KVMI_VCPU_INJECT_EXCEPTION + KVMI_EVENT_TRAP
  KVM: introspection: add KVMI_EVENT_XSETBV
  KVM: introspection: add KVMI_VCPU_GET_XSAVE
  KVM: introspection: add KVMI_VCPU_GET_MTRR_TYPE
  KVM: introspection: add KVMI_VCPU_CONTROL_MSR and KVMI_EVENT_MSR
  KVM: introspection: add KVMI_VM_SET_PAGE_ACCESS
  KVM: introspection: add KVMI_EVENT_PF
  KVM: introspection: emulate a guest page table walk on SPT violations
    due to A/D bit updates
  KVM: x86: call the page tracking code on emulation failure

Mircea Cîrjaliu (2):
  KVM: x86: disable gpa_available optimization for fetch and page-walk
    NPF/EPT violations
  KVM: introspection: add vCPU related data

Nicușor Cîțu (20):
  KVM: x86: add kvm_arch_vcpu_set_regs()
  KVM: x86: add .bp_intercepted() to struct kvm_x86_ops
  KVM: x86: add .cr3_write_intercepted()
  KVM: svm: add support for descriptor-table exits
  KVM: x86: add .desc_intercepted()
  KVM: x86: export .msr_write_intercepted()
  KVM: x86: use MSR_TYPE_R, MSR_TYPE_W and MSR_TYPE_RW with AMD code too
  KVM: svm: pass struct kvm_vcpu to set_msr_interception()
  KVM: vmx: pass struct kvm_vcpu to the intercept msr related functions
  KVM: x86: add .control_singlestep()
  KVM: x86: export kvm_arch_vcpu_set_guest_debug()
  KVM: x86: export kvm_inject_pending_exception()
  KVM: x86: export kvm_vcpu_ioctl_x86_get_xsave()
  KVM: introspection: restore the state of #BP interception on unhook
  KVM: introspection: restore the state of CR3 interception on unhook
  KVM: introspection: add KVMI_EVENT_DESCRIPTOR
  KVM: introspection: restore the state of descriptor-table register
    interception on unhook
  KVM: introspection: restore the state of MSR interception on unhook
  KVM: introspection: add KVMI_VCPU_CONTROL_SINGLESTEP
  KVM: introspection: add KVMI_EVENT_SINGLESTEP

Ștefan Șicleru (2):
  KVM: add kvm_get_max_gfn()
  KVM: introspection: add KVMI_VM_GET_MAX_GFN

 Documentation/virt/kvm/api.rst                |  150 ++
 Documentation/virt/kvm/hypercalls.rst         |   39 +-
 Documentation/virt/kvm/kvmi.rst               | 1440 +++++++++++++
 arch/x86/include/asm/kvm_emulate.h            |    1 +
 arch/x86/include/asm/kvm_host.h               |   37 +-
 arch/x86/include/asm/kvm_page_track.h         |   71 +-
 arch/x86/include/asm/kvmi_host.h              |   91 +
 arch/x86/include/asm/vmx.h                    |    2 +
 arch/x86/include/uapi/asm/kvmi.h              |  147 ++
 arch/x86/kvm/Kconfig                          |    9 +
 arch/x86/kvm/Makefile                         |    2 +
 arch/x86/kvm/emulate.c                        |    4 +
 arch/x86/kvm/kvmi.c                           | 1267 +++++++++++
 arch/x86/kvm/mmu.h                            |    4 +
 arch/x86/kvm/mmu/mmu.c                        |  160 +-
 arch/x86/kvm/mmu/page_track.c                 |  142 +-
 arch/x86/kvm/svm.c                            |  281 ++-
 arch/x86/kvm/vmx/capabilities.h               |    7 +-
 arch/x86/kvm/vmx/vmx.c                        |  256 ++-
 arch/x86/kvm/vmx/vmx.h                        |    4 -
 arch/x86/kvm/x86.c                            |  306 ++-
 drivers/gpu/drm/i915/gvt/kvmgt.c              |    2 +-
 include/linux/kvm_host.h                      |   18 +
 include/linux/kvmi_host.h                     |  126 ++
 include/linux/swait.h                         |   11 +
 include/uapi/linux/kvm.h                      |   20 +
 include/uapi/linux/kvm_para.h                 |    5 +
 include/uapi/linux/kvmi.h                     |  227 ++
 kernel/signal.c                               |    1 +
 tools/testing/selftests/kvm/Makefile          |    1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 1857 +++++++++++++++++
 virt/kvm/introspection/kvmi.c                 | 1409 +++++++++++++
 virt/kvm/introspection/kvmi_int.h             |  135 ++
 virt/kvm/introspection/kvmi_msg.c             | 1057 ++++++++++
 virt/kvm/kvm_main.c                           |   70 +
 35 files changed, 9178 insertions(+), 181 deletions(-)
 create mode 100644 Documentation/virt/kvm/kvmi.rst
 create mode 100644 arch/x86/include/asm/kvmi_host.h
 create mode 100644 arch/x86/include/uapi/asm/kvmi.h
 create mode 100644 arch/x86/kvm/kvmi.c
 create mode 100644 include/linux/kvmi_host.h
 create mode 100644 include/uapi/linux/kvmi.h
 create mode 100644 tools/testing/selftests/kvm/x86_64/kvmi_test.c
 create mode 100644 virt/kvm/introspection/kvmi.c
 create mode 100644 virt/kvm/introspection/kvmi_int.h
 create mode 100644 virt/kvm/introspection/kvmi_msg.c


base-commit: 428b8f1d9f92f838b73997adc10046d3c6e05790
CC: Edwin Zhai <edwin.zhai@intel.com>
CC: Jan Kiszka <jan.kiszka@siemens.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: Mathieu Tarral <mathieu.tarral@protonmail.com>
CC: Patrick Colp <patrick.colp@oracle.com>
CC: Samuel Laurén <samuel.lauren@iki.fi>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Tamas K Lengyel <tamas@tklengyel.com>
CC: Weijiang Yang <weijiang.yang@intel.com>
CC: Yu C Zhang <yu.c.zhang@intel.com>
CC: Sean Christopherson <sean.j.christopherson@intel.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Wanpeng Li <wanpengli@tencent.com>
CC: Jim Mattson <jmattson@google.com>

[PATCH v8 01/81] sched/swait: add swait_event_killable_exclusive()

[Adalbert Lazăr]

When a vCPU is introspected, it waits for introspection commands or event
replies. If the introspection channel is closed, the receiving thread
will wake-up the vCPU threads. With this function the vCPU thread will
wake-up on SIGKILL too.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 include/linux/swait.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/swait.h b/include/linux/swait.h
index 73e06e9986d4..9c53383219f6 100644
--- a/include/linux/swait.h
+++ b/include/linux/swait.h
@@ -297,4 +297,15 @@ do {									\
 	__ret;								\
 })
 
+#define __swait_event_killable(wq, condition)				\
+	___swait_event(wq, condition, TASK_KILLABLE, 0,	schedule())
+
+#define swait_event_killable_exclusive(wq, condition)			\
+({									\
+	int __ret = 0;							\
+	if (!(condition))						\
+		__ret = __swait_event_killable(wq, condition);		\
+	__ret;								\
+})
+
 #endif /* _LINUX_SWAIT_H */

[PATCH v8 02/81] export kill_pid_info()

[Adalbert Lazăr]

From: Mathieu Tarral <mathieu.tarral@protonmail.com>

This function is used by KVMI (KVM introspection sub-system) to
ungracefully shutdown the guest when an introspection tool requests it.

A security application will use it as a last resort in stopping the
spread of a malware from a guest

Signed-off-by: Mathieu Tarral <mathieu.tarral@protonmail.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 kernel/signal.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/signal.c b/kernel/signal.c
index 9ad8dea93dbb..ae62d1155ba8 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1451,6 +1451,7 @@ int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid)
 		 */
 	}
 }
+EXPORT_SYMBOL(kill_pid_info);
 
 static int kill_proc_info(int sig, struct kernel_siginfo *info, pid_t pid)
 {

[PATCH v8 03/81] KVM: add new error codes for VM introspection

[Adalbert Lazăr]

These new error codes can give the introspection tool more information
about why a introspection command failed, helping it to handle some
error cases.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 include/uapi/linux/kvm_para.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h
index 8b86609849b9..3ce388249682 100644
--- a/include/uapi/linux/kvm_para.h
+++ b/include/uapi/linux/kvm_para.h
@@ -17,6 +17,10 @@
 #define KVM_E2BIG		E2BIG
 #define KVM_EPERM		EPERM
 #define KVM_EOPNOTSUPP		95
+#define KVM_EAGAIN		11
+#define KVM_ENOENT		ENOENT
+#define KVM_ENOMEM		ENOMEM
+#define KVM_EBUSY		EBUSY
 
 #define KVM_HC_VAPIC_POLL_IRQ		1
 #define KVM_HC_MMU_OP			2

[PATCH v8 04/81] KVM: add kvm_vcpu_kick_and_wait()

[Adalbert Lazăr]

This function is needed for the KVMI_VCPU_PAUSE command. There are
cases when it is easier for the introspection tool if it knows that
the vCPU doesn't run guest code when the command completed, without
the need to wait for the KVMI_EVENT_PAUSE_VCPU event.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 include/linux/kvm_host.h |  1 +
 virt/kvm/kvm_main.c      | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index bcb9b2ac0791..6890f0a85dba 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -799,6 +799,7 @@ void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu);
 bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu);
 void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
+void kvm_vcpu_kick_and_wait(struct kvm_vcpu *vcpu);
 int kvm_vcpu_yield_to(struct kvm_vcpu *target);
 void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool usermode_vcpu_not_eligible);
 
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 70f03ce0e5c1..4c69ce5aa79c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2567,6 +2567,16 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
 EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
 #endif /* !CONFIG_S390 */
 
+void kvm_vcpu_kick_and_wait(struct kvm_vcpu *vcpu)
+{
+	if (kvm_vcpu_wake_up(vcpu))
+		return;
+
+	if (kvm_request_needs_ipi(vcpu, KVM_REQUEST_WAIT))
+		smp_call_function_single(vcpu->cpu, ack_flush, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_kick_and_wait);
+
 int kvm_vcpu_yield_to(struct kvm_vcpu *target)
 {
 	struct pid *pid;

[PATCH v8 05/81] KVM: add kvm_get_max_gfn()

[Adalbert Lazăr]

From: Ștefan Șicleru <ssicleru@bitdefender.com>

This function is needed for the KVMI_VM_GET_MAX_GFN command.

Signed-off-by: Ștefan Șicleru <ssicleru@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 include/linux/kvm_host.h |  1 +
 virt/kvm/kvm_main.c      | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6890f0a85dba..6680592f2de1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -765,6 +765,7 @@ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn);
 bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn);
 unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn);
 void mark_page_dirty(struct kvm *kvm, gfn_t gfn);
+gfn_t kvm_get_max_gfn(struct kvm *kvm);
 
 struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu);
 struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4c69ce5aa79c..a6eb3f8ea62f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1175,6 +1175,29 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 	return kvm_set_memory_region(kvm, mem);
 }
 
+gfn_t kvm_get_max_gfn(struct kvm *kvm)
+{
+	struct kvm_memory_slot *memslot;
+	struct kvm_memslots *slots;
+	gfn_t max_gfn = 0;
+	int i, idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+
+	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+		slots = __kvm_memslots(kvm, i);
+		kvm_for_each_memslot(memslot, slots)
+			max_gfn = max(max_gfn, memslot->base_gfn
+						+ memslot->npages);
+	}
+
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+
+	return max_gfn;
+}
+
 int kvm_get_dirty_log(struct kvm *kvm,
 			struct kvm_dirty_log *log, int *is_dirty)
 {

[PATCH v8 06/81] KVM: doc: fix the hypercall numbering

[Adalbert Lazăr]

The next hypercalls will use proper numbers.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/hypercalls.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/virt/kvm/hypercalls.rst b/Documentation/virt/kvm/hypercalls.rst
index dbaf207e560d..81294aaea07a 100644
--- a/Documentation/virt/kvm/hypercalls.rst
+++ b/Documentation/virt/kvm/hypercalls.rst
@@ -137,7 +137,7 @@ compute the CLOCK_REALTIME for its clock, at the same instant.
 Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource,
 or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK.
 
-6. KVM_HC_SEND_IPI
+7. KVM_HC_SEND_IPI
 ------------------
 
 :Architecture: x86
@@ -158,7 +158,7 @@ corresponds to the APIC ID a2+1, and so on.
 
 Returns the number of CPUs to which the IPIs were delivered successfully.
 
-7. KVM_HC_SCHED_YIELD
+8. KVM_HC_SCHED_YIELD
 ---------------------
 
 :Architecture: x86

[PATCH v8 07/81] KVM: x86: add kvm_arch_vcpu_get_regs() and kvm_arch_vcpu_get_sregs()

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

These functions are needed for VM introspection (KVMI_VCPU_GET_REGISTERS
command and all events sending the vCPU registers to the introspection
tool).

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/x86.c       | 10 ++++++++++
 include/linux/kvm_host.h |  3 +++
 2 files changed, 13 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d65ff2008cf1..d45b5093fdd3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8788,6 +8788,11 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 	return 0;
 }
 
+void kvm_arch_vcpu_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+	__get_regs(vcpu, regs);
+}
+
 static void __set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
 	vcpu->arch.emulate_regs_need_sync_from_vcpu = true;
@@ -8883,6 +8888,11 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+void kvm_arch_vcpu_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
+{
+	__get_sregs(vcpu, sregs);
+}
+
 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
 				    struct kvm_mp_state *mp_state)
 {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6680592f2de1..18b7d2a259b7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -853,9 +853,12 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 				    struct kvm_translation *tr);
 
 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
+void kvm_arch_vcpu_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 				  struct kvm_sregs *sregs);
+void kvm_arch_vcpu_get_sregs(struct kvm_vcpu *vcpu,
+				  struct kvm_sregs *sregs);
 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 				  struct kvm_sregs *sregs);
 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,

[PATCH v8 08/81] KVM: x86: add kvm_arch_vcpu_set_regs()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This is needed for the KVMI_VCPU_SET_REGISTERS command,
but without clearing the pending exception.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/x86.c       | 21 ++++++++++++++-------
 include/linux/kvm_host.h |  2 ++
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d45b5093fdd3..7f23e015fc86 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8819,16 +8819,23 @@ static void __set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 
 	kvm_rip_write(vcpu, regs->rip);
 	kvm_set_rflags(vcpu, regs->rflags | X86_EFLAGS_FIXED);
-
-	vcpu->arch.exception.pending = false;
-
-	kvm_make_request(KVM_REQ_EVENT, vcpu);
 }
 
-int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+void kvm_arch_vcpu_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs,
+			    bool clear_exception)
 {
-	vcpu_load(vcpu);
 	__set_regs(vcpu, regs);
+
+	if (clear_exception)
+		vcpu->arch.exception.pending = false;
+
+	kvm_make_request(KVM_REQ_EVENT, vcpu);
+}
+
+int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+	vcpu_load(vcpu);
+	kvm_arch_vcpu_set_regs(vcpu, regs, true);
 	vcpu_put(vcpu);
 	return 0;
 }
@@ -9235,7 +9242,7 @@ static int sync_regs(struct kvm_vcpu *vcpu)
 		return -EINVAL;
 
 	if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_REGS) {
-		__set_regs(vcpu, &vcpu->run->s.regs.regs);
+		kvm_arch_vcpu_set_regs(vcpu, &vcpu->run->s.regs.regs, true);
 		vcpu->run->kvm_dirty_regs &= ~KVM_SYNC_X86_REGS;
 	}
 	if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_SREGS) {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 18b7d2a259b7..3cfc38ef4048 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -855,6 +855,8 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
 void kvm_arch_vcpu_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
+void kvm_arch_vcpu_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs,
+			    bool clear_exception);
 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 				  struct kvm_sregs *sregs);
 void kvm_arch_vcpu_get_sregs(struct kvm_vcpu *vcpu,

[PATCH v8 09/81] KVM: x86: avoid injecting #PF when emulate the VMCALL instruction

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

It can happened to end up emulating the VMCALL instruction as a result
of the handling of an EPT write fault. In this situation,
the emulator will try to unconditionally patch the correct hypercall
opcode bytes using emulator_write_emulated(). However, this last call
uses the fault GPA (if available) or walks the guest page tables at RIP,
otherwise. The trouble begins when using VM introspection,
when we forbid the use of the fault GPA and fallback to the guest pt walk:
in Windows (8.1 and newer) the page that we try to write into
is marked read-execute and as such emulator_write_emulated() fails
and we inject a write #PF, leading to a guest crash.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/x86.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7f23e015fc86..bfd8e3515c0d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7580,11 +7580,15 @@ static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt)
 	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
 	char instruction[3];
 	unsigned long rip = kvm_rip_read(vcpu);
+	int err;
 
 	kvm_x86_ops->patch_hypercall(vcpu, instruction);
 
-	return emulator_write_emulated(ctxt, rip, instruction, 3,
+	err = emulator_write_emulated(ctxt, rip, instruction, 3,
 		&ctxt->exception);
+	if (err == X86EMUL_PROPAGATE_FAULT)
+		err = X86EMUL_CONTINUE;
+	return err;
 }
 
 static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)

[PATCH v8 10/81] KVM: x86: add .bp_intercepted() to struct kvm_x86_ops

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

The introspection tool and the userspace can request #BP interception.
This function will be used to check if this interception is enabled
by either side.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/svm.c              | 15 +++++++++++++++
 arch/x86/kvm/vmx/vmx.c          |  6 ++++++
 3 files changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 98959e8cd448..afc5bf3fa730 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1077,6 +1077,7 @@ struct kvm_x86_ops {
 	void (*vcpu_load)(struct kvm_vcpu *vcpu, int cpu);
 	void (*vcpu_put)(struct kvm_vcpu *vcpu);
 
+	bool (*bp_intercepted)(struct kvm_vcpu *vcpu);
 	void (*update_bp_intercept)(struct kvm_vcpu *vcpu);
 	int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
 	int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 50d1ebafe0b3..73871f28ad7b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -611,6 +611,13 @@ static inline void clr_exception_intercept(struct vcpu_svm *svm, int bit)
 	recalc_intercepts(svm);
 }
 
+static inline bool get_exception_intercept(struct vcpu_svm *svm, int bit)
+{
+	struct vmcb *vmcb = get_host_vmcb(svm);
+
+	return (vmcb->control.intercept_exceptions & (1U << bit));
+}
+
 static inline void set_intercept(struct vcpu_svm *svm, int bit)
 {
 	struct vmcb *vmcb = get_host_vmcb(svm);
@@ -7393,6 +7400,13 @@ static void svm_pre_update_apicv_exec_ctrl(struct kvm *kvm, bool activate)
 	avic_update_access_page(kvm, activate);
 }
 
+static inline bool svm_bp_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	return get_exception_intercept(svm, BP_VECTOR);
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -7419,6 +7433,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.vcpu_blocking = svm_vcpu_blocking,
 	.vcpu_unblocking = svm_vcpu_unblocking,
 
+	.bp_intercepted = svm_bp_intercepted,
 	.update_bp_intercept = update_bp_intercept,
 	.get_msr_feature = svm_get_msr_feature,
 	.get_msr = svm_get_msr,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 079d9fbf278e..eee8d81f7083 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7849,6 +7849,11 @@ static bool vmx_check_apicv_inhibit_reasons(ulong bit)
 	return supported & BIT(bit);
 }
 
+static bool vmx_bp_intercepted(struct kvm_vcpu *vcpu)
+{
+	return (vmcs_read32(EXCEPTION_BITMAP) & (1u << BP_VECTOR));
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -7872,6 +7877,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.vcpu_load = vmx_vcpu_load,
 	.vcpu_put = vmx_vcpu_put,
 
+	.bp_intercepted = vmx_bp_intercepted,
 	.update_bp_intercept = update_exception_bitmap,
 	.get_msr_feature = vmx_get_msr_feature,
 	.get_msr = vmx_get_msr,

[PATCH v8 11/81] KVM: x86: add .control_cr3_intercept() to struct kvm_x86_ops

[Adalbert Lazăr]

This function is needed for the KVMI_VCPU_CONTROL_CR command.

Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  6 ++++++
 arch/x86/kvm/svm.c              | 14 ++++++++++++++
 arch/x86/kvm/vmx/vmx.c          | 26 ++++++++++++++++++++------
 3 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index afc5bf3fa730..10cf8f3f29d8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -136,6 +136,10 @@ static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level)
 #define KVM_NR_FIXED_MTRR_REGION 88
 #define KVM_NR_VAR_MTRR 8
 
+#define CR_TYPE_R	1
+#define CR_TYPE_W	2
+#define CR_TYPE_RW	3
+
 #define ASYNC_PF_PER_VCPU 64
 
 enum kvm_reg {
@@ -1093,6 +1097,8 @@ struct kvm_x86_ops {
 	void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0);
 	void (*set_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3);
 	int (*set_cr4)(struct kvm_vcpu *vcpu, unsigned long cr4);
+	void (*control_cr3_intercept)(struct kvm_vcpu *vcpu, int type,
+				      bool enable);
 	void (*set_efer)(struct kvm_vcpu *vcpu, u64 efer);
 	void (*get_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	void (*set_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 73871f28ad7b..1dfe646e47c1 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7407,6 +7407,19 @@ static inline bool svm_bp_intercepted(struct kvm_vcpu *vcpu)
 	return get_exception_intercept(svm, BP_VECTOR);
 }
 
+static void svm_control_cr3_intercept(struct kvm_vcpu *vcpu, int type,
+				      bool enable)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	if (type & CR_TYPE_R)
+		enable ? set_cr_intercept(svm, INTERCEPT_CR3_READ) :
+			 clr_cr_intercept(svm, INTERCEPT_CR3_READ);
+	if (type & CR_TYPE_W)
+		enable ? set_cr_intercept(svm, INTERCEPT_CR3_WRITE) :
+			 clr_cr_intercept(svm, INTERCEPT_CR3_WRITE);
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -7448,6 +7461,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.set_cr0 = svm_set_cr0,
 	.set_cr3 = svm_set_cr3,
 	.set_cr4 = svm_set_cr4,
+	.control_cr3_intercept = svm_control_cr3_intercept,
 	.set_efer = svm_set_efer,
 	.get_idt = svm_get_idt,
 	.set_idt = svm_set_idt,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index eee8d81f7083..923e1d382077 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2933,24 +2933,37 @@ void ept_save_pdptrs(struct kvm_vcpu *vcpu)
 	kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
 }
 
+static void vmx_control_cr3_intercept(struct kvm_vcpu *vcpu, int type,
+				      bool enable)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	u32 cr3_exec_control = 0;
+
+	if (type & CR_TYPE_R)
+		cr3_exec_control |= CPU_BASED_CR3_STORE_EXITING;
+	if (type & CR_TYPE_W)
+		cr3_exec_control |= CPU_BASED_CR3_LOAD_EXITING;
+
+	if (enable)
+		exec_controls_setbit(vmx, cr3_exec_control);
+	else
+		exec_controls_clearbit(vmx, cr3_exec_control);
+}
+
 static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
 					unsigned long cr0,
 					struct kvm_vcpu *vcpu)
 {
-	struct vcpu_vmx *vmx = to_vmx(vcpu);
-
 	if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
 		vmx_cache_reg(vcpu, VCPU_EXREG_CR3);
 	if (!(cr0 & X86_CR0_PG)) {
 		/* From paging/starting to nonpaging */
-		exec_controls_setbit(vmx, CPU_BASED_CR3_LOAD_EXITING |
-					  CPU_BASED_CR3_STORE_EXITING);
+		vmx_control_cr3_intercept(vcpu, CR_TYPE_RW, true);
 		vcpu->arch.cr0 = cr0;
 		vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
 	} else if (!is_paging(vcpu)) {
 		/* From nonpaging to paging */
-		exec_controls_clearbit(vmx, CPU_BASED_CR3_LOAD_EXITING |
-					    CPU_BASED_CR3_STORE_EXITING);
+		vmx_control_cr3_intercept(vcpu, CR_TYPE_RW, false);
 		vcpu->arch.cr0 = cr0;
 		vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
 	}
@@ -7892,6 +7905,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.set_cr0 = vmx_set_cr0,
 	.set_cr3 = vmx_set_cr3,
 	.set_cr4 = vmx_set_cr4,
+	.control_cr3_intercept = vmx_control_cr3_intercept,
 	.set_efer = vmx_set_efer,
 	.get_idt = vmx_get_idt,
 	.set_idt = vmx_set_idt,

[PATCH v8 12/81] KVM: x86: add .cr3_write_intercepted()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This function will be used to allow the introspection tool to disable the
CR3-write interception when it is no longer interested in these events,
but only if nothing depends on these VM-exits.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm.c              | 8 ++++++++
 arch/x86/kvm/vmx/vmx.c          | 8 ++++++++
 3 files changed, 17 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 10cf8f3f29d8..bf36ed2c5e9b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1099,6 +1099,7 @@ struct kvm_x86_ops {
 	int (*set_cr4)(struct kvm_vcpu *vcpu, unsigned long cr4);
 	void (*control_cr3_intercept)(struct kvm_vcpu *vcpu, int type,
 				      bool enable);
+	bool (*cr3_write_intercepted)(struct kvm_vcpu *vcpu);
 	void (*set_efer)(struct kvm_vcpu *vcpu, u64 efer);
 	void (*get_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	void (*set_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1dfe646e47c1..de409d73ce0c 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7407,6 +7407,13 @@ static inline bool svm_bp_intercepted(struct kvm_vcpu *vcpu)
 	return get_exception_intercept(svm, BP_VECTOR);
 }
 
+static inline bool svm_cr3_write_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	return is_cr_intercept(svm, INTERCEPT_CR3_WRITE);
+}
+
 static void svm_control_cr3_intercept(struct kvm_vcpu *vcpu, int type,
 				      bool enable)
 {
@@ -7462,6 +7469,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.set_cr3 = svm_set_cr3,
 	.set_cr4 = svm_set_cr4,
 	.control_cr3_intercept = svm_control_cr3_intercept,
+	.cr3_write_intercepted = svm_cr3_write_intercepted,
 	.set_efer = svm_set_efer,
 	.get_idt = svm_get_idt,
 	.set_idt = svm_set_idt,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 923e1d382077..ba47f5f2ea91 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7867,6 +7867,13 @@ static bool vmx_bp_intercepted(struct kvm_vcpu *vcpu)
 	return (vmcs_read32(EXCEPTION_BITMAP) & (1u << BP_VECTOR));
 }
 
+static bool vmx_cr3_write_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+	return !!(exec_controls_get(vmx) & CPU_BASED_CR3_LOAD_EXITING);
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -7906,6 +7913,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.set_cr3 = vmx_set_cr3,
 	.set_cr4 = vmx_set_cr4,
 	.control_cr3_intercept = vmx_control_cr3_intercept,
+	.cr3_write_intercepted = vmx_cr3_write_intercepted,
 	.set_efer = vmx_set_efer,
 	.get_idt = vmx_get_idt,
 	.set_idt = vmx_set_idt,

[PATCH v8 13/81] KVM: x86: add .desc_ctrl_supported()

[Adalbert Lazăr]

This function is needed for the KVMI_EVENT_DESCRIPTOR event.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm.c              | 6 ++++++
 arch/x86/kvm/vmx/capabilities.h | 7 ++++++-
 arch/x86/kvm/vmx/vmx.c          | 1 +
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index bf36ed2c5e9b..81a59b03b0c5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1105,6 +1105,7 @@ struct kvm_x86_ops {
 	void (*set_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	void (*get_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	void (*set_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
+	bool (*desc_ctrl_supported)(void);
 	u64 (*get_dr6)(struct kvm_vcpu *vcpu);
 	void (*set_dr6)(struct kvm_vcpu *vcpu, unsigned long value);
 	void (*sync_dirty_debug_regs)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index de409d73ce0c..f9185f0b0c2b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6109,6 +6109,11 @@ static bool svm_xsaves_supported(void)
 	return boot_cpu_has(X86_FEATURE_XSAVES);
 }
 
+static bool svm_desc_ctrl_supported(void)
+{
+	return true;
+}
+
 static bool svm_umip_emulated(void)
 {
 	return false;
@@ -7475,6 +7480,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.set_idt = svm_set_idt,
 	.get_gdt = svm_get_gdt,
 	.set_gdt = svm_set_gdt,
+	.desc_ctrl_supported = svm_desc_ctrl_supported,
 	.get_dr6 = svm_get_dr6,
 	.set_dr6 = svm_set_dr6,
 	.set_dr7 = svm_set_dr7,
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index f486e2606247..22301cc979cb 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -140,12 +140,17 @@ static inline bool cpu_has_vmx_ept(void)
 		SECONDARY_EXEC_ENABLE_EPT;
 }
 
-static inline bool vmx_umip_emulated(void)
+static inline bool vmx_desc_ctrl_supported(void)
 {
 	return vmcs_config.cpu_based_2nd_exec_ctrl &
 		SECONDARY_EXEC_DESC;
 }
 
+static inline bool vmx_umip_emulated(void)
+{
+	return vmx_desc_ctrl_supported();
+}
+
 static inline bool vmx_pku_supported(void)
 {
 	return boot_cpu_has(X86_FEATURE_PKU);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ba47f5f2ea91..657c9ac0070b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7919,6 +7919,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.set_idt = vmx_set_idt,
 	.get_gdt = vmx_get_gdt,
 	.set_gdt = vmx_set_gdt,
+	.desc_ctrl_supported = vmx_desc_ctrl_supported,
 	.get_dr6 = vmx_get_dr6,
 	.set_dr6 = vmx_set_dr6,
 	.set_dr7 = vmx_set_dr7,

[PATCH v8 14/81] KVM: svm: add support for descriptor-table exits

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This function is needed for the KVMI_EVENT_DESCRIPTOR event.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/svm.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f9185f0b0c2b..fd21439475b5 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4792,6 +4792,13 @@ static int avic_unaccelerated_access_interception(struct vcpu_svm *svm)
 	return ret;
 }
 
+static int descriptor_access_interception(struct vcpu_svm *svm)
+{
+	struct kvm_vcpu *vcpu = &svm->vcpu;
+
+	return kvm_emulate_instruction(vcpu, 0);
+}
+
 static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
 	[SVM_EXIT_READ_CR0]			= cr_interception,
 	[SVM_EXIT_READ_CR3]			= cr_interception,
@@ -4858,6 +4865,14 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
 	[SVM_EXIT_RSM]                          = rsm_interception,
 	[SVM_EXIT_AVIC_INCOMPLETE_IPI]		= avic_incomplete_ipi_interception,
 	[SVM_EXIT_AVIC_UNACCELERATED_ACCESS]	= avic_unaccelerated_access_interception,
+	[SVM_EXIT_IDTR_READ]			= descriptor_access_interception,
+	[SVM_EXIT_GDTR_READ]			= descriptor_access_interception,
+	[SVM_EXIT_LDTR_READ]			= descriptor_access_interception,
+	[SVM_EXIT_TR_READ]			= descriptor_access_interception,
+	[SVM_EXIT_IDTR_WRITE]			= descriptor_access_interception,
+	[SVM_EXIT_GDTR_WRITE]			= descriptor_access_interception,
+	[SVM_EXIT_LDTR_WRITE]			= descriptor_access_interception,
+	[SVM_EXIT_TR_WRITE]			= descriptor_access_interception,
 };
 
 static void dump_vmcb(struct kvm_vcpu *vcpu)

[PATCH v8 15/81] KVM: x86: add .control_desc_intercept()

[Adalbert Lazăr]

This function is needed for the KVMI_EVENT_DESCRIPTOR event.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/svm.c              | 26 ++++++++++++++++++++++++++
 arch/x86/kvm/vmx/vmx.c          | 15 +++++++++++++--
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 81a59b03b0c5..11e49dbec78c 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1106,6 +1106,7 @@ struct kvm_x86_ops {
 	void (*get_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	void (*set_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	bool (*desc_ctrl_supported)(void);
+	void (*control_desc_intercept)(struct kvm_vcpu *vcpu, bool enable);
 	u64 (*get_dr6)(struct kvm_vcpu *vcpu);
 	void (*set_dr6)(struct kvm_vcpu *vcpu, unsigned long value);
 	void (*sync_dirty_debug_regs)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fd21439475b5..ea4f02cab67d 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7447,6 +7447,31 @@ static void svm_control_cr3_intercept(struct kvm_vcpu *vcpu, int type,
 			 clr_cr_intercept(svm, INTERCEPT_CR3_WRITE);
 }
 
+static void svm_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	if (enable) {
+		set_intercept(svm, INTERCEPT_STORE_IDTR);
+		set_intercept(svm, INTERCEPT_STORE_GDTR);
+		set_intercept(svm, INTERCEPT_STORE_LDTR);
+		set_intercept(svm, INTERCEPT_STORE_TR);
+		set_intercept(svm, INTERCEPT_LOAD_IDTR);
+		set_intercept(svm, INTERCEPT_LOAD_GDTR);
+		set_intercept(svm, INTERCEPT_LOAD_LDTR);
+		set_intercept(svm, INTERCEPT_LOAD_TR);
+	} else {
+		clr_intercept(svm, INTERCEPT_STORE_IDTR);
+		clr_intercept(svm, INTERCEPT_STORE_GDTR);
+		clr_intercept(svm, INTERCEPT_STORE_LDTR);
+		clr_intercept(svm, INTERCEPT_STORE_TR);
+		clr_intercept(svm, INTERCEPT_LOAD_IDTR);
+		clr_intercept(svm, INTERCEPT_LOAD_GDTR);
+		clr_intercept(svm, INTERCEPT_LOAD_LDTR);
+		clr_intercept(svm, INTERCEPT_LOAD_TR);
+	}
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -7496,6 +7521,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.get_gdt = svm_get_gdt,
 	.set_gdt = svm_set_gdt,
 	.desc_ctrl_supported = svm_desc_ctrl_supported,
+	.control_desc_intercept = svm_control_desc_intercept,
 	.get_dr6 = svm_get_dr6,
 	.set_dr6 = svm_set_dr6,
 	.set_dr7 = svm_set_dr7,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 657c9ac0070b..c710bd200c56 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3034,6 +3034,16 @@ u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa)
 	return eptp;
 }
 
+static void vmx_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+	if (enable)
+		secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_DESC);
+	else
+		secondary_exec_controls_clearbit(vmx, SECONDARY_EXEC_DESC);
+}
+
 void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -3090,11 +3100,11 @@ int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 
 	if (!boot_cpu_has(X86_FEATURE_UMIP) && vmx_umip_emulated()) {
 		if (cr4 & X86_CR4_UMIP) {
-			secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_DESC);
+			vmx_control_desc_intercept(vcpu, true);
 			hw_cr4 &= ~X86_CR4_UMIP;
 		} else if (!is_guest_mode(vcpu) ||
 			!nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC)) {
-			secondary_exec_controls_clearbit(vmx, SECONDARY_EXEC_DESC);
+			vmx_control_desc_intercept(vcpu, false);
 		}
 	}
 
@@ -7920,6 +7930,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.get_gdt = vmx_get_gdt,
 	.set_gdt = vmx_set_gdt,
 	.desc_ctrl_supported = vmx_desc_ctrl_supported,
+	.control_desc_intercept = vmx_control_desc_intercept,
 	.get_dr6 = vmx_get_dr6,
 	.set_dr6 = vmx_set_dr6,
 	.set_dr7 = vmx_set_dr7,

[PATCH v8 16/81] KVM: x86: add .desc_intercepted()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This function will be used to test if the descriptor access events
are already tracked by another user.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/svm.c              | 22 ++++++++++++++++++++++
 arch/x86/kvm/vmx/vmx.c          |  8 ++++++++
 3 files changed, 31 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 11e49dbec78c..89968ec63b64 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1107,6 +1107,7 @@ struct kvm_x86_ops {
 	void (*set_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
 	bool (*desc_ctrl_supported)(void);
 	void (*control_desc_intercept)(struct kvm_vcpu *vcpu, bool enable);
+	bool (*desc_intercepted)(struct kvm_vcpu *vcpu);
 	u64 (*get_dr6)(struct kvm_vcpu *vcpu);
 	void (*set_dr6)(struct kvm_vcpu *vcpu, unsigned long value);
 	void (*sync_dirty_debug_regs)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ea4f02cab67d..34e7f4f18cd8 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -636,6 +636,13 @@ static inline void clr_intercept(struct vcpu_svm *svm, int bit)
 	recalc_intercepts(svm);
 }
 
+static inline bool get_intercept(struct vcpu_svm *svm, int bit)
+{
+	struct vmcb *vmcb = get_host_vmcb(svm);
+
+	return (vmcb->control.intercept & (1ULL << bit));
+}
+
 static inline bool vgif_enabled(struct vcpu_svm *svm)
 {
 	return !!(svm->vmcb->control.int_ctl & V_GIF_ENABLE_MASK);
@@ -7472,6 +7479,20 @@ static void svm_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
 	}
 }
 
+static inline bool svm_desc_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	return (get_intercept(svm, INTERCEPT_STORE_IDTR) ||
+		get_intercept(svm, INTERCEPT_STORE_GDTR) ||
+		get_intercept(svm, INTERCEPT_STORE_LDTR) ||
+		get_intercept(svm, INTERCEPT_STORE_TR) ||
+		get_intercept(svm, INTERCEPT_LOAD_IDTR) ||
+		get_intercept(svm, INTERCEPT_LOAD_GDTR) ||
+		get_intercept(svm, INTERCEPT_LOAD_LDTR) ||
+		get_intercept(svm, INTERCEPT_LOAD_TR));
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -7522,6 +7543,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.set_gdt = svm_set_gdt,
 	.desc_ctrl_supported = svm_desc_ctrl_supported,
 	.control_desc_intercept = svm_control_desc_intercept,
+	.desc_intercepted = svm_desc_intercepted,
 	.get_dr6 = svm_get_dr6,
 	.set_dr6 = svm_set_dr6,
 	.set_dr7 = svm_set_dr7,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c710bd200c56..4651d1283698 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7884,6 +7884,13 @@ static bool vmx_cr3_write_intercepted(struct kvm_vcpu *vcpu)
 	return !!(exec_controls_get(vmx) & CPU_BASED_CR3_LOAD_EXITING);
 }
 
+static bool vmx_desc_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+	return !!(secondary_exec_controls_get(vmx) & SECONDARY_EXEC_DESC);
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -7931,6 +7938,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.set_gdt = vmx_set_gdt,
 	.desc_ctrl_supported = vmx_desc_ctrl_supported,
 	.control_desc_intercept = vmx_control_desc_intercept,
+	.desc_intercepted = vmx_desc_intercepted,
 	.get_dr6 = vmx_get_dr6,
 	.set_dr6 = vmx_set_dr6,
 	.set_dr7 = vmx_set_dr7,

[PATCH v8 17/81] KVM: x86: export .msr_write_intercepted()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This function will be used to test if a MSR access is already tracked.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm.c              | 1 +
 arch/x86/kvm/vmx/vmx.c          | 1 +
 3 files changed, 3 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 89968ec63b64..8d5012330e2d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1085,6 +1085,7 @@ struct kvm_x86_ops {
 	void (*update_bp_intercept)(struct kvm_vcpu *vcpu);
 	int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
 	int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
+	bool (*msr_write_intercepted)(struct kvm_vcpu *vcpu, u32 msr);
 	u64 (*get_segment_base)(struct kvm_vcpu *vcpu, int seg);
 	void (*get_segment)(struct kvm_vcpu *vcpu,
 			    struct kvm_segment *var, int seg);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 34e7f4f18cd8..463fe8112f22 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7524,6 +7524,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.get_msr_feature = svm_get_msr_feature,
 	.get_msr = svm_get_msr,
 	.set_msr = svm_set_msr,
+	.msr_write_intercepted = msr_write_intercepted,
 	.get_segment_base = svm_get_segment_base,
 	.get_segment = svm_get_segment,
 	.set_segment = svm_set_segment,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 4651d1283698..2801b1f7054f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7919,6 +7919,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.get_msr_feature = vmx_get_msr_feature,
 	.get_msr = vmx_get_msr,
 	.set_msr = vmx_set_msr,
+	.msr_write_intercepted = msr_write_intercepted,
 	.get_segment_base = vmx_get_segment_base,
 	.get_segment = vmx_get_segment,
 	.set_segment = vmx_set_segment,

[PATCH v8 18/81] KVM: x86: use MSR_TYPE_R, MSR_TYPE_W and MSR_TYPE_RW with AMD code too

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

We can than use a common interface to enable/disable the MSR interception.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  4 +++
 arch/x86/kvm/svm.c              | 44 ++++++++++++++++++++++-----------
 arch/x86/kvm/vmx/vmx.h          |  4 ---
 3 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8d5012330e2d..9ae0e0364caf 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -140,6 +140,10 @@ static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level)
 #define CR_TYPE_W	2
 #define CR_TYPE_RW	3
 
+#define MSR_TYPE_R	1
+#define MSR_TYPE_W	2
+#define MSR_TYPE_RW	3
+
 #define ASYNC_PF_PER_VCPU 64
 
 enum kvm_reg {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 463fe8112f22..70c8c913f14e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1081,7 +1081,7 @@ static bool msr_write_intercepted(struct kvm_vcpu *vcpu, unsigned msr)
 }
 
 static void set_msr_interception(u32 *msrpm, unsigned msr,
-				 int read, int write)
+				 int type, bool value)
 {
 	u8 bit_read, bit_write;
 	unsigned long tmp;
@@ -1100,8 +1100,11 @@ static void set_msr_interception(u32 *msrpm, unsigned msr,
 
 	BUG_ON(offset == MSR_INVALID);
 
-	read  ? clear_bit(bit_read,  &tmp) : set_bit(bit_read,  &tmp);
-	write ? clear_bit(bit_write, &tmp) : set_bit(bit_write, &tmp);
+	if (type & MSR_TYPE_R)
+		value ? clear_bit(bit_read,  &tmp) : set_bit(bit_read,  &tmp);
+	if (type & MSR_TYPE_W)
+		value ? clear_bit(bit_write, &tmp) : set_bit(bit_write, &tmp);
+
 
 	msrpm[offset] = tmp;
 }
@@ -1116,7 +1119,8 @@ static void svm_vcpu_init_msrpm(u32 *msrpm)
 		if (!direct_access_msrs[i].always)
 			continue;
 
-		set_msr_interception(msrpm, direct_access_msrs[i].index, 1, 1);
+		set_msr_interception(msrpm, direct_access_msrs[i].index,
+				     MSR_TYPE_RW, 1);
 	}
 }
 
@@ -1168,10 +1172,14 @@ static void svm_enable_lbrv(struct vcpu_svm *svm)
 	u32 *msrpm = svm->msrpm;
 
 	svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK;
-	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP, 1, 1);
-	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP, 1, 1);
-	set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP, 1, 1);
-	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP, 1, 1);
+	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP,
+			     MSR_TYPE_RW, 1);
+	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP,
+			     MSR_TYPE_RW, 1);
+	set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP,
+			     MSR_TYPE_RW, 1);
+	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP,
+			     MSR_TYPE_RW, 1);
 }
 
 static void svm_disable_lbrv(struct vcpu_svm *svm)
@@ -1179,10 +1187,14 @@ static void svm_disable_lbrv(struct vcpu_svm *svm)
 	u32 *msrpm = svm->msrpm;
 
 	svm->vmcb->control.virt_ext &= ~LBR_CTL_ENABLE_MASK;
-	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP, 0, 0);
-	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP, 0, 0);
-	set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP, 0, 0);
-	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP, 0, 0);
+	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP,
+			     MSR_TYPE_RW, 0);
+	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP,
+			     MSR_TYPE_RW, 0);
+	set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP,
+			     MSR_TYPE_RW, 0);
+	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP,
+			     MSR_TYPE_RW, 0);
 }
 
 static void disable_nmi_singlestep(struct vcpu_svm *svm)
@@ -4350,7 +4362,8 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 		 * We update the L1 MSR bit as well since it will end up
 		 * touching the MSR anyway now.
 		 */
-		set_msr_interception(svm->msrpm, MSR_IA32_SPEC_CTRL, 1, 1);
+		set_msr_interception(svm->msrpm, MSR_IA32_SPEC_CTRL,
+				     MSR_TYPE_RW, 1);
 		break;
 	case MSR_IA32_PRED_CMD:
 		if (!msr->host_initiated &&
@@ -4365,7 +4378,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 			break;
 
 		wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
-		set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD, 0, 1);
+		set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD,
+				     MSR_TYPE_R, 0);
+		set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD,
+				     MSR_TYPE_W, 1);
 		break;
 	case MSR_AMD64_VIRT_SPEC_CTRL:
 		if (!msr->host_initiated &&
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index e64da06c7009..e55748ad68c1 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -16,10 +16,6 @@ extern u64 host_efer;
 
 extern u32 get_umwait_control_msr(void);
 
-#define MSR_TYPE_R	1
-#define MSR_TYPE_W	2
-#define MSR_TYPE_RW	3
-
 #define X2APIC_MSR(r) (APIC_BASE_MSR + ((r) >> 4))
 
 #ifdef CONFIG_X86_64

[PATCH v8 19/81] KVM: svm: pass struct kvm_vcpu to set_msr_interception()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This is needed in order to handle clients controlling the MSR related
VM-exits.

Passing NULL during initialization is OK
because a vCPU can be introspected only after initialization.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/svm.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 70c8c913f14e..37c78bb4ba0b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1080,7 +1080,8 @@ static bool msr_write_intercepted(struct kvm_vcpu *vcpu, unsigned msr)
 	return !!test_bit(bit_write,  &tmp);
 }
 
-static void set_msr_interception(u32 *msrpm, unsigned msr,
+static void set_msr_interception(struct kvm_vcpu *vcpu,
+				 u32 *msrpm, unsigned msr,
 				 int type, bool value)
 {
 	u8 bit_read, bit_write;
@@ -1119,7 +1120,7 @@ static void svm_vcpu_init_msrpm(u32 *msrpm)
 		if (!direct_access_msrs[i].always)
 			continue;
 
-		set_msr_interception(msrpm, direct_access_msrs[i].index,
+		set_msr_interception(NULL, msrpm, direct_access_msrs[i].index,
 				     MSR_TYPE_RW, 1);
 	}
 }
@@ -1172,13 +1173,13 @@ static void svm_enable_lbrv(struct vcpu_svm *svm)
 	u32 *msrpm = svm->msrpm;
 
 	svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK;
-	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP,
+	set_msr_interception(&svm->vcpu, msrpm, MSR_IA32_LASTBRANCHFROMIP,
 			     MSR_TYPE_RW, 1);
-	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP,
+	set_msr_interception(&svm->vcpu, msrpm, MSR_IA32_LASTBRANCHTOIP,
 			     MSR_TYPE_RW, 1);
-	set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP,
+	set_msr_interception(&svm->vcpu, msrpm, MSR_IA32_LASTINTFROMIP,
 			     MSR_TYPE_RW, 1);
-	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP,
+	set_msr_interception(&svm->vcpu, msrpm, MSR_IA32_LASTINTTOIP,
 			     MSR_TYPE_RW, 1);
 }
 
@@ -1187,13 +1188,13 @@ static void svm_disable_lbrv(struct vcpu_svm *svm)
 	u32 *msrpm = svm->msrpm;
 
 	svm->vmcb->control.virt_ext &= ~LBR_CTL_ENABLE_MASK;
-	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP,
+	set_msr_interception(&svm->vcpu, msrpm, MSR_IA32_LASTBRANCHFROMIP,
 			     MSR_TYPE_RW, 0);
-	set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP,
+	set_msr_interception(&svm->vcpu, msrpm, MSR_IA32_LASTBRANCHTOIP,
 			     MSR_TYPE_RW, 0);
-	set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP,
+	set_msr_interception(&svm->vcpu, msrpm, MSR_IA32_LASTINTFROMIP,
 			     MSR_TYPE_RW, 0);
-	set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP,
+	set_msr_interception(&svm->vcpu, msrpm, MSR_IA32_LASTINTTOIP,
 			     MSR_TYPE_RW, 0);
 }
 
@@ -4362,7 +4363,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 		 * We update the L1 MSR bit as well since it will end up
 		 * touching the MSR anyway now.
 		 */
-		set_msr_interception(svm->msrpm, MSR_IA32_SPEC_CTRL,
+		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SPEC_CTRL,
 				     MSR_TYPE_RW, 1);
 		break;
 	case MSR_IA32_PRED_CMD:
@@ -4378,9 +4379,9 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 			break;
 
 		wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
-		set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD,
+		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_PRED_CMD,
 				     MSR_TYPE_R, 0);
-		set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD,
+		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_PRED_CMD,
 				     MSR_TYPE_W, 1);
 		break;
 	case MSR_AMD64_VIRT_SPEC_CTRL:

[PATCH v8 20/81] KVM: vmx: pass struct kvm_vcpu to the intercept msr related functions

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This is needed in order to handle clients controlling the MSR related
VM-exits.

Passing NULL during initialization is OK
because a vCPU can be introspected only after initialization.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/vmx/vmx.c | 70 +++++++++++++++++++++++-------------------
 1 file changed, 38 insertions(+), 32 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2801b1f7054f..4dc6fbf91ca5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -343,7 +343,8 @@ module_param_cb(vmentry_l1d_flush, &vmentry_l1d_flush_ops, NULL, 0644);
 
 static bool guest_state_valid(struct kvm_vcpu *vcpu);
 static u32 vmx_segment_access_rights(struct kvm_segment *var);
-static __always_inline void vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
+static __always_inline void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu,
+							  unsigned long *msr_bitmap,
 							  u32 msr, int type);
 
 void vmx_vmexit(void);
@@ -2067,7 +2068,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		 * in the merging. We update the vmcs01 here for L1 as well
 		 * since it will end up touching the MSR anyway now.
 		 */
-		vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap,
+		vmx_disable_intercept_for_msr(vcpu, vmx->vmcs01.msr_bitmap,
 					      MSR_IA32_SPEC_CTRL,
 					      MSR_TYPE_RW);
 		break;
@@ -2103,8 +2104,8 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		 * vmcs02.msr_bitmap here since it gets completely overwritten
 		 * in the merging.
 		 */
-		vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD,
-					      MSR_TYPE_W);
+		vmx_disable_intercept_for_msr(vcpu, vmx->vmcs01.msr_bitmap,
+					      MSR_IA32_PRED_CMD, MSR_TYPE_W);
 		break;
 	case MSR_IA32_CR_PAT:
 		if (!kvm_pat_valid(data))
@@ -3644,7 +3645,8 @@ void free_vpid(int vpid)
 	spin_unlock(&vmx_vpid_lock);
 }
 
-static __always_inline void vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
+static __always_inline void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu,
+							  unsigned long *msr_bitmap,
 							  u32 msr, int type)
 {
 	int f = sizeof(unsigned long);
@@ -3682,7 +3684,8 @@ static __always_inline void vmx_disable_intercept_for_msr(unsigned long *msr_bit
 	}
 }
 
-static __always_inline void vmx_enable_intercept_for_msr(unsigned long *msr_bitmap,
+static __always_inline void vmx_enable_intercept_for_msr(struct kvm_vcpu *vcpu,
+							 unsigned long *msr_bitmap,
 							 u32 msr, int type)
 {
 	int f = sizeof(unsigned long);
@@ -3720,13 +3723,14 @@ static __always_inline void vmx_enable_intercept_for_msr(unsigned long *msr_bitm
 	}
 }
 
-static __always_inline void vmx_set_intercept_for_msr(unsigned long *msr_bitmap,
+static __always_inline void vmx_set_intercept_for_msr(struct kvm_vcpu *vcpu,
+						      unsigned long *msr_bitmap,
 			     			      u32 msr, int type, bool value)
 {
 	if (value)
-		vmx_enable_intercept_for_msr(msr_bitmap, msr, type);
+		vmx_enable_intercept_for_msr(vcpu, msr_bitmap, msr, type);
 	else
-		vmx_disable_intercept_for_msr(msr_bitmap, msr, type);
+		vmx_disable_intercept_for_msr(vcpu, msr_bitmap, msr, type);
 }
 
 static u8 vmx_msr_bitmap_mode(struct kvm_vcpu *vcpu)
@@ -3744,7 +3748,8 @@ static u8 vmx_msr_bitmap_mode(struct kvm_vcpu *vcpu)
 	return mode;
 }
 
-static void vmx_update_msr_bitmap_x2apic(unsigned long *msr_bitmap,
+static void vmx_update_msr_bitmap_x2apic(struct kvm_vcpu *vcpu,
+					 unsigned long *msr_bitmap,
 					 u8 mode)
 {
 	int msr;
@@ -3760,11 +3765,11 @@ static void vmx_update_msr_bitmap_x2apic(unsigned long *msr_bitmap,
 		 * TPR reads and writes can be virtualized even if virtual interrupt
 		 * delivery is not in use.
 		 */
-		vmx_disable_intercept_for_msr(msr_bitmap, X2APIC_MSR(APIC_TASKPRI), MSR_TYPE_RW);
+		vmx_disable_intercept_for_msr(vcpu, msr_bitmap, X2APIC_MSR(APIC_TASKPRI), MSR_TYPE_RW);
 		if (mode & MSR_BITMAP_MODE_X2APIC_APICV) {
-			vmx_enable_intercept_for_msr(msr_bitmap, X2APIC_MSR(APIC_TMCCT), MSR_TYPE_R);
-			vmx_disable_intercept_for_msr(msr_bitmap, X2APIC_MSR(APIC_EOI), MSR_TYPE_W);
-			vmx_disable_intercept_for_msr(msr_bitmap, X2APIC_MSR(APIC_SELF_IPI), MSR_TYPE_W);
+			vmx_enable_intercept_for_msr(vcpu, msr_bitmap, X2APIC_MSR(APIC_TMCCT), MSR_TYPE_R);
+			vmx_disable_intercept_for_msr(vcpu, msr_bitmap, X2APIC_MSR(APIC_EOI), MSR_TYPE_W);
+			vmx_disable_intercept_for_msr(vcpu, msr_bitmap, X2APIC_MSR(APIC_SELF_IPI), MSR_TYPE_W);
 		}
 	}
 }
@@ -3780,7 +3785,7 @@ void vmx_update_msr_bitmap(struct kvm_vcpu *vcpu)
 		return;
 
 	if (changed & (MSR_BITMAP_MODE_X2APIC | MSR_BITMAP_MODE_X2APIC_APICV))
-		vmx_update_msr_bitmap_x2apic(msr_bitmap, mode);
+		vmx_update_msr_bitmap_x2apic(vcpu, msr_bitmap, mode);
 
 	vmx->msr_bitmap_mode = mode;
 }
@@ -3789,20 +3794,21 @@ void pt_update_intercept_for_msr(struct vcpu_vmx *vmx)
 {
 	unsigned long *msr_bitmap = vmx->vmcs01.msr_bitmap;
 	bool flag = !(vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN);
+	struct kvm_vcpu *vcpu = &vmx->vcpu;
 	u32 i;
 
-	vmx_set_intercept_for_msr(msr_bitmap, MSR_IA32_RTIT_STATUS,
+	vmx_set_intercept_for_msr(vcpu, msr_bitmap, MSR_IA32_RTIT_STATUS,
 							MSR_TYPE_RW, flag);
-	vmx_set_intercept_for_msr(msr_bitmap, MSR_IA32_RTIT_OUTPUT_BASE,
+	vmx_set_intercept_for_msr(vcpu, msr_bitmap, MSR_IA32_RTIT_OUTPUT_BASE,
 							MSR_TYPE_RW, flag);
-	vmx_set_intercept_for_msr(msr_bitmap, MSR_IA32_RTIT_OUTPUT_MASK,
+	vmx_set_intercept_for_msr(vcpu, msr_bitmap, MSR_IA32_RTIT_OUTPUT_MASK,
 							MSR_TYPE_RW, flag);
-	vmx_set_intercept_for_msr(msr_bitmap, MSR_IA32_RTIT_CR3_MATCH,
+	vmx_set_intercept_for_msr(vcpu, msr_bitmap, MSR_IA32_RTIT_CR3_MATCH,
 							MSR_TYPE_RW, flag);
 	for (i = 0; i < vmx->pt_desc.addr_range; i++) {
-		vmx_set_intercept_for_msr(msr_bitmap,
+		vmx_set_intercept_for_msr(vcpu, msr_bitmap,
 			MSR_IA32_RTIT_ADDR0_A + i * 2, MSR_TYPE_RW, flag);
-		vmx_set_intercept_for_msr(msr_bitmap,
+		vmx_set_intercept_for_msr(vcpu, msr_bitmap,
 			MSR_IA32_RTIT_ADDR0_B + i * 2, MSR_TYPE_RW, flag);
 	}
 }
@@ -6804,18 +6810,18 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
 		goto free_pml;
 
 	msr_bitmap = vmx->vmcs01.msr_bitmap;
-	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_TSC, MSR_TYPE_R);
-	vmx_disable_intercept_for_msr(msr_bitmap, MSR_FS_BASE, MSR_TYPE_RW);
-	vmx_disable_intercept_for_msr(msr_bitmap, MSR_GS_BASE, MSR_TYPE_RW);
-	vmx_disable_intercept_for_msr(msr_bitmap, MSR_KERNEL_GS_BASE, MSR_TYPE_RW);
-	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_CS, MSR_TYPE_RW);
-	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_ESP, MSR_TYPE_RW);
-	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_EIP, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_IA32_TSC, MSR_TYPE_R);
+	vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_FS_BASE, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_GS_BASE, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_KERNEL_GS_BASE, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_IA32_SYSENTER_CS, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_IA32_SYSENTER_ESP, MSR_TYPE_RW);
+	vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_IA32_SYSENTER_EIP, MSR_TYPE_RW);
 	if (kvm_cstate_in_guest(vcpu->kvm)) {
-		vmx_disable_intercept_for_msr(msr_bitmap, MSR_CORE_C1_RES, MSR_TYPE_R);
-		vmx_disable_intercept_for_msr(msr_bitmap, MSR_CORE_C3_RESIDENCY, MSR_TYPE_R);
-		vmx_disable_intercept_for_msr(msr_bitmap, MSR_CORE_C6_RESIDENCY, MSR_TYPE_R);
-		vmx_disable_intercept_for_msr(msr_bitmap, MSR_CORE_C7_RESIDENCY, MSR_TYPE_R);
+		vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_CORE_C1_RES, MSR_TYPE_R);
+		vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_CORE_C3_RESIDENCY, MSR_TYPE_R);
+		vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_CORE_C6_RESIDENCY, MSR_TYPE_R);
+		vmx_disable_intercept_for_msr(NULL, msr_bitmap, MSR_CORE_C7_RESIDENCY, MSR_TYPE_R);
 	}
 	vmx->msr_bitmap_mode = 0;
 

[PATCH v8 21/81] KVM: x86: add .control_msr_intercept()

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This is needed for the KVMI_EVENT_MSR event.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  2 ++
 arch/x86/kvm/svm.c              | 11 +++++++++++
 arch/x86/kvm/vmx/vmx.c          | 10 ++++++++++
 3 files changed, 23 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9ae0e0364caf..73c9fcd800f8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1089,6 +1089,8 @@ struct kvm_x86_ops {
 	void (*update_bp_intercept)(struct kvm_vcpu *vcpu);
 	int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
 	int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
+	void (*control_msr_intercept)(struct kvm_vcpu *vcpu, unsigned int msr,
+				      int type, bool enable);
 	bool (*msr_write_intercepted)(struct kvm_vcpu *vcpu, u32 msr);
 	u64 (*get_segment_base)(struct kvm_vcpu *vcpu, int seg);
 	void (*get_segment)(struct kvm_vcpu *vcpu,
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 37c78bb4ba0b..13360429986e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7510,6 +7510,16 @@ static inline bool svm_desc_intercepted(struct kvm_vcpu *vcpu)
 		get_intercept(svm, INTERCEPT_LOAD_TR));
 }
 
+static void svm_control_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
+				      int type, bool enable)
+{
+	const struct vcpu_svm *svm = to_svm(vcpu);
+	u32 *msrpm = is_guest_mode(vcpu) ? svm->nested.msrpm :
+					   svm->msrpm;
+
+	set_msr_interception(vcpu, msrpm, msr, type, !enable);
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -7541,6 +7551,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.get_msr_feature = svm_get_msr_feature,
 	.get_msr = svm_get_msr,
 	.set_msr = svm_set_msr,
+	.control_msr_intercept = svm_control_msr_intercept,
 	.msr_write_intercepted = msr_write_intercepted,
 	.get_segment_base = svm_get_segment_base,
 	.get_segment = svm_get_segment,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 4dc6fbf91ca5..845bf6885ae0 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7897,6 +7897,15 @@ static bool vmx_desc_intercepted(struct kvm_vcpu *vcpu)
 	return !!(secondary_exec_controls_get(vmx) & SECONDARY_EXEC_DESC);
 }
 
+static void vmx_control_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
+				      int type, bool enable)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	unsigned long *msr_bitmap = vmx->vmcs01.msr_bitmap;
+
+	vmx_set_intercept_for_msr(vcpu, msr_bitmap, msr, type, enable);
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -7925,6 +7934,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.get_msr_feature = vmx_get_msr_feature,
 	.get_msr = vmx_get_msr,
 	.set_msr = vmx_set_msr,
+	.control_msr_intercept = vmx_control_msr_intercept,
 	.msr_write_intercepted = msr_write_intercepted,
 	.get_segment_base = vmx_get_segment_base,
 	.get_segment = vmx_get_segment,

[PATCH v8 22/81] KVM: x86: vmx: use a symbolic constant when checking the exit qualifications

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This should make the code more readable.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/vmx/vmx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 845bf6885ae0..f596238dd369 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5220,8 +5220,8 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 			EPT_VIOLATION_EXECUTABLE))
 		      ? PFERR_PRESENT_MASK : 0;
 
-	error_code |= (exit_qualification & 0x100) != 0 ?
-	       PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
+	error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED)
+		      ? PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
 
 	vcpu->arch.exit_qualification = exit_qualification;
 	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);

[PATCH v8 23/81] KVM: x86: save the error code during EPT/NPF exits handling

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This is needed for kvm_page_track_emulation_failure().

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h | 3 +++
 arch/x86/kvm/svm.c              | 2 ++
 arch/x86/kvm/vmx/vmx.c          | 1 +
 3 files changed, 6 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 73c9fcd800f8..fb1ac5646d33 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -828,6 +828,9 @@ struct kvm_vcpu_arch {
 
 	/* AMD MSRC001_0015 Hardware Configuration */
 	u64 msr_hwcr;
+
+	/* #PF translated error code from EPT/NPT exit reason */
+	u64 error_code;
 };
 
 struct kvm_lpage_info {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 13360429986e..d7e1e2d20e49 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2782,6 +2782,8 @@ static int npf_interception(struct vcpu_svm *svm)
 	u64 fault_address = __sme_clr(svm->vmcb->control.exit_info_2);
 	u64 error_code = svm->vmcb->control.exit_info_1;
 
+	svm->vcpu.arch.error_code = error_code;
+
 	trace_kvm_page_fault(fault_address, error_code);
 	return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code,
 			static_cpu_has(X86_FEATURE_DECODEASSISTS) ?
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f596238dd369..d3d5fcdd7534 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5224,6 +5224,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 		      ? PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
 
 	vcpu->arch.exit_qualification = exit_qualification;
+	vcpu->arch.error_code = error_code;
 	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
 }
 

[PATCH v8 24/81] KVM: x86: add .fault_gla()

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This function is needed for kvmi_update_ad_flags()
and kvm_page_track_emulation_failure().

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h | 2 ++
 arch/x86/include/asm/vmx.h      | 2 ++
 arch/x86/kvm/svm.c              | 9 +++++++++
 arch/x86/kvm/vmx/vmx.c          | 9 +++++++++
 4 files changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index fb1ac5646d33..c425bf1d257a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1288,6 +1288,8 @@ struct kvm_x86_ops {
 
 	bool (*apic_init_signal_blocked)(struct kvm_vcpu *vcpu);
 	int (*enable_direct_tlbflush)(struct kvm_vcpu *vcpu);
+
+	u64 (*fault_gla)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_arch_async_pf {
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 8521af3fef27..014cccb2d25d 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -529,6 +529,7 @@ struct vmx_msr_entry {
 #define EPT_VIOLATION_READABLE_BIT	3
 #define EPT_VIOLATION_WRITABLE_BIT	4
 #define EPT_VIOLATION_EXECUTABLE_BIT	5
+#define EPT_VIOLATION_GLA_VALID_BIT	7
 #define EPT_VIOLATION_GVA_TRANSLATED_BIT 8
 #define EPT_VIOLATION_ACC_READ		(1 << EPT_VIOLATION_ACC_READ_BIT)
 #define EPT_VIOLATION_ACC_WRITE		(1 << EPT_VIOLATION_ACC_WRITE_BIT)
@@ -536,6 +537,7 @@ struct vmx_msr_entry {
 #define EPT_VIOLATION_READABLE		(1 << EPT_VIOLATION_READABLE_BIT)
 #define EPT_VIOLATION_WRITABLE		(1 << EPT_VIOLATION_WRITABLE_BIT)
 #define EPT_VIOLATION_EXECUTABLE	(1 << EPT_VIOLATION_EXECUTABLE_BIT)
+#define EPT_VIOLATION_GLA_VALID		(1 << EPT_VIOLATION_GLA_VALID_BIT)
 #define EPT_VIOLATION_GVA_TRANSLATED	(1 << EPT_VIOLATION_GVA_TRANSLATED_BIT)
 
 /*
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d7e1e2d20e49..767ffd3ce4b1 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7522,6 +7522,13 @@ static void svm_control_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
 	set_msr_interception(vcpu, msrpm, msr, type, !enable);
 }
 
+static u64 svm_fault_gla(struct kvm_vcpu *vcpu)
+{
+	const struct vcpu_svm *svm = to_svm(vcpu);
+
+	return svm->vcpu.arch.cr2 ? svm->vcpu.arch.cr2 : ~0ull;
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -7670,6 +7677,8 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.need_emulation_on_page_fault = svm_need_emulation_on_page_fault,
 
 	.apic_init_signal_blocked = svm_apic_init_signal_blocked,
+
+	.fault_gla = svm_fault_gla,
 };
 
 static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d3d5fcdd7534..c1c6485aebf1 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7907,6 +7907,13 @@ static void vmx_control_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
 	vmx_set_intercept_for_msr(vcpu, msr_bitmap, msr, type, enable);
 }
 
+static u64 vmx_fault_gla(struct kvm_vcpu *vcpu)
+{
+	if (vcpu->arch.exit_qualification & EPT_VIOLATION_GLA_VALID)
+		return vmcs_readl(GUEST_LINEAR_ADDRESS);
+	return ~0ull;
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -8067,6 +8074,8 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.nested_get_evmcs_version = NULL,
 	.need_emulation_on_page_fault = vmx_need_emulation_on_page_fault,
 	.apic_init_signal_blocked = vmx_apic_init_signal_blocked,
+
+	.fault_gla = vmx_fault_gla,
 };
 
 static void vmx_cleanup_l1d_flush(void)

[PATCH v8 25/81] KVM: x86: add .spt_fault()

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This function is needed for the KVMI_EVENT_PF event.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/svm.c              | 9 +++++++++
 arch/x86/kvm/vmx/vmx.c          | 8 ++++++++
 3 files changed, 18 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c425bf1d257a..18e879d508c2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1290,6 +1290,7 @@ struct kvm_x86_ops {
 	int (*enable_direct_tlbflush)(struct kvm_vcpu *vcpu);
 
 	u64 (*fault_gla)(struct kvm_vcpu *vcpu);
+	bool (*spt_fault)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 767ffd3ce4b1..42fab46e6553 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7529,6 +7529,14 @@ static u64 svm_fault_gla(struct kvm_vcpu *vcpu)
 	return svm->vcpu.arch.cr2 ? svm->vcpu.arch.cr2 : ~0ull;
 }
 
+static bool svm_spt_fault(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+	struct vmcb *vmcb = get_host_vmcb(svm);
+
+	return (vmcb->control.exit_code == SVM_EXIT_NPF);
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -7679,6 +7687,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.apic_init_signal_blocked = svm_apic_init_signal_blocked,
 
 	.fault_gla = svm_fault_gla,
+	.spt_fault = svm_spt_fault,
 };
 
 static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c1c6485aebf1..cc30513eca95 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7914,6 +7914,13 @@ static u64 vmx_fault_gla(struct kvm_vcpu *vcpu)
 	return ~0ull;
 }
 
+static bool vmx_spt_fault(struct kvm_vcpu *vcpu)
+{
+	const struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+	return (vmx->exit_reason == EXIT_REASON_EPT_VIOLATION);
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -8076,6 +8083,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.apic_init_signal_blocked = vmx_apic_init_signal_blocked,
 
 	.fault_gla = vmx_fault_gla,
+	.spt_fault = vmx_spt_fault,
 };
 
 static void vmx_cleanup_l1d_flush(void)

[PATCH v8 26/81] KVM: x86: add .gpt_translation_fault()

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This function is needed for the KVMI_EVENT_PF event.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/svm.c              | 12 ++++++++++++
 arch/x86/kvm/vmx/vmx.c          |  8 ++++++++
 3 files changed, 21 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 18e879d508c2..2e993b240b66 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1291,6 +1291,7 @@ struct kvm_x86_ops {
 
 	u64 (*fault_gla)(struct kvm_vcpu *vcpu);
 	bool (*spt_fault)(struct kvm_vcpu *vcpu);
+	bool (*gpt_translation_fault)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 42fab46e6553..2be8f9313611 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7537,6 +7537,17 @@ static bool svm_spt_fault(struct kvm_vcpu *vcpu)
 	return (vmcb->control.exit_code == SVM_EXIT_NPF);
 }
 
+static bool svm_gpt_translation_fault(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+	struct vmcb *vmcb = get_host_vmcb(svm);
+
+	if (vmcb->control.exit_info_1 & PFERR_GUEST_PAGE_MASK)
+		return true;
+
+	return false;
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -7688,6 +7699,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 
 	.fault_gla = svm_fault_gla,
 	.spt_fault = svm_spt_fault,
+	.gpt_translation_fault = svm_gpt_translation_fault,
 };
 
 static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cc30513eca95..5422c35a3216 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7921,6 +7921,13 @@ static bool vmx_spt_fault(struct kvm_vcpu *vcpu)
 	return (vmx->exit_reason == EXIT_REASON_EPT_VIOLATION);
 }
 
+static bool vmx_gpt_translation_fault(struct kvm_vcpu *vcpu)
+{
+	if (vcpu->arch.exit_qualification & EPT_VIOLATION_GVA_TRANSLATED)
+		return false;
+	return true;
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -8084,6 +8091,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 
 	.fault_gla = vmx_fault_gla,
 	.spt_fault = vmx_spt_fault,
+	.gpt_translation_fault = vmx_gpt_translation_fault,
 };
 
 static void vmx_cleanup_l1d_flush(void)

[PATCH v8 27/81] KVM: x86: add .control_singlestep()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This function is needed for KVMI_VCPU_CONTROL_SINGLESTEP
and KVMI_EVENT_SINGLESTEP.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/vmx/vmx.c          | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2e993b240b66..5b8e44e494b1 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1292,6 +1292,7 @@ struct kvm_x86_ops {
 	u64 (*fault_gla)(struct kvm_vcpu *vcpu);
 	bool (*spt_fault)(struct kvm_vcpu *vcpu);
 	bool (*gpt_translation_fault)(struct kvm_vcpu *vcpu);
+	void (*control_singlestep)(struct kvm_vcpu *vcpu, bool enable);
 };
 
 struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5422c35a3216..13462ef2ce9e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7928,6 +7928,16 @@ static bool vmx_gpt_translation_fault(struct kvm_vcpu *vcpu)
 	return true;
 }
 
+static void vmx_control_singlestep(struct kvm_vcpu *vcpu, bool enable)
+{
+	if (enable)
+		exec_controls_setbit(to_vmx(vcpu),
+			      CPU_BASED_MONITOR_TRAP_FLAG);
+	else
+		exec_controls_clearbit(to_vmx(vcpu),
+				CPU_BASED_MONITOR_TRAP_FLAG);
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -8092,6 +8102,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.fault_gla = vmx_fault_gla,
 	.spt_fault = vmx_spt_fault,
 	.gpt_translation_fault = vmx_gpt_translation_fault,
+	.control_singlestep = vmx_control_singlestep,
 };
 
 static void vmx_cleanup_l1d_flush(void)

[PATCH v8 28/81] KVM: x86: export kvm_arch_vcpu_set_guest_debug()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This function is needed for the KVMI_EVENT_BP event.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/x86.c       | 18 +++++++++++++-----
 include/linux/kvm_host.h |  2 ++
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bfd8e3515c0d..4a4d6663608a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9103,14 +9103,12 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
-int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
-					struct kvm_guest_debug *dbg)
+int kvm_arch_vcpu_set_guest_debug(struct kvm_vcpu *vcpu,
+				  struct kvm_guest_debug *dbg)
 {
 	unsigned long rflags;
 	int i, r;
 
-	vcpu_load(vcpu);
-
 	if (dbg->control & (KVM_GUESTDBG_INJECT_DB | KVM_GUESTDBG_INJECT_BP)) {
 		r = -EBUSY;
 		if (vcpu->arch.exception.pending)
@@ -9156,10 +9154,20 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 	r = 0;
 
 out:
-	vcpu_put(vcpu);
 	return r;
 }
 
+int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
+					struct kvm_guest_debug *dbg)
+{
+	int ret;
+
+	vcpu_load(vcpu);
+	ret = kvm_arch_vcpu_set_guest_debug(vcpu, dbg);
+	vcpu_put(vcpu);
+	return ret;
+}
+
 /*
  * Translate a guest virtual address to a guest physical address.
  */
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 3cfc38ef4048..158fc782bf4a 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -869,6 +869,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 				    struct kvm_mp_state *mp_state);
 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 					struct kvm_guest_debug *dbg);
+int kvm_arch_vcpu_set_guest_debug(struct kvm_vcpu *vcpu,
+				  struct kvm_guest_debug *dbg);
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run);
 
 int kvm_arch_init(void *opaque);

[PATCH v8 29/81] KVM: x86: extend kvm_mmu_gva_to_gpa_system() with the 'access' parameter

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This is needed for the introspection subsytem to emulate a guest page
table walk on SPT violations due to A/D bit updates.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h | 2 +-
 arch/x86/kvm/x86.c              | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5b8e44e494b1..85d3c9c2983f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1522,7 +1522,7 @@ gpa_t kvm_mmu_gva_to_gpa_fetch(struct kvm_vcpu *vcpu, gva_t gva,
 gpa_t kvm_mmu_gva_to_gpa_write(struct kvm_vcpu *vcpu, gva_t gva,
 			       struct x86_exception *exception);
 gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
-				struct x86_exception *exception);
+				u32 access, struct x86_exception *exception);
 
 bool kvm_apicv_activated(struct kvm *kvm);
 void kvm_apicv_init(struct kvm *kvm, bool enable);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4a4d6663608a..ed6eb1241cf1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5414,9 +5414,9 @@ gpa_t kvm_mmu_gva_to_gpa_write(struct kvm_vcpu *vcpu, gva_t gva,
 
 /* uses this to access any guest's mapped memory without checking CPL */
 gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
-				struct x86_exception *exception)
+				u32 access, struct x86_exception *exception)
 {
-	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, 0, exception);
+	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
 }
 
 static int kvm_read_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
@@ -9181,7 +9181,7 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 	vcpu_load(vcpu);
 
 	idx = srcu_read_lock(&vcpu->kvm->srcu);
-	gpa = kvm_mmu_gva_to_gpa_system(vcpu, vaddr, NULL);
+	gpa = kvm_mmu_gva_to_gpa_system(vcpu, vaddr, 0, NULL);
 	srcu_read_unlock(&vcpu->kvm->srcu, idx);
 	tr->physical_address = gpa;
 	tr->valid = gpa != UNMAPPED_GVA;

[PATCH v8 30/81] KVM: x86: export kvm_inject_pending_exception()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This function is needed for the KVMI_VCPU_INJECT_EXCEPTION command.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/x86.c              | 71 ++++++++++++++++++---------------
 2 files changed, 39 insertions(+), 33 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 85d3c9c2983f..9772e07f8253 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1473,6 +1473,7 @@ unsigned long kvm_get_rflags(struct kvm_vcpu *vcpu);
 void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
 bool kvm_rdpmc(struct kvm_vcpu *vcpu);
 
+void kvm_inject_pending_exception(struct kvm_vcpu *vcpu);
 void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr);
 void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);
 void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ed6eb1241cf1..328d6b8429a2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7636,6 +7636,43 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu)
 	kvm_x86_ops->update_cr8_intercept(vcpu, tpr, max_irr);
 }
 
+void kvm_inject_pending_exception(struct kvm_vcpu *vcpu)
+{
+	if (vcpu->arch.exception.pending) {
+		trace_kvm_inj_exception(vcpu->arch.exception.nr,
+					vcpu->arch.exception.has_error_code,
+					vcpu->arch.exception.error_code);
+
+		WARN_ON_ONCE(vcpu->arch.exception.injected);
+		vcpu->arch.exception.pending = false;
+		vcpu->arch.exception.injected = true;
+
+		if (exception_type(vcpu->arch.exception.nr) == EXCPT_FAULT)
+			__kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
+					     X86_EFLAGS_RF);
+
+		if (vcpu->arch.exception.nr == DB_VECTOR) {
+			/*
+			 * This code assumes that nSVM doesn't use
+			 * check_nested_events(). If it does, the
+			 * DR6/DR7 changes should happen before L1
+			 * gets a #VMEXIT for an intercepted #DB in
+			 * L2.  (Under VMX, on the other hand, the
+			 * DR6/DR7 changes should not happen in the
+			 * event of a VM-exit to L1 for an intercepted
+			 * #DB in L2.)
+			 */
+			kvm_deliver_exception_payload(vcpu);
+			if (vcpu->arch.dr7 & DR7_GD) {
+				vcpu->arch.dr7 &= ~DR7_GD;
+				kvm_update_dr7(vcpu);
+			}
+		}
+
+		kvm_x86_ops->queue_exception(vcpu);
+	}
+}
+
 static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
 {
 	int r;
@@ -7678,39 +7715,7 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
 	}
 
 	/* try to inject new event if pending */
-	if (vcpu->arch.exception.pending) {
-		trace_kvm_inj_exception(vcpu->arch.exception.nr,
-					vcpu->arch.exception.has_error_code,
-					vcpu->arch.exception.error_code);
-
-		WARN_ON_ONCE(vcpu->arch.exception.injected);
-		vcpu->arch.exception.pending = false;
-		vcpu->arch.exception.injected = true;
-
-		if (exception_type(vcpu->arch.exception.nr) == EXCPT_FAULT)
-			__kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
-					     X86_EFLAGS_RF);
-
-		if (vcpu->arch.exception.nr == DB_VECTOR) {
-			/*
-			 * This code assumes that nSVM doesn't use
-			 * check_nested_events(). If it does, the
-			 * DR6/DR7 changes should happen before L1
-			 * gets a #VMEXIT for an intercepted #DB in
-			 * L2.  (Under VMX, on the other hand, the
-			 * DR6/DR7 changes should not happen in the
-			 * event of a VM-exit to L1 for an intercepted
-			 * #DB in L2.)
-			 */
-			kvm_deliver_exception_payload(vcpu);
-			if (vcpu->arch.dr7 & DR7_GD) {
-				vcpu->arch.dr7 &= ~DR7_GD;
-				kvm_update_dr7(vcpu);
-			}
-		}
-
-		kvm_x86_ops->queue_exception(vcpu);
-	}
+	kvm_inject_pending_exception(vcpu);
 
 	/* Don't consider new event if we re-injected an event */
 	if (kvm_event_needs_reinjection(vcpu))

[PATCH v8 31/81] KVM: x86: export kvm_vcpu_ioctl_x86_get_xsave()

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This function is needed for the KVMI_VCPU_GET_XSAVE command.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/x86.c       | 4 ++--
 include/linux/kvm_host.h | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 328d6b8429a2..73022eed9a94 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4070,8 +4070,8 @@ static void load_xsave(struct kvm_vcpu *vcpu, u8 *src)
 	}
 }
 
-static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
-					 struct kvm_xsave *guest_xsave)
+void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
+				  struct kvm_xsave *guest_xsave)
 {
 	if (boot_cpu_has(X86_FEATURE_XSAVE)) {
 		memset(guest_xsave, 0, sizeof(struct kvm_xsave));
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 158fc782bf4a..4a82fcf713d1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -872,6 +872,8 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 int kvm_arch_vcpu_set_guest_debug(struct kvm_vcpu *vcpu,
 				  struct kvm_guest_debug *dbg);
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run);
+void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
+				  struct kvm_xsave *guest_xsave);
 
 int kvm_arch_init(void *opaque);
 void kvm_arch_exit(void);

[PATCH v8 32/81] KVM: x86: page track: provide all page tracking hooks with the guest virtual address

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This is needed because the emulator calls the page tracking code
irrespective of the current VM-exit reason or available information.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h       |  2 +-
 arch/x86/include/asm/kvm_page_track.h | 10 ++++++----
 arch/x86/kvm/mmu/mmu.c                |  2 +-
 arch/x86/kvm/mmu/page_track.c         |  6 +++---
 arch/x86/kvm/x86.c                    | 16 ++++++++--------
 drivers/gpu/drm/i915/gvt/kvmgt.c      |  2 +-
 6 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9772e07f8253..6169e12d2540 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1359,7 +1359,7 @@ void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned long kvm_nr_mmu_pages);
 int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3);
 bool pdptrs_changed(struct kvm_vcpu *vcpu);
 
-int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
+int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			  const void *val, int bytes);
 
 struct kvm_irq_mask_notifier {
diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h
index 172f9749dbb2..e91f5a16e741 100644
--- a/arch/x86/include/asm/kvm_page_track.h
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -28,12 +28,14 @@ struct kvm_page_track_notifier_node {
 	 *
 	 * @vcpu: the vcpu where the write access happened.
 	 * @gpa: the physical address written by guest.
+	 * @gva: the virtual address written by guest.
 	 * @new: the data was written to the address.
 	 * @bytes: the written length.
 	 * @node: this node
 	 */
-	void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
-			    int bytes, struct kvm_page_track_notifier_node *node);
+	void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			    const u8 *new, int bytes,
+			    struct kvm_page_track_notifier_node *node);
 	/*
 	 * It is called when memory slot is being moved or removed
 	 * users can drop write-protection for the pages in that memory slot
@@ -69,7 +71,7 @@ kvm_page_track_register_notifier(struct kvm *kvm,
 void
 kvm_page_track_unregister_notifier(struct kvm *kvm,
 				   struct kvm_page_track_notifier_node *n);
-void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
-			  int bytes);
+void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			  const u8 *new, int bytes);
 void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot);
 #endif
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 87e9ba27ada1..4edeb3e275bc 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5329,7 +5329,7 @@ static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte)
 	return spte;
 }
 
-static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			      const u8 *new, int bytes,
 			      struct kvm_page_track_notifier_node *node)
 {
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 3521e2d176f2..dc891d6a2553 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -220,8 +220,8 @@ EXPORT_SYMBOL_GPL(kvm_page_track_unregister_notifier);
  * The node should figure out if the written page is the one that node is
  * interested in by itself.
  */
-void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
-			  int bytes)
+void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			  const u8 *new, int bytes)
 {
 	struct kvm_page_track_notifier_head *head;
 	struct kvm_page_track_notifier_node *n;
@@ -235,7 +235,7 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
 	idx = srcu_read_lock(&head->track_srcu);
 	hlist_for_each_entry_rcu(n, &head->track_notifier_list, node)
 		if (n->track_write)
-			n->track_write(vcpu, gpa, new, bytes, n);
+			n->track_write(vcpu, gpa, gva, new, bytes, n);
 	srcu_read_unlock(&head->track_srcu, idx);
 }
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 73022eed9a94..d35ea19417ca 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5643,7 +5643,7 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
 	return vcpu_is_mmio_gpa(vcpu, gva, *gpa, write);
 }
 
-int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
+int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			const void *val, int bytes)
 {
 	int ret;
@@ -5651,14 +5651,14 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
 	ret = kvm_vcpu_write_guest(vcpu, gpa, val, bytes);
 	if (ret < 0)
 		return 0;
-	kvm_page_track_write(vcpu, gpa, val, bytes);
+	kvm_page_track_write(vcpu, gpa, gva, val, bytes);
 	return 1;
 }
 
 struct read_write_emulator_ops {
 	int (*read_write_prepare)(struct kvm_vcpu *vcpu, void *val,
 				  int bytes);
-	int (*read_write_emulate)(struct kvm_vcpu *vcpu, gpa_t gpa,
+	int (*read_write_emulate)(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 				  void *val, int bytes);
 	int (*read_write_mmio)(struct kvm_vcpu *vcpu, gpa_t gpa,
 			       int bytes, void *val);
@@ -5679,16 +5679,16 @@ static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes)
 	return 0;
 }
 
-static int read_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,
+static int read_emulate(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			void *val, int bytes)
 {
 	return !kvm_vcpu_read_guest(vcpu, gpa, val, bytes);
 }
 
-static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,
+static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			 void *val, int bytes)
 {
-	return emulator_write_phys(vcpu, gpa, val, bytes);
+	return emulator_write_phys(vcpu, gpa, gva, val, bytes);
 }
 
 static int write_mmio(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes, void *val)
@@ -5757,7 +5757,7 @@ static int emulator_read_write_onepage(unsigned long addr, void *val,
 			return X86EMUL_PROPAGATE_FAULT;
 	}
 
-	if (!ret && ops->read_write_emulate(vcpu, gpa, val, bytes))
+	if (!ret && ops->read_write_emulate(vcpu, gpa, addr, val, bytes))
 		return X86EMUL_CONTINUE;
 
 	/*
@@ -5916,7 +5916,7 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
 	if (!exchanged)
 		return X86EMUL_CMPXCHG_FAILED;
 
-	kvm_page_track_write(vcpu, gpa, new, bytes);
+	kvm_page_track_write(vcpu, gpa, addr, new, bytes);
 
 	return X86EMUL_CONTINUE;
 
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 3259a1fa69e1..ddad63aba9b4 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1682,7 +1682,7 @@ static int kvmgt_page_track_remove(unsigned long handle, u64 gfn)
 	return 0;
 }
 
-static void kvmgt_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa,
+static void kvmgt_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 		const u8 *val, int len,
 		struct kvm_page_track_notifier_node *node)
 {

[PATCH v8 33/81] KVM: x86: page track: add track_create_slot() callback

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This is used to add page access notifications as soon as a slot appears.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_page_track.h | 13 ++++++++++++-
 arch/x86/kvm/mmu/page_track.c         | 16 +++++++++++++++-
 arch/x86/kvm/x86.c                    |  2 +-
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h
index e91f5a16e741..dc528c6f2eb0 100644
--- a/arch/x86/include/asm/kvm_page_track.h
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -36,6 +36,17 @@ struct kvm_page_track_notifier_node {
 	void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			    const u8 *new, int bytes,
 			    struct kvm_page_track_notifier_node *node);
+	/*
+	 * It is called when memory slot is being created
+	 *
+	 * @kvm: the kvm where memory slot being moved or removed
+	 * @slot: the memory slot being moved or removed
+	 * @npages: the number of pages
+	 * @node: this node
+	 */
+	void (*track_create_slot)(struct kvm *kvm, struct kvm_memory_slot *slot,
+				  unsigned long npages,
+				  struct kvm_page_track_notifier_node *node);
 	/*
 	 * It is called when memory slot is being moved or removed
 	 * users can drop write-protection for the pages in that memory slot
@@ -53,7 +64,7 @@ void kvm_page_track_cleanup(struct kvm *kvm);
 
 void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
 				 struct kvm_memory_slot *dont);
-int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
+int kvm_page_track_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
 				  unsigned long npages);
 
 void kvm_slot_page_track_add_page(struct kvm *kvm,
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index dc891d6a2553..f36e74430ad2 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -32,9 +32,12 @@ void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
 		}
 }
 
-int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
+int kvm_page_track_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
 				  unsigned long npages)
 {
+	struct kvm_page_track_notifier_head *head;
+	struct kvm_page_track_notifier_node *n;
+	int idx;
 	int  i;
 
 	for (i = 0; i < KVM_PAGE_TRACK_MAX; i++) {
@@ -45,6 +48,17 @@ int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
 			goto track_free;
 	}
 
+	head = &kvm->arch.track_notifier_head;
+
+	if (hlist_empty(&head->track_notifier_list))
+		return 0;
+
+	idx = srcu_read_lock(&head->track_srcu);
+	hlist_for_each_entry_rcu(n, &head->track_notifier_list, node)
+		if (n->track_create_slot)
+			n->track_create_slot(kvm, slot, npages, n);
+	srcu_read_unlock(&head->track_srcu, idx);
+
 	return 0;
 
 track_free:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d35ea19417ca..17e8a9d4e138 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9946,7 +9946,7 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
 		}
 	}
 
-	if (kvm_page_track_create_memslot(slot, npages))
+	if (kvm_page_track_create_memslot(kvm, slot, npages))
 		goto out_free;
 
 	return 0;

[PATCH v8 34/81] KVM: x86: page_track: add support for preread, prewrite and preexec

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

These callbacks return a boolean value. If false, the emulation should
stop and the instruction should be reexecuted in guest.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_page_track.h |  48 ++++++++++-
 arch/x86/kvm/mmu.h                    |   4 +
 arch/x86/kvm/mmu/mmu.c                |  81 +++++++++++++++++
 arch/x86/kvm/mmu/page_track.c         | 120 ++++++++++++++++++++++++--
 4 files changed, 243 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h
index dc528c6f2eb0..646cbfa07676 100644
--- a/arch/x86/include/asm/kvm_page_track.h
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -3,7 +3,10 @@
 #define _ASM_X86_KVM_PAGE_TRACK_H
 
 enum kvm_page_track_mode {
+	KVM_PAGE_TRACK_PREREAD,
+	KVM_PAGE_TRACK_PREWRITE,
 	KVM_PAGE_TRACK_WRITE,
+	KVM_PAGE_TRACK_PREEXEC,
 	KVM_PAGE_TRACK_MAX,
 };
 
@@ -22,6 +25,33 @@ struct kvm_page_track_notifier_head {
 struct kvm_page_track_notifier_node {
 	struct hlist_node node;
 
+	/*
+	 * It is called when guest is reading the read-tracked page
+	 * and the read emulation is about to happen.
+	 *
+	 * @vcpu: the vcpu where the read access happened.
+	 * @gpa: the physical address read by guest.
+	 * @gva: the virtual address read by guest.
+	 * @bytes: the read length.
+	 * @node: this node.
+	 */
+	bool (*track_preread)(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			      int bytes,
+			      struct kvm_page_track_notifier_node *node);
+	/*
+	 * It is called when guest is writing the write-tracked page
+	 * and the write emulation didn't happened yet.
+	 *
+	 * @vcpu: the vcpu where the write access happened.
+	 * @gpa: the physical address written by guest.
+	 * @gva: the virtual address written by guest.
+	 * @new: the data was written to the address.
+	 * @bytes: the written length.
+	 * @node: this node
+	 */
+	bool (*track_prewrite)(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			       const u8 *new, int bytes,
+			       struct kvm_page_track_notifier_node *node);
 	/*
 	 * It is called when guest is writing the write-tracked page
 	 * and write emulation is finished at that time.
@@ -36,6 +66,17 @@ struct kvm_page_track_notifier_node {
 	void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			    const u8 *new, int bytes,
 			    struct kvm_page_track_notifier_node *node);
+	/*
+	 * It is called when guest is fetching from a exec-tracked page
+	 * and the fetch emulation is about to happen.
+	 *
+	 * @vcpu: the vcpu where the fetch access happened.
+	 * @gpa: the physical address fetched by guest.
+	 * @gva: the virtual address fetched by guest.
+	 * @node: this node.
+	 */
+	bool (*track_preexec)(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			      struct kvm_page_track_notifier_node *node);
 	/*
 	 * It is called when memory slot is being created
 	 *
@@ -49,7 +90,7 @@ struct kvm_page_track_notifier_node {
 				  struct kvm_page_track_notifier_node *node);
 	/*
 	 * It is called when memory slot is being moved or removed
-	 * users can drop write-protection for the pages in that memory slot
+	 * users can drop active protection for the pages in that memory slot
 	 *
 	 * @kvm: the kvm where memory slot being moved or removed
 	 * @slot: the memory slot being moved or removed
@@ -82,7 +123,12 @@ kvm_page_track_register_notifier(struct kvm *kvm,
 void
 kvm_page_track_unregister_notifier(struct kvm *kvm,
 				   struct kvm_page_track_notifier_node *n);
+bool kvm_page_track_preread(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			    int bytes);
+bool kvm_page_track_prewrite(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			     const u8 *new, int bytes);
 void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			  const u8 *new, int bytes);
+bool kvm_page_track_preexec(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva);
 void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot);
 #endif
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index a647601c9e1c..2b5a7163ff39 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -222,6 +222,10 @@ void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
 void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);
 bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
 				    struct kvm_memory_slot *slot, u64 gfn);
+bool kvm_mmu_slot_gfn_read_protect(struct kvm *kvm,
+				   struct kvm_memory_slot *slot, u64 gfn);
+bool kvm_mmu_slot_gfn_exec_protect(struct kvm *kvm,
+				   struct kvm_memory_slot *slot, u64 gfn);
 int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu);
 
 int kvm_mmu_post_init_vm(struct kvm *kvm);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 4edeb3e275bc..bd82cf1fb6a2 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1587,6 +1587,31 @@ static bool spte_write_protect(u64 *sptep, bool pt_protect)
 	return mmu_spte_update(sptep, spte);
 }
 
+static bool spte_read_protect(u64 *sptep)
+{
+	u64 spte = *sptep;
+	bool exec_only_supported = (shadow_present_mask == 0ull);
+
+	rmap_printk("rmap_read_protect: spte %p %llx\n", sptep, *sptep);
+
+	WARN_ON_ONCE(!exec_only_supported);
+
+	spte = spte & ~(PT_WRITABLE_MASK | PT_PRESENT_MASK);
+
+	return mmu_spte_update(sptep, spte);
+}
+
+static bool spte_exec_protect(u64 *sptep)
+{
+	u64 spte = *sptep;
+
+	rmap_printk("rmap_exec_protect: spte %p %llx\n", sptep, *sptep);
+
+	spte = spte & ~PT_USER_MASK;
+
+	return mmu_spte_update(sptep, spte);
+}
+
 static bool __rmap_write_protect(struct kvm *kvm,
 				 struct kvm_rmap_head *rmap_head,
 				 bool pt_protect)
@@ -1601,6 +1626,32 @@ static bool __rmap_write_protect(struct kvm *kvm,
 	return flush;
 }
 
+static bool __rmap_read_protect(struct kvm *kvm,
+				struct kvm_rmap_head *rmap_head)
+{
+	struct rmap_iterator iter;
+	bool flush = false;
+	u64 *sptep;
+
+	for_each_rmap_spte(rmap_head, &iter, sptep)
+		flush |= spte_read_protect(sptep);
+
+	return flush;
+}
+
+static bool __rmap_exec_protect(struct kvm *kvm,
+				struct kvm_rmap_head *rmap_head)
+{
+	struct rmap_iterator iter;
+	bool flush = false;
+	u64 *sptep;
+
+	for_each_rmap_spte(rmap_head, &iter, sptep)
+		flush |= spte_exec_protect(sptep);
+
+	return flush;
+}
+
 static bool spte_clear_dirty(u64 *sptep)
 {
 	u64 spte = *sptep;
@@ -1776,6 +1827,36 @@ bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
 	return write_protected;
 }
 
+bool kvm_mmu_slot_gfn_read_protect(struct kvm *kvm,
+				   struct kvm_memory_slot *slot, u64 gfn)
+{
+	struct kvm_rmap_head *rmap_head;
+	bool read_protected = false;
+	int i;
+
+	for (i = PT_PAGE_TABLE_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
+		rmap_head = __gfn_to_rmap(gfn, i, slot);
+		read_protected |= __rmap_read_protect(kvm, rmap_head);
+	}
+
+	return read_protected;
+}
+
+bool kvm_mmu_slot_gfn_exec_protect(struct kvm *kvm,
+				   struct kvm_memory_slot *slot, u64 gfn)
+{
+	struct kvm_rmap_head *rmap_head;
+	bool exec_protected = false;
+	int i;
+
+	for (i = PT_PAGE_TABLE_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
+		rmap_head = __gfn_to_rmap(gfn, i, slot);
+		exec_protected |= __rmap_exec_protect(kvm, rmap_head);
+	}
+
+	return exec_protected;
+}
+
 static bool rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
 {
 	struct kvm_memory_slot *slot;
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index f36e74430ad2..cc3eb2cc7e38 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Support KVM gust page tracking
+ * Support KVM guest page tracking
  *
  * This feature allows us to track page access in guest. Currently, only
  * write access is tracked.
@@ -99,7 +99,7 @@ static void update_gfn_track(struct kvm_memory_slot *slot, gfn_t gfn,
  * @kvm: the guest instance we are interested in.
  * @slot: the @gfn belongs to.
  * @gfn: the guest page.
- * @mode: tracking mode, currently only write track is supported.
+ * @mode: tracking mode.
  */
 void kvm_slot_page_track_add_page(struct kvm *kvm,
 				  struct kvm_memory_slot *slot, gfn_t gfn,
@@ -117,9 +117,16 @@ void kvm_slot_page_track_add_page(struct kvm *kvm,
 	 */
 	kvm_mmu_gfn_disallow_lpage(slot, gfn);
 
-	if (mode == KVM_PAGE_TRACK_WRITE)
+	if (mode == KVM_PAGE_TRACK_PREWRITE || mode == KVM_PAGE_TRACK_WRITE) {
 		if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn))
 			kvm_flush_remote_tlbs(kvm);
+	} else if (mode == KVM_PAGE_TRACK_PREREAD) {
+		if (kvm_mmu_slot_gfn_read_protect(kvm, slot, gfn))
+			kvm_flush_remote_tlbs(kvm);
+	} else if (mode == KVM_PAGE_TRACK_PREEXEC) {
+		if (kvm_mmu_slot_gfn_exec_protect(kvm, slot, gfn))
+			kvm_flush_remote_tlbs(kvm);
+	}
 }
 EXPORT_SYMBOL_GPL(kvm_slot_page_track_add_page);
 
@@ -134,7 +141,7 @@ EXPORT_SYMBOL_GPL(kvm_slot_page_track_add_page);
  * @kvm: the guest instance we are interested in.
  * @slot: the @gfn belongs to.
  * @gfn: the guest page.
- * @mode: tracking mode, currently only write track is supported.
+ * @mode: tracking mode.
  */
 void kvm_slot_page_track_remove_page(struct kvm *kvm,
 				     struct kvm_memory_slot *slot, gfn_t gfn,
@@ -227,12 +234,78 @@ kvm_page_track_unregister_notifier(struct kvm *kvm,
 }
 EXPORT_SYMBOL_GPL(kvm_page_track_unregister_notifier);
 
+/*
+ * Notify the node that a read access is about to happen. Returning false
+ * doesn't stop the other nodes from being called, but it will stop
+ * the emulation.
+ *
+ * The node should figure out if the read page is the one that the node
+ * is interested in by itself.
+ *
+ * The nodes will always be in conflict if they track the same page:
+ * - accepting a read won't guarantee that the next node will not override
+ *   the data (filling new/bytes and setting data_ready)
+ * - filling new/bytes with custom data won't guarantee that the next node
+ *   will not override that
+ */
+bool kvm_page_track_preread(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			    int bytes)
+{
+	struct kvm_page_track_notifier_head *head;
+	struct kvm_page_track_notifier_node *n;
+	int idx;
+	bool ret = true;
+
+	head = &vcpu->kvm->arch.track_notifier_head;
+
+	if (hlist_empty(&head->track_notifier_list))
+		return ret;
+
+	idx = srcu_read_lock(&head->track_srcu);
+	hlist_for_each_entry_rcu(n, &head->track_notifier_list, node)
+		if (n->track_preread)
+			if (!n->track_preread(vcpu, gpa, gva, bytes, n))
+				ret = false;
+	srcu_read_unlock(&head->track_srcu, idx);
+	return ret;
+}
+
+/*
+ * Notify the node that a write access is about to happen. Returning false
+ * doesn't stop the other nodes from being called, but it will stop
+ * the emulation.
+ *
+ * The node should figure out if the written page is the one that the node
+ * is interested in by itself.
+ */
+bool kvm_page_track_prewrite(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			     const u8 *new, int bytes)
+{
+	struct kvm_page_track_notifier_head *head;
+	struct kvm_page_track_notifier_node *n;
+	int idx;
+	bool ret = true;
+
+	head = &vcpu->kvm->arch.track_notifier_head;
+
+	if (hlist_empty(&head->track_notifier_list))
+		return ret;
+
+	idx = srcu_read_lock(&head->track_srcu);
+	hlist_for_each_entry_rcu(n, &head->track_notifier_list, node)
+		if (n->track_prewrite)
+			if (!n->track_prewrite(vcpu, gpa, gva, new, bytes, n))
+				ret = false;
+	srcu_read_unlock(&head->track_srcu, idx);
+	return ret;
+}
+
 /*
  * Notify the node that write access is intercepted and write emulation is
  * finished at this time.
  *
- * The node should figure out if the written page is the one that node is
- * interested in by itself.
+ * The node should figure out if the written page is the one that the node
+ * is interested in by itself.
  */
 void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			  const u8 *new, int bytes)
@@ -253,12 +326,41 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 	srcu_read_unlock(&head->track_srcu, idx);
 }
 
+/*
+ * Notify the node that an instruction is about to be executed.
+ * Returning false doesn't stop the other nodes from being called,
+ * but it will stop the emulation with X86EMUL_RETRY_INSTR.
+ *
+ * The node should figure out if the page is the one that the node
+ * is interested in by itself.
+ */
+bool kvm_page_track_preexec(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva)
+{
+	struct kvm_page_track_notifier_head *head;
+	struct kvm_page_track_notifier_node *n;
+	int idx;
+	bool ret = true;
+
+	head = &vcpu->kvm->arch.track_notifier_head;
+
+	if (hlist_empty(&head->track_notifier_list))
+		return ret;
+
+	idx = srcu_read_lock(&head->track_srcu);
+	hlist_for_each_entry_rcu(n, &head->track_notifier_list, node)
+		if (n->track_preexec)
+			if (!n->track_preexec(vcpu, gpa, gva, n))
+				ret = false;
+	srcu_read_unlock(&head->track_srcu, idx);
+	return ret;
+}
+
 /*
  * Notify the node that memory slot is being removed or moved so that it can
- * drop write-protection for the pages in the memory slot.
+ * drop active protection for the pages in the memory slot.
  *
- * The node should figure out it has any write-protected pages in this slot
- * by itself.
+ * The node should figure out if the page is the one that the node
+ * is interested in by itself.
  */
 void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot)
 {

[PATCH v8 35/81] KVM: x86: wire in the preread/prewrite/preexec page trackers

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

These are needed by the introspection subsystem.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Marian Rotariu <marian.c.rotariu@gmail.com>
Signed-off-by: Marian Rotariu <marian.c.rotariu@gmail.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_emulate.h |  1 +
 arch/x86/kvm/emulate.c             |  4 +++
 arch/x86/kvm/mmu/mmu.c             | 57 +++++++++++++++++++++++-------
 arch/x86/kvm/x86.c                 | 42 +++++++++++++++++-----
 4 files changed, 83 insertions(+), 21 deletions(-)

diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index c06e8353efd3..3dac53d56a85 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -461,6 +461,7 @@ bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt);
 #define EMULATION_OK 0
 #define EMULATION_RESTART 1
 #define EMULATION_INTERCEPTED 2
+#define EMULATION_RETRY_INSTR 3
 void init_decode_cache(struct x86_emulate_ctxt *ctxt);
 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt);
 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index bc00642e5d3b..6503f8ce7be3 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5447,6 +5447,8 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
 					ctxt->memopp->addr.mem.ea + ctxt->_eip);
 
 done:
+	if (rc == X86EMUL_RETRY_INSTR)
+		return EMULATION_RETRY_INSTR;
 	if (rc == X86EMUL_PROPAGATE_FAULT)
 		ctxt->have_exception = true;
 	return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
@@ -5816,6 +5818,8 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 	if (rc == X86EMUL_INTERCEPTED)
 		return EMULATION_INTERCEPTED;
 
+	if (rc == X86EMUL_RETRY_INSTR)
+		return EMULATION_RETRY_INSTR;
 	if (rc == X86EMUL_CONTINUE)
 		writeback_registers(ctxt);
 
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index bd82cf1fb6a2..7c6368ddc6a5 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1233,9 +1233,13 @@ static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
 	slot = __gfn_to_memslot(slots, gfn);
 
 	/* the non-leaf shadow pages are keeping readonly. */
-	if (sp->role.level > PT_PAGE_TABLE_LEVEL)
-		return kvm_slot_page_track_add_page(kvm, slot, gfn,
-						    KVM_PAGE_TRACK_WRITE);
+	if (sp->role.level > PT_PAGE_TABLE_LEVEL) {
+		kvm_slot_page_track_add_page(kvm, slot, gfn,
+					     KVM_PAGE_TRACK_PREWRITE);
+		kvm_slot_page_track_add_page(kvm, slot, gfn,
+					     KVM_PAGE_TRACK_WRITE);
+		return;
+	}
 
 	kvm_mmu_gfn_disallow_lpage(slot, gfn);
 }
@@ -1261,9 +1265,13 @@ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
 	gfn = sp->gfn;
 	slots = kvm_memslots_for_spte_role(kvm, sp->role);
 	slot = __gfn_to_memslot(slots, gfn);
-	if (sp->role.level > PT_PAGE_TABLE_LEVEL)
-		return kvm_slot_page_track_remove_page(kvm, slot, gfn,
-						       KVM_PAGE_TRACK_WRITE);
+	if (sp->role.level > PT_PAGE_TABLE_LEVEL) {
+		kvm_slot_page_track_remove_page(kvm, slot, gfn,
+						KVM_PAGE_TRACK_PREWRITE);
+		kvm_slot_page_track_remove_page(kvm, slot, gfn,
+						KVM_PAGE_TRACK_WRITE);
+		return;
+	}
 
 	kvm_mmu_gfn_allow_lpage(slot, gfn);
 }
@@ -3000,7 +3008,8 @@ static bool mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
 {
 	struct kvm_mmu_page *sp;
 
-	if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+	if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREWRITE) ||
+	    kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
 		return true;
 
 	for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {
@@ -3423,6 +3432,21 @@ static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it,
 	}
 }
 
+static unsigned int kvm_mmu_apply_introspection_access(struct kvm_vcpu *vcpu,
+							gfn_t gfn,
+							unsigned int acc)
+{
+	if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREREAD))
+		acc &= ~ACC_USER_MASK;
+	if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREWRITE) ||
+	    kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+		acc &= ~ACC_WRITE_MASK;
+	if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREEXEC))
+		acc &= ~ACC_EXEC_MASK;
+
+	return acc;
+}
+
 static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write,
 			int map_writable, int max_level, kvm_pfn_t pfn,
 			bool prefault, bool account_disallowed_nx_lpage)
@@ -3432,6 +3456,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write,
 	int level, ret;
 	gfn_t gfn = gpa >> PAGE_SHIFT;
 	gfn_t base_gfn = gfn;
+	unsigned int acc;
 
 	if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa)))
 		return RET_PF_RETRY;
@@ -3461,7 +3486,9 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write,
 		}
 	}
 
-	ret = mmu_set_spte(vcpu, it.sptep, ACC_ALL,
+	acc = kvm_mmu_apply_introspection_access(vcpu, base_gfn, ACC_ALL);
+
+	ret = mmu_set_spte(vcpu, it.sptep, acc,
 			   write, level, base_gfn, pfn, prefault,
 			   map_writable);
 	direct_pte_prefetch(vcpu, it.sptep);
@@ -4125,15 +4152,21 @@ static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu,
 	if (unlikely(error_code & PFERR_RSVD_MASK))
 		return false;
 
-	if (!(error_code & PFERR_PRESENT_MASK) ||
-	      !(error_code & PFERR_WRITE_MASK))
+	if (!(error_code & PFERR_PRESENT_MASK))
 		return false;
 
 	/*
-	 * guest is writing the page which is write tracked which can
+	 * guest is reading/writing/fetching the page which is
+	 * read/write/execute tracked which can
 	 * not be fixed by page fault handler.
 	 */
-	if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+	if (((error_code & PFERR_USER_MASK)
+		&& kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREREAD))
+	    || ((error_code & PFERR_WRITE_MASK)
+		&& (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREWRITE)
+		 || kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE)))
+	    || ((error_code & PFERR_FETCH_MASK)
+		&& kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREEXEC)))
 		return true;
 
 	return false;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 17e8a9d4e138..d35cdda115cc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5435,6 +5435,8 @@ static int kvm_read_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
 
 		if (gpa == UNMAPPED_GVA)
 			return X86EMUL_PROPAGATE_FAULT;
+		if (!kvm_page_track_preread(vcpu, gpa, addr, toread))
+			return X86EMUL_RETRY_INSTR;
 		ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, data,
 					       offset, toread);
 		if (ret < 0) {
@@ -5466,6 +5468,9 @@ static int kvm_fetch_guest_virt(struct x86_emulate_ctxt *ctxt,
 	if (unlikely(gpa == UNMAPPED_GVA))
 		return X86EMUL_PROPAGATE_FAULT;
 
+	if (!kvm_page_track_preexec(vcpu, gpa, addr))
+		return X86EMUL_RETRY_INSTR;
+
 	offset = addr & (PAGE_SIZE-1);
 	if (WARN_ON(offset + bytes > PAGE_SIZE))
 		bytes = (unsigned)PAGE_SIZE - offset;
@@ -5646,13 +5651,22 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
 int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			const void *val, int bytes)
 {
-	int ret;
-
-	ret = kvm_vcpu_write_guest(vcpu, gpa, val, bytes);
-	if (ret < 0)
-		return 0;
+	if (!kvm_page_track_prewrite(vcpu, gpa, gva, val, bytes))
+		return X86EMUL_RETRY_INSTR;
+	if (kvm_vcpu_write_guest(vcpu, gpa, val, bytes) < 0)
+		return X86EMUL_UNHANDLEABLE;
 	kvm_page_track_write(vcpu, gpa, gva, val, bytes);
-	return 1;
+	return X86EMUL_CONTINUE;
+}
+
+static int emulator_read_phys(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			      void *val, int bytes)
+{
+	if (!kvm_page_track_preread(vcpu, gpa, gva, bytes))
+		return X86EMUL_RETRY_INSTR;
+	if (kvm_vcpu_read_guest(vcpu, gpa, val, bytes) < 0)
+		return X86EMUL_UNHANDLEABLE;
+	return X86EMUL_CONTINUE;
 }
 
 struct read_write_emulator_ops {
@@ -5682,7 +5696,7 @@ static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes)
 static int read_emulate(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			void *val, int bytes)
 {
-	return !kvm_vcpu_read_guest(vcpu, gpa, val, bytes);
+	return emulator_read_phys(vcpu, gpa, gva, val, bytes);
 }
 
 static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
@@ -5757,8 +5771,11 @@ static int emulator_read_write_onepage(unsigned long addr, void *val,
 			return X86EMUL_PROPAGATE_FAULT;
 	}
 
-	if (!ret && ops->read_write_emulate(vcpu, gpa, addr, val, bytes))
-		return X86EMUL_CONTINUE;
+	if (!ret) {
+		ret = ops->read_write_emulate(vcpu, gpa, addr, val, bytes);
+		if (ret == X86EMUL_CONTINUE || ret == X86EMUL_RETRY_INSTR)
+			return ret;
+	}
 
 	/*
 	 * Is this MMIO handled locally?
@@ -5892,6 +5909,9 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
 	if (kvm_vcpu_map(vcpu, gpa_to_gfn(gpa), &map))
 		goto emul_write;
 
+	if (!kvm_page_track_prewrite(vcpu, gpa, addr, new, bytes))
+		return X86EMUL_RETRY_INSTR;
+
 	kaddr = map.hva + offset_in_page(gpa);
 
 	switch (bytes) {
@@ -6787,6 +6807,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 
 		trace_kvm_emulate_insn_start(vcpu);
 		++vcpu->stat.insn_emulation;
+		if (r == EMULATION_RETRY_INSTR)
+			return 1;
 		if (r != EMULATION_OK)  {
 			if ((emulation_type & EMULTYPE_TRAP_UD) ||
 			    (emulation_type & EMULTYPE_TRAP_UD_FORCED)) {
@@ -6845,6 +6867,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 
 	r = x86_emulate_insn(ctxt);
 
+	if (r == EMULATION_RETRY_INSTR)
+		return 1;
 	if (r == EMULATION_INTERCEPTED)
 		return 1;
 

[PATCH v8 36/81] KVM: x86: intercept the write access on sidt and other emulated instructions

[Adalbert Lazăr]

This is needed for the introspection subsystem to track the changes to
descriptor table registers.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/x86.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d35cdda115cc..2aaa0dd8b02a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5539,11 +5539,14 @@ static int kvm_write_guest_virt_helper(gva_t addr, void *val, unsigned int bytes
 
 		if (gpa == UNMAPPED_GVA)
 			return X86EMUL_PROPAGATE_FAULT;
+		if (!kvm_page_track_prewrite(vcpu, gpa, addr, data, towrite))
+			return X86EMUL_RETRY_INSTR;
 		ret = kvm_vcpu_write_guest(vcpu, gpa, data, towrite);
 		if (ret < 0) {
 			r = X86EMUL_IO_NEEDED;
 			goto out;
 		}
+		kvm_page_track_write(vcpu, gpa, addr, data, towrite);
 
 		bytes -= towrite;
 		data += towrite;

[PATCH v8 37/81] KVM: x86: disable gpa_available optimization for fetch and page-walk NPF/EPT violations

[Adalbert Lazăr]

From: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>

This change is needed because the introspection tool can write-protect
guest page tables or exec-protect heap/stack pages.

Signed-off-by: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/mmu/mmu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 7c6368ddc6a5..35be9f2a2fc7 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5536,8 +5536,13 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
 	if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa)))
 		return RET_PF_RETRY;
 
-	/* With shadow page tables, fault_address contains a GVA or nGPA.  */
-	if (vcpu->arch.mmu->direct_map) {
+	/*
+	 * With shadow page tables, fault_address contains a GVA or nGPA.
+	 * On a fetch fault, fault_address contains the instruction pointer.
+	 */
+	if (vcpu->arch.mmu->direct_map &&
+	    likely(!(error_code & PFERR_FETCH_MASK)) &&
+	    (error_code & PFERR_GUEST_FINAL_MASK)) {
 		vcpu->arch.gpa_available = true;
 		vcpu->arch.gpa_val = cr2_or_gpa;
 	}

[PATCH v8 38/81] KVM: introduce VM introspection

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

The KVM introspection subsystem provides a facility for applications
to control the execution of any running VMs (pause, resume, shutdown),
query the state of the vCPUs (GPRs, MSRs etc.), alter the page access bits
in the shadow page tables and receive notifications when events of interest
have taken place (shadow page table level faults, key MSR writes,
hypercalls etc.). Some notifications can be responded to with an action
(like preventing an MSR from being written), others are mere informative
(like breakpoint events which can be used for execution tracing).

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Marian Rotariu <marian.c.rotariu@gmail.com>
Signed-off-by: Marian Rotariu <marian.c.rotariu@gmail.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst   | 139 ++++++++++++++++++++++++++++++
 arch/x86/kvm/Kconfig              |   9 ++
 arch/x86/kvm/Makefile             |   2 +
 include/linux/kvm_host.h          |   2 +
 include/linux/kvmi_host.h         |  23 +++++
 virt/kvm/introspection/kvmi.c     |  25 ++++++
 virt/kvm/introspection/kvmi_int.h |   7 ++
 virt/kvm/kvm_main.c               |  13 +++
 8 files changed, 220 insertions(+)
 create mode 100644 Documentation/virt/kvm/kvmi.rst
 create mode 100644 include/linux/kvmi_host.h
 create mode 100644 virt/kvm/introspection/kvmi.c
 create mode 100644 virt/kvm/introspection/kvmi_int.h

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
new file mode 100644
index 000000000000..2ee37c03585a
--- /dev/null
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -0,0 +1,139 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=========================================================
+KVMI - The kernel virtual machine introspection subsystem
+=========================================================
+
+The KVM introspection subsystem provides a facility for applications running
+on the host or in a separate VM, to control the execution of any running VMs
+(pause, resume, shutdown), query the state of the vCPUs (GPRs, MSRs etc.),
+alter the page access bits in the shadow page tables (only for the hardware
+backed ones, eg. Intel's EPT) and receive notifications when events of
+interest have taken place (shadow page table level faults, key MSR writes,
+hypercalls etc.). Some notifications can be responded to with an action
+(like preventing an MSR from being written), others are mere informative
+(like breakpoint events which can be used for execution tracing).
+With few exceptions, all events are optional. An application using this
+subsystem will explicitly register for them.
+
+The use case that gave way for the creation of this subsystem is to monitor
+the guest OS and as such the ABI/API is highly influenced by how the guest
+software (kernel, applications) sees the world. For example, some events
+provide information specific for the host CPU architecture
+(eg. MSR_IA32_SYSENTER_EIP) merely because its leveraged by guest software
+to implement a critical feature (fast system calls).
+
+At the moment, the target audience for KVMI are security software authors
+that wish to perform forensics on newly discovered threats (exploits) or
+to implement another layer of security like preventing a large set of
+kernel rootkits simply by "locking" the kernel image in the shadow page
+tables (ie. enforce .text r-x, .rodata rw- etc.). It's the latter case that
+made KVMI a separate subsystem, even though many of these features are
+available in the device manager (eg. QEMU). The ability to build a security
+application that does not interfere (in terms of performance) with the
+guest software asks for a specialized interface that is designed for minimum
+overhead.
+
+API/ABI
+=======
+
+This chapter describes the VMI interface used to monitor and control local
+guests from a user application.
+
+Overview
+--------
+
+The interface is socket based, one connection for every VM. One end is in the
+host kernel while the other is held by the user application (introspection
+tool).
+
+The initial connection is established by an application running on the host
+(eg. QEMU) that connects to the introspection tool and after a handshake
+the socket is passed to the host kernel making all further communication
+take place between it and the introspection tool.
+
+The socket protocol allows for commands and events to be multiplexed over
+the same connection. As such, it is possible for the introspection tool to
+receive an event while waiting for the result of a command. Also, it can
+send a command while the host kernel is waiting for a reply to an event.
+
+The kernel side of the socket communication is blocking and will wait for
+an answer from its peer indefinitely or until the guest is powered off
+(killed), restarted or the peer goes away, at which point it will wake
+up and properly cleanup as if the introspection subsystem has never been
+used on that guest. Obviously, whether the guest can really continue
+normal execution depends on whether the introspection tool has made any
+modifications that require an active KVMI channel.
+
+Handshake
+---------
+
+Although this falls out of the scope of the introspection subsystem, below
+is a proposal of a handshake that can be used by implementors.
+
+Based on the system administration policies, the management tool
+(eg. libvirt) starts device managers (eg. QEMU) with some extra arguments:
+what introspection tool could monitor/control that specific guest (and
+how to connect to) and what introspection commands/events are allowed.
+
+The device manager will connect to the introspection tool and wait for a
+cryptographic hash of a cookie that should be known by both peers. If the
+hash is correct (the destination has been "authenticated"), the device
+manager will send another cryptographic hash and random salt. The peer
+recomputes the hash of the cookie bytes including the salt and if they match,
+the device manager has been "authenticated" too. This is a rather crude
+system that makes it difficult for device manager exploits to trick the
+introspection tool into believing its working OK.
+
+The cookie would normally be generated by a management tool (eg. libvirt)
+and make it available to the device manager and to a properly authenticated
+client. It is the job of a third party to retrieve the cookie from the
+management application and pass it over a secure channel to the introspection
+tool.
+
+Once the basic "authentication" has taken place, the introspection tool
+can receive information on the guest (its UUID) and other flags (endianness
+or features supported by the host kernel).
+
+In the end, the device manager will pass the file handle (plus the allowed
+commands/events) to KVM. It will detect when the socket is shutdown
+and it will reinitiate the handshake.
+
+Unhooking
+---------
+
+During a VMI session it is possible for the guest to be patched and for
+some of these patches to "talk" with the introspection tool. It thus
+becomes necessary to remove them before the guest is suspended, moved
+(migrated) or a snapshot with memory is created.
+
+The actions are normally performed by the device manager. In the case
+of QEMU, it will use another ioctl to notify the introspection tool and
+wait for a limited amount of time (a few seconds) for a confirmation that
+is OK to proceed.
+
+Live migrations
+---------------
+
+Before the live migration takes place, the introspection tool has to be
+notified and have a chance to unhook (see **Unhooking**).
+
+The QEMU instance on the receiving end, if configured for KVMI, will need
+to establish a connection to the introspection tool after the migration
+has completed.
+
+Obviously, this creates a window in which the guest is not introspected.
+The user will need to be aware of this detail. Future introspection
+technologies can choose not to disconnect and instead transfer the
+necessary context to the introspection tool at the migration destination
+via a separate channel.
+
+Memory access safety
+--------------------
+
+The KVMI API gives access to the entire guest physical address space but
+provides no information on which parts of it are system RAM and which are
+device-specific memory (DMA, emulated MMIO, reserved by a passthrough
+device etc.). It is up to the user to determine, using the guest operating
+system data structures, the areas that are safe to access (code, stack, heap
+etc.).
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 9fea0757db92..67ecba602d92 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -107,6 +107,15 @@ config KVM_MMU_AUDIT
 	 This option adds a R/W kVM module parameter 'mmu_audit', which allows
 	 auditing of KVM MMU events at runtime.
 
+config KVM_INTROSPECTION
+	bool "KVM Introspection"
+	depends on KVM && (KVM_INTEL || KVM_AMD)
+	default n
+	help
+	  Provides the introspection interface, which allows the control
+	  of any running VM. It must be explicitly enabled by setting
+	  the module parameter 'kvm.introspection'.
+
 # OK, it's a little counter-intuitive to do this, but it puts it neatly under
 # the virtualization menu.
 source "drivers/vhost/Kconfig"
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index e553f0fdd87d..f443198f782c 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -4,10 +4,12 @@ ccflags-y += -Iarch/x86/kvm
 ccflags-$(CONFIG_KVM_WERROR) += -Werror
 
 KVM := ../../../virt/kvm
+KVMI := $(KVM)/introspection
 
 kvm-y			+= $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \
 				$(KVM)/eventfd.o $(KVM)/irqchip.o $(KVM)/vfio.o
 kvm-$(CONFIG_KVM_ASYNC_PF)	+= $(KVM)/async_pf.o
+kvm-$(CONFIG_KVM_INTROSPECTION) += $(KVMI)/kvmi.o
 
 kvm-y			+= x86.o emulate.o i8259.o irq.o lapic.o \
 			   i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4a82fcf713d1..5d1a73b5d94f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -35,6 +35,8 @@
 
 #include <asm/kvm_host.h>
 
+#include <linux/kvmi_host.h>
+
 #ifndef KVM_MAX_VCPU_ID
 #define KVM_MAX_VCPU_ID KVM_MAX_VCPUS
 #endif
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
new file mode 100644
index 000000000000..8cd613fdd4f2
--- /dev/null
+++ b/include/linux/kvmi_host.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __KVMI_HOST_H
+#define __KVMI_HOST_H
+
+struct kvm;
+
+#ifdef CONFIG_KVM_INTROSPECTION
+
+int kvmi_init(void);
+void kvmi_uninit(void);
+void kvmi_create_vm(struct kvm *kvm);
+void kvmi_destroy_vm(struct kvm *kvm);
+
+#else
+
+static inline int kvmi_init(void) { return 0; }
+static inline void kvmi_uninit(void) { }
+static inline void kvmi_create_vm(struct kvm *kvm) { }
+static inline void kvmi_destroy_vm(struct kvm *kvm) { }
+
+#endif /* CONFIG_KVM_INTROSPECTION */
+
+#endif
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
new file mode 100644
index 000000000000..c74ddb8075cd
--- /dev/null
+++ b/virt/kvm/introspection/kvmi.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM introspection
+ *
+ * Copyright (C) 2017-2020 Bitdefender S.R.L.
+ *
+ */
+#include "kvmi_int.h"
+
+int kvmi_init(void)
+{
+	return 0;
+}
+
+void kvmi_uninit(void)
+{
+}
+
+void kvmi_create_vm(struct kvm *kvm)
+{
+}
+
+void kvmi_destroy_vm(struct kvm *kvm)
+{
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
new file mode 100644
index 000000000000..34af926f9838
--- /dev/null
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __KVMI_INT_H__
+#define __KVMI_INT_H__
+
+#include <linux/kvm_host.h>
+
+#endif
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a6eb3f8ea62f..b43923b5aa79 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -90,6 +90,9 @@ unsigned int halt_poll_ns_shrink;
 module_param(halt_poll_ns_shrink, uint, 0644);
 EXPORT_SYMBOL_GPL(halt_poll_ns_shrink);
 
+static bool enable_introspection;
+module_param_named(introspection, enable_introspection, bool, 0644);
+
 /*
  * Ordering of locks:
  *
@@ -736,6 +739,9 @@ static struct kvm *kvm_create_vm(unsigned long type)
 	if (r)
 		goto out_err;
 
+	if (enable_introspection)
+		kvmi_create_vm(kvm);
+
 	mutex_lock(&kvm_lock);
 	list_add(&kvm->vm_list, &vm_list);
 	mutex_unlock(&kvm_lock);
@@ -788,6 +794,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
 	int i;
 	struct mm_struct *mm = kvm->mm;
 
+	kvmi_destroy_vm(kvm);
 	kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm);
 	kvm_destroy_vm_debugfs(kvm);
 	kvm_arch_sync_events(kvm);
@@ -4553,6 +4560,11 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 	r = kvm_vfio_ops_init();
 	WARN_ON(r);
 
+	if (enable_introspection) {
+		r = kvmi_init();
+		WARN_ON(r);
+	}
+
 	return 0;
 
 out_unreg:
@@ -4577,6 +4589,7 @@ EXPORT_SYMBOL_GPL(kvm_init);
 
 void kvm_exit(void)
 {
+	kvmi_uninit();
 	debugfs_remove_recursive(kvm_debugfs_dir);
 	misc_deregister(&kvm_dev);
 	kmem_cache_destroy(kvm_vcpu_cache);

[PATCH v8 39/81] KVM: introspection: add hook/unhook ioctls

[Adalbert Lazăr]

On hook, a new thread is created to handle the messages coming from the
introspection tool (commands or event replies).

Co-developed-by: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>
Signed-off-by: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/api.rst                |  50 ++++++
 arch/x86/include/asm/kvmi_host.h              |   8 +
 arch/x86/kvm/Makefile                         |   2 +-
 arch/x86/kvm/x86.c                            |   5 +
 include/linux/kvm_host.h                      |   4 +
 include/linux/kvmi_host.h                     |  17 ++
 include/uapi/linux/kvm.h                      |  10 ++
 include/uapi/linux/kvmi.h                     |  13 ++
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  |  83 +++++++++
 virt/kvm/introspection/kvmi.c                 | 161 ++++++++++++++++++
 virt/kvm/introspection/kvmi_int.h             |  20 +++
 virt/kvm/introspection/kvmi_msg.c             |  39 +++++
 virt/kvm/kvm_main.c                           |  11 ++
 14 files changed, 423 insertions(+), 1 deletion(-)
 create mode 100644 arch/x86/include/asm/kvmi_host.h
 create mode 100644 include/uapi/linux/kvmi.h
 create mode 100644 tools/testing/selftests/kvm/x86_64/kvmi_test.c
 create mode 100644 virt/kvm/introspection/kvmi_msg.c

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index ebd383fba939..3ff42e5e6d63 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -4648,6 +4648,56 @@ This ioctl resets VCPU registers and control structures according to
 the clear cpu reset definition in the POP. However, the cpu is not put
 into ESA mode. This reset is a superset of the initial reset.
 
+4.125 KVM_INTROSPECTION_HOOK
+----------------------------
+
+:Capability: KVM_CAP_INTROSPECTION
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_introspection (in)
+:Returns: 0 on success, a negative value on error
+
+Errors:
+
+  ======     ==========================================================
+  EFAULT     the introspection is not enabled
+  ENOMEM     the memory allocation failed
+  EEXIST     the VM is already introspected
+  EINVAL     the file descriptor doesn't correspond to an active socket
+  EINVAL     the padding is not zero
+  EPERM      the introspection is disabled (kvm.introspection=0)
+  ======     ==========================================================
+
+This ioctl is used to enable the introspection of the current VM.
+
+::
+
+  struct kvm_introspection {
+	__s32 fd;
+	__u32 padding;
+	__u8 uuid[16];
+  };
+
+fd is the file descriptor of a socket connected to the introspection tool,
+
+padding must be zero (it might be used in the future),
+
+uuid is used for debug and error messages.
+
+The KVMI version can be retrieved using the KVM_CAP_INTROSPECTION of
+the KVM_CHECK_EXTENSION ioctl() at run-time.
+
+4.126 KVM_INTROSPECTION_UNHOOK
+------------------------------
+
+:Capability: KVM_CAP_INTROSPECTION
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: none
+:Returns: 0 on success, a negative value on error
+
+This ioctl is used to free all introspection structures
+related to this VM.
 
 5. The kvm_run structure
 ========================
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
new file mode 100644
index 000000000000..38c398262913
--- /dev/null
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_KVMI_HOST_H
+#define _ASM_X86_KVMI_HOST_H
+
+struct kvm_arch_introspection {
+};
+
+#endif /* _ASM_X86_KVMI_HOST_H */
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index f443198f782c..9d05b5bf2360 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -9,7 +9,7 @@ KVMI := $(KVM)/introspection
 kvm-y			+= $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \
 				$(KVM)/eventfd.o $(KVM)/irqchip.o $(KVM)/vfio.o
 kvm-$(CONFIG_KVM_ASYNC_PF)	+= $(KVM)/async_pf.o
-kvm-$(CONFIG_KVM_INTROSPECTION) += $(KVMI)/kvmi.o
+kvm-$(CONFIG_KVM_INTROSPECTION) += $(KVMI)/kvmi.o $(KVMI)/kvmi_msg.o
 
 kvm-y			+= x86.o emulate.o i8259.o irq.o lapic.o \
 			   i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2aaa0dd8b02a..4fa11c998325 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3403,6 +3403,11 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_HYPERV_ENLIGHTENED_VMCS:
 		r = kvm_x86_ops->nested_enable_evmcs != NULL;
 		break;
+#ifdef CONFIG_KVM_INTROSPECTION
+	case KVM_CAP_INTROSPECTION:
+		r = KVMI_VERSION;
+		break;
+#endif
 	default:
 		break;
 	}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 5d1a73b5d94f..1f1b0dffabaa 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -501,6 +501,10 @@ struct kvm {
 	struct srcu_struct srcu;
 	struct srcu_struct irq_srcu;
 	pid_t userspace_pid;
+	struct mutex kvmi_lock;
+	refcount_t kvmi_ref;
+	struct completion kvmi_complete;
+	struct kvm_introspection *kvmi;
 };
 
 #define kvm_err(fmt, ...) \
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 8cd613fdd4f2..c8b9c87ecff2 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -2,8 +2,22 @@
 #ifndef __KVMI_HOST_H
 #define __KVMI_HOST_H
 
+#include <uapi/linux/kvmi.h>
+
 struct kvm;
 
+#include <asm/kvmi_host.h>
+
+struct kvm_introspection {
+	struct kvm_arch_introspection arch;
+	struct kvm *kvm;
+
+	uuid_t uuid;
+
+	struct socket *sock;
+	struct task_struct *recv;
+};
+
 #ifdef CONFIG_KVM_INTROSPECTION
 
 int kvmi_init(void);
@@ -11,6 +25,9 @@ void kvmi_uninit(void);
 void kvmi_create_vm(struct kvm *kvm);
 void kvmi_destroy_vm(struct kvm *kvm);
 
+int kvmi_ioctl_hook(struct kvm *kvm, void __user *argp);
+int kvmi_ioctl_unhook(struct kvm *kvm);
+
 #else
 
 static inline int kvmi_init(void) { return 0; }
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 4b95f9a31a2f..6d1076ed93a7 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1010,6 +1010,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_ARM_NISV_TO_USER 177
 #define KVM_CAP_ARM_INJECT_EXT_DABT 178
 #define KVM_CAP_S390_VCPU_RESETS 179
+#define KVM_CAP_INTROSPECTION 180
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -1558,6 +1559,15 @@ struct kvm_sev_dbg {
 	__u32 len;
 };
 
+struct kvm_introspection_hook {
+	__s32 fd;
+	__u32 padding;
+	__u8 uuid[16];
+};
+
+#define KVM_INTROSPECTION_HOOK    _IOW(KVMIO, 0xc3, struct kvm_introspection_hook)
+#define KVM_INTROSPECTION_UNHOOK  _IO(KVMIO, 0xc4)
+
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)
 #define KVM_DEV_ASSIGN_MASK_INTX	(1 << 2)
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
new file mode 100644
index 000000000000..34dda91016db
--- /dev/null
+++ b/include/uapi/linux/kvmi.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI__LINUX_KVMI_H
+#define _UAPI__LINUX_KVMI_H
+
+/*
+ * KVMI structures and definitions
+ */
+
+enum {
+	KVMI_VERSION = 0x00000001
+};
+
+#endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index d91c53b726e6..ed334fd48ce4 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -15,6 +15,7 @@ LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c
 TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
 TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
 TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
+TEST_GEN_PROGS_x86_64 += x86_64/kvmi_test
 TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test
 TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
 TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
new file mode 100644
index 000000000000..100f05c518aa
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM introspection tests
+ *
+ * Copyright (C) 2020, Bitdefender S.R.L.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "test_util.h"
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "../lib/kvm_util_internal.h"
+
+#include "linux/kvmi.h"
+
+#define VCPU_ID         5
+
+static int socket_pair[2];
+#define Kvm_socket       socket_pair[0]
+#define Userspace_socket socket_pair[1]
+
+void setup_socket(void)
+{
+	int r;
+
+	r = socketpair(AF_UNIX, SOCK_STREAM, 0, socket_pair);
+	TEST_ASSERT(r == 0,
+		"socketpair() failed, errno %d (%s)\n",
+		errno, strerror(errno));
+}
+
+static void hook_introspection(struct kvm_vm *vm)
+{
+	struct kvm_introspection_hook hook = {.fd = Kvm_socket};
+	int r;
+
+	r = ioctl(vm->fd, KVM_INTROSPECTION_HOOK, &hook);
+	TEST_ASSERT(r == 0,
+		"KVM_INTROSPECTION_HOOK failed, errno %d (%s)\n",
+		errno, strerror(errno));
+}
+
+static void unhook_introspection(struct kvm_vm *vm)
+{
+	int r;
+
+	r = ioctl(vm->fd, KVM_INTROSPECTION_UNHOOK, NULL);
+	TEST_ASSERT(r == 0,
+		"KVM_INTROSPECTION_UNHOOK failed, errno %d (%s)\n",
+		errno, strerror(errno));
+}
+
+static void test_introspection(struct kvm_vm *vm)
+{
+	setup_socket();
+	hook_introspection(vm);
+	unhook_introspection(vm);
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vm *vm;
+	int version;
+
+	version = kvm_check_cap(KVM_CAP_INTROSPECTION);
+	if (version != KVMI_VERSION) {
+		fprintf(stderr,
+			"KVM_CAP_INTROSPECTION not available, skipping tests\n");
+		exit(KSFT_SKIP);
+	}
+
+	vm = vm_create_default(VCPU_ID, 0, NULL);
+	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+	test_introspection(vm);
+
+	kvm_vm_free(vm);
+	return 0;
+}
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index c74ddb8075cd..ecebb00b4245 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -6,6 +6,7 @@
  *
  */
 #include "kvmi_int.h"
+#include <linux/kthread.h>
 
 int kvmi_init(void)
 {
@@ -16,10 +17,170 @@ void kvmi_uninit(void)
 {
 }
 
+static void free_kvmi(struct kvm *kvm)
+{
+	kfree(kvm->kvmi);
+	kvm->kvmi = NULL;
+}
+
+static struct kvm_introspection *
+alloc_kvmi(struct kvm *kvm, const struct kvm_introspection_hook *hook)
+{
+	struct kvm_introspection *kvmi;
+
+	kvmi = kzalloc(sizeof(*kvmi), GFP_KERNEL);
+	if (!kvmi)
+		return NULL;
+
+	BUILD_BUG_ON(sizeof(hook->uuid) != sizeof(kvmi->uuid));
+	memcpy(&kvmi->uuid, &hook->uuid, sizeof(kvmi->uuid));
+
+	kvmi->kvm = kvm;
+
+	return kvmi;
+}
+
+static void kvmi_destroy(struct kvm_introspection *kvmi)
+{
+	struct kvm *kvm = kvmi->kvm;
+
+	free_kvmi(kvm);
+}
+
+static void kvmi_stop_recv_thread(struct kvm_introspection *kvmi)
+{
+	kvmi_sock_shutdown(kvmi);
+}
+
+static void __kvmi_unhook(struct kvm *kvm)
+{
+	struct kvm_introspection *kvmi = KVMI(kvm);
+
+	wait_for_completion_killable(&kvm->kvmi_complete);
+	kvmi_sock_put(kvmi);
+}
+
+static void kvmi_unhook(struct kvm *kvm)
+{
+	struct kvm_introspection *kvmi;
+
+	mutex_lock(&kvm->kvmi_lock);
+
+	kvmi = KVMI(kvm);
+	if (kvmi) {
+		kvmi_stop_recv_thread(kvmi);
+		__kvmi_unhook(kvm);
+		kvmi_destroy(kvmi);
+	}
+
+	mutex_unlock(&kvm->kvmi_lock);
+}
+
+int kvmi_ioctl_unhook(struct kvm *kvm)
+{
+	kvmi_unhook(kvm);
+	return 0;
+}
+
+void kvmi_put(struct kvm *kvm)
+{
+	if (refcount_dec_and_test(&kvm->kvmi_ref))
+		complete(&kvm->kvmi_complete);
+}
+
+static int __kvmi_hook(struct kvm *kvm,
+		       const struct kvm_introspection_hook *hook)
+{
+	struct kvm_introspection *kvmi = KVMI(kvm);
+
+	if (!kvmi_sock_get(kvmi, hook->fd))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int kvmi_recv_thread(void *arg)
+{
+	struct kvm_introspection *kvmi = arg;
+
+	while (kvmi_msg_process(kvmi))
+		;
+
+	/*
+	 * Signal userspace (which might wait for POLLHUP only)
+	 * and prevent the vCPUs from sending other events.
+	 */
+	kvmi_sock_shutdown(kvmi);
+
+	kvmi_put(kvmi->kvm);
+	return 0;
+}
+
+int kvmi_hook(struct kvm *kvm, const struct kvm_introspection_hook *hook)
+{
+	struct kvm_introspection *kvmi;
+	int err = 0;
+
+	mutex_lock(&kvm->kvmi_lock);
+
+	if (kvm->kvmi) {
+		err = -EEXIST;
+		goto out;
+	}
+
+	kvmi = alloc_kvmi(kvm, hook);
+	if (!kvmi) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	kvm->kvmi = kvmi;
+
+	err = __kvmi_hook(kvm, hook);
+	if (err)
+		goto destroy;
+
+	init_completion(&kvm->kvmi_complete);
+
+	refcount_set(&kvm->kvmi_ref, 1);
+
+	kvmi->recv = kthread_run(kvmi_recv_thread, kvmi, "kvmi-recv");
+	if (IS_ERR(kvmi->recv)) {
+		err = -ENOMEM;
+		kvmi_put(kvm);
+		goto unhook;
+	}
+
+	goto out;
+
+unhook:
+	__kvmi_unhook(kvm);
+destroy:
+	kvmi_destroy(kvmi);
+out:
+	mutex_unlock(&kvm->kvmi_lock);
+	return err;
+}
+
+int kvmi_ioctl_hook(struct kvm *kvm, void __user *argp)
+{
+	struct kvm_introspection_hook i;
+
+	if (copy_from_user(&i, argp, sizeof(i)))
+		return -EFAULT;
+
+	if (i.padding)
+		return -EINVAL;
+
+	return kvmi_hook(kvm, &i);
+}
+
 void kvmi_create_vm(struct kvm *kvm)
 {
+	mutex_init(&kvm->kvmi_lock);
 }
 
 void kvmi_destroy_vm(struct kvm *kvm)
 {
+	kvmi_unhook(kvm);
 }
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 34af926f9838..1c9cc15ab4d9 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -4,4 +4,24 @@
 
 #include <linux/kvm_host.h>
 
+#define kvmi_warn(kvmi, fmt, ...) \
+	kvm_info("%pU WARNING: " fmt, &kvmi->uuid, ## __VA_ARGS__)
+#define kvmi_warn_once(kvmi, fmt, ...) ({                     \
+		static bool __section(.data.once) __warned;   \
+		if (!__warned) {                              \
+			__warned = true;                      \
+			kvmi_warn(kvmi, fmt, ## __VA_ARGS__); \
+		}                                             \
+	})
+#define kvmi_err(kvmi, fmt, ...) \
+	kvm_info("%pU ERROR: " fmt, &kvmi->uuid, ## __VA_ARGS__)
+
+#define KVMI(kvm) ((kvm)->kvmi)
+
+/* kvmi_msg.c */
+bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd);
+void kvmi_sock_shutdown(struct kvm_introspection *kvmi);
+void kvmi_sock_put(struct kvm_introspection *kvmi);
+bool kvmi_msg_process(struct kvm_introspection *kvmi);
+
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
new file mode 100644
index 000000000000..f9e66274fb43
--- /dev/null
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM introspection (message handling)
+ *
+ * Copyright (C) 2017-2020 Bitdefender S.R.L.
+ *
+ */
+#include <linux/net.h>
+#include "kvmi_int.h"
+
+bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd)
+{
+	struct socket *sock;
+	int r;
+
+	sock = sockfd_lookup(fd, &r);
+	if (!sock)
+		return false;
+
+	kvmi->sock = sock;
+
+	return true;
+}
+
+void kvmi_sock_put(struct kvm_introspection *kvmi)
+{
+	if (kvmi->sock)
+		sockfd_put(kvmi->sock);
+}
+
+void kvmi_sock_shutdown(struct kvm_introspection *kvmi)
+{
+	kernel_sock_shutdown(kvmi->sock, SHUT_RDWR);
+}
+
+bool kvmi_msg_process(struct kvm_introspection *kvmi)
+{
+	return false;
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b43923b5aa79..82634be560e6 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3580,6 +3580,17 @@ static long kvm_vm_ioctl(struct file *filp,
 	case KVM_CHECK_EXTENSION:
 		r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
 		break;
+#ifdef CONFIG_KVM_INTROSPECTION
+	case KVM_INTROSPECTION_HOOK:
+		if (enable_introspection)
+			r = kvmi_ioctl_hook(kvm, argp);
+		else
+			r = -EPERM;
+		break;
+	case KVM_INTROSPECTION_UNHOOK:
+		r = kvmi_ioctl_unhook(kvm);
+		break;
+#endif /* CONFIG_KVM_INTROSPECTION */
 	default:
 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
 	}

[PATCH v8 40/81] KVM: introspection: add permission access ioctls

[Adalbert Lazăr]

KVM_INTROSPECTION_COMMAND and KVM_INTROSPECTION_EVENTS ioctls
are used by userspace to allow access for specific (or all)
introspection commands and events.

By default, all events and almost all commands are disallowed.
Some commands, those querying the introspection capabilities,
are always allowed.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/api.rst                |  72 +++++++++++++
 include/linux/kvmi_host.h                     |   7 ++
 include/uapi/linux/kvm.h                      |   8 ++
 include/uapi/linux/kvmi.h                     |   8 ++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  |  28 +++++
 virt/kvm/introspection/kvmi.c                 | 101 ++++++++++++++++++
 virt/kvm/kvm_main.c                           |   6 ++
 7 files changed, 230 insertions(+)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 3ff42e5e6d63..4d81a2f2f8f7 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -4699,6 +4699,78 @@ the KVM_CHECK_EXTENSION ioctl() at run-time.
 This ioctl is used to free all introspection structures
 related to this VM.
 
+Errors:
+
+  ======     ================================
+  EFAULT     the introspection is not enabled
+  ======     ================================
+
+4.127 KVM_INTROSPECTION_COMMAND
+-------------------------------
+
+:Capability: KVM_CAP_INTROSPECTION
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_introspection_feature (in)
+:Returns: 0 on success, a negative value on error
+
+Errors:
+
+  ======     =======================================================
+  EFAULT     the introspection is not enabled
+  EINVAL     the command is unknown
+  EPERM      the command can't be disallowed (e.g. KVMI_GET_VERSION)
+  ======     =======================================================
+
+This ioctl is used to allow or disallow introspection commands
+for the current VM. By default, almost all commands are disallowed
+except for those used to query the API.
+
+::
+
+  struct kvm_introspection_feature {
+	__u32 allow;
+	__s32 id;
+  };
+
+If allow is 1, the command specified by id is allowed. If allow is 0,
+the command is disallowed.
+
+Unless set to -1 (meaning all commands), id must be a command ID
+(e.g. KVMI_GET_VERSION)
+
+4.128 KVM_INTROSPECTION_EVENT
+-----------------------------
+
+:Capability: KVM_CAP_INTROSPECTION
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_introspection_feature (in)
+:Returns: 0 on success, a negative value on error
+
+Errors:
+
+  ======     ====================
+  EFAULT     the introspection is not enabled
+  EINVAL     the event is unknown
+  ======     ====================
+
+This ioctl is used to allow or disallow introspection events
+for the current VM. By default, all events are disallowed.
+
+::
+
+  struct kvm_introspection_feature {
+	__u32 allow;
+	__s32 id;
+  };
+
+If allow is 1, the event specified by id is allowed. If allow is 0,
+the event is disallowed.
+
+Unless set to -1 (meaning all event), id must be a event ID
+(e.g. KVMI_EVENT_UNHOOK, KVMI_EVENT_CR, etc.)
+
 5. The kvm_run structure
 ========================
 
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index c8b9c87ecff2..4e77a0227c08 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -8,6 +8,8 @@ struct kvm;
 
 #include <asm/kvmi_host.h>
 
+#define KVMI_NUM_COMMANDS KVMI_NUM_MESSAGES
+
 struct kvm_introspection {
 	struct kvm_arch_introspection arch;
 	struct kvm *kvm;
@@ -16,6 +18,9 @@ struct kvm_introspection {
 
 	struct socket *sock;
 	struct task_struct *recv;
+
+	DECLARE_BITMAP(cmd_allow_mask, KVMI_NUM_COMMANDS);
+	DECLARE_BITMAP(event_allow_mask, KVMI_NUM_EVENTS);
 };
 
 #ifdef CONFIG_KVM_INTROSPECTION
@@ -27,6 +32,8 @@ void kvmi_destroy_vm(struct kvm *kvm);
 
 int kvmi_ioctl_hook(struct kvm *kvm, void __user *argp);
 int kvmi_ioctl_unhook(struct kvm *kvm);
+int kvmi_ioctl_command(struct kvm *kvm, void __user *argp);
+int kvmi_ioctl_event(struct kvm *kvm, void __user *argp);
 
 #else
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 6d1076ed93a7..dd4ab88f0012 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1568,6 +1568,14 @@ struct kvm_introspection_hook {
 #define KVM_INTROSPECTION_HOOK    _IOW(KVMIO, 0xc3, struct kvm_introspection_hook)
 #define KVM_INTROSPECTION_UNHOOK  _IO(KVMIO, 0xc4)
 
+struct kvm_introspection_feature {
+	__u32 allow;
+	__s32 id;
+};
+
+#define KVM_INTROSPECTION_COMMAND _IOW(KVMIO, 0xc5, struct kvm_introspection_feature)
+#define KVM_INTROSPECTION_EVENT   _IOW(KVMIO, 0xc6, struct kvm_introspection_feature)
+
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)
 #define KVM_DEV_ASSIGN_MASK_INTX	(1 << 2)
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 34dda91016db..d7b18ffef4fa 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -10,4 +10,12 @@ enum {
 	KVMI_VERSION = 0x00000001
 };
 
+enum {
+	KVMI_NUM_MESSAGES
+};
+
+enum {
+	KVMI_NUM_EVENTS
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 100f05c518aa..d1d02e067393 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -33,15 +33,43 @@ void setup_socket(void)
 		errno, strerror(errno));
 }
 
+static void toggle_event_permission(struct kvm_vm *vm, __s32 id, bool allow)
+{
+	struct kvm_introspection_feature feat = {
+		.allow = allow ? 1 : 0,
+		.id = id
+	};
+	int r;
+
+	r = ioctl(vm->fd, KVM_INTROSPECTION_EVENT, &feat);
+	TEST_ASSERT(r == 0,
+		"KVM_INTROSPECTION_EVENT failed, id %d, errno %d (%s)\n",
+		id, errno, strerror(errno));
+}
+
+static void allow_event(struct kvm_vm *vm, __s32 event_id)
+{
+	toggle_event_permission(vm, event_id, true);
+}
+
 static void hook_introspection(struct kvm_vm *vm)
 {
+	__s32 all_IDs = -1;
 	struct kvm_introspection_hook hook = {.fd = Kvm_socket};
+	struct kvm_introspection_feature feat = {.allow = 1, .id = all_IDs};
 	int r;
 
 	r = ioctl(vm->fd, KVM_INTROSPECTION_HOOK, &hook);
 	TEST_ASSERT(r == 0,
 		"KVM_INTROSPECTION_HOOK failed, errno %d (%s)\n",
 		errno, strerror(errno));
+
+	r = ioctl(vm->fd, KVM_INTROSPECTION_COMMAND, &feat);
+	TEST_ASSERT(r == 0,
+		"KVM_INTROSPECTION_COMMAND failed, errno %d (%s)\n",
+		errno, strerror(errno));
+
+	allow_event(vm, all_IDs);
 }
 
 static void unhook_introspection(struct kvm_vm *vm)
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index ecebb00b4245..95b08a40d814 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -184,3 +184,104 @@ void kvmi_destroy_vm(struct kvm *kvm)
 {
 	kvmi_unhook(kvm);
 }
+
+static int kvmi_ioctl_get_feature(void __user *argp, bool *allow, int *id,
+				  unsigned int nbits)
+{
+	struct kvm_introspection_feature feat;
+	int all_bits = -1;
+
+	if (copy_from_user(&feat, argp, sizeof(feat)))
+		return -EFAULT;
+
+	if (feat.id < 0 && feat.id != all_bits)
+		return -EINVAL;
+
+	if (feat.id > 0 && feat.id >= nbits)
+		return -EINVAL;
+
+	*allow = feat.allow == 1;
+	*id = feat.id;
+
+	return 0;
+}
+
+static void kvmi_control_allowed_events(struct kvm_introspection *kvmi,
+					int id, bool allow)
+{
+	int all_events = -1;
+
+	if (allow) {
+		if (id == all_events)
+			bitmap_fill(kvmi->event_allow_mask, KVMI_NUM_EVENTS);
+		else
+			set_bit(id, kvmi->event_allow_mask);
+	} else {
+		if (id == all_events)
+			bitmap_zero(kvmi->event_allow_mask, KVMI_NUM_EVENTS);
+		else
+			clear_bit(id, kvmi->event_allow_mask);
+	}
+}
+
+int kvmi_ioctl_event(struct kvm *kvm, void __user *argp)
+{
+	struct kvm_introspection *kvmi;
+	int err, id;
+	bool allow;
+
+	err = kvmi_ioctl_get_feature(argp, &allow, &id, KVMI_NUM_EVENTS);
+	if (err)
+		return err;
+
+	mutex_lock(&kvm->kvmi_lock);
+
+	kvmi = KVMI(kvm);
+	if (kvmi)
+		kvmi_control_allowed_events(kvmi, id, allow);
+	else
+		err = -EFAULT;
+
+	mutex_unlock(&kvm->kvmi_lock);
+	return err;
+}
+
+static void kvmi_control_allowed_commands(struct kvm_introspection *kvmi,
+					  int id, bool allow)
+{
+	int all_commands = -1;
+
+	if (allow) {
+		if (id == all_commands)
+			bitmap_fill(kvmi->cmd_allow_mask, KVMI_NUM_COMMANDS);
+		else
+			set_bit(id, kvmi->cmd_allow_mask);
+	} else {
+		if (id == all_commands)
+			bitmap_zero(kvmi->cmd_allow_mask, KVMI_NUM_COMMANDS);
+		else
+			clear_bit(id, kvmi->cmd_allow_mask);
+	}
+}
+
+int kvmi_ioctl_command(struct kvm *kvm, void __user *argp)
+{
+	struct kvm_introspection *kvmi;
+	int err, id;
+	bool allow;
+
+	err = kvmi_ioctl_get_feature(argp, &allow, &id, KVMI_NUM_COMMANDS);
+	if (err)
+		return err;
+
+	mutex_lock(&kvm->kvmi_lock);
+
+	kvmi = KVMI(kvm);
+	if (kvmi)
+		kvmi_control_allowed_commands(kvmi, id, allow);
+	else
+		err = -EFAULT;
+
+	mutex_unlock(&kvm->kvmi_lock);
+	return err;
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 82634be560e6..4ca8625575bb 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3590,6 +3590,12 @@ static long kvm_vm_ioctl(struct file *filp,
 	case KVM_INTROSPECTION_UNHOOK:
 		r = kvmi_ioctl_unhook(kvm);
 		break;
+	case KVM_INTROSPECTION_COMMAND:
+		r = kvmi_ioctl_command(kvm, argp);
+		break;
+	case KVM_INTROSPECTION_EVENT:
+		r = kvmi_ioctl_event(kvm, argp);
+		break;
 #endif /* CONFIG_KVM_INTROSPECTION */
 	default:
 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);

[PATCH v8 41/81] KVM: introspection: add the read/dispatch message function

[Adalbert Lazăr]

Based on the common header (struct kvmi_msg_hdr), the receiving thread
will read/validate all messages, execute the VM introspection commands
(eg. KVMI_VM_GET_INFO) and dispatch the vCPU introspection commands
(eg. KVMI_VCPU_GET_REGISTERS) and the replies to vCPU events.

The vCPU threads will reply to vCPU introspection commands without the
help of the receiving thread.

This thread will end when the socket is closed (by userspace or the
introspection tool) or on the first API error (eg. wrong message size).

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  86 ++++++++++
 include/uapi/linux/kvmi.h                     |  22 +++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  |  98 ++++++++++++
 virt/kvm/introspection/kvmi.c                 |  38 ++++-
 virt/kvm/introspection/kvmi_int.h             |   4 +
 virt/kvm/introspection/kvmi_msg.c             | 149 +++++++++++++++++-
 6 files changed, 395 insertions(+), 2 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 2ee37c03585a..efde4b771586 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -65,6 +65,85 @@ used on that guest. Obviously, whether the guest can really continue
 normal execution depends on whether the introspection tool has made any
 modifications that require an active KVMI channel.
 
+All messages (commands or events) have a common header::
+
+	struct kvmi_msg_hdr {
+		__u16 id;
+		__u16 size;
+		__u32 seq;
+	};
+
+The replies have the same header, with the sequence number (``seq``)
+and message id (``id``) matching the command/event.
+
+After ``kvmi_msg_hdr``, ``id`` specific data of ``size`` bytes will
+follow.
+
+The message header and its data must be sent with one ``sendmsg()`` call
+to the socket. This simplifies the receiver loop and avoids
+the reconstruction of messages on the other side.
+
+The wire protocol uses the host native byte-order. The introspection tool
+must check this during the handshake and do the necessary conversion.
+
+A command reply begins with::
+
+	struct kvmi_error_code {
+		__s32 err;
+		__u32 padding;
+	}
+
+followed by the command specific data if the error code ``err`` is zero.
+
+The error code -KVM_ENOSYS is returned for unsupported commands.
+
+The error code -KVM_EPERM is returned for disallowed commands (see **Hooking**).
+
+The error code is related to the message processing, including unsupported
+commands. For all the other errors (incomplete messages, wrong sequence
+numbers, socket errors etc.) the socket will be closed. The device
+manager should reconnect.
+
+While all commands will have a reply as soon as possible, the replies
+to events will probably be delayed until a set of (new) commands will
+complete::
+
+   Host kernel               Tool
+   -----------               ----
+   event 1 ->
+                             <- command 1
+   command 1 reply ->
+                             <- command 2
+   command 2 reply ->
+                             <- event 1 reply
+
+If both ends send a message at the same time::
+
+   Host kernel               Tool
+   -----------               ----
+   event X ->                <- command X
+
+the host kernel will reply to 'command X', regardless of the receive time
+(before or after the 'event X' was sent).
+
+As it can be seen below, the wire protocol specifies occasional padding. This
+is to permit working with the data by directly using C structures or to round
+the structure size to a multiple of 8 bytes (64bit) to improve the copy
+operations that happen during ``recvmsg()`` or ``sendmsg()``. The members
+should have the native alignment of the host (4 bytes on x86). All padding
+must be initialized with zero otherwise the respective commands will fail
+with -KVM_EINVAL.
+
+To describe the commands/events, we reuse some conventions from api.txt:
+
+  - Architectures: which instruction set architectures provide this command/event
+
+  - Versions: which versions provide this command/event
+
+  - Parameters: incoming message data
+
+  - Returns: outgoing/reply message data
+
 Handshake
 ---------
 
@@ -99,6 +178,13 @@ In the end, the device manager will pass the file handle (plus the allowed
 commands/events) to KVM. It will detect when the socket is shutdown
 and it will reinitiate the handshake.
 
+Once the file handle reaches KVM, the introspection tool should
+use the *KVMI_GET_VERSION* command to get the API version and/or the
+*KVMI_VM_CHECK_COMMAND* and *KVMI_VM_CHECK_EVENT* commands to see which
+commands/events are allowed for this guest. The error code -KVM_EPERM
+will be returned if the introspection tool uses a command or enables an
+event which is disallowed.
+
 Unhooking
 ---------
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index d7b18ffef4fa..6fdaa92393a4 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -18,4 +18,26 @@ enum {
 	KVMI_NUM_EVENTS
 };
 
+struct kvmi_msg_hdr {
+	__u16 id;
+	__u16 size;
+	__u32 seq;
+};
+
+/*
+ * kvmi_msg_hdr.size is limited to KVMI_MSG_SIZE.
+ * The kernel side will close the socket if userspace
+ * uses a bigger value.
+ * This limit is used to accommodate the biggest known message,
+ * the commands to read/write a 4K page from/to guest memory.
+ */
+enum {
+	KVMI_MSG_SIZE = (4096 * 2 - sizeof(struct kvmi_msg_hdr))
+};
+
+struct kvmi_error_code {
+	__s32 err;
+	__u32 padding;
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index d1d02e067393..4c1fe67c8e35 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -15,6 +15,7 @@
 #include "processor.h"
 #include "../lib/kvm_util_internal.h"
 
+#include "linux/kvm_para.h"
 #include "linux/kvmi.h"
 
 #define VCPU_ID         5
@@ -82,10 +83,107 @@ static void unhook_introspection(struct kvm_vm *vm)
 		errno, strerror(errno));
 }
 
+static void receive_data(void *dest, size_t size)
+{
+	ssize_t r;
+
+	r = recv(Userspace_socket, dest, size, MSG_WAITALL);
+	TEST_ASSERT(r == size,
+		"recv() failed, expected %d, result %d, errno %d (%s)\n",
+		size, r, errno, strerror(errno));
+}
+
+static int receive_cmd_reply(struct kvmi_msg_hdr *req, void *rpl,
+			     size_t rpl_size)
+{
+	struct kvmi_msg_hdr hdr;
+	struct kvmi_error_code ec;
+
+	receive_data(&hdr, sizeof(hdr));
+
+	TEST_ASSERT(hdr.seq == req->seq,
+		"Unexpected messages sequence 0x%x, expected 0x%x\n",
+		hdr.seq, req->seq);
+
+	TEST_ASSERT(hdr.size >= sizeof(ec),
+		"Invalid message size %d, expected %d bytes (at least)\n",
+		hdr.size, sizeof(ec));
+
+	receive_data(&ec, sizeof(ec));
+
+	if (ec.err) {
+		TEST_ASSERT(hdr.size == sizeof(ec),
+			"Invalid command reply on error\n");
+	} else {
+		TEST_ASSERT(hdr.size == sizeof(ec) + rpl_size,
+			"Invalid command reply\n");
+
+		if (rpl && rpl_size)
+			receive_data(rpl, rpl_size);
+	}
+
+	return ec.err;
+}
+
+static unsigned int new_seq(void)
+{
+	static unsigned int seq;
+
+	return seq++;
+}
+
+static void send_message(int msg_id, struct kvmi_msg_hdr *hdr, size_t size)
+{
+	ssize_t r;
+
+	hdr->id = msg_id;
+	hdr->seq = new_seq();
+	hdr->size = size - sizeof(*hdr);
+
+	r = send(Userspace_socket, hdr, size, 0);
+	TEST_ASSERT(r == size,
+		"send() failed, sending %d, result %d, errno %d (%s)\n",
+		size, r, errno, strerror(errno));
+}
+
+static const char *kvm_strerror(int error)
+{
+	switch (error) {
+	case KVM_ENOSYS:
+		return "Invalid system call number";
+	case KVM_EOPNOTSUPP:
+		return "Operation not supported on transport endpoint";
+	default:
+		return strerror(error);
+	}
+}
+
+static int do_command(int cmd_id, struct kvmi_msg_hdr *req,
+		      size_t req_size, void *rpl, size_t rpl_size)
+{
+	send_message(cmd_id, req, req_size);
+	return receive_cmd_reply(req, rpl, rpl_size);
+}
+
+static void test_cmd_invalid(void)
+{
+	int invalid_msg_id = 0xffff;
+	struct kvmi_msg_hdr req;
+	int r;
+
+	r = do_command(invalid_msg_id, &req, sizeof(req), NULL, 0);
+	TEST_ASSERT(r == -KVM_ENOSYS,
+		"Invalid command didn't failed with KVM_ENOSYS, error %d (%s)\n",
+		-r, kvm_strerror(-r));
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	setup_socket();
 	hook_introspection(vm);
+
+	test_cmd_invalid();
+
 	unhook_introspection(vm);
 }
 
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 95b08a40d814..88d29408fbf1 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -8,13 +8,49 @@
 #include "kvmi_int.h"
 #include <linux/kthread.h>
 
+#define KVMI_MSG_SIZE_ALLOC (sizeof(struct kvmi_msg_hdr) + KVMI_MSG_SIZE)
+
+static struct kmem_cache *msg_cache;
+
+void *kvmi_msg_alloc(void)
+{
+	return kmem_cache_zalloc(msg_cache, GFP_KERNEL);
+}
+
+void kvmi_msg_free(void *addr)
+{
+	if (addr)
+		kmem_cache_free(msg_cache, addr);
+}
+
+static void kvmi_cache_destroy(void)
+{
+	kmem_cache_destroy(msg_cache);
+	msg_cache = NULL;
+}
+
+static int kvmi_cache_create(void)
+{
+	msg_cache = kmem_cache_create("kvmi_msg", KVMI_MSG_SIZE_ALLOC,
+				      4096, SLAB_ACCOUNT, NULL);
+
+	if (!msg_cache) {
+		kvmi_cache_destroy();
+
+		return -1;
+	}
+
+	return 0;
+}
+
 int kvmi_init(void)
 {
-	return 0;
+	return kvmi_cache_create();
 }
 
 void kvmi_uninit(void)
 {
+	kvmi_cache_destroy();
 }
 
 static void free_kvmi(struct kvm *kvm)
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 1c9cc15ab4d9..36f5e504e791 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -24,4 +24,8 @@ void kvmi_sock_shutdown(struct kvm_introspection *kvmi);
 void kvmi_sock_put(struct kvm_introspection *kvmi);
 bool kvmi_msg_process(struct kvm_introspection *kvmi);
 
+/* kvmi.c */
+void *kvmi_msg_alloc(void);
+void kvmi_msg_free(void *addr);
+
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index f9e66274fb43..02fc5d95fef6 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -33,7 +33,154 @@ void kvmi_sock_shutdown(struct kvm_introspection *kvmi)
 	kernel_sock_shutdown(kvmi->sock, SHUT_RDWR);
 }
 
+static int kvmi_sock_read(struct kvm_introspection *kvmi, void *buf,
+			  size_t size)
+{
+	struct kvec i = {
+		.iov_base = buf,
+		.iov_len = size,
+	};
+	struct msghdr m = { };
+	int rc;
+
+	rc = kernel_recvmsg(kvmi->sock, &m, &i, 1, size, MSG_WAITALL);
+
+	if (unlikely(rc != size && rc >= 0))
+		rc = -EPIPE;
+
+	return rc >= 0 ? 0 : rc;
+}
+
+static int kvmi_sock_write(struct kvm_introspection *kvmi, struct kvec *i,
+			   size_t n, size_t size)
+{
+	struct msghdr m = { };
+	int rc;
+
+	rc = kernel_sendmsg(kvmi->sock, &m, i, n, size);
+
+	if (unlikely(rc != size && rc >= 0))
+		rc = -EPIPE;
+
+	return rc >= 0 ? 0 : rc;
+}
+
+static int kvmi_msg_reply(struct kvm_introspection *kvmi,
+			  const struct kvmi_msg_hdr *msg, int err,
+			  const void *rpl, size_t rpl_size)
+{
+	struct kvmi_error_code ec;
+	struct kvmi_msg_hdr h;
+	struct kvec vec[3] = {
+		{ .iov_base = &h, .iov_len = sizeof(h) },
+		{ .iov_base = &ec, .iov_len = sizeof(ec) },
+		{ .iov_base = (void *)rpl, .iov_len = rpl_size },
+	};
+	size_t size = sizeof(h) + sizeof(ec) + (err ? 0 : rpl_size);
+	size_t n = err ? ARRAY_SIZE(vec) - 1 : ARRAY_SIZE(vec);
+
+	memset(&h, 0, sizeof(h));
+	h.id = msg->id;
+	h.seq = msg->seq;
+	h.size = size - sizeof(h);
+
+	memset(&ec, 0, sizeof(ec));
+	ec.err = err;
+
+	return kvmi_sock_write(kvmi, vec, n, size);
+}
+
+static int kvmi_msg_vm_reply(struct kvm_introspection *kvmi,
+			     const struct kvmi_msg_hdr *msg,
+			     int err, const void *rpl,
+			     size_t rpl_size)
+{
+	return kvmi_msg_reply(kvmi, msg, err, rpl, rpl_size);
+}
+
+static bool is_command_allowed(struct kvm_introspection *kvmi, u16 id)
+{
+	return id < KVMI_NUM_COMMANDS && test_bit(id, kvmi->cmd_allow_mask);
+}
+
+/*
+ * These commands are executed by the receiving thread/worker.
+ */
+static int(*const msg_vm[])(struct kvm_introspection *,
+			    const struct kvmi_msg_hdr *, const void *) = {
+};
+
+static bool is_vm_command(u16 id)
+{
+	return id < ARRAY_SIZE(msg_vm) && !!msg_vm[id];
+}
+
+static struct kvmi_msg_hdr *kvmi_msg_recv(struct kvm_introspection *kvmi)
+{
+	struct kvmi_msg_hdr *msg;
+	int err;
+
+	msg = kvmi_msg_alloc();
+	if (!msg)
+		goto out_err;
+
+	err = kvmi_sock_read(kvmi, msg, sizeof(*msg));
+	if (err)
+		goto out_err;
+
+	if (msg->size) {
+		if (msg->size > KVMI_MSG_SIZE)
+			goto out_err;
+
+		err = kvmi_sock_read(kvmi, msg + 1, msg->size);
+		if (err)
+			goto out_err;
+	}
+
+	return msg;
+
+out_err:
+	kvmi_msg_free(msg);
+
+	return NULL;
+}
+
+static int kvmi_msg_dispatch_vm_cmd(struct kvm_introspection *kvmi,
+				    const struct kvmi_msg_hdr *msg)
+{
+	return msg_vm[msg->id](kvmi, msg, msg + 1);
+}
+
+static bool is_message_allowed(struct kvm_introspection *kvmi, u16 id)
+{
+	return is_command_allowed(kvmi, id);
+}
+
+static int kvmi_msg_vm_reply_ec(struct kvm_introspection *kvmi,
+				const struct kvmi_msg_hdr *msg, int ec)
+{
+	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
+}
+
 bool kvmi_msg_process(struct kvm_introspection *kvmi)
 {
-	return false;
+	struct kvmi_msg_hdr *msg;
+	int err = -1;
+
+	msg = kvmi_msg_recv(kvmi);
+	if (!msg)
+		goto out;
+
+	if (is_vm_command(msg->id)) {
+		if (is_message_allowed(kvmi, msg->id))
+			err = kvmi_msg_dispatch_vm_cmd(kvmi, msg);
+		else
+			err = kvmi_msg_vm_reply_ec(kvmi, msg, -KVM_EPERM);
+	} else {
+		err = kvmi_msg_vm_reply_ec(kvmi, msg, -KVM_ENOSYS);
+	}
+
+	kvmi_msg_free(msg);
+out:
+	return err == 0;
 }

[PATCH v8 42/81] KVM: introspection: add KVMI_GET_VERSION

[Adalbert Lazăr]

This command is used to identify the commands/events supported
by the introspection subsystem and it is always allowed.
Any attempt from userspace to explicitly disallow this command through
the KVM_INTROSPECTION_COMMAND ioctl will get -EPERM, unless userspace
disables all commands, using id=-1, in which case KVMI_GET_VERSION is
silently allowed, without error.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 35 +++++++++++++++++++
 include/uapi/linux/kvmi.h                     | 10 ++++++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 25 +++++++++++++
 virt/kvm/introspection/kvmi.c                 | 27 +++++++++++---
 virt/kvm/introspection/kvmi_msg.c             | 12 +++++++
 5 files changed, 105 insertions(+), 4 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index efde4b771586..d848e56f42e9 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -223,3 +223,38 @@ device-specific memory (DMA, emulated MMIO, reserved by a passthrough
 device etc.). It is up to the user to determine, using the guest operating
 system data structures, the areas that are safe to access (code, stack, heap
 etc.).
+
+Commands
+--------
+
+The following C structures are meant to be used directly when communicating
+over the wire. The peer that detects any size mismatch should simply close
+the connection and report the error.
+
+1. KVMI_GET_VERSION
+-------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters: none
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_get_version_reply {
+		__u32 version;
+		__u32 padding;
+	};
+
+Returns the introspection API version.
+
+This command is always allowed and successful (if the introspection is
+built in kernel).
+
+The userspace should use this command to identify the commands/events
+supported by the kernel side and what messages must be used for event
+replies. These messages might be extended in futures versions and while
+the kernel will accept shorter messages (older versions) or bigger
+messages (newer versions, ignoring the extra information) it will not
+accept bigger/newer event replies.
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 6fdaa92393a4..b0a5b72d3936 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -6,11 +6,16 @@
  * KVMI structures and definitions
  */
 
+#include <linux/kernel.h>
+#include <linux/types.h>
+
 enum {
 	KVMI_VERSION = 0x00000001
 };
 
 enum {
+	KVMI_GET_VERSION = 2,
+
 	KVMI_NUM_MESSAGES
 };
 
@@ -40,4 +45,9 @@ struct kvmi_error_code {
 	__u32 padding;
 };
 
+struct kvmi_get_version_reply {
+	__u32 version;
+	__u32 padding;
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 4c1fe67c8e35..327272e266ff 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -177,12 +177,37 @@ static void test_cmd_invalid(void)
 		-r, kvm_strerror(-r));
 }
 
+static void test_vm_command(int cmd_id, struct kvmi_msg_hdr *req,
+			    size_t req_size, void *rpl, size_t rpl_size)
+{
+	int r;
+
+	r = do_command(cmd_id, req, req_size, rpl, rpl_size);
+	TEST_ASSERT(r == 0,
+		    "Command %d failed, error %d (%s)\n",
+		    cmd_id, -r, kvm_strerror(-r));
+}
+
+static void test_cmd_get_version(void)
+{
+	struct kvmi_get_version_reply rpl;
+	struct kvmi_msg_hdr req;
+
+	test_vm_command(KVMI_GET_VERSION, &req, sizeof(req), &rpl, sizeof(rpl));
+	TEST_ASSERT(rpl.version == KVMI_VERSION,
+		    "Unexpected KVMI version %d, expecting %d\n",
+		    rpl.version, KVMI_VERSION);
+
+	DEBUG("KVMI version: %u\n", rpl.version);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	setup_socket();
 	hook_introspection(vm);
 
 	test_cmd_invalid();
+	test_cmd_get_version();
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 88d29408fbf1..8cd66b1dac02 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -10,6 +10,8 @@
 
 #define KVMI_MSG_SIZE_ALLOC (sizeof(struct kvmi_msg_hdr) + KVMI_MSG_SIZE)
 
+static DECLARE_BITMAP(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS);
+
 static struct kmem_cache *msg_cache;
 
 void *kvmi_msg_alloc(void)
@@ -43,8 +45,16 @@ static int kvmi_cache_create(void)
 	return 0;
 }
 
+static void setup_always_allowed_commands(void)
+{
+	bitmap_zero(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS);
+	set_bit(KVMI_GET_VERSION, Kvmi_always_allowed_commands);
+}
+
 int kvmi_init(void)
 {
+	setup_always_allowed_commands();
+
 	return kvmi_cache_create();
 }
 
@@ -71,6 +81,9 @@ alloc_kvmi(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 	BUILD_BUG_ON(sizeof(hook->uuid) != sizeof(kvmi->uuid));
 	memcpy(&kvmi->uuid, &hook->uuid, sizeof(kvmi->uuid));
 
+	bitmap_copy(kvmi->cmd_allow_mask, Kvmi_always_allowed_commands,
+		    KVMI_NUM_COMMANDS);
+
 	kvmi->kvm = kvm;
 
 	return kvmi;
@@ -282,8 +295,8 @@ int kvmi_ioctl_event(struct kvm *kvm, void __user *argp)
 	return err;
 }
 
-static void kvmi_control_allowed_commands(struct kvm_introspection *kvmi,
-					  int id, bool allow)
+static int kvmi_control_allowed_commands(struct kvm_introspection *kvmi,
+					 int id, bool allow)
 {
 	int all_commands = -1;
 
@@ -294,10 +307,16 @@ static void kvmi_control_allowed_commands(struct kvm_introspection *kvmi,
 			set_bit(id, kvmi->cmd_allow_mask);
 	} else {
 		if (id == all_commands)
-			bitmap_zero(kvmi->cmd_allow_mask, KVMI_NUM_COMMANDS);
+			bitmap_copy(kvmi->cmd_allow_mask,
+				    Kvmi_always_allowed_commands,
+				    KVMI_NUM_COMMANDS);
+		else if (test_bit(id, Kvmi_always_allowed_commands))
+			return -EPERM;
 		else
 			clear_bit(id, kvmi->cmd_allow_mask);
 	}
+
+	return 0;
 }
 
 int kvmi_ioctl_command(struct kvm *kvm, void __user *argp)
@@ -314,7 +333,7 @@ int kvmi_ioctl_command(struct kvm *kvm, void __user *argp)
 
 	kvmi = KVMI(kvm);
 	if (kvmi)
-		kvmi_control_allowed_commands(kvmi, id, allow);
+		err = kvmi_control_allowed_commands(kvmi, id, allow);
 	else
 		err = -EFAULT;
 
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 02fc5d95fef6..9efcd896f0c6 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -103,11 +103,23 @@ static bool is_command_allowed(struct kvm_introspection *kvmi, u16 id)
 	return id < KVMI_NUM_COMMANDS && test_bit(id, kvmi->cmd_allow_mask);
 }
 
+static int handle_get_version(struct kvm_introspection *kvmi,
+			      const struct kvmi_msg_hdr *msg, const void *req)
+{
+	struct kvmi_get_version_reply rpl;
+
+	memset(&rpl, 0, sizeof(rpl));
+	rpl.version = KVMI_VERSION;
+
+	return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl));
+}
+
 /*
  * These commands are executed by the receiving thread/worker.
  */
 static int(*const msg_vm[])(struct kvm_introspection *,
 			    const struct kvmi_msg_hdr *, const void *) = {
+	[KVMI_GET_VERSION] = handle_get_version,
 };
 
 static bool is_vm_command(u16 id)

[PATCH v8 43/81] KVM: introspection: add KVMI_VM_CHECK_COMMAND and KVMI_VM_CHECK_EVENT

[Adalbert Lazăr]

These commands are used to check what introspection commands and events
are supported (by kernel) and allowed (by userspace).

These are alternative methods to KVMI_GET_VERSION in checking if the
introspection supports a specific command/event.

As with the KVMI_GET_VERSION command, these two can never be disallowed
by userspace.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 62 +++++++++++++++++++
 include/uapi/linux/kvmi.h                     | 16 ++++-
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 55 ++++++++++++++++
 virt/kvm/introspection/kvmi.c                 |  9 +++
 virt/kvm/introspection/kvmi_int.h             |  2 +
 virt/kvm/introspection/kvmi_msg.c             | 49 ++++++++++++++-
 6 files changed, 191 insertions(+), 2 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index d848e56f42e9..5db38848c6d4 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -258,3 +258,65 @@ replies. These messages might be extended in futures versions and while
 the kernel will accept shorter messages (older versions) or bigger
 messages (newer versions, ignoring the extra information) it will not
 accept bigger/newer event replies.
+
+2. KVMI_VM_CHECK_COMMAND
+------------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vm_check_command {
+		__u16 id;
+		__u16 padding1;
+		__u32 padding2;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+
+Checks if the command specified by ``id`` is supported and allowed.
+
+This command is always allowed.
+
+:Errors:
+
+* -KVM_ENOENT - the command specified by ``id`` is unsupported
+* -KVM_EPERM - the command specified by ``id`` is disallowed
+* -KVM_EINVAL - the padding is not zero
+
+3. KVMI_VM_CHECK_EVENT
+----------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vm_check_event {
+		__u16 id;
+		__u16 padding1;
+		__u32 padding2;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+
+Checks if the event specified by ``id`` is supported and allowed.
+
+This command is always allowed.
+
+:Errors:
+
+* -KVM_ENOENT - the event specified by ``id`` is unsupported
+* -KVM_EPERM - the event specified by ``id`` is disallowed
+* -KVM_EINVAL - the padding is not zero
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index b0a5b72d3936..b47de1733e49 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -14,7 +14,9 @@ enum {
 };
 
 enum {
-	KVMI_GET_VERSION = 2,
+	KVMI_GET_VERSION      = 2,
+	KVMI_VM_CHECK_COMMAND = 3,
+	KVMI_VM_CHECK_EVENT   = 4,
 
 	KVMI_NUM_MESSAGES
 };
@@ -50,4 +52,16 @@ struct kvmi_get_version_reply {
 	__u32 padding;
 };
 
+struct kvmi_vm_check_command {
+	__u16 id;
+	__u16 padding1;
+	__u32 padding2;
+};
+
+struct kvmi_vm_check_event {
+	__u16 id;
+	__u16 padding1;
+	__u32 padding2;
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 327272e266ff..f434a9611857 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -201,6 +201,59 @@ static void test_cmd_get_version(void)
 	DEBUG("KVMI version: %u\n", rpl.version);
 }
 
+static int cmd_check_command(__u16 id)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vm_check_command cmd;
+	} req = {};
+
+	req.cmd.id = id;
+
+	return do_command(KVMI_VM_CHECK_COMMAND, &req.hdr, sizeof(req), NULL,
+			     0);
+}
+
+static void test_cmd_check_command(void)
+{
+	__u16 valid_id = KVMI_GET_VERSION;
+	__u16 invalid_id = 0xffff;
+	int r;
+
+	r = cmd_check_command(valid_id);
+	TEST_ASSERT(r == 0,
+		"KVMI_VM_CHECK_COMMAND failed, error %d (%s)\n",
+		-r, kvm_strerror(-r));
+
+	r = cmd_check_command(invalid_id);
+	TEST_ASSERT(r == -KVM_ENOENT,
+		"KVMI_VM_CHECK_COMMAND didn't failed with -KVM_ENOENT, error %d (%s)\n",
+		-r, kvm_strerror(-r));
+}
+
+static int cmd_check_event(__u16 id)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vm_check_event cmd;
+	} req = {};
+
+	req.cmd.id = id;
+
+	return do_command(KVMI_VM_CHECK_EVENT, &req.hdr, sizeof(req), NULL, 0);
+}
+
+static void test_cmd_check_event(void)
+{
+	__u16 invalid_id = 0xffff;
+	int r;
+
+	r = cmd_check_event(invalid_id);
+	TEST_ASSERT(r == -KVM_ENOENT,
+		"KVMI_VM_CHECK_EVENT didn't failed with -KVM_ENOENT, error %d (%s)\n",
+		-r, kvm_strerror(-r));
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	setup_socket();
@@ -208,6 +261,8 @@ static void test_introspection(struct kvm_vm *vm)
 
 	test_cmd_invalid();
 	test_cmd_get_version();
+	test_cmd_check_command();
+	test_cmd_check_event();
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 8cd66b1dac02..5c17f548b457 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -11,6 +11,7 @@
 #define KVMI_MSG_SIZE_ALLOC (sizeof(struct kvmi_msg_hdr) + KVMI_MSG_SIZE)
 
 static DECLARE_BITMAP(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS);
+DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
 
 static struct kmem_cache *msg_cache;
 
@@ -49,11 +50,19 @@ static void setup_always_allowed_commands(void)
 {
 	bitmap_zero(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS);
 	set_bit(KVMI_GET_VERSION, Kvmi_always_allowed_commands);
+	set_bit(KVMI_VM_CHECK_COMMAND, Kvmi_always_allowed_commands);
+	set_bit(KVMI_VM_CHECK_EVENT, Kvmi_always_allowed_commands);
+}
+
+static void setup_known_events(void)
+{
+	bitmap_zero(Kvmi_known_events, KVMI_NUM_EVENTS);
 }
 
 int kvmi_init(void)
 {
 	setup_always_allowed_commands();
+	setup_known_events();
 
 	return kvmi_cache_create();
 }
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 36f5e504e791..f755c66ceecc 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -16,6 +16,8 @@
 #define kvmi_err(kvmi, fmt, ...) \
 	kvm_info("%pU ERROR: " fmt, &kvmi->uuid, ## __VA_ARGS__)
 
+extern DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
+
 #define KVMI(kvm) ((kvm)->kvmi)
 
 /* kvmi_msg.c */
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 9efcd896f0c6..4fc8b7a0b6d9 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -8,6 +8,8 @@
 #include <linux/net.h>
 #include "kvmi_int.h"
 
+static bool is_vm_command(u16 id);
+
 bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd)
 {
 	struct socket *sock;
@@ -114,12 +116,57 @@ static int handle_get_version(struct kvm_introspection *kvmi,
 	return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl));
 }
 
+static int handle_check_command(struct kvm_introspection *kvmi,
+				const struct kvmi_msg_hdr *msg,
+				const void *_req)
+{
+	const struct kvmi_vm_check_command *req = _req;
+	int ec = 0;
+
+	if (req->padding1 || req->padding2)
+		ec = -KVM_EINVAL;
+	else if (!is_vm_command(req->id))
+		ec = -KVM_ENOENT;
+	else if (!is_command_allowed(kvmi, req->id))
+		ec = -KVM_EPERM;
+
+	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
+}
+
+static bool is_event_known(u16 id)
+{
+	return id < KVMI_NUM_EVENTS && test_bit(id, Kvmi_known_events);
+}
+
+static bool is_event_allowed(struct kvm_introspection *kvmi, u16 id)
+{
+	return id < KVMI_NUM_EVENTS && test_bit(id, kvmi->event_allow_mask);
+}
+
+static int handle_check_event(struct kvm_introspection *kvmi,
+			      const struct kvmi_msg_hdr *msg, const void *_req)
+{
+	const struct kvmi_vm_check_event *req = _req;
+	int ec = 0;
+
+	if (req->padding1 || req->padding2)
+		ec = -KVM_EINVAL;
+	else if (!is_event_known(req->id))
+		ec = -KVM_ENOENT;
+	else if (!is_event_allowed(kvmi, req->id))
+		ec = -KVM_EPERM;
+
+	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed by the receiving thread/worker.
  */
 static int(*const msg_vm[])(struct kvm_introspection *,
 			    const struct kvmi_msg_hdr *, const void *) = {
-	[KVMI_GET_VERSION] = handle_get_version,
+	[KVMI_GET_VERSION]      = handle_get_version,
+	[KVMI_VM_CHECK_COMMAND] = handle_check_command,
+	[KVMI_VM_CHECK_EVENT]   = handle_check_event,
 };
 
 static bool is_vm_command(u16 id)

[PATCH v8 44/81] KVM: introspection: add KVMI_VM_GET_INFO

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

For now, this command returns only the number of online vCPUs.

The introspection tool uses the vCPU index on commands related to
vCPUs.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst                | 18 ++++++++++++++++++
 include/uapi/linux/kvmi.h                      |  6 ++++++
 tools/testing/selftests/kvm/x86_64/kvmi_test.c | 15 +++++++++++++++
 virt/kvm/introspection/kvmi_msg.c              | 13 +++++++++++++
 4 files changed, 52 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 5db38848c6d4..36b34e09d2c2 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -320,3 +320,21 @@ This command is always allowed.
 * -KVM_ENOENT - the event specified by ``id`` is unsupported
 * -KVM_EPERM - the event specified by ``id`` is disallowed
 * -KVM_EINVAL - the padding is not zero
+
+4. KVMI_VM_GET_INFO
+-------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters: none
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_vm_get_info_reply {
+		__u32 vcpu_count;
+		__u32 padding[3];
+	};
+
+Returns the number of online vCPUs.
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index b47de1733e49..bfa1526798e6 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -17,6 +17,7 @@ enum {
 	KVMI_GET_VERSION      = 2,
 	KVMI_VM_CHECK_COMMAND = 3,
 	KVMI_VM_CHECK_EVENT   = 4,
+	KVMI_VM_GET_INFO      = 5,
 
 	KVMI_NUM_MESSAGES
 };
@@ -64,4 +65,9 @@ struct kvmi_vm_check_event {
 	__u32 padding2;
 };
 
+struct kvmi_vm_get_info_reply {
+	__u32 vcpu_count;
+	__u32 padding[3];
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index f434a9611857..ba58081bfec4 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -254,6 +254,20 @@ static void test_cmd_check_event(void)
 		-r, kvm_strerror(-r));
 }
 
+static void test_cmd_get_vm_info(void)
+{
+	struct kvmi_vm_get_info_reply rpl;
+	struct kvmi_msg_hdr req;
+
+	test_vm_command(KVMI_VM_GET_INFO, &req, sizeof(req), &rpl,
+			sizeof(rpl));
+	TEST_ASSERT(rpl.vcpu_count == 1,
+		    "Unexpected number of vCPU count %u\n",
+		    rpl.vcpu_count);
+
+	DEBUG("vcpu count: %u\n", rpl.vcpu_count);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	setup_socket();
@@ -263,6 +277,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_get_version();
 	test_cmd_check_command();
 	test_cmd_check_event();
+	test_cmd_get_vm_info();
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 4fc8b7a0b6d9..ceec31ae4581 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -159,6 +159,18 @@ static int handle_check_event(struct kvm_introspection *kvmi,
 	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
 }
 
+static int handle_get_info(struct kvm_introspection *kvmi,
+			   const struct kvmi_msg_hdr *msg,
+			   const void *req)
+{
+	struct kvmi_vm_get_info_reply rpl;
+
+	memset(&rpl, 0, sizeof(rpl));
+	rpl.vcpu_count = atomic_read(&kvmi->kvm->online_vcpus);
+
+	return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl));
+}
+
 /*
  * These commands are executed by the receiving thread/worker.
  */
@@ -167,6 +179,7 @@ static int(*const msg_vm[])(struct kvm_introspection *,
 	[KVMI_GET_VERSION]      = handle_get_version,
 	[KVMI_VM_CHECK_COMMAND] = handle_check_command,
 	[KVMI_VM_CHECK_EVENT]   = handle_check_event,
+	[KVMI_VM_GET_INFO]      = handle_get_info,
 };
 
 static bool is_vm_command(u16 id)

[PATCH v8 45/81] KVM: introspection: add KVMI_EVENT_UNHOOK

[Adalbert Lazăr]

In certain situations (when the guest has to be paused, suspended,
migrated, etc.), userspace will use the KVM_INTROSPECTION_PREUNHOOK ioctl
in order to trigger the KVMI_EVENT_UNHOOK event. If the event is sent
successfully (the VM has an active introspection channel), userspace
should delay the action (pause/suspend/...) to give the introspection
tool the chance to remove its hooks (eg. breakpoints) while the guest
is still running. Once a timeout is reached or the introspection tool
has closed the socket, userspace should resume the action.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/api.rst                | 28 ++++++++
 Documentation/virt/kvm/kvmi.rst               | 69 ++++++++++++++++++-
 arch/x86/include/uapi/asm/kvmi.h              | 29 ++++++++
 include/linux/kvmi_host.h                     |  3 +
 include/uapi/linux/kvm.h                      |  2 +
 include/uapi/linux/kvmi.h                     | 13 ++++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 42 +++++++++++
 virt/kvm/introspection/kvmi.c                 | 42 ++++++++++-
 virt/kvm/introspection/kvmi_int.h             |  1 +
 virt/kvm/introspection/kvmi_msg.c             | 38 ++++++++++
 virt/kvm/kvm_main.c                           |  3 +
 11 files changed, 266 insertions(+), 4 deletions(-)
 create mode 100644 arch/x86/include/uapi/asm/kvmi.h

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 4d81a2f2f8f7..4178e1317647 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -4771,6 +4771,34 @@ the event is disallowed.
 Unless set to -1 (meaning all event), id must be a event ID
 (e.g. KVMI_EVENT_UNHOOK, KVMI_EVENT_CR, etc.)
 
+4.129 KVM_INTROSPECTION_PREUNHOOK
+---------------------------------
+
+:Capability: KVM_CAP_INTROSPECTION
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: none
+:Returns: 0 on success, a negative value on error
+
+Errors:
+
+  ======     ============================================================
+  EFAULT     the introspection is not enabled
+  EFAULT     the socket (passed with KVM_INTROSPECTION_HOOK) had an error
+  ENOENT     the introspection tool didn't subscribed
+             to this type of introspection event (unhook)
+  ======     ============================================================
+
+This ioctl is used to inform that the current VM is
+paused/suspended/migrated/etc.
+
+KVM should send an 'unhook' introspection event to the introspection tool.
+
+If this ioctl is successful, the userspace should give the
+introspection tool a chance to unhook the VM and then it should use
+KVM_INTROSPECTION_UNHOOK to make sure all the introspection structures
+are freed.
+
 5. The kvm_run structure
 ========================
 
diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 36b34e09d2c2..e652bdd65052 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -194,9 +194,10 @@ becomes necessary to remove them before the guest is suspended, moved
 (migrated) or a snapshot with memory is created.
 
 The actions are normally performed by the device manager. In the case
-of QEMU, it will use another ioctl to notify the introspection tool and
-wait for a limited amount of time (a few seconds) for a confirmation that
-is OK to proceed.
+of QEMU, it will use the *KVM_INTROSPECTION_PREUNHOOK* ioctl to trigger
+the *KVMI_EVENT_UNHOOK* event and wait for a limited amount of time
+(a few seconds) for a confirmation from the introspection tool
+that is OK to proceed.
 
 Live migrations
 ---------------
@@ -338,3 +339,65 @@ This command is always allowed.
 	};
 
 Returns the number of online vCPUs.
+
+Events
+======
+
+All introspection events (VM or vCPU related) are sent
+using the *KVMI_EVENT* message id.
+
+The *KVMI_EVENT_UNHOOK* event doesn't have a reply and share the kvmi_event
+structure, for consistency with the vCPU events.
+
+The message data begins with a common structure, having the size of the
+structure, the vCPU index and the event id::
+
+	struct kvmi_event {
+		__u16 size;
+		__u16 vcpu;
+		__u8 event;
+		__u8 padding[3];
+		struct kvmi_event_arch arch;
+	}
+
+On x86 the structure looks like this::
+
+	struct kvmi_event_arch {
+		__u8 mode;
+		__u8 padding[7];
+		struct kvm_regs regs;
+		struct kvm_sregs sregs;
+		struct {
+			__u64 sysenter_cs;
+			__u64 sysenter_esp;
+			__u64 sysenter_eip;
+			__u64 efer;
+			__u64 star;
+			__u64 lstar;
+			__u64 cstar;
+			__u64 pat;
+			__u64 shadow_gs;
+		} msrs;
+	};
+
+It contains information about the vCPU state at the time of the event.
+
+Specific data can follow these common structures.
+
+1. KVMI_EVENT_UNHOOK
+--------------------
+
+:Architecture: all
+:Versions: >= 1
+:Actions: none
+:Parameters:
+
+::
+
+	struct kvmi_event;
+
+:Returns: none
+
+This event is sent when the device manager has to pause/stop/migrate the
+guest (see **Unhooking**).  The introspection tool has a chance to unhook
+and close the KVMI channel (signaling that the operation can proceed).
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
new file mode 100644
index 000000000000..551f9ed1ed9c
--- /dev/null
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_ASM_X86_KVMI_H
+#define _UAPI_ASM_X86_KVMI_H
+
+/*
+ * KVM introspection - x86 specific structures and definitions
+ */
+
+#include <asm/kvm.h>
+
+struct kvmi_event_arch {
+	__u8 mode;		/* 2, 4 or 8 */
+	__u8 padding[7];
+	struct kvm_regs regs;
+	struct kvm_sregs sregs;
+	struct {
+		__u64 sysenter_cs;
+		__u64 sysenter_esp;
+		__u64 sysenter_eip;
+		__u64 efer;
+		__u64 star;
+		__u64 lstar;
+		__u64 cstar;
+		__u64 pat;
+		__u64 shadow_gs;
+	} msrs;
+};
+
+#endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 4e77a0227c08..180e26335a8f 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -21,6 +21,8 @@ struct kvm_introspection {
 
 	DECLARE_BITMAP(cmd_allow_mask, KVMI_NUM_COMMANDS);
 	DECLARE_BITMAP(event_allow_mask, KVMI_NUM_EVENTS);
+
+	atomic_t ev_seq;
 };
 
 #ifdef CONFIG_KVM_INTROSPECTION
@@ -34,6 +36,7 @@ int kvmi_ioctl_hook(struct kvm *kvm, void __user *argp);
 int kvmi_ioctl_unhook(struct kvm *kvm);
 int kvmi_ioctl_command(struct kvm *kvm, void __user *argp);
 int kvmi_ioctl_event(struct kvm *kvm, void __user *argp);
+int kvmi_ioctl_preunhook(struct kvm *kvm);
 
 #else
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index dd4ab88f0012..b8448cd797ec 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1576,6 +1576,8 @@ struct kvm_introspection_feature {
 #define KVM_INTROSPECTION_COMMAND _IOW(KVMIO, 0xc5, struct kvm_introspection_feature)
 #define KVM_INTROSPECTION_EVENT   _IOW(KVMIO, 0xc6, struct kvm_introspection_feature)
 
+#define KVM_INTROSPECTION_PREUNHOOK  _IO(KVMIO, 0xc7)
+
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)
 #define KVM_DEV_ASSIGN_MASK_INTX	(1 << 2)
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index bfa1526798e6..689eba32c031 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -8,12 +8,15 @@
 
 #include <linux/kernel.h>
 #include <linux/types.h>
+#include <asm/kvmi.h>
 
 enum {
 	KVMI_VERSION = 0x00000001
 };
 
 enum {
+	KVMI_EVENT            = 1,
+
 	KVMI_GET_VERSION      = 2,
 	KVMI_VM_CHECK_COMMAND = 3,
 	KVMI_VM_CHECK_EVENT   = 4,
@@ -23,6 +26,8 @@ enum {
 };
 
 enum {
+	KVMI_EVENT_UNHOOK = 0,
+
 	KVMI_NUM_EVENTS
 };
 
@@ -70,4 +75,12 @@ struct kvmi_vm_get_info_reply {
 	__u32 padding[3];
 };
 
+struct kvmi_event {
+	__u16 size;
+	__u16 vcpu;
+	__u8 event;
+	__u8 padding[3];
+	struct kvmi_event_arch arch;
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index ba58081bfec4..9cb65f8c946f 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -268,6 +268,47 @@ static void test_cmd_get_vm_info(void)
 	DEBUG("vcpu count: %u\n", rpl.vcpu_count);
 }
 
+static void trigger_event_unhook_notification(struct kvm_vm *vm)
+{
+	int r;
+
+	r = ioctl(vm->fd, KVM_INTROSPECTION_PREUNHOOK, NULL);
+	TEST_ASSERT(r == 0,
+		"KVM_INTROSPECTION_PREUNHOOK failed, errno %d (%s)\n",
+		errno, strerror(errno));
+}
+
+static void receive_event(struct kvmi_msg_hdr *hdr, struct kvmi_event *ev,
+			 size_t ev_size, int event_id)
+{
+	receive_data(hdr, sizeof(*hdr));
+
+	TEST_ASSERT(hdr->id == KVMI_EVENT,
+		"Unexpected messages id %d, expected %d\n",
+		hdr->id, KVMI_EVENT);
+
+	TEST_ASSERT(hdr->size == ev_size,
+		"Invalid event size %d, expected %d bytes\n",
+		hdr->size, ev_size);
+
+	receive_data(ev, ev_size);
+
+	TEST_ASSERT(ev->event == event_id,
+		"Unexpected event %d, expected %d\n",
+		ev->event, event_id);
+}
+
+static void test_event_unhook(struct kvm_vm *vm)
+{
+	__u16 id = KVMI_EVENT_UNHOOK;
+	struct kvmi_msg_hdr hdr;
+	struct kvmi_event ev;
+
+	trigger_event_unhook_notification(vm);
+
+	receive_event(&hdr, &ev, sizeof(ev), id);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	setup_socket();
@@ -278,6 +319,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_check_command();
 	test_cmd_check_event();
 	test_cmd_get_vm_info();
+	test_event_unhook(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 5c17f548b457..bf6d5ec951c8 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -12,6 +12,8 @@
 
 static DECLARE_BITMAP(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS);
 DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
+static DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
+static DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 
 static struct kmem_cache *msg_cache;
 
@@ -56,7 +58,13 @@ static void setup_always_allowed_commands(void)
 
 static void setup_known_events(void)
 {
-	bitmap_zero(Kvmi_known_events, KVMI_NUM_EVENTS);
+	bitmap_zero(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
+	set_bit(KVMI_EVENT_UNHOOK, Kvmi_known_vm_events);
+
+	bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
+
+	bitmap_or(Kvmi_known_events, Kvmi_known_vm_events,
+		  Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 }
 
 int kvmi_init(void)
@@ -93,6 +101,8 @@ alloc_kvmi(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 	bitmap_copy(kvmi->cmd_allow_mask, Kvmi_always_allowed_commands,
 		    KVMI_NUM_COMMANDS);
 
+	atomic_set(&kvmi->ev_seq, 0);
+
 	kvmi->kvm = kvm;
 
 	return kvmi;
@@ -349,3 +359,33 @@ int kvmi_ioctl_command(struct kvm *kvm, void __user *argp)
 	mutex_unlock(&kvm->kvmi_lock);
 	return err;
 }
+
+static bool kvmi_unhook_event(struct kvm_introspection *kvmi)
+{
+	int err;
+
+	err = kvmi_msg_send_unhook(kvmi);
+
+	return !err;
+}
+
+int kvmi_ioctl_preunhook(struct kvm *kvm)
+{
+	struct kvm_introspection *kvmi;
+	int err = 0;
+
+	mutex_lock(&kvm->kvmi_lock);
+
+	kvmi = KVMI(kvm);
+	if (!kvmi) {
+		err = -EFAULT;
+		goto out;
+	}
+
+	if (!kvmi_unhook_event(kvmi))
+		err = -ENOENT;
+
+out:
+	mutex_unlock(&kvm->kvmi_lock);
+	return err;
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index f755c66ceecc..ecd0625e0c9e 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -25,6 +25,7 @@ bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd);
 void kvmi_sock_shutdown(struct kvm_introspection *kvmi);
 void kvmi_sock_put(struct kvm_introspection *kvmi);
 bool kvmi_msg_process(struct kvm_introspection *kvmi);
+int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
 
 /* kvmi.c */
 void *kvmi_msg_alloc(void);
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index ceec31ae4581..b381273b7355 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -256,3 +256,41 @@ bool kvmi_msg_process(struct kvm_introspection *kvmi)
 out:
 	return err == 0;
 }
+
+static void kvmi_setup_event_msg_hdr(struct kvm_introspection *kvmi,
+				     struct kvmi_msg_hdr *hdr,
+				     size_t msg_size)
+{
+	memset(hdr, 0, sizeof(*hdr));
+
+	hdr->id = KVMI_EVENT;
+	hdr->seq = atomic_inc_return(&kvmi->ev_seq);
+	hdr->size = msg_size - sizeof(*hdr);
+}
+
+static void kvmi_setup_event_common(struct kvmi_event *ev, u32 ev_id,
+				    u16 vcpu_idx)
+{
+	memset(ev, 0, sizeof(*ev));
+
+	ev->vcpu = vcpu_idx;
+	ev->event = ev_id;
+	ev->size = sizeof(*ev);
+}
+
+int kvmi_msg_send_unhook(struct kvm_introspection *kvmi)
+{
+	struct kvmi_msg_hdr hdr;
+	struct kvmi_event common;
+	struct kvec vec[] = {
+		{.iov_base = &hdr,	.iov_len = sizeof(hdr)	 },
+		{.iov_base = &common,	.iov_len = sizeof(common)},
+	};
+	size_t msg_size = sizeof(hdr) + sizeof(common);
+	size_t n = ARRAY_SIZE(vec);
+
+	kvmi_setup_event_msg_hdr(kvmi, &hdr, msg_size);
+	kvmi_setup_event_common(&common, KVMI_EVENT_UNHOOK, 0);
+
+	return kvmi_sock_write(kvmi, vec, n, msg_size);
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4ca8625575bb..86bc2ed680ce 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3596,6 +3596,9 @@ static long kvm_vm_ioctl(struct file *filp,
 	case KVM_INTROSPECTION_EVENT:
 		r = kvmi_ioctl_event(kvm, argp);
 		break;
+	case KVM_INTROSPECTION_PREUNHOOK:
+		r = kvmi_ioctl_preunhook(kvm);
+		break;
 #endif /* CONFIG_KVM_INTROSPECTION */
 	default:
 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);

Re: [PATCH v8 45/81] KVM: introspection: add KVMI_EVENT_UNHOOK

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 2145 bytes --]

Hi "Adalbert,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on linus/master v5.6]
[cannot apply to kvm/linux-next vhost/linux-next next-20200330]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Adalbert-Laz-r/VM-introspection/20200330-234749
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: s390-randconfig-a001-20200331 (attached as .config)
compiler: s390-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=9.3.0 make.cross ARCH=s390 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from include/linux/kvmi_host.h:5,
                    from include/linux/kvm_host.h:38,
                    from arch/s390/kernel/asm-offsets.c:11:
>> include/uapi/linux/kvmi.h:11:10: fatal error: asm/kvmi.h: No such file or directory
      11 | #include <asm/kvmi.h>
         |          ^~~~~~~~~~~~
   compilation terminated.
   make[2]: *** [scripts/Makefile.build:101: arch/s390/kernel/asm-offsets.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [Makefile:1113: prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:180: sub-make] Error 2
   32 real  8 user  18 sys  82.93% cpu 	make prepare

vim +11 include/uapi/linux/kvmi.h

     4	
     5	/*
     6	 * KVMI structures and definitions
     7	 */
     8	
     9	#include <linux/kernel.h>
    10	#include <linux/types.h>
  > 11	#include <asm/kvmi.h>
    12	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 28213 bytes --]

[PATCH v8 46/81] KVM: introspection: add KVMI_VM_CONTROL_EVENTS

[Adalbert Lazăr]

With this command the introspection tool enables/disables VM events
(ie. KVMI_EVENT_UNHOOK).

By default, all events are disabled.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 44 +++++++++++++--
 include/linux/kvmi_host.h                     |  2 +
 include/uapi/linux/kvmi.h                     | 18 +++++--
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 54 +++++++++++++++++++
 virt/kvm/introspection/kvmi.c                 | 21 +++++++-
 virt/kvm/introspection/kvmi_int.h             |  3 ++
 virt/kvm/introspection/kvmi_msg.c             | 31 +++++++++--
 7 files changed, 159 insertions(+), 14 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index e652bdd65052..7a47fade7f08 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -340,11 +340,45 @@ This command is always allowed.
 
 Returns the number of online vCPUs.
 
+5. KVMI_VM_CONTROL_EVENTS
+-------------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vm_control_events {
+		__u16 event_id;
+		__u8 enable;
+		__u8 padding1;
+		__u32 padding2;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Enables/disables VM introspection events. This command can be used with
+the following events::
+
+	KVMI_EVENT_UNHOOK
+
+:Errors:
+
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EINVAL - the event ID is unknown (use *KVMI_VM_CHECK_EVENT* first)
+* -KVM_EPERM - the access is disallowed (use *KVMI_VM_CHECK_EVENT* first)
+
 Events
 ======
 
 All introspection events (VM or vCPU related) are sent
-using the *KVMI_EVENT* message id.
+using the *KVMI_EVENT* message id. No event will be sent unless
+it is explicitly enabled.
 
 The *KVMI_EVENT_UNHOOK* event doesn't have a reply and share the kvmi_event
 structure, for consistency with the vCPU events.
@@ -398,6 +432,8 @@ Specific data can follow these common structures.
 
 :Returns: none
 
-This event is sent when the device manager has to pause/stop/migrate the
-guest (see **Unhooking**).  The introspection tool has a chance to unhook
-and close the KVMI channel (signaling that the operation can proceed).
+This event is sent when the device manager has to pause/stop/migrate
+the guest (see **Unhooking**) and the introspection has been enabled
+for this event (see **KVMI_VM_CONTROL_EVENTS**). The introspection tool
+has a chance to unhook and close the KVMI channel (signaling that the
+operation can proceed).
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 180e26335a8f..41b22af771fb 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -22,6 +22,8 @@ struct kvm_introspection {
 	DECLARE_BITMAP(cmd_allow_mask, KVMI_NUM_COMMANDS);
 	DECLARE_BITMAP(event_allow_mask, KVMI_NUM_EVENTS);
 
+	DECLARE_BITMAP(vm_event_enable_mask, KVMI_NUM_EVENTS);
+
 	atomic_t ev_seq;
 };
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 689eba32c031..66e04a82f054 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -15,12 +15,13 @@ enum {
 };
 
 enum {
-	KVMI_EVENT            = 1,
+	KVMI_EVENT             = 1,
 
-	KVMI_GET_VERSION      = 2,
-	KVMI_VM_CHECK_COMMAND = 3,
-	KVMI_VM_CHECK_EVENT   = 4,
-	KVMI_VM_GET_INFO      = 5,
+	KVMI_GET_VERSION       = 2,
+	KVMI_VM_CHECK_COMMAND  = 3,
+	KVMI_VM_CHECK_EVENT    = 4,
+	KVMI_VM_GET_INFO       = 5,
+	KVMI_VM_CONTROL_EVENTS = 6,
 
 	KVMI_NUM_MESSAGES
 };
@@ -75,6 +76,13 @@ struct kvmi_vm_get_info_reply {
 	__u32 padding[3];
 };
 
+struct kvmi_vm_control_events {
+	__u16 event_id;
+	__u8 enable;
+	__u8 padding1;
+	__u32 padding2;
+};
+
 struct kvmi_event {
 	__u16 size;
 	__u16 vcpu;
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 9cb65f8c946f..c3beea3feb26 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -245,9 +245,15 @@ static int cmd_check_event(__u16 id)
 
 static void test_cmd_check_event(void)
 {
+	__u16 valid_id = KVMI_EVENT_UNHOOK;
 	__u16 invalid_id = 0xffff;
 	int r;
 
+	r = cmd_check_event(valid_id);
+	TEST_ASSERT(r == 0,
+		"KVMI_VM_CHECK_EVENT failed, error %d (%s)\n",
+		-r, kvm_strerror(-r));
+
 	r = cmd_check_event(invalid_id);
 	TEST_ASSERT(r == -KVM_ENOENT,
 		"KVMI_VM_CHECK_EVENT didn't failed with -KVM_ENOENT, error %d (%s)\n",
@@ -298,15 +304,62 @@ static void receive_event(struct kvmi_msg_hdr *hdr, struct kvmi_event *ev,
 		ev->event, event_id);
 }
 
+static int cmd_vm_control_events(__u16 event_id, bool enable)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vm_control_events cmd;
+	} req = {};
+
+	req.cmd.event_id = event_id;
+	req.cmd.enable = enable ? 1 : 0;
+
+	return do_command(KVMI_VM_CONTROL_EVENTS, &req.hdr, sizeof(req),
+			     NULL, 0);
+}
+
+static void enable_vm_event(__u16 event_id)
+{
+	int r;
+
+	r = cmd_vm_control_events(event_id, true);
+	TEST_ASSERT(r == 0,
+		"KVMI_VM_CONTROL_EVENTS failed to enable VM event %d, error %d (%s)\n",
+		event_id, -r, kvm_strerror(-r));
+}
+
+static void disable_vm_event(__u16 event_id)
+{
+	int r;
+
+	r = cmd_vm_control_events(event_id, false);
+	TEST_ASSERT(r == 0,
+		"KVMI_VM_CONTROL_EVENTS failed to disable VM event %d, error %d (%s)\n",
+		event_id, -r, kvm_strerror(-r));
+}
+
 static void test_event_unhook(struct kvm_vm *vm)
 {
 	__u16 id = KVMI_EVENT_UNHOOK;
 	struct kvmi_msg_hdr hdr;
 	struct kvmi_event ev;
 
+	enable_vm_event(id);
+
 	trigger_event_unhook_notification(vm);
 
 	receive_event(&hdr, &ev, sizeof(ev), id);
+
+	disable_vm_event(id);
+}
+
+static void test_cmd_vm_control_events(void)
+{
+	__u16 id = KVMI_EVENT_UNHOOK;
+
+	enable_vm_event(id);
+
+	disable_vm_event(id);
 }
 
 static void test_introspection(struct kvm_vm *vm)
@@ -320,6 +373,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_check_event();
 	test_cmd_get_vm_info();
 	test_event_unhook(vm);
+	test_cmd_vm_control_events();
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index bf6d5ec951c8..ec4515be5acc 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -12,7 +12,7 @@
 
 static DECLARE_BITMAP(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS);
 DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
-static DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
+DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
 static DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 
 static struct kmem_cache *msg_cache;
@@ -360,10 +360,18 @@ int kvmi_ioctl_command(struct kvm *kvm, void __user *argp)
 	return err;
 }
 
+static bool is_vm_event_enabled(struct kvm_introspection *kvmi, int event)
+{
+	return test_bit(event, kvmi->vm_event_enable_mask);
+}
+
 static bool kvmi_unhook_event(struct kvm_introspection *kvmi)
 {
 	int err;
 
+	if (!is_vm_event_enabled(kvmi, KVMI_EVENT_UNHOOK))
+		return false;
+
 	err = kvmi_msg_send_unhook(kvmi);
 
 	return !err;
@@ -389,3 +397,14 @@ int kvmi_ioctl_preunhook(struct kvm *kvm)
 	mutex_unlock(&kvm->kvmi_lock);
 	return err;
 }
+
+int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
+				unsigned int event_id, bool enable)
+{
+	if (enable)
+		set_bit(event_id, kvmi->vm_event_enable_mask);
+	else
+		clear_bit(event_id, kvmi->vm_event_enable_mask);
+
+	return 0;
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index ecd0625e0c9e..75078248a69c 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -17,6 +17,7 @@
 	kvm_info("%pU ERROR: " fmt, &kvmi->uuid, ## __VA_ARGS__)
 
 extern DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
+extern DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
 
 #define KVMI(kvm) ((kvm)->kvmi)
 
@@ -30,5 +31,7 @@ int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
 /* kvmi.c */
 void *kvmi_msg_alloc(void);
 void kvmi_msg_free(void *addr);
+int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
+				unsigned int event_id, bool enable);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index b381273b7355..4d897c65085b 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -171,15 +171,38 @@ static int handle_get_info(struct kvm_introspection *kvmi,
 	return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl));
 }
 
+static int handle_vm_control_events(struct kvm_introspection *kvmi,
+				    const struct kvmi_msg_hdr *msg,
+				    const void *_req)
+{
+	const struct kvmi_vm_control_events *req = _req;
+	int ec;
+
+	if (req->padding1 || req->padding2 || req->enable > 1)
+		ec = -KVM_EINVAL;
+	else if (req->event_id >= KVMI_NUM_EVENTS)
+		ec = -KVM_EINVAL;
+	else if (!test_bit(req->event_id, Kvmi_known_vm_events))
+		ec = -KVM_EINVAL;
+	else if (!is_event_allowed(kvmi, req->event_id))
+		ec = -KVM_EPERM;
+	else
+		ec = kvmi_cmd_vm_control_events(kvmi, req->event_id,
+						req->enable == 1);
+
+	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed by the receiving thread/worker.
  */
 static int(*const msg_vm[])(struct kvm_introspection *,
 			    const struct kvmi_msg_hdr *, const void *) = {
-	[KVMI_GET_VERSION]      = handle_get_version,
-	[KVMI_VM_CHECK_COMMAND] = handle_check_command,
-	[KVMI_VM_CHECK_EVENT]   = handle_check_event,
-	[KVMI_VM_GET_INFO]      = handle_get_info,
+	[KVMI_GET_VERSION]       = handle_get_version,
+	[KVMI_VM_CHECK_COMMAND]  = handle_check_command,
+	[KVMI_VM_CHECK_EVENT]    = handle_check_event,
+	[KVMI_VM_CONTROL_EVENTS] = handle_vm_control_events,
+	[KVMI_VM_GET_INFO]       = handle_get_info,
 };
 
 static bool is_vm_command(u16 id)

[PATCH v8 47/81] KVM: introspection: add KVMI_VM_READ_PHYSICAL/KVMI_VM_WRITE_PHYSICAL

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

These commands allow the introspection tool to read/write from/to
the guest memory.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  68 +++++++
 include/uapi/linux/kvmi.h                     |  17 ++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 169 ++++++++++++++++++
 virt/kvm/introspection/kvmi.c                 | 108 +++++++++++
 virt/kvm/introspection/kvmi_int.h             |   7 +
 virt/kvm/introspection/kvmi_msg.c             |  51 ++++++
 6 files changed, 420 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 7a47fade7f08..748d786d1c08 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -373,6 +373,74 @@ the following events::
 * -KVM_EINVAL - the event ID is unknown (use *KVMI_VM_CHECK_EVENT* first)
 * -KVM_EPERM - the access is disallowed (use *KVMI_VM_CHECK_EVENT* first)
 
+6. KVMI_VM_READ_PHYSICAL
+------------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vm_read_physical {
+		__u64 gpa;
+		__u16 size;
+		__u16 padding1;
+		__u32 padding2;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	__u8 data[0];
+
+Reads from the guest memory.
+
+Currently, the size must be non-zero and the read must be restricted to
+one page (offset + size <= PAGE_SIZE).
+
+:Errors:
+
+* -KVM_ENOENT - the guest page doesn't exists
+* -KVM_EINVAL - the specified gpa/size pair is invalid
+* -KVM_EINVAL - the padding is not zero
+
+7. KVMI_VM_WRITE_PHYSICAL
+-------------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vm_write_physical {
+		__u64 gpa;
+		__u16 size;
+		__u16 padding1;
+		__u32 padding2;
+		__u8  data[0];
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Writes into the guest memory.
+
+Currently, the size must be non-zero and the write must be restricted to
+one page (offset + size <= PAGE_SIZE).
+
+:Errors:
+
+* -KVM_ENOENT - the guest page doesn't exists
+* -KVM_EINVAL - the specified gpa/size pair is invalid
+* -KVM_EINVAL - the padding is not zero
+
 Events
 ======
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 66e04a82f054..335e3d879df9 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -22,6 +22,8 @@ enum {
 	KVMI_VM_CHECK_EVENT    = 4,
 	KVMI_VM_GET_INFO       = 5,
 	KVMI_VM_CONTROL_EVENTS = 6,
+	KVMI_VM_READ_PHYSICAL  = 7,
+	KVMI_VM_WRITE_PHYSICAL = 8,
 
 	KVMI_NUM_MESSAGES
 };
@@ -83,6 +85,21 @@ struct kvmi_vm_control_events {
 	__u32 padding2;
 };
 
+struct kvmi_vm_read_physical {
+	__u64 gpa;
+	__u16 size;
+	__u16 padding1;
+	__u32 padding2;
+};
+
+struct kvmi_vm_write_physical {
+	__u64 gpa;
+	__u16 size;
+	__u16 padding1;
+	__u32 padding2;
+	__u8  data[0];
+};
+
 struct kvmi_event {
 	__u16 size;
 	__u16 vcpu;
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index c3beea3feb26..ccb30d09d5cd 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -8,6 +8,7 @@
 #define _GNU_SOURCE /* for program_invocation_short_name */
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <time.h>
 
 #include "test_util.h"
 
@@ -24,6 +25,13 @@ static int socket_pair[2];
 #define Kvm_socket       socket_pair[0]
 #define Userspace_socket socket_pair[1]
 
+static vm_vaddr_t test_gva;
+static void *test_hva;
+static vm_paddr_t test_gpa;
+
+static uint8_t test_write_pattern;
+static int page_size;
+
 void setup_socket(void)
 {
 	int r;
@@ -362,8 +370,153 @@ static void test_cmd_vm_control_events(void)
 	disable_vm_event(id);
 }
 
+static int cmd_write_page(__u64 gpa, __u64 size, void *p)
+{
+	struct kvmi_vm_write_physical *cmd;
+	struct kvmi_msg_hdr *req;
+	size_t req_size;
+	int r;
+
+	req_size = sizeof(*req) + sizeof(*cmd) + size;
+
+	req = calloc(1, req_size);
+	TEST_ASSERT(req, "Insufficient Memory\n");
+
+	cmd = (struct kvmi_vm_write_physical *)(req + 1);
+	cmd->gpa = gpa;
+	cmd->size = size;
+
+	memcpy(cmd + 1, p, size);
+
+	r = do_command(KVMI_VM_WRITE_PHYSICAL, req, req_size, NULL, 0);
+
+	free(req);
+
+	return r;
+}
+
+static void write_guest_page(__u64 gpa, void *p)
+{
+	int r;
+
+	r = cmd_write_page(gpa, page_size, p);
+	TEST_ASSERT(r == 0,
+		"KVMI_VM_WRITE_PHYSICAL failed, gpa 0x%lx, error %d (%s)\n",
+		gpa, -r, kvm_strerror(-r));
+}
+
+static void write_with_invalid_arguments(__u64 gpa, __u64 size, void *p)
+{
+	int r;
+
+	r = cmd_write_page(gpa, size, p);
+	TEST_ASSERT(r == -KVM_EINVAL,
+		"KVMI_VM_WRITE_PHYSICAL did not failed with EINVAL, gpa 0x%lx, error %d (%s)\n",
+		gpa, -r, kvm_strerror(-r));
+}
+
+static void write_invalid_guest_page(struct kvm_vm *vm, void *p)
+{
+	uint64_t gpa = vm->max_gfn << vm->page_shift;
+	int r;
+
+	r = cmd_write_page(gpa, 1, p);
+	TEST_ASSERT(r == -KVM_ENOENT,
+		"KVMI_VM_WRITE_PHYSICAL did not failed with ENOENT, gpa 0x%lx, error %d (%s)\n",
+		gpa, -r, kvm_strerror(-r));
+}
+
+static int cmd_read_page(__u64 gpa, __u64 size, void *p)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vm_read_physical cmd;
+	} req = { };
+
+	req.cmd.gpa = gpa;
+	req.cmd.size = size;
+
+	return do_command(KVMI_VM_READ_PHYSICAL, &req.hdr, sizeof(req), p,
+			  size);
+}
+
+static void read_guest_page(__u64 gpa, void *p)
+{
+	int r;
+
+	r = cmd_read_page(gpa, page_size, p);
+	TEST_ASSERT(r == 0,
+		"KVMI_VM_READ_PHYSICAL failed, gpa 0x%lx, error %d (%s)\n",
+		gpa, -r, kvm_strerror(-r));
+}
+
+static void read_with_invalid_arguments(__u64 gpa, __u64 size, void *p)
+{
+	int r;
+
+	r = cmd_read_page(gpa, size, p);
+	TEST_ASSERT(r == -KVM_EINVAL,
+		"KVMI_VM_READ_PHYSICAL did not failed with EINVAL, gpa 0x%lx, error %d (%s)\n",
+		gpa, -r, kvm_strerror(-r));
+}
+
+static void read_invalid_guest_page(struct kvm_vm *vm)
+{
+	uint64_t gpa = vm->max_gfn << vm->page_shift;
+	int r;
+
+	r = cmd_read_page(gpa, 1, NULL);
+	TEST_ASSERT(r == -KVM_ENOENT,
+		"KVMI_VM_READ_PHYSICAL did not failed with ENOENT, gpa 0x%lx, error %d (%s)\n",
+		gpa, -r, kvm_strerror(-r));
+}
+
+static void new_test_write_pattern(struct kvm_vm *vm)
+{
+	uint8_t n;
+
+	do {
+		n = random();
+	} while (!n || n == test_write_pattern);
+
+	test_write_pattern = n;
+	sync_global_to_guest(vm, test_write_pattern);
+}
+
+static void test_memory_access(struct kvm_vm *vm)
+{
+	void *pw, *pr;
+
+	new_test_write_pattern(vm);
+
+	pw = malloc(page_size);
+	TEST_ASSERT(pw, "Insufficient Memory\n");
+
+	memset(pw, test_write_pattern, page_size);
+
+	write_guest_page(test_gpa, pw);
+	TEST_ASSERT(memcmp(pw, test_hva, page_size) == 0,
+		"Write page test failed");
+
+	pr = malloc(page_size);
+	TEST_ASSERT(pr, "Insufficient Memory\n");
+
+	read_guest_page(test_gpa, pr);
+	TEST_ASSERT(memcmp(pw, pr, page_size) == 0,
+		"Read page test failed");
+
+	read_with_invalid_arguments(test_gpa, 0, pr);
+	write_with_invalid_arguments(test_gpa, 0, pw);
+	write_invalid_guest_page(vm, pw);
+
+	free(pw);
+	free(pr);
+
+	read_invalid_guest_page(vm);
+}
 static void test_introspection(struct kvm_vm *vm)
 {
+	srandom(time(0));
 	setup_socket();
 	hook_introspection(vm);
 
@@ -374,10 +527,23 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_get_vm_info();
 	test_event_unhook(vm);
 	test_cmd_vm_control_events();
+	test_memory_access(vm);
 
 	unhook_introspection(vm);
 }
 
+static void setup_test_pages(struct kvm_vm *vm)
+{
+	test_gva = vm_vaddr_alloc(vm, page_size, KVM_UTIL_MIN_VADDR, 0, 0);
+
+	sync_global_to_guest(vm, test_gva);
+
+	test_hva = addr_gva2hva(vm, test_gva);
+	memset(test_hva, 0, page_size);
+
+	test_gpa = addr_gva2gpa(vm, test_gva);
+}
+
 int main(int argc, char *argv[])
 {
 	struct kvm_vm *vm;
@@ -393,6 +559,9 @@ int main(int argc, char *argv[])
 	vm = vm_create_default(VCPU_ID, 0, NULL);
 	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
 
+	page_size = getpagesize();
+	setup_test_pages(vm);
+
 	test_introspection(vm);
 
 	kvm_vm_free(vm);
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index ec4515be5acc..661e49a75835 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2017-2020 Bitdefender S.R.L.
  *
  */
+#include <linux/mmu_context.h>
 #include "kvmi_int.h"
 #include <linux/kthread.h>
 
@@ -408,3 +409,110 @@ int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 
 	return 0;
 }
+
+static unsigned long gfn_to_hva_safe(struct kvm *kvm, gfn_t gfn)
+{
+	unsigned long hva;
+	int srcu_idx;
+
+	srcu_idx = srcu_read_lock(&kvm->srcu);
+	hva = gfn_to_hva(kvm, gfn);
+	srcu_read_unlock(&kvm->srcu, srcu_idx);
+
+	return hva;
+}
+
+static long
+get_user_pages_remote_unlocked(struct mm_struct *mm, unsigned long start,
+				unsigned long nr_pages, unsigned int gup_flags,
+				struct page **pages)
+{
+	struct vm_area_struct **vmas = NULL;
+	struct task_struct *tsk = NULL;
+	int locked = 1;
+	long r;
+
+	down_read(&mm->mmap_sem);
+	r = get_user_pages_remote(tsk, mm, start, nr_pages, gup_flags,
+				  pages, vmas, &locked);
+	if (locked)
+		up_read(&mm->mmap_sem);
+
+	return r;
+}
+
+static void *get_page_ptr(struct kvm *kvm, gpa_t gpa, struct page **page,
+			  bool write)
+{
+	unsigned int flags = write ? FOLL_WRITE : 0;
+	unsigned long hva;
+
+	*page = NULL;
+
+	hva = gfn_to_hva_safe(kvm, gpa_to_gfn(gpa));
+
+	if (kvm_is_error_hva(hva))
+		return NULL;
+
+	if (get_user_pages_remote_unlocked(kvm->mm, hva, 1, flags, page) != 1)
+		return NULL;
+
+	return write ? kmap_atomic(*page) : kmap(*page);
+}
+
+static void put_page_ptr(void *ptr, struct page *page, bool write)
+{
+	if (ptr) {
+		if (write)
+			kunmap_atomic(ptr);
+		else
+			kunmap(ptr);
+	}
+	if (page)
+		put_page(page);
+}
+
+int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size,
+			   int (*send)(struct kvm_introspection *,
+					const struct kvmi_msg_hdr *,
+					int err, const void *buf, size_t),
+			   const struct kvmi_msg_hdr *ctx)
+{
+	void *ptr_page = NULL, *ptr;
+	struct page *page = NULL;
+	size_t ptr_size;
+	int err, ec;
+
+	ptr_page = get_page_ptr(kvm, gpa, &page, false);
+	if (ptr_page) {
+		ptr = ptr_page + (gpa & ~PAGE_MASK);
+		ptr_size = size;
+		ec = 0;
+	} else {
+		ptr = NULL;
+		ptr_size = 0;
+		ec = -KVM_ENOENT;
+	}
+
+	err = send(KVMI(kvm), ctx, ec, ptr, ptr_size);
+
+	put_page_ptr(ptr_page, page, false);
+	return err;
+}
+
+int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, size_t size,
+			    const void *buf)
+{
+	struct page *page;
+	void *ptr;
+
+	ptr = get_page_ptr(kvm, gpa, &page, true);
+	if (!ptr)
+		return -KVM_ENOENT;
+
+	memcpy(ptr + (gpa & ~PAGE_MASK), buf, size);
+
+	put_page_ptr(ptr, page, true);
+
+	return 0;
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 75078248a69c..6a1808585a32 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -33,5 +33,12 @@ void *kvmi_msg_alloc(void);
 void kvmi_msg_free(void *addr);
 int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 				unsigned int event_id, bool enable);
+int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size,
+			   int (*send)(struct kvm_introspection *,
+					const struct kvmi_msg_hdr*,
+					int err, const void *buf, size_t),
+			   const struct kvmi_msg_hdr *ctx);
+int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, size_t size,
+			    const void *buf);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 4d897c65085b..1faf70945123 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -193,6 +193,55 @@ static int handle_vm_control_events(struct kvm_introspection *kvmi,
 	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
 }
 
+static bool invalid_page_access(u64 gpa, u64 size)
+{
+	u64 off = gpa & ~PAGE_MASK;
+
+	return (size == 0 || size > PAGE_SIZE || off + size > PAGE_SIZE);
+}
+
+static int handle_read_physical(struct kvm_introspection *kvmi,
+				const struct kvmi_msg_hdr *msg,
+				const void *_req)
+{
+	const struct kvmi_vm_read_physical *req = _req;
+	int ec = 0;
+
+	if (invalid_page_access(req->gpa, req->size))
+		ec = -KVM_EINVAL;
+	else if (req->padding1 || req->padding2)
+		ec = -KVM_EINVAL;
+
+	if (ec)
+		return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
+
+	return kvmi_cmd_read_physical(kvmi->kvm, req->gpa, req->size,
+				      kvmi_msg_vm_reply, msg);
+}
+
+static int handle_write_physical(struct kvm_introspection *kvmi,
+				 const struct kvmi_msg_hdr *msg,
+				 const void *_req)
+{
+	const struct kvmi_vm_write_physical *req = _req;
+	size_t req_size;
+	int ec;
+
+	req_size = struct_size(req, data, req->size);
+	if (msg->size != req_size)
+		return -EINVAL;
+
+	if (invalid_page_access(req->gpa, req->size))
+		ec = -KVM_EINVAL;
+	else if (req->padding1 || req->padding2)
+		ec = -KVM_EINVAL;
+	else
+		ec = kvmi_cmd_write_physical(kvmi->kvm, req->gpa,
+					     req->size, req->data);
+
+	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed by the receiving thread/worker.
  */
@@ -203,6 +252,8 @@ static int(*const msg_vm[])(struct kvm_introspection *,
 	[KVMI_VM_CHECK_EVENT]    = handle_check_event,
 	[KVMI_VM_CONTROL_EVENTS] = handle_vm_control_events,
 	[KVMI_VM_GET_INFO]       = handle_get_info,
+	[KVMI_VM_READ_PHYSICAL]  = handle_read_physical,
+	[KVMI_VM_WRITE_PHYSICAL] = handle_write_physical,
 };
 
 static bool is_vm_command(u16 id)

[PATCH v8 48/81] KVM: introspection: add vCPU related data

[Adalbert Lazăr]

From: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>

Add an introspection structure to all vCPUs when the VM is hooked.

Signed-off-by: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvmi_host.h |  3 ++
 include/linux/kvm_host.h         |  1 +
 include/linux/kvmi_host.h        |  7 +++++
 virt/kvm/introspection/kvmi.c    | 51 ++++++++++++++++++++++++++++++++
 virt/kvm/kvm_main.c              |  2 ++
 5 files changed, 64 insertions(+)

diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 38c398262913..360a57dd9019 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -2,6 +2,9 @@
 #ifndef _ASM_X86_KVMI_HOST_H
 #define _ASM_X86_KVMI_HOST_H
 
+struct kvm_vcpu_arch_introspection {
+};
+
 struct kvm_arch_introspection {
 };
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 1f1b0dffabaa..8db92cbba435 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -321,6 +321,7 @@ struct kvm_vcpu {
 	bool ready;
 	struct kvm_vcpu_arch arch;
 	struct dentry *debugfs_dentry;
+	struct kvm_vcpu_introspection *kvmi;
 };
 
 static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 41b22af771fb..ca2db8043a53 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -5,11 +5,16 @@
 #include <uapi/linux/kvmi.h>
 
 struct kvm;
+struct kvm_vcpu;
 
 #include <asm/kvmi_host.h>
 
 #define KVMI_NUM_COMMANDS KVMI_NUM_MESSAGES
 
+struct kvm_vcpu_introspection {
+	struct kvm_vcpu_arch_introspection arch;
+};
+
 struct kvm_introspection {
 	struct kvm_arch_introspection arch;
 	struct kvm *kvm;
@@ -33,6 +38,7 @@ int kvmi_init(void);
 void kvmi_uninit(void);
 void kvmi_create_vm(struct kvm *kvm);
 void kvmi_destroy_vm(struct kvm *kvm);
+void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu);
 
 int kvmi_ioctl_hook(struct kvm *kvm, void __user *argp);
 int kvmi_ioctl_unhook(struct kvm *kvm);
@@ -46,6 +52,7 @@ static inline int kvmi_init(void) { return 0; }
 static inline void kvmi_uninit(void) { }
 static inline void kvmi_create_vm(struct kvm *kvm) { }
 static inline void kvmi_destroy_vm(struct kvm *kvm) { }
+static inline void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu) { }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 661e49a75835..a9f9afba6ba2 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -81,16 +81,58 @@ void kvmi_uninit(void)
 	kvmi_cache_destroy();
 }
 
+static bool alloc_vcpui(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui;
+
+	vcpui = kzalloc(sizeof(*vcpui), GFP_KERNEL);
+	if (!vcpui)
+		return false;
+
+	vcpu->kvmi = vcpui;
+
+	return true;
+}
+
+static int create_vcpui(struct kvm_vcpu *vcpu)
+{
+	if (!alloc_vcpui(vcpu))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void free_vcpui(struct kvm_vcpu *vcpu)
+{
+	kfree(vcpu->kvmi);
+	vcpu->kvmi = NULL;
+}
+
 static void free_kvmi(struct kvm *kvm)
 {
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		free_vcpui(vcpu);
+
 	kfree(kvm->kvmi);
 	kvm->kvmi = NULL;
 }
 
+void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+	mutex_lock(&vcpu->kvm->kvmi_lock);
+	free_vcpui(vcpu);
+	mutex_unlock(&vcpu->kvm->kvmi_lock);
+}
+
 static struct kvm_introspection *
 alloc_kvmi(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 {
 	struct kvm_introspection *kvmi;
+	struct kvm_vcpu *vcpu;
+	int i;
 
 	kvmi = kzalloc(sizeof(*kvmi), GFP_KERNEL);
 	if (!kvmi)
@@ -104,6 +146,15 @@ alloc_kvmi(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 
 	atomic_set(&kvmi->ev_seq, 0);
 
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		int err = create_vcpui(vcpu);
+
+		if (err) {
+			free_kvmi(kvm);
+			return NULL;
+		}
+	}
+
 	kvmi->kvm = kvm;
 
 	return kvmi;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 86bc2ed680ce..8d2a4a1ae3b0 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -361,6 +361,8 @@ static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 
 void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
 {
+	kvmi_vcpu_uninit(vcpu);
+
 	kvm_arch_vcpu_destroy(vcpu);
 
 	/*

[PATCH v8 49/81] KVM: introspection: add a jobs list to every introspected vCPU

[Adalbert Lazăr]

Every vCPU has a lock-protected list in which the receiving worker
places the jobs that has to be done by the vCPU thread
once it is kicked out of guest (KVM_REQ_INTROSPECTION).

A job is defined by a "do" function, a "free" function and a pointer
(the context).

Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 include/linux/kvmi_host.h         | 10 +++++
 virt/kvm/introspection/kvmi.c     | 72 ++++++++++++++++++++++++++++++-
 virt/kvm/introspection/kvmi_int.h |  1 +
 3 files changed, 81 insertions(+), 2 deletions(-)

diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index ca2db8043a53..1d80d233fbd5 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -11,8 +11,18 @@ struct kvm_vcpu;
 
 #define KVMI_NUM_COMMANDS KVMI_NUM_MESSAGES
 
+struct kvmi_job {
+	struct list_head link;
+	void *ctx;
+	void (*fct)(struct kvm_vcpu *vcpu, void *ctx);
+	void (*free_fct)(void *ctx);
+};
+
 struct kvm_vcpu_introspection {
 	struct kvm_vcpu_arch_introspection arch;
+
+	struct list_head job_list;
+	spinlock_t job_lock;
 };
 
 struct kvm_introspection {
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index a9f9afba6ba2..e36460b755e9 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -17,6 +17,7 @@ DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
 static DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 
 static struct kmem_cache *msg_cache;
+static struct kmem_cache *job_cache;
 
 void *kvmi_msg_alloc(void)
 {
@@ -33,14 +34,19 @@ static void kvmi_cache_destroy(void)
 {
 	kmem_cache_destroy(msg_cache);
 	msg_cache = NULL;
+	kmem_cache_destroy(job_cache);
+	job_cache = NULL;
 }
 
 static int kvmi_cache_create(void)
 {
 	msg_cache = kmem_cache_create("kvmi_msg", KVMI_MSG_SIZE_ALLOC,
 				      4096, SLAB_ACCOUNT, NULL);
+	job_cache = kmem_cache_create("kvmi_job",
+				      sizeof(struct kvmi_job),
+				      0, SLAB_ACCOUNT, NULL);
 
-	if (!msg_cache) {
+	if (!msg_cache || !job_cache) {
 		kvmi_cache_destroy();
 
 		return -1;
@@ -81,6 +87,48 @@ void kvmi_uninit(void)
 	kvmi_cache_destroy();
 }
 
+static int __kvmi_add_job(struct kvm_vcpu *vcpu,
+			  void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
+			  void *ctx, void (*free_fct)(void *ctx))
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+	struct kvmi_job *job;
+
+	job = kmem_cache_zalloc(job_cache, GFP_KERNEL);
+	if (unlikely(!job))
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&job->link);
+	job->fct = fct;
+	job->ctx = ctx;
+	job->free_fct = free_fct;
+
+	spin_lock(&vcpui->job_lock);
+	list_add_tail(&job->link, &vcpui->job_list);
+	spin_unlock(&vcpui->job_lock);
+
+	return 0;
+}
+
+int kvmi_add_job(struct kvm_vcpu *vcpu,
+		 void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
+		 void *ctx, void (*free_fct)(void *ctx))
+{
+	int err;
+
+	err = __kvmi_add_job(vcpu, fct, ctx, free_fct);
+
+	return err;
+}
+
+static void kvmi_free_job(struct kvmi_job *job)
+{
+	if (job->free_fct)
+		job->free_fct(job->ctx);
+
+	kmem_cache_free(job_cache, job);
+}
+
 static bool alloc_vcpui(struct kvm_vcpu *vcpu)
 {
 	struct kvm_vcpu_introspection *vcpui;
@@ -89,6 +137,9 @@ static bool alloc_vcpui(struct kvm_vcpu *vcpu)
 	if (!vcpui)
 		return false;
 
+	INIT_LIST_HEAD(&vcpui->job_list);
+	spin_lock_init(&vcpui->job_lock);
+
 	vcpu->kvmi = vcpui;
 
 	return true;
@@ -102,9 +153,26 @@ static int create_vcpui(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static void free_vcpu_jobs(struct kvm_vcpu_introspection *vcpui)
+{
+	struct kvmi_job *cur, *next;
+
+	list_for_each_entry_safe(cur, next, &vcpui->job_list, link) {
+		list_del(&cur->link);
+		kvmi_free_job(cur);
+	}
+}
+
 static void free_vcpui(struct kvm_vcpu *vcpu)
 {
-	kfree(vcpu->kvmi);
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	if (!vcpui)
+		return;
+
+	free_vcpu_jobs(vcpui);
+
+	kfree(vcpui);
 	vcpu->kvmi = NULL;
 }
 
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 6a1808585a32..5d40d872e493 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -20,6 +20,7 @@ extern DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
 extern DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
 
 #define KVMI(kvm) ((kvm)->kvmi)
+#define VCPUI(vcpu) ((vcpu)->kvmi)
 
 /* kvmi_msg.c */
 bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd);

[PATCH v8 50/81] KVM: introspection: handle vCPU introspection requests

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

The introspection requests (KVM_REQ_INTROSPECTION) are checked before
entering guest or when the vCPU is halted.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>
Signed-off-by: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/x86.c              |  3 ++
 include/linux/kvmi_host.h       |  4 +++
 virt/kvm/introspection/kvmi.c   | 58 +++++++++++++++++++++++++++++++++
 virt/kvm/kvm_main.c             |  2 ++
 5 files changed, 68 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6169e12d2540..c2176012676d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -80,6 +80,7 @@
 #define KVM_REQ_GET_VMCS12_PAGES	KVM_ARCH_REQ(24)
 #define KVM_REQ_APICV_UPDATE \
 	KVM_ARCH_REQ_FLAGS(25, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
+#define KVM_REQ_INTROSPECTION		KVM_ARCH_REQ(26)
 
 #define CR0_RESERVED_BITS                                               \
 	(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4fa11c998325..967c83791b37 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8549,6 +8549,9 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
 	vcpu->arch.l1tf_flush_l1d = true;
 
 	for (;;) {
+		if (kvm_check_request(KVM_REQ_INTROSPECTION, vcpu))
+			kvmi_handle_requests(vcpu);
+
 		if (kvm_vcpu_running(vcpu)) {
 			r = vcpu_enter_guest(vcpu);
 		} else {
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 1d80d233fbd5..6a0fb481b192 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -56,6 +56,8 @@ int kvmi_ioctl_command(struct kvm *kvm, void __user *argp);
 int kvmi_ioctl_event(struct kvm *kvm, void __user *argp);
 int kvmi_ioctl_preunhook(struct kvm *kvm);
 
+void kvmi_handle_requests(struct kvm_vcpu *vcpu);
+
 #else
 
 static inline int kvmi_init(void) { return 0; }
@@ -64,6 +66,8 @@ static inline void kvmi_create_vm(struct kvm *kvm) { }
 static inline void kvmi_destroy_vm(struct kvm *kvm) { }
 static inline void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu) { }
 
+static inline void kvmi_handle_requests(struct kvm_vcpu *vcpu) { }
+
 #endif /* CONFIG_KVM_INTROSPECTION */
 
 #endif
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index e36460b755e9..65a77b8d2616 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -87,6 +87,12 @@ void kvmi_uninit(void)
 	kvmi_cache_destroy();
 }
 
+static void kvmi_make_request(struct kvm_vcpu *vcpu)
+{
+	kvm_make_request(KVM_REQ_INTROSPECTION, vcpu);
+	kvm_vcpu_kick(vcpu);
+}
+
 static int __kvmi_add_job(struct kvm_vcpu *vcpu,
 			  void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
 			  void *ctx, void (*free_fct)(void *ctx))
@@ -118,6 +124,9 @@ int kvmi_add_job(struct kvm_vcpu *vcpu,
 
 	err = __kvmi_add_job(vcpu, fct, ctx, free_fct);
 
+	if (!err)
+		kvmi_make_request(vcpu);
+
 	return err;
 }
 
@@ -270,6 +279,14 @@ int kvmi_ioctl_unhook(struct kvm *kvm)
 	return 0;
 }
 
+struct kvm_introspection * __must_check kvmi_get(struct kvm *kvm)
+{
+	if (refcount_inc_not_zero(&kvm->kvmi_ref))
+		return kvm->kvmi;
+
+	return NULL;
+}
+
 void kvmi_put(struct kvm *kvm)
 {
 	if (refcount_dec_and_test(&kvm->kvmi_ref))
@@ -331,6 +348,10 @@ int kvmi_hook(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 	init_completion(&kvm->kvmi_complete);
 
 	refcount_set(&kvm->kvmi_ref, 1);
+	/*
+	 * Paired with refcount_inc_not_zero() from kvmi_get().
+	 */
+	smp_wmb();
 
 	kvmi->recv = kthread_run(kvmi_recv_thread, kvmi, "kvmi-recv");
 	if (IS_ERR(kvmi->recv)) {
@@ -635,3 +656,40 @@ int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, size_t size,
 
 	return 0;
 }
+
+static struct kvmi_job *kvmi_pull_job(struct kvm_vcpu_introspection *vcpui)
+{
+	struct kvmi_job *job = NULL;
+
+	spin_lock(&vcpui->job_lock);
+	job = list_first_entry_or_null(&vcpui->job_list, typeof(*job), link);
+	if (job)
+		list_del(&job->link);
+	spin_unlock(&vcpui->job_lock);
+
+	return job;
+}
+
+void kvmi_run_jobs(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+	struct kvmi_job *job;
+
+	while ((job = kvmi_pull_job(vcpui))) {
+		job->fct(vcpu, job->ctx);
+		kvmi_free_job(job);
+	}
+}
+
+void kvmi_handle_requests(struct kvm_vcpu *vcpu)
+{
+	struct kvm_introspection *kvmi;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return;
+
+	kvmi_run_jobs(vcpu);
+
+	kvmi_put(vcpu->kvm);
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8d2a4a1ae3b0..5f2031234636 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2484,6 +2484,8 @@ static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
 		goto out;
 	if (signal_pending(current))
 		goto out;
+	if (kvm_test_request(KVM_REQ_INTROSPECTION, vcpu))
+		goto out;
 
 	ret = 0;
 out:

[PATCH v8 51/81] KVM: introspection: handle vCPU commands

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

Based on the common structure (kvmi_vcpu_hdr) used for all vCPU commands,
the receiving thread validates and dispatches the message to the proper
vCPU (adding the handling function to its jobs list).

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst   |   8 ++
 include/uapi/linux/kvmi.h         |   6 ++
 virt/kvm/introspection/kvmi_int.h |   3 +
 virt/kvm/introspection/kvmi_msg.c | 169 +++++++++++++++++++++++++++++-
 4 files changed, 184 insertions(+), 2 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 748d786d1c08..271aed21f634 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -232,6 +232,14 @@ The following C structures are meant to be used directly when communicating
 over the wire. The peer that detects any size mismatch should simply close
 the connection and report the error.
 
+The vCPU commands start with::
+
+	struct kvmi_vcpu_hdr {
+		__u16 vcpu;
+		__u16 padding1;
+		__u32 padding2;
+	}
+
 1. KVMI_GET_VERSION
 -------------------
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 335e3d879df9..4a75bc28d7e0 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -100,6 +100,12 @@ struct kvmi_vm_write_physical {
 	__u8  data[0];
 };
 
+struct kvmi_vcpu_hdr {
+	__u16 vcpu;
+	__u16 padding1;
+	__u32 padding2;
+};
+
 struct kvmi_event {
 	__u16 size;
 	__u16 vcpu;
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 5d40d872e493..55500b89398b 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -32,6 +32,9 @@ int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
 /* kvmi.c */
 void *kvmi_msg_alloc(void);
 void kvmi_msg_free(void *addr);
+int kvmi_add_job(struct kvm_vcpu *vcpu,
+		 void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
+		 void *ctx, void (*free_fct)(void *ctx));
 int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 				unsigned int event_id, bool enable);
 int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size,
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 1faf70945123..57e082c3bb43 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -9,6 +9,30 @@
 #include "kvmi_int.h"
 
 static bool is_vm_command(u16 id);
+static bool is_vcpu_command(u16 id);
+
+struct kvmi_vcpu_cmd_job {
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr cmd;
+	} *msg;
+	struct kvm_vcpu *vcpu;
+};
+
+static const char *const msg_IDs[] = {
+	[KVMI_GET_VERSION]       = "KVMI_GET_VERSION",
+	[KVMI_VM_CHECK_COMMAND]  = "KVMI_VM_CHECK_COMMAND",
+	[KVMI_VM_CHECK_EVENT]    = "KVMI_VM_CHECK_EVENT",
+	[KVMI_VM_CONTROL_EVENTS] = "KVMI_VM_CONTROL_EVENTS",
+	[KVMI_VM_GET_INFO]       = "KVMI_VM_GET_INFO",
+	[KVMI_VM_READ_PHYSICAL]  = "KVMI_VM_READ_PHYSICAL",
+	[KVMI_VM_WRITE_PHYSICAL] = "KVMI_VM_WRITE_PHYSICAL",
+};
+
+static const char *id2str(u16 id)
+{
+	return id < ARRAY_SIZE(msg_IDs) ? msg_IDs[id] : "unknown";
+}
 
 bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd)
 {
@@ -105,6 +129,28 @@ static bool is_command_allowed(struct kvm_introspection *kvmi, u16 id)
 	return id < KVMI_NUM_COMMANDS && test_bit(id, kvmi->cmd_allow_mask);
 }
 
+static bool invalid_vcpu_hdr(const struct kvmi_vcpu_hdr *hdr)
+{
+	return hdr->padding1 || hdr->padding2;
+}
+
+static int kvmi_get_vcpu(struct kvm_introspection *kvmi, unsigned int vcpu_idx,
+			 struct kvm_vcpu **dest)
+{
+	struct kvm *kvm = kvmi->kvm;
+	struct kvm_vcpu *vcpu;
+
+	if (vcpu_idx >= atomic_read(&kvm->online_vcpus))
+		return -KVM_EINVAL;
+
+	vcpu = kvm_get_vcpu(kvm, vcpu_idx);
+	if (!vcpu)
+		return -KVM_EINVAL;
+
+	*dest = vcpu;
+	return 0;
+}
+
 static int handle_get_version(struct kvm_introspection *kvmi,
 			      const struct kvmi_msg_hdr *msg, const void *req)
 {
@@ -125,7 +171,7 @@ static int handle_check_command(struct kvm_introspection *kvmi,
 
 	if (req->padding1 || req->padding2)
 		ec = -KVM_EINVAL;
-	else if (!is_vm_command(req->id))
+	else if (!is_vm_command(req->id) && !is_vcpu_command(req->id))
 		ec = -KVM_ENOENT;
 	else if (!is_command_allowed(kvmi, req->id))
 		ec = -KVM_EPERM;
@@ -261,6 +307,60 @@ static bool is_vm_command(u16 id)
 	return id < ARRAY_SIZE(msg_vm) && !!msg_vm[id];
 }
 
+/*
+ * These commands are executed from the vCPU thread. The receiving thread
+ * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
+ * and signals the vCPU to handle the command (which includes
+ * sending back the reply).
+ */
+static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
+			      const struct kvmi_msg_hdr *, const void *) = {
+};
+
+static bool is_vcpu_command(u16 id)
+{
+	return id < ARRAY_SIZE(msg_vcpu) && !!msg_vcpu[id];
+}
+
+static void kvmi_job_vcpu_cmd(struct kvm_vcpu *vcpu, void *ctx)
+{
+	struct kvmi_vcpu_cmd_job *job = ctx;
+	size_t id = job->msg->hdr.id;
+	int err;
+
+	job->vcpu = vcpu;
+
+	err = msg_vcpu[id](job, &job->msg->hdr, job->msg + 1);
+
+	if (err) {
+		struct kvm_introspection *kvmi = KVMI(vcpu->kvm);
+
+		kvmi_err(kvmi, "%s: msg id %zu (%s) size %u err %d\n",
+			 __func__, id, id2str(id), job->msg->hdr.size, err);
+		kvmi_sock_shutdown(kvmi);
+	}
+}
+
+static void kvmi_free_ctx(void *_ctx)
+{
+	const struct kvmi_vcpu_cmd_job *ctx = _ctx;
+
+	kvmi_msg_free(ctx->msg);
+	kfree(ctx);
+}
+
+static int kvmi_msg_queue_to_vcpu(struct kvm_vcpu *vcpu,
+				  const struct kvmi_vcpu_cmd_job *cmd)
+{
+	return kvmi_add_job(vcpu, kvmi_job_vcpu_cmd, (void *)cmd,
+			    kvmi_free_ctx);
+}
+
+static bool is_vcpu_message(u16 id)
+{
+	return is_vcpu_command(id);
+}
+
 static struct kvmi_msg_hdr *kvmi_msg_recv(struct kvm_introspection *kvmi)
 {
 	struct kvmi_msg_hdr *msg;
@@ -308,9 +408,68 @@ static int kvmi_msg_vm_reply_ec(struct kvm_introspection *kvmi,
 	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
 }
 
+static bool vcpu_can_handle_commands(struct kvm_vcpu *vcpu)
+{
+	return vcpu->arch.mp_state != KVM_MP_STATE_UNINITIALIZED;
+}
+
+static bool kvmi_get_vcpu_if_ready(struct kvm_introspection *kvmi,
+				   unsigned int vcpu_idx,
+				   struct kvm_vcpu **vcpu)
+{
+	int err;
+
+	err = kvmi_get_vcpu(kvmi, vcpu_idx, vcpu);
+
+	return !err && vcpu_can_handle_commands(*vcpu);
+}
+
+static int kvmi_validate_vcpu_cmd(struct kvm_introspection *kvmi,
+				  struct kvmi_msg_hdr *msg,
+				  struct kvm_vcpu **vcpu)
+{
+	struct kvmi_vcpu_hdr *cmd = (struct kvmi_vcpu_hdr *)(msg + 1);
+	unsigned int vcpu_idx = cmd->vcpu;
+
+	if (invalid_vcpu_hdr(cmd))
+		return -KVM_EINVAL;
+
+	if (!kvmi_get_vcpu_if_ready(kvmi, vcpu_idx, vcpu))
+		return -KVM_EAGAIN;
+
+	return 0;
+}
+
+static int kvmi_msg_dispatch_vcpu_cmd(struct kvm_introspection *kvmi,
+				      struct kvmi_msg_hdr *msg,
+				      bool *queued)
+{
+	struct kvmi_vcpu_cmd_job *job_cmd;
+	struct kvm_vcpu *vcpu = NULL;
+	int err, ec;
+
+	ec = kvmi_validate_vcpu_cmd(kvmi, msg, &vcpu);
+	if (ec)
+		return kvmi_msg_vm_reply_ec(kvmi, msg, ec);
+
+	job_cmd = kzalloc(sizeof(*job_cmd), GFP_KERNEL);
+	if (!job_cmd)
+		return -KVM_ENOMEM;
+
+	job_cmd->msg = (void *)msg;
+
+	err = kvmi_msg_queue_to_vcpu(vcpu, job_cmd);
+	if (err)
+		kfree(job_cmd);
+
+	*queued = err == 0;
+	return err;
+}
+
 bool kvmi_msg_process(struct kvm_introspection *kvmi)
 {
 	struct kvmi_msg_hdr *msg;
+	bool queued = false;
 	int err = -1;
 
 	msg = kvmi_msg_recv(kvmi);
@@ -322,11 +481,17 @@ bool kvmi_msg_process(struct kvm_introspection *kvmi)
 			err = kvmi_msg_dispatch_vm_cmd(kvmi, msg);
 		else
 			err = kvmi_msg_vm_reply_ec(kvmi, msg, -KVM_EPERM);
+	} else if (is_vcpu_message(msg->id)) {
+		if (is_message_allowed(kvmi, msg->id))
+			err = kvmi_msg_dispatch_vcpu_cmd(kvmi, msg, &queued);
+		else
+			err = kvmi_msg_vm_reply_ec(kvmi, msg, -KVM_EPERM);
 	} else {
 		err = kvmi_msg_vm_reply_ec(kvmi, msg, -KVM_ENOSYS);
 	}
 
-	kvmi_msg_free(msg);
+	if (!queued)
+		kvmi_msg_free(msg);
 out:
 	return err == 0;
 }

[PATCH v8 52/81] KVM: introspection: add KVMI_VCPU_GET_INFO

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

For now, this command returns the TSC frequency (in HZ) for the specified
vCPU if available (otherwise it returns zero).

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  29 ++++
 arch/x86/include/uapi/asm/kvmi.h              |   4 +
 arch/x86/kvm/Makefile                         |   2 +-
 arch/x86/kvm/kvmi.c                           |  19 +++
 include/uapi/linux/kvmi.h                     |   2 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 144 +++++++++++++++++-
 virt/kvm/introspection/kvmi_int.h             |   4 +
 virt/kvm/introspection/kvmi_msg.c             |  23 +++
 8 files changed, 225 insertions(+), 2 deletions(-)
 create mode 100644 arch/x86/kvm/kvmi.c

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 271aed21f634..16438e863003 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -449,6 +449,35 @@ one page (offset + size <= PAGE_SIZE).
 * -KVM_EINVAL - the specified gpa/size pair is invalid
 * -KVM_EINVAL - the padding is not zero
 
+8. KVMI_VCPU_GET_INFO
+---------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_vcpu_get_info_reply {
+		__u64 tsc_speed;
+	};
+
+Returns the TSC frequency (in HZ) for the specified vCPU if available
+(otherwise it returns zero).
+
+:Errors:
+
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+
 Events
 ======
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 551f9ed1ed9c..89adf84cefe4 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -26,4 +26,8 @@ struct kvmi_event_arch {
 	} msrs;
 };
 
+struct kvmi_vcpu_get_info_reply {
+	__u64 tsc_speed;
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index 9d05b5bf2360..e67acfda6fa0 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -9,7 +9,7 @@ KVMI := $(KVM)/introspection
 kvm-y			+= $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \
 				$(KVM)/eventfd.o $(KVM)/irqchip.o $(KVM)/vfio.o
 kvm-$(CONFIG_KVM_ASYNC_PF)	+= $(KVM)/async_pf.o
-kvm-$(CONFIG_KVM_INTROSPECTION) += $(KVMI)/kvmi.o $(KVMI)/kvmi_msg.o
+kvm-$(CONFIG_KVM_INTROSPECTION) += $(KVMI)/kvmi.o $(KVMI)/kvmi_msg.o kvmi.o
 
 kvm-y			+= x86.o emulate.o i8259.o irq.o lapic.o \
 			   i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
new file mode 100644
index 000000000000..2afb3abc97fa
--- /dev/null
+++ b/arch/x86/kvm/kvmi.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM introspection - x86
+ *
+ * Copyright (C) 2019-2020 Bitdefender S.R.L.
+ */
+
+#include "../../../virt/kvm/introspection/kvmi_int.h"
+
+int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
+				struct kvmi_vcpu_get_info_reply *rpl)
+{
+	if (kvm_has_tsc_control)
+		rpl->tsc_speed = 1000ul * vcpu->arch.virtual_tsc_khz;
+	else
+		rpl->tsc_speed = 0;
+
+	return 0;
+}
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 4a75bc28d7e0..4cdaad656de4 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -25,6 +25,8 @@ enum {
 	KVMI_VM_READ_PHYSICAL  = 7,
 	KVMI_VM_WRITE_PHYSICAL = 8,
 
+	KVMI_VCPU_GET_INFO     = 9,
+
 	KVMI_NUM_MESSAGES
 };
 
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index ccb30d09d5cd..c765b1e5707d 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -9,6 +9,7 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <time.h>
+#include <pthread.h>
 
 #include "test_util.h"
 
@@ -25,6 +26,7 @@ static int socket_pair[2];
 #define Kvm_socket       socket_pair[0]
 #define Userspace_socket socket_pair[1]
 
+static int test_id;
 static vm_vaddr_t test_gva;
 static void *test_hva;
 static vm_paddr_t test_gpa;
@@ -32,6 +34,39 @@ static vm_paddr_t test_gpa;
 static uint8_t test_write_pattern;
 static int page_size;
 
+struct vcpu_worker_data {
+	struct kvm_vm *vm;
+	int vcpu_id;
+	int test_id;
+	bool stop;
+};
+
+enum {
+	GUEST_TEST_NOOP = 0,
+};
+
+#define GUEST_REQUEST_TEST()     GUEST_SYNC(0)
+#define GUEST_SIGNAL_TEST_DONE() GUEST_SYNC(1)
+
+#define HOST_SEND_TEST(uc)       (uc.cmd == UCALL_SYNC && uc.args[1] == 0)
+
+static int guest_test_id(void)
+{
+	GUEST_REQUEST_TEST();
+	return READ_ONCE(test_id);
+}
+
+static void guest_code(void)
+{
+	while (true) {
+		switch (guest_test_id()) {
+		case GUEST_TEST_NOOP:
+			break;
+		}
+		GUEST_SIGNAL_TEST_DONE();
+	}
+}
+
 void setup_socket(void)
 {
 	int r;
@@ -514,6 +549,112 @@ static void test_memory_access(struct kvm_vm *vm)
 
 	read_invalid_guest_page(vm);
 }
+
+static void *vcpu_worker(void *data)
+{
+	struct vcpu_worker_data *ctx = data;
+	struct kvm_run *run;
+
+	run = vcpu_state(ctx->vm, ctx->vcpu_id);
+
+	while (!READ_ONCE(ctx->stop)) {
+		struct ucall uc;
+
+		vcpu_run(ctx->vm, ctx->vcpu_id);
+
+		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+			"vcpu_run() failed, test_id %d, exit reason %u (%s)\n",
+			ctx->test_id, run->exit_reason,
+			exit_reason_str(run->exit_reason));
+
+		TEST_ASSERT(get_ucall(ctx->vm, ctx->vcpu_id, &uc),
+			"No guest request\n");
+
+		if (HOST_SEND_TEST(uc)) {
+			test_id = READ_ONCE(ctx->test_id);
+			sync_global_to_guest(ctx->vm, test_id);
+		}
+	}
+
+	return NULL;
+}
+
+static pthread_t start_vcpu_worker(struct vcpu_worker_data *data)
+{
+	pthread_t thread_id;
+
+	pthread_create(&thread_id, NULL, vcpu_worker, data);
+
+	return thread_id;
+}
+
+static void wait_vcpu_worker(pthread_t vcpu_thread)
+{
+	pthread_join(vcpu_thread, NULL);
+}
+
+static void stop_vcpu_worker(pthread_t vcpu_thread,
+			     struct vcpu_worker_data *data)
+{
+	WRITE_ONCE(data->stop, true);
+
+	wait_vcpu_worker(vcpu_thread);
+}
+
+static int do_vcpu_command(struct kvm_vm *vm, int cmd_id,
+			   struct kvmi_msg_hdr *req, size_t req_size,
+			   void *rpl, size_t rpl_size)
+{
+	struct vcpu_worker_data data = {.vm = vm, .vcpu_id = VCPU_ID };
+	pthread_t vcpu_thread;
+	int r;
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	send_message(cmd_id, req, req_size);
+	r = receive_cmd_reply(req, rpl, rpl_size);
+
+	stop_vcpu_worker(vcpu_thread, &data);
+	return r;
+}
+
+static int do_vcpu0_command(struct kvm_vm *vm, int cmd_id,
+			    struct kvmi_msg_hdr *req, size_t req_size,
+			    void *rpl, size_t rpl_size)
+{
+	struct kvmi_vcpu_hdr *vcpu_hdr = (struct kvmi_vcpu_hdr *)req;
+
+	vcpu_hdr->vcpu = 0;
+
+	return do_vcpu_command(vm, cmd_id, req, req_size, rpl, rpl_size);
+}
+
+static void test_vcpu0_command(struct kvm_vm *vm, int cmd_id,
+			       struct kvmi_msg_hdr *req, size_t req_size,
+			       void *rpl, size_t rpl_size)
+{
+	int r;
+
+	r = do_vcpu0_command(vm, cmd_id, req, req_size, rpl, rpl_size);
+	TEST_ASSERT(r == 0,
+		    "Command %d failed, error %d (%s)\n",
+		    cmd_id, -r, kvm_strerror(-r));
+}
+
+static void test_cmd_get_vcpu_info(struct kvm_vm *vm)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+	} req = {};
+	struct kvmi_vcpu_get_info_reply rpl;
+
+	test_vcpu0_command(vm, KVMI_VCPU_GET_INFO, &req.hdr, sizeof(req),
+			   &rpl, sizeof(rpl));
+
+	DEBUG("tsc_speed: %llu HZ\n", rpl.tsc_speed);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -528,6 +669,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_event_unhook(vm);
 	test_cmd_vm_control_events();
 	test_memory_access(vm);
+	test_cmd_get_vcpu_info(vm);
 
 	unhook_introspection(vm);
 }
@@ -556,7 +698,7 @@ int main(int argc, char *argv[])
 		exit(KSFT_SKIP);
 	}
 
-	vm = vm_create_default(VCPU_ID, 0, NULL);
+	vm = vm_create_default(VCPU_ID, 0, guest_code);
 	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
 
 	page_size = getpagesize();
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 55500b89398b..4a71e33d46ef 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -45,4 +45,8 @@ int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size,
 int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, size_t size,
 			    const void *buf);
 
+/* arch */
+int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
+				struct kvmi_vcpu_get_info_reply *rpl);
+
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 57e082c3bb43..62dc50060a1e 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -27,6 +27,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VM_GET_INFO]       = "KVMI_VM_GET_INFO",
 	[KVMI_VM_READ_PHYSICAL]  = "KVMI_VM_READ_PHYSICAL",
 	[KVMI_VM_WRITE_PHYSICAL] = "KVMI_VM_WRITE_PHYSICAL",
+	[KVMI_VCPU_GET_INFO]     = "KVMI_VCPU_GET_INFO",
 };
 
 static const char *id2str(u16 id)
@@ -124,6 +125,15 @@ static int kvmi_msg_vm_reply(struct kvm_introspection *kvmi,
 	return kvmi_msg_reply(kvmi, msg, err, rpl, rpl_size);
 }
 
+static int kvmi_msg_vcpu_reply(const struct kvmi_vcpu_cmd_job *job,
+				const struct kvmi_msg_hdr *msg, int err,
+				const void *rpl, size_t rpl_size)
+{
+	struct kvm_introspection *kvmi = KVMI(job->vcpu->kvm);
+
+	return kvmi_msg_reply(kvmi, msg, err, rpl, rpl_size);
+}
+
 static bool is_command_allowed(struct kvm_introspection *kvmi, u16 id)
 {
 	return id < KVMI_NUM_COMMANDS && test_bit(id, kvmi->cmd_allow_mask);
@@ -307,6 +317,18 @@ static bool is_vm_command(u16 id)
 	return id < ARRAY_SIZE(msg_vm) && !!msg_vm[id];
 }
 
+static int handle_get_vcpu_info(const struct kvmi_vcpu_cmd_job *job,
+				const struct kvmi_msg_hdr *msg,
+				const void *req)
+{
+	struct kvmi_vcpu_get_info_reply rpl;
+
+	memset(&rpl, 0, sizeof(rpl));
+	kvmi_arch_cmd_vcpu_get_info(job->vcpu, &rpl);
+
+	return kvmi_msg_vcpu_reply(job, msg, 0, &rpl, sizeof(rpl));
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -315,6 +337,7 @@ static bool is_vm_command(u16 id)
  */
 static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 			      const struct kvmi_msg_hdr *, const void *) = {
+	[KVMI_VCPU_GET_INFO] = handle_get_vcpu_info,
 };
 
 static bool is_vcpu_command(u16 id)

[PATCH v8 53/81] KVM: introspection: add KVMI_VCPU_PAUSE

[Adalbert Lazăr]

This is the only vCPU command handled by the receiving thread.
It increments a pause request counter and kicks the vCPU out of guest.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 64 ++++++++++++++++++-
 include/linux/kvmi_host.h                     |  2 +
 include/uapi/linux/kvmi.h                     | 11 +++-
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 31 +++++++++
 virt/kvm/introspection/kvmi.c                 | 63 ++++++++++++++++--
 virt/kvm/introspection/kvmi_int.h             |  1 +
 virt/kvm/introspection/kvmi_msg.c             | 44 +++++++++++++
 7 files changed, 210 insertions(+), 6 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 16438e863003..642e2f10adfd 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -478,12 +478,51 @@ Returns the TSC frequency (in HZ) for the specified vCPU if available
 * -KVM_EINVAL - the selected vCPU is invalid
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 
+9. KVMI_VCPU_PAUSE
+------------------
+
+:Architecture: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_pause {
+		__u8 wait;
+		__u8 padding1;
+		__u16 padding2;
+		__u32 padding3;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+
+Kicks the vCPU out of guest.
+
+If `wait` is 1, the command will wait for vCPU to acknowledge the IPI.
+
+The vCPU will handle the pending commands/events and send the
+*KVMI_EVENT_PAUSE_VCPU* event (one for every successful *KVMI_VCPU_PAUSE*
+command) before returning to guest.
+
+:Errors:
+
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_EBUSY  - the selected vCPU has too many queued *KVMI_EVENT_PAUSE_VCPU* events
+* -KVM_EPERM  - the *KVMI_EVENT_PAUSE_VCPU* event is disallowed
+
 Events
 ======
 
 All introspection events (VM or vCPU related) are sent
 using the *KVMI_EVENT* message id. No event will be sent unless
-it is explicitly enabled.
+it is explicitly enabled or requested (eg. *KVMI_EVENT_PAUSE_VCPU*).
 
 The *KVMI_EVENT_UNHOOK* event doesn't have a reply and share the kvmi_event
 structure, for consistency with the vCPU events.
@@ -542,3 +581,26 @@ the guest (see **Unhooking**) and the introspection has been enabled
 for this event (see **KVMI_VM_CONTROL_EVENTS**). The introspection tool
 has a chance to unhook and close the KVMI channel (signaling that the
 operation can proceed).
+
+2. KVMI_EVENT_PAUSE_VCPU
+------------------------
+
+:Architectures: all
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+	struct kvmi_event;
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+
+This event is sent in response to a *KVMI_VCPU_PAUSE* command.
+Because it has a low priority, it will be sent after any other vCPU
+introspection event and when no vCPU introspection command is queued.
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 6a0fb481b192..988927c29bf5 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -23,6 +23,8 @@ struct kvm_vcpu_introspection {
 
 	struct list_head job_list;
 	spinlock_t job_lock;
+
+	atomic_t pause_requests;
 };
 
 struct kvm_introspection {
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 4cdaad656de4..38954a5297da 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -26,12 +26,14 @@ enum {
 	KVMI_VM_WRITE_PHYSICAL = 8,
 
 	KVMI_VCPU_GET_INFO     = 9,
+	KVMI_VCPU_PAUSE        = 10,
 
 	KVMI_NUM_MESSAGES
 };
 
 enum {
-	KVMI_EVENT_UNHOOK = 0,
+	KVMI_EVENT_UNHOOK     = 0,
+	KVMI_EVENT_PAUSE_VCPU = 1,
 
 	KVMI_NUM_EVENTS
 };
@@ -108,6 +110,13 @@ struct kvmi_vcpu_hdr {
 	__u32 padding2;
 };
 
+struct kvmi_vcpu_pause {
+	__u8 wait;
+	__u8 padding1;
+	__u16 padding2;
+	__u32 padding3;
+};
+
 struct kvmi_event {
 	__u16 size;
 	__u16 vcpu;
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index c765b1e5707d..bc84d478ff6b 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -655,6 +655,36 @@ static void test_cmd_get_vcpu_info(struct kvm_vm *vm)
 	DEBUG("tsc_speed: %llu HZ\n", rpl.tsc_speed);
 }
 
+static int cmd_pause_vcpu(struct kvm_vm *vm)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_pause cmd;
+	} req = {};
+	__u16 vcpu_index = 0;
+
+	req.vcpu_hdr.vcpu = vcpu_index;
+
+	return do_command(KVMI_VCPU_PAUSE, &req.hdr, sizeof(req),
+			     NULL, 0);
+}
+
+static void pause_vcpu(struct kvm_vm *vm)
+{
+	int r;
+
+	r = cmd_pause_vcpu(vm);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_PAUSE failed, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+}
+
+static void test_pause(struct kvm_vm *vm)
+{
+	pause_vcpu(vm);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -670,6 +700,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vm_control_events();
 	test_memory_access(vm);
 	test_cmd_get_vcpu_info(vm);
+	test_pause(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 65a77b8d2616..c4da264ad5a6 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -11,6 +11,8 @@
 
 #define KVMI_MSG_SIZE_ALLOC (sizeof(struct kvmi_msg_hdr) + KVMI_MSG_SIZE)
 
+#define MAX_PAUSE_REQUESTS 1001
+
 static DECLARE_BITMAP(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS);
 DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
 DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
@@ -69,6 +71,7 @@ static void setup_known_events(void)
 	set_bit(KVMI_EVENT_UNHOOK, Kvmi_known_vm_events);
 
 	bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
+	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
 
 	bitmap_or(Kvmi_known_events, Kvmi_known_vm_events,
 		  Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
@@ -87,10 +90,14 @@ void kvmi_uninit(void)
 	kvmi_cache_destroy();
 }
 
-static void kvmi_make_request(struct kvm_vcpu *vcpu)
+static void kvmi_make_request(struct kvm_vcpu *vcpu, bool wait)
 {
 	kvm_make_request(KVM_REQ_INTROSPECTION, vcpu);
-	kvm_vcpu_kick(vcpu);
+
+	if (wait)
+		kvm_vcpu_kick_and_wait(vcpu);
+	else
+		kvm_vcpu_kick(vcpu);
 }
 
 static int __kvmi_add_job(struct kvm_vcpu *vcpu,
@@ -125,7 +132,7 @@ int kvmi_add_job(struct kvm_vcpu *vcpu,
 	err = __kvmi_add_job(vcpu, fct, ctx, free_fct);
 
 	if (!err)
-		kvmi_make_request(vcpu);
+		kvmi_make_request(vcpu, false);
 
 	return err;
 }
@@ -304,6 +311,22 @@ static int __kvmi_hook(struct kvm *kvm,
 	return 0;
 }
 
+static void kvmi_job_release_vcpu(struct kvm_vcpu *vcpu, void *ctx)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	atomic_set(&vcpui->pause_requests, 0);
+}
+
+static void kvmi_release_vcpus(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		kvmi_add_job(vcpu, kvmi_job_release_vcpu, NULL, NULL);
+}
+
 static int kvmi_recv_thread(void *arg)
 {
 	struct kvm_introspection *kvmi = arg;
@@ -317,6 +340,8 @@ static int kvmi_recv_thread(void *arg)
 	 */
 	kvmi_sock_shutdown(kvmi);
 
+	kvmi_release_vcpus(kvmi->kvm);
+
 	kvmi_put(kvmi->kvm);
 	return 0;
 }
@@ -681,15 +706,45 @@ void kvmi_run_jobs(struct kvm_vcpu *vcpu)
 	}
 }
 
+static void kvmi_vcpu_pause_event(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	atomic_dec(&vcpui->pause_requests);
+	/* to be implemented */
+}
+
 void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 {
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
 	struct kvm_introspection *kvmi;
 
 	kvmi = kvmi_get(vcpu->kvm);
 	if (!kvmi)
 		return;
 
-	kvmi_run_jobs(vcpu);
+	for (;;) {
+		kvmi_run_jobs(vcpu);
+
+		if (atomic_read(&vcpui->pause_requests))
+			kvmi_vcpu_pause_event(vcpu);
+		else
+			break;
+	}
 
 	kvmi_put(vcpu->kvm);
 }
+
+int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	if (atomic_read(&vcpui->pause_requests) > MAX_PAUSE_REQUESTS)
+		return -KVM_EBUSY;
+
+	atomic_inc(&vcpui->pause_requests);
+
+	kvmi_make_request(vcpu, wait);
+
+	return 0;
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 4a71e33d46ef..bd968e837a54 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -44,6 +44,7 @@ int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size,
 			   const struct kvmi_msg_hdr *ctx);
 int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, size_t size,
 			    const void *buf);
+int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait);
 
 /* arch */
 int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 62dc50060a1e..772ba1d7d9df 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -28,6 +28,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VM_READ_PHYSICAL]  = "KVMI_VM_READ_PHYSICAL",
 	[KVMI_VM_WRITE_PHYSICAL] = "KVMI_VM_WRITE_PHYSICAL",
 	[KVMI_VCPU_GET_INFO]     = "KVMI_VCPU_GET_INFO",
+	[KVMI_VCPU_PAUSE]        = "KVMI_VCPU_PAUSE",
 };
 
 static const char *id2str(u16 id)
@@ -298,6 +299,48 @@ static int handle_write_physical(struct kvm_introspection *kvmi,
 	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
 }
 
+/*
+ * This vCPU command is handled from the receiving thread instead of
+ * the vCPU thread, to make it easier for userspace to implement a 'pause VM'
+ * command by sending a 'pause vCPU' command (with wait=1) for every vCPU.
+ * By handling the command here, the userspace can consider that the VM
+ * is stopped (no vCPU runs guest code) once it receives the reply
+ * for the last 'pause vCPU' command.
+ */
+static int handle_pause_vcpu(struct kvm_introspection *kvmi,
+			     const struct kvmi_msg_hdr *msg,
+			     const void *_req)
+{
+	const struct kvmi_vcpu_pause *req = _req;
+	const struct kvmi_vcpu_hdr *cmd;
+	struct kvm_vcpu *vcpu = NULL;
+	int err;
+
+	cmd = (const struct kvmi_vcpu_hdr *) (msg + 1);
+
+	if (invalid_vcpu_hdr(cmd) || req->wait > 0) {
+		err = -KVM_EINVAL;
+		goto reply;
+	}
+
+	if (req->padding1 || req->padding2 || req->padding3) {
+		err = -KVM_EINVAL;
+		goto reply;
+	}
+
+	if (!is_event_allowed(kvmi, KVMI_EVENT_PAUSE_VCPU)) {
+		err = -KVM_EPERM;
+		goto reply;
+	}
+
+	err = kvmi_get_vcpu(kvmi, cmd->vcpu, &vcpu);
+	if (!err)
+		err = kvmi_cmd_vcpu_pause(vcpu, req->wait == 1);
+
+reply:
+	return kvmi_msg_vm_reply(kvmi, msg, err, NULL, 0);
+}
+
 /*
  * These commands are executed by the receiving thread/worker.
  */
@@ -310,6 +353,7 @@ static int(*const msg_vm[])(struct kvm_introspection *,
 	[KVMI_VM_GET_INFO]       = handle_get_info,
 	[KVMI_VM_READ_PHYSICAL]  = handle_read_physical,
 	[KVMI_VM_WRITE_PHYSICAL] = handle_write_physical,
+	[KVMI_VCPU_PAUSE]        = handle_pause_vcpu,
 };
 
 static bool is_vm_command(u16 id)

[PATCH v8 54/81] KVM: introspection: add KVMI_EVENT_PAUSE_VCPU

[Adalbert Lazăr]

This event is send by the vCPU thread and has a low priority.
It will be sent after any other introspection event
and when no introspection command is queued.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  22 ++-
 arch/x86/kvm/kvmi.c                           |  81 +++++++++
 include/linux/kvmi_host.h                     |  11 ++
 include/uapi/linux/kvmi.h                     |  13 ++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  |  42 +++++
 virt/kvm/introspection/kvmi.c                 |  21 ++-
 virt/kvm/introspection/kvmi_int.h             |   3 +
 virt/kvm/introspection/kvmi_msg.c             | 164 +++++++++++++++++-
 8 files changed, 353 insertions(+), 4 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 642e2f10adfd..d841d266b1a9 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -560,6 +560,25 @@ On x86 the structure looks like this::
 
 It contains information about the vCPU state at the time of the event.
 
+An event reply begins with two common structures::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply {
+		__u8 action;
+		__u8 event;
+		__u16 padding1;
+		__u32 padding2;
+	};
+
+All events accept the KVMI_EVENT_ACTION_CRASH action, which stops the
+guest ungracefully, but as soon as possible.
+
+Most of the events accept the KVMI_EVENT_ACTION_CONTINUE action, which
+lets the instruction that caused the event to continue.
+
+Some of the events accept the KVMI_EVENT_ACTION_RETRY action, to continue
+by re-entering the guest.
+
 Specific data can follow these common structures.
 
 1. KVMI_EVENT_UNHOOK
@@ -601,6 +620,7 @@ operation can proceed).
 	struct kvmi_vcpu_hdr;
 	struct kvmi_event_reply;
 
-This event is sent in response to a *KVMI_VCPU_PAUSE* command.
+This event is sent in response to a *KVMI_VCPU_PAUSE* command and
+cannot be disabled via *KVMI_VCPU_CONTROL_EVENTS*.
 Because it has a low priority, it will be sent after any other vCPU
 introspection event and when no vCPU introspection command is queued.
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 2afb3abc97fa..21ff48cfdb89 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -5,8 +5,89 @@
  * Copyright (C) 2019-2020 Bitdefender S.R.L.
  */
 
+#include "linux/kvm_host.h"
+#include "x86.h"
 #include "../../../virt/kvm/introspection/kvmi_int.h"
 
+static unsigned int kvmi_vcpu_mode(const struct kvm_vcpu *vcpu,
+				   const struct kvm_sregs *sregs)
+{
+	unsigned int mode = 0;
+
+	if (is_long_mode((struct kvm_vcpu *) vcpu)) {
+		if (sregs->cs.l)
+			mode = 8;
+		else if (!sregs->cs.db)
+			mode = 2;
+		else
+			mode = 4;
+	} else if (sregs->cr0 & X86_CR0_PE) {
+		if (!sregs->cs.db)
+			mode = 2;
+		else
+			mode = 4;
+	} else if (!sregs->cs.db) {
+		mode = 2;
+	} else {
+		mode = 4;
+	}
+
+	return mode;
+}
+
+static void kvmi_get_msrs(struct kvm_vcpu *vcpu, struct kvmi_event_arch *event)
+{
+	struct msr_data msr;
+
+	msr.host_initiated = true;
+
+	msr.index = MSR_IA32_SYSENTER_CS;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.sysenter_cs = msr.data;
+
+	msr.index = MSR_IA32_SYSENTER_ESP;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.sysenter_esp = msr.data;
+
+	msr.index = MSR_IA32_SYSENTER_EIP;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.sysenter_eip = msr.data;
+
+	msr.index = MSR_EFER;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.efer = msr.data;
+
+	msr.index = MSR_STAR;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.star = msr.data;
+
+	msr.index = MSR_LSTAR;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.lstar = msr.data;
+
+	msr.index = MSR_CSTAR;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.cstar = msr.data;
+
+	msr.index = MSR_IA32_CR_PAT;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.pat = msr.data;
+
+	msr.index = MSR_KERNEL_GS_BASE;
+	kvm_x86_ops->get_msr(vcpu, &msr);
+	event->msrs.shadow_gs = msr.data;
+}
+
+void kvmi_arch_setup_event(struct kvm_vcpu *vcpu, struct kvmi_event *ev)
+{
+	struct kvmi_event_arch *event = &ev->arch;
+
+	kvm_arch_vcpu_get_regs(vcpu, &event->regs);
+	kvm_arch_vcpu_get_sregs(vcpu, &event->sregs);
+	ev->arch.mode = kvmi_vcpu_mode(vcpu, &event->sregs);
+	kvmi_get_msrs(vcpu, event);
+}
+
 int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
 				struct kvmi_vcpu_get_info_reply *rpl)
 {
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 988927c29bf5..49e68777a390 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -11,6 +11,14 @@ struct kvm_vcpu;
 
 #define KVMI_NUM_COMMANDS KVMI_NUM_MESSAGES
 
+struct kvmi_vcpu_reply {
+	int error;
+	int action;
+	u32 seq;
+	void *data;
+	size_t size;
+};
+
 struct kvmi_job {
 	struct list_head link;
 	void *ctx;
@@ -25,6 +33,9 @@ struct kvm_vcpu_introspection {
 	spinlock_t job_lock;
 
 	atomic_t pause_requests;
+
+	struct kvmi_vcpu_reply reply;
+	bool waiting_for_reply;
 };
 
 struct kvm_introspection {
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 38954a5297da..e6a4667546b5 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -38,6 +38,12 @@ enum {
 	KVMI_NUM_EVENTS
 };
 
+enum {
+	KVMI_EVENT_ACTION_CONTINUE = 0,
+	KVMI_EVENT_ACTION_RETRY    = 1,
+	KVMI_EVENT_ACTION_CRASH    = 2,
+};
+
 struct kvmi_msg_hdr {
 	__u16 id;
 	__u16 size;
@@ -125,4 +131,11 @@ struct kvmi_event {
 	struct kvmi_event_arch arch;
 };
 
+struct kvmi_event_reply {
+	__u8 action;
+	__u8 event;
+	__u16 padding1;
+	__u32 padding2;
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index bc84d478ff6b..990c78a7af0a 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -34,6 +34,12 @@ static vm_paddr_t test_gpa;
 static uint8_t test_write_pattern;
 static int page_size;
 
+struct vcpu_reply {
+	struct kvmi_msg_hdr hdr;
+	struct kvmi_vcpu_hdr vcpu_hdr;
+	struct kvmi_event_reply reply;
+};
+
 struct vcpu_worker_data {
 	struct kvm_vm *vm;
 	int vcpu_id;
@@ -680,9 +686,45 @@ static void pause_vcpu(struct kvm_vm *vm)
 		-r, kvm_strerror(-r));
 }
 
+static void reply_to_event(struct kvmi_msg_hdr *ev_hdr, struct kvmi_event *ev,
+			   __u8 action, struct vcpu_reply *rpl, size_t rpl_size)
+{
+	ssize_t r;
+
+	rpl->hdr.id = ev_hdr->id;
+	rpl->hdr.seq = ev_hdr->seq;
+	rpl->hdr.size = rpl_size - sizeof(rpl->hdr);
+
+	rpl->vcpu_hdr.vcpu = ev->vcpu;
+
+	rpl->reply.action = action;
+	rpl->reply.event = ev->event;
+
+	r = send(Userspace_socket, rpl, rpl_size, 0);
+	TEST_ASSERT(r == rpl_size,
+		"send() failed, sending %d, result %d, errno %d (%s)\n",
+		rpl_size, r, errno, strerror(errno));
+}
+
 static void test_pause(struct kvm_vm *vm)
 {
+	struct vcpu_worker_data data = {.vm = vm, .vcpu_id = VCPU_ID};
+	__u16 event_id = KVMI_EVENT_PAUSE_VCPU;
+	struct vcpu_reply rpl = {};
+	struct kvmi_msg_hdr hdr;
+	pthread_t vcpu_thread;
+	struct kvmi_event ev;
+
 	pause_vcpu(vm);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	receive_event(&hdr, &ev, sizeof(ev), event_id);
+
+	reply_to_event(&hdr, &ev, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+
+	stop_vcpu_worker(vcpu_thread, &data);
 }
 
 static void test_introspection(struct kvm_vm *vm)
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index c4da264ad5a6..2b8e6910e57b 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -316,6 +316,7 @@ static void kvmi_job_release_vcpu(struct kvm_vcpu *vcpu, void *ctx)
 	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
 
 	atomic_set(&vcpui->pause_requests, 0);
+	vcpui->waiting_for_reply = false;
 }
 
 static void kvmi_release_vcpus(struct kvm *kvm)
@@ -706,12 +707,30 @@ void kvmi_run_jobs(struct kvm_vcpu *vcpu)
 	}
 }
 
+void kvmi_handle_common_event_actions(struct kvm *kvm,
+				      u32 action, const char *str)
+{
+	switch (action) {
+	default:
+		kvmi_err(KVMI(kvm), "Unsupported action %d for event %s\n",
+			 action, str);
+	}
+}
+
 static void kvmi_vcpu_pause_event(struct kvm_vcpu *vcpu)
 {
 	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+	u32 action;
 
 	atomic_dec(&vcpui->pause_requests);
-	/* to be implemented */
+
+	action = kvmi_msg_send_vcpu_pause(vcpu);
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action, "PAUSE");
+	}
 }
 
 void kvmi_handle_requests(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index bd968e837a54..8fe74b32a5f6 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -28,6 +28,7 @@ void kvmi_sock_shutdown(struct kvm_introspection *kvmi);
 void kvmi_sock_put(struct kvm_introspection *kvmi);
 bool kvmi_msg_process(struct kvm_introspection *kvmi);
 int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
+u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
 
 /* kvmi.c */
 void *kvmi_msg_alloc(void);
@@ -35,6 +36,7 @@ void kvmi_msg_free(void *addr);
 int kvmi_add_job(struct kvm_vcpu *vcpu,
 		 void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
 		 void *ctx, void (*free_fct)(void *ctx));
+void kvmi_run_jobs(struct kvm_vcpu *vcpu);
 int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 				unsigned int event_id, bool enable);
 int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size,
@@ -49,5 +51,6 @@ int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait);
 /* arch */
 int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
 				struct kvmi_vcpu_get_info_reply *rpl);
+void kvmi_arch_setup_event(struct kvm_vcpu *vcpu, struct kvmi_event *ev);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 772ba1d7d9df..a56926f22bc6 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -20,6 +20,7 @@ struct kvmi_vcpu_cmd_job {
 };
 
 static const char *const msg_IDs[] = {
+	[KVMI_EVENT]             = "KVMI_EVENT",
 	[KVMI_GET_VERSION]       = "KVMI_GET_VERSION",
 	[KVMI_VM_CHECK_COMMAND]  = "KVMI_VM_CHECK_COMMAND",
 	[KVMI_VM_CHECK_EVENT]    = "KVMI_VM_CHECK_EVENT",
@@ -373,6 +374,74 @@ static int handle_get_vcpu_info(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, 0, &rpl, sizeof(rpl));
 }
 
+static int check_event_reply(const struct kvmi_msg_hdr *msg,
+			     const struct kvmi_event_reply *reply,
+			     const struct kvmi_vcpu_reply *expected,
+			     u8 *action, size_t *received)
+{
+	size_t msg_size, common, event_size;
+	int err = -EINVAL;
+
+	if (unlikely(msg->seq != expected->seq))
+		return err;
+
+	msg_size = msg->size;
+	common = sizeof(struct kvmi_vcpu_hdr) + sizeof(*reply);
+
+	if (check_sub_overflow(msg_size, common, &event_size))
+		return err;
+
+	if (unlikely(event_size > expected->size))
+		return err;
+
+	if (unlikely(reply->padding1 || reply->padding2))
+		return err;
+
+	*received = event_size;
+	*action = reply->action;
+	return 0;
+}
+
+static int handle_event_reply(const struct kvmi_vcpu_cmd_job *job,
+			      const struct kvmi_msg_hdr *msg, const void *rpl)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(job->vcpu);
+	struct kvmi_vcpu_reply *expected = &vcpui->reply;
+	const struct kvmi_event_reply *reply = rpl;
+	const void *reply_data = reply + 1;
+	size_t useful, received;
+	u8 action;
+
+	if (unlikely(!vcpui->waiting_for_reply)) {
+		expected->error = -EINTR;
+		goto out;
+	}
+
+	expected->error = check_event_reply(msg, reply, expected, &action,
+					    &received);
+	if (unlikely(expected->error)) {
+		kvmi_err(KVMI(job->vcpu->kvm),
+			 "Invalid event reply %d seq %x\n",
+			 reply->event, msg->seq);
+		goto out;
+	}
+
+	useful = min(received, expected->size);
+	if (useful)
+		memcpy(expected->data, reply_data, useful);
+
+	if (expected->size > useful)
+		memset((char *)expected->data + useful, 0,
+			expected->size - useful);
+
+	expected->action = action;
+	expected->error = 0;
+
+out:
+	vcpui->waiting_for_reply = false;
+	return expected->error;
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -381,6 +450,7 @@ static int handle_get_vcpu_info(const struct kvmi_vcpu_cmd_job *job,
  */
 static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 			      const struct kvmi_msg_hdr *, const void *) = {
+	[KVMI_EVENT]         = handle_event_reply,
 	[KVMI_VCPU_GET_INFO] = handle_get_vcpu_info,
 };
 
@@ -466,7 +536,7 @@ static int kvmi_msg_dispatch_vm_cmd(struct kvm_introspection *kvmi,
 
 static bool is_message_allowed(struct kvm_introspection *kvmi, u16 id)
 {
-	return is_command_allowed(kvmi, id);
+	return id == KVMI_EVENT || is_command_allowed(kvmi, id);
 }
 
 static int kvmi_msg_vm_reply_ec(struct kvm_introspection *kvmi,
@@ -477,7 +547,8 @@ static int kvmi_msg_vm_reply_ec(struct kvm_introspection *kvmi,
 
 static bool vcpu_can_handle_commands(struct kvm_vcpu *vcpu)
 {
-	return vcpu->arch.mp_state != KVM_MP_STATE_UNINITIALIZED;
+	return VCPUI(vcpu)->waiting_for_reply
+		|| vcpu->arch.mp_state != KVM_MP_STATE_UNINITIALIZED;
 }
 
 static bool kvmi_get_vcpu_if_ready(struct kvm_introspection *kvmi,
@@ -584,6 +655,13 @@ static void kvmi_setup_event_common(struct kvmi_event *ev, u32 ev_id,
 	ev->size = sizeof(*ev);
 }
 
+static void kvmi_setup_event(struct kvm_vcpu *vcpu, struct kvmi_event *ev,
+			     u32 ev_id)
+{
+	kvmi_setup_event_common(ev, ev_id, kvm_vcpu_get_idx(vcpu));
+	kvmi_arch_setup_event(vcpu, ev);
+}
+
 int kvmi_msg_send_unhook(struct kvm_introspection *kvmi)
 {
 	struct kvmi_msg_hdr hdr;
@@ -600,3 +678,85 @@ int kvmi_msg_send_unhook(struct kvm_introspection *kvmi)
 
 	return kvmi_sock_write(kvmi, vec, n, msg_size);
 }
+
+static int kvmi_wait_for_reply(struct kvm_vcpu *vcpu)
+{
+	struct swait_queue_head *wq = kvm_arch_vcpu_wq(vcpu);
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+	int err = 0;
+
+	while (vcpui->waiting_for_reply && !err) {
+		kvmi_run_jobs(vcpu);
+
+		err = swait_event_killable_exclusive(*wq,
+			!vcpui->waiting_for_reply ||
+			!list_empty(&vcpui->job_list));
+	}
+
+	return err;
+}
+
+static void kvmi_setup_vcpu_reply(struct kvm_vcpu_introspection *vcpui,
+				  u32 event_seq, void *rpl, size_t rpl_size)
+{
+	memset(&vcpui->reply, 0, sizeof(vcpui->reply));
+
+	vcpui->reply.seq = event_seq;
+	vcpui->reply.data = rpl;
+	vcpui->reply.size = rpl_size;
+	vcpui->reply.error = -EINTR;
+	vcpui->waiting_for_reply = true;
+}
+
+static int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
+			   void *ev, size_t ev_size,
+			   void *rpl, size_t rpl_size, int *action)
+{
+	struct kvmi_msg_hdr hdr;
+	struct kvmi_event common;
+	struct kvec vec[] = {
+		{.iov_base = &hdr,	.iov_len = sizeof(hdr)	 },
+		{.iov_base = &common,	.iov_len = sizeof(common)},
+		{.iov_base = ev,	.iov_len = ev_size	 },
+	};
+	size_t msg_size = sizeof(hdr) + sizeof(common) + ev_size;
+	size_t n = ev_size ? ARRAY_SIZE(vec) : ARRAY_SIZE(vec)-1;
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+	struct kvm_introspection *kvmi = KVMI(vcpu->kvm);
+	int err;
+
+	kvmi_setup_event_msg_hdr(kvmi, &hdr, msg_size);
+	kvmi_setup_event(vcpu, &common, ev_id);
+	kvmi_setup_vcpu_reply(vcpui, hdr.seq, rpl, rpl_size);
+
+	err = kvmi_sock_write(kvmi, vec, n, msg_size);
+	if (err)
+		goto out;
+
+	err = kvmi_wait_for_reply(vcpu);
+	if (err)
+		goto out;
+
+	err = vcpui->reply.error;
+	if (err)
+		goto out;
+
+	*action = vcpui->reply.action;
+
+out:
+	if (err)
+		kvmi_sock_shutdown(kvmi);
+	return err;
+}
+
+u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu)
+{
+	int err, action;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_PAUSE_VCPU, NULL, 0,
+			      NULL, 0, &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	return action;
+}

[PATCH v8 55/81] KVM: introspection: add crash action handling on event reply

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This action is used in extreme cases such as blocking the spread of
malware as quickly as possible.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 virt/kvm/introspection/kvmi.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 2b8e6910e57b..517e77ab39c2 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -707,10 +707,38 @@ void kvmi_run_jobs(struct kvm_vcpu *vcpu)
 	}
 }
 
+static int kvmi_vcpu_kill(int sig, struct kvm_vcpu *vcpu)
+{
+	struct kernel_siginfo siginfo[1] = {};
+	int err = -ESRCH;
+	struct pid *pid;
+
+	rcu_read_lock();
+	pid = rcu_dereference(vcpu->pid);
+	if (pid)
+		err = kill_pid_info(sig, siginfo, pid);
+	rcu_read_unlock();
+
+	return err;
+}
+
+static void kvmi_vm_shutdown(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		kvmi_vcpu_kill(SIGTERM, vcpu);
+}
+
 void kvmi_handle_common_event_actions(struct kvm *kvm,
 				      u32 action, const char *str)
 {
 	switch (action) {
+	case KVMI_EVENT_ACTION_CRASH:
+		kvmi_vm_shutdown(kvm);
+		break;
+
 	default:
 		kvmi_err(KVMI(kvm), "Unsupported action %d for event %s\n",
 			 action, str);

[PATCH v8 56/81] KVM: introspection: add KVMI_VCPU_CONTROL_EVENTS

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This command enables/disables vCPU introspection events.

By default, all events are disabled.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 52 +++++++++++-
 include/linux/kvmi_host.h                     |  2 +
 include/uapi/linux/kvmi.h                     | 26 +++---
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 81 +++++++++++++++++++
 virt/kvm/introspection/kvmi.c                 | 15 +++-
 virt/kvm/introspection/kvmi_int.h             |  3 +
 virt/kvm/introspection/kvmi_msg.c             | 49 ++++++++---
 7 files changed, 205 insertions(+), 23 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index d841d266b1a9..b0eb2649b10c 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -375,6 +375,9 @@ the following events::
 
 	KVMI_EVENT_UNHOOK
 
+The vCPU events (e.g. *KVMI_EVENT_PAUSE_VCPU*) are controlled with
+the *KVMI_VCPU_CONTROL_EVENTS* command.
+
 :Errors:
 
 * -KVM_EINVAL - the padding is not zero
@@ -517,12 +520,59 @@ command) before returning to guest.
 * -KVM_EBUSY  - the selected vCPU has too many queued *KVMI_EVENT_PAUSE_VCPU* events
 * -KVM_EPERM  - the *KVMI_EVENT_PAUSE_VCPU* event is disallowed
 
+10. KVMI_VCPU_CONTROL_EVENTS
+----------------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_control_events {
+		__u16 event_id;
+		__u8 enable;
+		__u8 padding1;
+		__u32 padding2;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Enables/disables vCPU introspection events.
+
+When an event is enabled, the introspection tool is notified and
+must reply with: continue, retry, crash, etc. (see **Events** below).
+
+The following vCPU events do not need to be enabled or disabled,
+because these are sent as a result of certain commands::
+
+	KVMI_EVENT_PAUSE_VCPU
+
+However, the events mentioned above can be disallowed.
+
+The VM events (e.g. *KVMI_EVENT_UNHOOK*) are controlled with
+the *KVMI_VM_CONTROL_EVENTS* command.
+
+:Errors:
+
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the event ID is unknown (use *KVMI_VM_CHECK_EVENT* first)
+* -KVM_EPERM - the access is disallowed (use *KVMI_VM_CHECK_EVENT* first)
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+
 Events
 ======
 
 All introspection events (VM or vCPU related) are sent
 using the *KVMI_EVENT* message id. No event will be sent unless
-it is explicitly enabled or requested (eg. *KVMI_EVENT_PAUSE_VCPU*).
+it is explicitly enabled (see *KVMI_VM_CONTROL_EVENTS* and *KVMI_VCPU_CONTROL_EVENTS*)
+or requested (eg. *KVMI_EVENT_PAUSE_VCPU*).
 
 The *KVMI_EVENT_UNHOOK* event doesn't have a reply and share the kvmi_event
 structure, for consistency with the vCPU events.
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 49e68777a390..8e8ab9d836fe 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -36,6 +36,8 @@ struct kvm_vcpu_introspection {
 
 	struct kvmi_vcpu_reply reply;
 	bool waiting_for_reply;
+
+	DECLARE_BITMAP(ev_enable_mask, KVMI_NUM_EVENTS);
 };
 
 struct kvm_introspection {
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index e6a4667546b5..e361d6e6563d 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -17,16 +17,17 @@ enum {
 enum {
 	KVMI_EVENT             = 1,
 
-	KVMI_GET_VERSION       = 2,
-	KVMI_VM_CHECK_COMMAND  = 3,
-	KVMI_VM_CHECK_EVENT    = 4,
-	KVMI_VM_GET_INFO       = 5,
-	KVMI_VM_CONTROL_EVENTS = 6,
-	KVMI_VM_READ_PHYSICAL  = 7,
-	KVMI_VM_WRITE_PHYSICAL = 8,
+	KVMI_GET_VERSION         = 2,
+	KVMI_VM_CHECK_COMMAND    = 3,
+	KVMI_VM_CHECK_EVENT      = 4,
+	KVMI_VM_GET_INFO         = 5,
+	KVMI_VM_CONTROL_EVENTS   = 6,
+	KVMI_VM_READ_PHYSICAL    = 7,
+	KVMI_VM_WRITE_PHYSICAL   = 8,
 
-	KVMI_VCPU_GET_INFO     = 9,
-	KVMI_VCPU_PAUSE        = 10,
+	KVMI_VCPU_GET_INFO       = 9,
+	KVMI_VCPU_PAUSE          = 10,
+	KVMI_VCPU_CONTROL_EVENTS = 11,
 
 	KVMI_NUM_MESSAGES
 };
@@ -123,6 +124,13 @@ struct kvmi_vcpu_pause {
 	__u32 padding3;
 };
 
+struct kvmi_vcpu_control_events {
+	__u16 event_id;
+	__u8 enable;
+	__u8 padding1;
+	__u32 padding2;
+};
+
 struct kvmi_event {
 	__u16 size;
 	__u16 vcpu;
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 990c78a7af0a..94378066d69a 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -97,6 +97,11 @@ static void toggle_event_permission(struct kvm_vm *vm, __s32 id, bool allow)
 		id, errno, strerror(errno));
 }
 
+static void disallow_event(struct kvm_vm *vm, __s32 event_id)
+{
+	toggle_event_permission(vm, event_id, false);
+}
+
 static void allow_event(struct kvm_vm *vm, __s32 event_id)
 {
 	toggle_event_permission(vm, event_id, true);
@@ -727,6 +732,81 @@ static void test_pause(struct kvm_vm *vm)
 	stop_vcpu_worker(vcpu_thread, &data);
 }
 
+static int cmd_vcpu_control_event(struct kvm_vm *vm, __u16 event_id,
+				  bool enable)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_control_events cmd;
+	} req = {};
+
+	req.cmd.event_id = event_id;
+	req.cmd.enable = enable ? 1 : 0;
+
+	return do_vcpu0_command(vm, KVMI_VCPU_CONTROL_EVENTS,
+				&req.hdr, sizeof(req), NULL, 0);
+}
+
+static void enable_vcpu_event(struct kvm_vm *vm, __u16 event_id)
+{
+	int r;
+
+	r = cmd_vcpu_control_event(vm, event_id, true);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_CONTROL_EVENTS failed to enable vCPU event %d, error %d(%s)\n",
+		event_id, -r, kvm_strerror(-r));
+}
+
+static void disable_vcpu_event(struct kvm_vm *vm, __u16 event_id)
+{
+	int r;
+
+	r = cmd_vcpu_control_event(vm, event_id, false);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_CONTROL_EVENTS failed to disable vCPU event %d, error %d(%s)\n",
+		event_id, -r, kvm_strerror(-r));
+}
+
+static void test_disallowed_vcpu_event(struct kvm_vm *vm, __u16 event_id)
+{
+	bool enable = true;
+	int r;
+
+	disallow_event(vm, event_id);
+
+	r = cmd_vcpu_control_event(vm, event_id, enable);
+	TEST_ASSERT(r == -KVM_EPERM,
+		"KVMI_VCPU_CONTROL_EVENTS didn't failed with KVM_EPERM, id %d, error %d (%s)\n",
+		event_id, -r, kvm_strerror(-r));
+
+	allow_event(vm, event_id);
+}
+
+static void test_invalid_vcpu_event(struct kvm_vm *vm, __u16 event_id)
+{
+	bool enable = true;
+	int r;
+
+	r = cmd_vcpu_control_event(vm, event_id, enable);
+	TEST_ASSERT(r == -KVM_EINVAL,
+		"cmd_vcpu_control_event didn't failed with KVM_EINVAL, id %d, error %d (%s)\n",
+		event_id, -r, kvm_strerror(-r));
+}
+
+static void test_cmd_vcpu_control_events(struct kvm_vm *vm)
+{
+	__u16 valid_id = KVMI_EVENT_PAUSE_VCPU;
+	__u16 invalid_id = 0xffff;
+
+	enable_vcpu_event(vm, valid_id);
+	disable_vcpu_event(vm, valid_id);
+
+	test_disallowed_vcpu_event(vm, valid_id);
+
+	test_invalid_vcpu_event(vm, invalid_id);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -743,6 +823,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_memory_access(vm);
 	test_cmd_get_vcpu_info(vm);
 	test_pause(vm);
+	test_cmd_vcpu_control_events(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 517e77ab39c2..b6b3efd085c4 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -16,7 +16,7 @@
 static DECLARE_BITMAP(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS);
 DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
 DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
-static DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
+DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 
 static struct kmem_cache *msg_cache;
 static struct kmem_cache *job_cache;
@@ -576,6 +576,19 @@ int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 	return 0;
 }
 
+int kvmi_cmd_vcpu_control_events(struct kvm_vcpu *vcpu,
+				 unsigned int event_id, bool enable)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	if (enable)
+		set_bit(event_id, vcpui->ev_enable_mask);
+	else
+		clear_bit(event_id, vcpui->ev_enable_mask);
+
+	return 0;
+}
+
 static unsigned long gfn_to_hva_safe(struct kvm *kvm, gfn_t gfn)
 {
 	unsigned long hva;
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 8fe74b32a5f6..e94356516a05 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -18,6 +18,7 @@
 
 extern DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
 extern DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
+extern DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 
 #define KVMI(kvm) ((kvm)->kvmi)
 #define VCPUI(vcpu) ((vcpu)->kvmi)
@@ -39,6 +40,8 @@ int kvmi_add_job(struct kvm_vcpu *vcpu,
 void kvmi_run_jobs(struct kvm_vcpu *vcpu);
 int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 				unsigned int event_id, bool enable);
+int kvmi_cmd_vcpu_control_events(struct kvm_vcpu *vcpu,
+				 unsigned int event_id, bool enable);
 int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size,
 			   int (*send)(struct kvm_introspection *,
 					const struct kvmi_msg_hdr*,
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index a56926f22bc6..f819d0a942dc 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -20,16 +20,17 @@ struct kvmi_vcpu_cmd_job {
 };
 
 static const char *const msg_IDs[] = {
-	[KVMI_EVENT]             = "KVMI_EVENT",
-	[KVMI_GET_VERSION]       = "KVMI_GET_VERSION",
-	[KVMI_VM_CHECK_COMMAND]  = "KVMI_VM_CHECK_COMMAND",
-	[KVMI_VM_CHECK_EVENT]    = "KVMI_VM_CHECK_EVENT",
-	[KVMI_VM_CONTROL_EVENTS] = "KVMI_VM_CONTROL_EVENTS",
-	[KVMI_VM_GET_INFO]       = "KVMI_VM_GET_INFO",
-	[KVMI_VM_READ_PHYSICAL]  = "KVMI_VM_READ_PHYSICAL",
-	[KVMI_VM_WRITE_PHYSICAL] = "KVMI_VM_WRITE_PHYSICAL",
-	[KVMI_VCPU_GET_INFO]     = "KVMI_VCPU_GET_INFO",
-	[KVMI_VCPU_PAUSE]        = "KVMI_VCPU_PAUSE",
+	[KVMI_EVENT]               = "KVMI_EVENT",
+	[KVMI_GET_VERSION]         = "KVMI_GET_VERSION",
+	[KVMI_VM_CHECK_COMMAND]    = "KVMI_VM_CHECK_COMMAND",
+	[KVMI_VM_CHECK_EVENT]      = "KVMI_VM_CHECK_EVENT",
+	[KVMI_VM_CONTROL_EVENTS]   = "KVMI_VM_CONTROL_EVENTS",
+	[KVMI_VM_GET_INFO]         = "KVMI_VM_GET_INFO",
+	[KVMI_VM_READ_PHYSICAL]    = "KVMI_VM_READ_PHYSICAL",
+	[KVMI_VM_WRITE_PHYSICAL]   = "KVMI_VM_WRITE_PHYSICAL",
+	[KVMI_VCPU_CONTROL_EVENTS] = "KVMI_VCPU_CONTROL_EVENTS",
+	[KVMI_VCPU_GET_INFO]       = "KVMI_VCPU_GET_INFO",
+	[KVMI_VCPU_PAUSE]          = "KVMI_VCPU_PAUSE",
 };
 
 static const char *id2str(u16 id)
@@ -442,6 +443,29 @@ static int handle_event_reply(const struct kvmi_vcpu_cmd_job *job,
 	return expected->error;
 }
 
+static int handle_vcpu_control_events(const struct kvmi_vcpu_cmd_job *job,
+				      const struct kvmi_msg_hdr *msg,
+				      const void *_req)
+{
+	struct kvm_introspection *kvmi = KVMI(job->vcpu->kvm);
+	const struct kvmi_vcpu_control_events *req = _req;
+	int ec;
+
+	if (req->padding1 || req->padding2 || req->enable > 1)
+		ec = -KVM_EINVAL;
+	else if (req->event_id >= KVMI_NUM_EVENTS)
+		ec = -KVM_EINVAL;
+	else if (!test_bit(req->event_id, Kvmi_known_vcpu_events))
+		ec = -KVM_EINVAL;
+	else if (!is_event_allowed(kvmi, req->event_id))
+		ec = -KVM_EPERM;
+	else
+		ec = kvmi_cmd_vcpu_control_events(job->vcpu, req->event_id,
+						  req->enable == 1);
+
+	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -450,8 +474,9 @@ static int handle_event_reply(const struct kvmi_vcpu_cmd_job *job,
  */
 static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 			      const struct kvmi_msg_hdr *, const void *) = {
-	[KVMI_EVENT]         = handle_event_reply,
-	[KVMI_VCPU_GET_INFO] = handle_get_vcpu_info,
+	[KVMI_EVENT]               = handle_event_reply,
+	[KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events,
+	[KVMI_VCPU_GET_INFO]       = handle_get_vcpu_info,
 };
 
 static bool is_vcpu_command(u16 id)

[PATCH v8 57/81] KVM: introspection: add KVMI_VCPU_GET_REGISTERS

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This command is used to get kvm_regs and kvm_sregs structures,
plus the list of struct kvm_msrs.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 42 +++++++++
 arch/x86/include/uapi/asm/kvmi.h              | 15 +++
 arch/x86/kvm/kvmi.c                           | 91 +++++++++++++++++++
 include/uapi/linux/kvmi.h                     |  1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 26 ++++++
 virt/kvm/introspection/kvmi.c                 |  7 ++
 virt/kvm/introspection/kvmi_int.h             |  8 ++
 virt/kvm/introspection/kvmi_msg.c             | 21 +++++
 8 files changed, 211 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index b0eb2649b10c..0000099e8038 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -566,6 +566,48 @@ the *KVMI_VM_CONTROL_EVENTS* command.
 * -KVM_EPERM - the access is disallowed (use *KVMI_VM_CHECK_EVENT* first)
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 
+11. KVMI_VCPU_GET_REGISTERS
+---------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_get_registers {
+		__u16 nmsrs;
+		__u16 padding1;
+		__u32 padding2;
+		__u32 msrs_idx[0];
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_vcpu_get_registers_reply {
+		__u32 mode;
+		__u32 padding;
+		struct kvm_regs regs;
+		struct kvm_sregs sregs;
+		struct kvm_msrs msrs;
+	};
+
+For the given vCPU and the ``nmsrs`` sized array of MSRs registers,
+returns the current vCPU mode (in bytes: 2, 4 or 8), the general purpose
+registers, the special registers and the requested set of MSRs.
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - one of the indicated MSRs is invalid
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_ENOMEM - there is not enough memory to allocate the reply
+
 Events
 ======
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 89adf84cefe4..f14674c3c109 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -30,4 +30,19 @@ struct kvmi_vcpu_get_info_reply {
 	__u64 tsc_speed;
 };
 
+struct kvmi_vcpu_get_registers {
+	__u16 nmsrs;
+	__u16 padding1;
+	__u32 padding2;
+	__u32 msrs_idx[0];
+};
+
+struct kvmi_vcpu_get_registers_reply {
+	__u32 mode;
+	__u32 padding;
+	struct kvm_regs regs;
+	struct kvm_sregs sregs;
+	struct kvm_msrs msrs;
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 21ff48cfdb89..1ba264c10cff 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -98,3 +98,94 @@ int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
 
 	return 0;
 }
+
+int kvmi_arch_check_get_registers_req(const struct kvmi_msg_hdr *msg,
+				const struct kvmi_vcpu_get_registers *req)
+{
+	size_t req_size;
+
+	if (check_add_overflow(sizeof(struct kvmi_vcpu_hdr),
+				struct_size(req, msrs_idx, req->nmsrs),
+				&req_size))
+		return -1;
+
+	if (msg->size != req_size)
+		return -1;
+
+	return 0;
+}
+
+static void *alloc_get_registers_reply(const struct kvmi_msg_hdr *msg,
+				const struct kvmi_vcpu_get_registers *req,
+				size_t *rpl_size)
+{
+	struct kvmi_vcpu_get_registers_reply *rpl;
+	u16 k, n = req->nmsrs;
+
+	*rpl_size = struct_size(rpl, msrs.entries, n);
+	rpl = kvmi_msg_alloc_check(*rpl_size);
+	if (rpl) {
+		rpl->msrs.nmsrs = n;
+
+		for (k = 0; k < n; k++)
+			rpl->msrs.entries[k].index = req->msrs_idx[k];
+	}
+
+	return rpl;
+}
+
+static int kvmi_get_registers(struct kvm_vcpu *vcpu, u32 *mode,
+			      struct kvm_regs *regs,
+			      struct kvm_sregs *sregs,
+			      struct kvm_msrs *msrs)
+{
+	struct kvm_msr_entry *msr = msrs->entries;
+	struct kvm_msr_entry *end = msrs->entries + msrs->nmsrs;
+	int err = 0;
+
+	kvm_arch_vcpu_get_regs(vcpu, regs);
+	kvm_arch_vcpu_get_sregs(vcpu, sregs);
+	*mode = kvmi_vcpu_mode(vcpu, sregs);
+
+	for (; msr < end; msr++) {
+		struct msr_data m = {
+			.index = msr->index,
+			.host_initiated = true
+		};
+		int err = kvm_x86_ops->get_msr(vcpu, &m);
+
+		if (err)
+			break;
+
+		msr->data = m.data;
+	}
+
+	return err ? -KVM_EINVAL : 0;
+}
+
+int kvmi_arch_cmd_vcpu_get_registers(struct kvm_vcpu *vcpu,
+				const struct kvmi_msg_hdr *msg,
+				const struct kvmi_vcpu_get_registers *req,
+				struct kvmi_vcpu_get_registers_reply **dest,
+				size_t *dest_size)
+{
+	struct kvmi_vcpu_get_registers_reply *rpl;
+	size_t rpl_size;
+	int err;
+
+	if (req->padding1 || req->padding2)
+		return -KVM_EINVAL;
+
+	rpl = alloc_get_registers_reply(msg, req, &rpl_size);
+	if (!rpl)
+		return -KVM_ENOMEM;
+
+	err = kvmi_get_registers(vcpu, &rpl->mode, &rpl->regs,
+				 &rpl->sregs, &rpl->msrs);
+
+	*dest = rpl;
+	*dest_size = rpl_size;
+
+	return err;
+
+}
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index e361d6e6563d..c354c5e15be1 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -28,6 +28,7 @@ enum {
 	KVMI_VCPU_GET_INFO       = 9,
 	KVMI_VCPU_PAUSE          = 10,
 	KVMI_VCPU_CONTROL_EVENTS = 11,
+	KVMI_VCPU_GET_REGISTERS  = 12,
 
 	KVMI_NUM_MESSAGES
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 94378066d69a..2fb191740cae 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -807,6 +807,31 @@ static void test_cmd_vcpu_control_events(struct kvm_vm *vm)
 	test_invalid_vcpu_event(vm, invalid_id);
 }
 
+static void get_vcpu_registers(struct kvm_vm *vm,
+			       struct kvm_regs *regs)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_get_registers cmd;
+	} req = {};
+	struct kvmi_vcpu_get_registers_reply rpl;
+
+	test_vcpu0_command(vm, KVMI_VCPU_GET_REGISTERS, &req.hdr, sizeof(req),
+			   &rpl, sizeof(rpl));
+
+	memcpy(regs, &rpl.regs, sizeof(*regs));
+}
+
+static void test_cmd_vcpu_get_registers(struct kvm_vm *vm)
+{
+	struct kvm_regs regs = {};
+
+	get_vcpu_registers(vm, &regs);
+
+	DEBUG("get_registers rip 0x%llx\n", regs.rip);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -824,6 +849,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_get_vcpu_info(vm);
 	test_pause(vm);
 	test_cmd_vcpu_control_events(vm);
+	test_cmd_vcpu_get_registers(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index b6b3efd085c4..8d292a4be270 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -26,6 +26,13 @@ void *kvmi_msg_alloc(void)
 	return kmem_cache_zalloc(msg_cache, GFP_KERNEL);
 }
 
+void *kvmi_msg_alloc_check(size_t size)
+{
+	if (size > KVMI_MSG_SIZE_ALLOC)
+		return NULL;
+	return kvmi_msg_alloc();
+}
+
 void kvmi_msg_free(void *addr)
 {
 	if (addr)
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index e94356516a05..3e471e3a755d 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -33,6 +33,7 @@ u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
 
 /* kvmi.c */
 void *kvmi_msg_alloc(void);
+void *kvmi_msg_alloc_check(size_t size);
 void kvmi_msg_free(void *addr);
 int kvmi_add_job(struct kvm_vcpu *vcpu,
 		 void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
@@ -55,5 +56,12 @@ int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait);
 int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
 				struct kvmi_vcpu_get_info_reply *rpl);
 void kvmi_arch_setup_event(struct kvm_vcpu *vcpu, struct kvmi_event *ev);
+int kvmi_arch_check_get_registers_req(const struct kvmi_msg_hdr *msg,
+				const struct kvmi_vcpu_get_registers *req);
+int kvmi_arch_cmd_vcpu_get_registers(struct kvm_vcpu *vcpu,
+				const struct kvmi_msg_hdr *msg,
+				const struct kvmi_vcpu_get_registers *req,
+				struct kvmi_vcpu_get_registers_reply **dest,
+				size_t *dest_size);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index f819d0a942dc..e30e1ad5e443 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -30,6 +30,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VM_WRITE_PHYSICAL]   = "KVMI_VM_WRITE_PHYSICAL",
 	[KVMI_VCPU_CONTROL_EVENTS] = "KVMI_VCPU_CONTROL_EVENTS",
 	[KVMI_VCPU_GET_INFO]       = "KVMI_VCPU_GET_INFO",
+	[KVMI_VCPU_GET_REGISTERS]  = "KVMI_VCPU_GET_REGISTERS",
 	[KVMI_VCPU_PAUSE]          = "KVMI_VCPU_PAUSE",
 };
 
@@ -466,6 +467,25 @@ static int handle_vcpu_control_events(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
 }
 
+static int handle_get_registers(const struct kvmi_vcpu_cmd_job *job,
+				const struct kvmi_msg_hdr *msg,
+				const void *req)
+{
+	struct kvmi_vcpu_get_registers_reply *rpl = NULL;
+	size_t rpl_size = 0;
+	int err, ec;
+
+	if (kvmi_arch_check_get_registers_req(msg, req))
+		return -EINVAL;
+
+	ec = kvmi_arch_cmd_vcpu_get_registers(job->vcpu, msg, req,
+					      &rpl, &rpl_size);
+
+	err = kvmi_msg_vcpu_reply(job, msg, ec, rpl, rpl_size);
+	kvmi_msg_free(rpl);
+	return err;
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -477,6 +497,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 	[KVMI_EVENT]               = handle_event_reply,
 	[KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events,
 	[KVMI_VCPU_GET_INFO]       = handle_get_vcpu_info,
+	[KVMI_VCPU_GET_REGISTERS]  = handle_get_registers,
 };
 
 static bool is_vcpu_command(u16 id)

[PATCH v8 58/81] KVM: introspection: add KVMI_VCPU_SET_REGISTERS

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

During an introspection event, the introspection tool might need to
change the vCPU state, for example, to skip the current instruction.

This command is allowed only during vCPU events and the registers will
be set when the reply has been received.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>
Signed-off-by: Mircea Cîrjaliu <mcirjaliu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 29 +++++++
 include/linux/kvmi_host.h                     |  3 +
 include/uapi/linux/kvmi.h                     |  1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 78 +++++++++++++++++++
 virt/kvm/introspection/kvmi.c                 | 24 ++++++
 virt/kvm/introspection/kvmi_int.h             |  3 +
 virt/kvm/introspection/kvmi_msg.c             | 15 ++++
 7 files changed, 153 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 0000099e8038..7d6d85aa191a 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -608,6 +608,35 @@ registers, the special registers and the requested set of MSRs.
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 * -KVM_ENOMEM - there is not enough memory to allocate the reply
 
+12. KVMI_VCPU_SET_REGISTERS
+---------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvm_regs;
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Sets the general purpose registers for the given vCPU. The changes become
+visible to other threads accessing the KVM vCPU structure after the event
+currently being handled is replied to.
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_EOPNOTSUPP - the command hasn't been received during an introspection event
+
 Events
 ======
 
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 8e8ab9d836fe..fe071a92510c 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -38,6 +38,9 @@ struct kvm_vcpu_introspection {
 	bool waiting_for_reply;
 
 	DECLARE_BITMAP(ev_enable_mask, KVMI_NUM_EVENTS);
+
+	struct kvm_regs delayed_regs;
+	bool have_delayed_regs;
 };
 
 struct kvm_introspection {
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index c354c5e15be1..746f433b8269 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -29,6 +29,7 @@ enum {
 	KVMI_VCPU_PAUSE          = 10,
 	KVMI_VCPU_CONTROL_EVENTS = 11,
 	KVMI_VCPU_GET_REGISTERS  = 12,
+	KVMI_VCPU_SET_REGISTERS  = 13,
 
 	KVMI_NUM_MESSAGES
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 2fb191740cae..18ccc794c6cc 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -832,6 +832,83 @@ static void test_cmd_vcpu_get_registers(struct kvm_vm *vm)
 	DEBUG("get_registers rip 0x%llx\n", regs.rip);
 }
 
+static int __cmd_set_registers(struct kvm_vm *vm,
+			       struct kvm_regs *regs)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvm_regs regs;
+	} req = {};
+	__u16 vcpu_index = 0;
+
+	req.vcpu_hdr.vcpu = vcpu_index;
+
+	memcpy(&req.regs, regs, sizeof(req.regs));
+
+	return do_command(KVMI_VCPU_SET_REGISTERS,
+			  &req.hdr, sizeof(req), NULL, 0);
+}
+
+static int cmd_set_registers(struct kvm_vm *vm,
+			     struct kvm_regs *regs)
+{
+	struct vcpu_worker_data data = {.vm = vm, .vcpu_id = VCPU_ID};
+	pthread_t vcpu_thread;
+	int r;
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	r = __cmd_set_registers(vm, regs);
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	return r;
+}
+
+static void __set_registers(struct kvm_vm *vm,
+			    struct kvm_regs *regs)
+{
+	int r;
+
+	r = __cmd_set_registers(vm, regs);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_SET_REGISTERS failed, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+}
+
+static void test_cmd_vcpu_set_registers(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = {.vm = vm, .vcpu_id = VCPU_ID};
+	__u16 event_id = KVMI_EVENT_PAUSE_VCPU;
+	struct kvmi_msg_hdr hdr;
+	pthread_t vcpu_thread;
+	struct kvmi_event ev;
+	struct vcpu_reply rpl = {};
+	struct kvm_regs regs = {};
+	int r;
+
+	get_vcpu_registers(vm, &regs);
+
+	r = cmd_set_registers(vm, &regs);
+	TEST_ASSERT(r == -KVM_EOPNOTSUPP,
+		"KVMI_VCPU_SET_REGISTERS didn't failed with KVM_EOPNOTSUPP, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+
+	pause_vcpu(vm);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	receive_event(&hdr, &ev, sizeof(ev), event_id);
+
+	__set_registers(vm, &ev.arch.regs);
+
+	reply_to_event(&hdr, &ev, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+
+	stop_vcpu_worker(vcpu_thread, &data);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -850,6 +927,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_pause(vm);
 	test_cmd_vcpu_control_events(vm);
 	test_cmd_vcpu_get_registers(vm);
+	test_cmd_vcpu_set_registers(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 8d292a4be270..d1898bf8da1a 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -815,3 +815,27 @@ int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait)
 
 	return 0;
 }
+
+int kvmi_cmd_vcpu_set_registers(struct kvm_vcpu *vcpu,
+				const struct kvm_regs *regs)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	if (!vcpui->waiting_for_reply)
+		return -KVM_EOPNOTSUPP;
+
+	memcpy(&vcpui->delayed_regs, regs, sizeof(vcpui->delayed_regs));
+	vcpui->have_delayed_regs = true;
+
+	return 0;
+}
+
+void kvmi_post_reply(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	if (vcpui->have_delayed_regs) {
+		kvm_arch_vcpu_set_regs(vcpu, &vcpui->delayed_regs, false);
+		vcpui->have_delayed_regs = false;
+	}
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 3e471e3a755d..0f44893bcbdc 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -39,6 +39,7 @@ int kvmi_add_job(struct kvm_vcpu *vcpu,
 		 void (*fct)(struct kvm_vcpu *vcpu, void *ctx),
 		 void *ctx, void (*free_fct)(void *ctx));
 void kvmi_run_jobs(struct kvm_vcpu *vcpu);
+void kvmi_post_reply(struct kvm_vcpu *vcpu);
 int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 				unsigned int event_id, bool enable);
 int kvmi_cmd_vcpu_control_events(struct kvm_vcpu *vcpu,
@@ -51,6 +52,8 @@ int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size,
 int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, size_t size,
 			    const void *buf);
 int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait);
+int kvmi_cmd_vcpu_set_registers(struct kvm_vcpu *vcpu,
+				const struct kvm_regs *regs);
 
 /* arch */
 int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index e30e1ad5e443..38e1acdf744f 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -32,6 +32,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VCPU_GET_INFO]       = "KVMI_VCPU_GET_INFO",
 	[KVMI_VCPU_GET_REGISTERS]  = "KVMI_VCPU_GET_REGISTERS",
 	[KVMI_VCPU_PAUSE]          = "KVMI_VCPU_PAUSE",
+	[KVMI_VCPU_SET_REGISTERS]  = "KVMI_VCPU_SET_REGISTERS",
 };
 
 static const char *id2str(u16 id)
@@ -486,6 +487,18 @@ static int handle_get_registers(const struct kvmi_vcpu_cmd_job *job,
 	return err;
 }
 
+static int handle_set_registers(const struct kvmi_vcpu_cmd_job *job,
+				const struct kvmi_msg_hdr *msg,
+				const void *_req)
+{
+	const struct kvm_regs *regs = _req;
+	int ec;
+
+	ec = kvmi_cmd_vcpu_set_registers(job->vcpu, regs);
+
+	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -498,6 +511,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 	[KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events,
 	[KVMI_VCPU_GET_INFO]       = handle_get_vcpu_info,
 	[KVMI_VCPU_GET_REGISTERS]  = handle_get_registers,
+	[KVMI_VCPU_SET_REGISTERS]  = handle_set_registers,
 };
 
 static bool is_vcpu_command(u16 id)
@@ -787,6 +801,7 @@ static int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
 	if (err)
 		goto out;
 
+	kvmi_post_reply(vcpu);
 	*action = vcpui->reply.action;
 
 out:

[PATCH v8 59/81] KVM: introspection: add KVMI_VCPU_GET_CPUID

[Adalbert Lazăr]

From: Marian Rotariu <marian.c.rotariu@gmail.com>

This command returns a CPUID leaf (as seen by the guest OS).

Signed-off-by: Marian Rotariu <marian.c.rotariu@gmail.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 36 +++++++++++++++++++
 arch/x86/include/uapi/asm/kvmi.h              | 12 +++++++
 arch/x86/kvm/kvmi.c                           | 19 ++++++++++
 include/uapi/linux/kvmi.h                     |  1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 34 ++++++++++++++++++
 virt/kvm/introspection/kvmi_int.h             |  3 ++
 virt/kvm/introspection/kvmi_msg.c             | 16 +++++++++
 7 files changed, 121 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 7d6d85aa191a..76b22585feee 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -637,6 +637,42 @@ currently being handled is replied to.
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 * -KVM_EOPNOTSUPP - the command hasn't been received during an introspection event
 
+13. KVMI_VCPU_GET_CPUID
+-----------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_get_cpuid {
+		__u32 function;
+		__u32 index;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_vcpu_get_cpuid_reply {
+		__u32 eax;
+		__u32 ebx;
+		__u32 ecx;
+		__u32 edx;
+	};
+
+Returns a CPUID leaf (as seen by the guest OS).
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_ENOENT - the selected leaf is not present or is invalid
+
 Events
 ======
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index f14674c3c109..57c48ace417f 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -45,4 +45,16 @@ struct kvmi_vcpu_get_registers_reply {
 	struct kvm_msrs msrs;
 };
 
+struct kvmi_vcpu_get_cpuid {
+	__u32 function;
+	__u32 index;
+};
+
+struct kvmi_vcpu_get_cpuid_reply {
+	__u32 eax;
+	__u32 ebx;
+	__u32 ecx;
+	__u32 edx;
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 1ba264c10cff..ede8c7cbdf1e 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -7,6 +7,7 @@
 
 #include "linux/kvm_host.h"
 #include "x86.h"
+#include "cpuid.h"
 #include "../../../virt/kvm/introspection/kvmi_int.h"
 
 static unsigned int kvmi_vcpu_mode(const struct kvm_vcpu *vcpu,
@@ -189,3 +190,21 @@ int kvmi_arch_cmd_vcpu_get_registers(struct kvm_vcpu *vcpu,
 	return err;
 
 }
+
+int kvmi_arch_cmd_vcpu_get_cpuid(struct kvm_vcpu *vcpu,
+				 const struct kvmi_vcpu_get_cpuid *req,
+				 struct kvmi_vcpu_get_cpuid_reply *rpl)
+{
+	struct kvm_cpuid_entry2 *e;
+
+	e = kvm_find_cpuid_entry(vcpu, req->function, req->index);
+	if (!e)
+		return -KVM_ENOENT;
+
+	rpl->eax = e->eax;
+	rpl->ebx = e->ebx;
+	rpl->ecx = e->ecx;
+	rpl->edx = e->edx;
+
+	return 0;
+}
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 746f433b8269..3688fa26dbaf 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -30,6 +30,7 @@ enum {
 	KVMI_VCPU_CONTROL_EVENTS = 11,
 	KVMI_VCPU_GET_REGISTERS  = 12,
 	KVMI_VCPU_SET_REGISTERS  = 13,
+	KVMI_VCPU_GET_CPUID      = 14,
 
 	KVMI_NUM_MESSAGES
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 18ccc794c6cc..18ce7ddd9136 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -909,6 +909,39 @@ static void test_cmd_vcpu_set_registers(struct kvm_vm *vm)
 	stop_vcpu_worker(vcpu_thread, &data);
 }
 
+static int cmd_get_cpuid(struct kvm_vm *vm,
+			 __u32 function, __u32 index,
+			 struct kvmi_vcpu_get_cpuid_reply *rpl)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_get_cpuid cmd;
+	} req = {};
+
+	req.cmd.function = function;
+	req.cmd.index = index;
+
+	return do_vcpu0_command(vm, KVMI_VCPU_GET_CPUID, &req.hdr, sizeof(req),
+				rpl, sizeof(*rpl));
+}
+
+static void test_cmd_vcpu_get_cpuid(struct kvm_vm *vm)
+{
+	struct kvmi_vcpu_get_cpuid_reply rpl = {};
+	__u32 function = 0;
+	__u32 index = 0;
+	int r;
+
+	r = cmd_get_cpuid(vm, function, index, &rpl);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_GET_CPUID failed, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+
+	DEBUG("cpuid(%u, %u) => eax 0x%.8x, ebx 0x%.8x, ecx 0x%.8x, edx 0x%.8x\n",
+	      function, index, rpl.eax, rpl.ebx, rpl.ecx, rpl.edx);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -928,6 +961,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_control_events(vm);
 	test_cmd_vcpu_get_registers(vm);
 	test_cmd_vcpu_set_registers(vm);
+	test_cmd_vcpu_get_cpuid(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 0f44893bcbdc..a28966912427 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -66,5 +66,8 @@ int kvmi_arch_cmd_vcpu_get_registers(struct kvm_vcpu *vcpu,
 				const struct kvmi_vcpu_get_registers *req,
 				struct kvmi_vcpu_get_registers_reply **dest,
 				size_t *dest_size);
+int kvmi_arch_cmd_vcpu_get_cpuid(struct kvm_vcpu *vcpu,
+				 const struct kvmi_vcpu_get_cpuid *req,
+				 struct kvmi_vcpu_get_cpuid_reply *rpl);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 38e1acdf744f..d3889ce6e41b 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -29,6 +29,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VM_READ_PHYSICAL]    = "KVMI_VM_READ_PHYSICAL",
 	[KVMI_VM_WRITE_PHYSICAL]   = "KVMI_VM_WRITE_PHYSICAL",
 	[KVMI_VCPU_CONTROL_EVENTS] = "KVMI_VCPU_CONTROL_EVENTS",
+	[KVMI_VCPU_GET_CPUID]      = "KVMI_VCPU_GET_CPUID",
 	[KVMI_VCPU_GET_INFO]       = "KVMI_VCPU_GET_INFO",
 	[KVMI_VCPU_GET_REGISTERS]  = "KVMI_VCPU_GET_REGISTERS",
 	[KVMI_VCPU_PAUSE]          = "KVMI_VCPU_PAUSE",
@@ -499,6 +500,20 @@ static int handle_set_registers(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
 }
 
+static int handle_get_cpuid(const struct kvmi_vcpu_cmd_job *job,
+			    const struct kvmi_msg_hdr *msg,
+			    const void *req)
+{
+	struct kvmi_vcpu_get_cpuid_reply rpl;
+	int ec;
+
+	memset(&rpl, 0, sizeof(rpl));
+
+	ec = kvmi_arch_cmd_vcpu_get_cpuid(job->vcpu, req, &rpl);
+
+	return kvmi_msg_vcpu_reply(job, msg, ec, &rpl, sizeof(rpl));
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -509,6 +524,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 			      const struct kvmi_msg_hdr *, const void *) = {
 	[KVMI_EVENT]               = handle_event_reply,
 	[KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events,
+	[KVMI_VCPU_GET_CPUID]      = handle_get_cpuid,
 	[KVMI_VCPU_GET_INFO]       = handle_get_vcpu_info,
 	[KVMI_VCPU_GET_REGISTERS]  = handle_get_registers,
 	[KVMI_VCPU_SET_REGISTERS]  = handle_set_registers,

[PATCH v8 60/81] KVM: introspection: add KVMI_EVENT_HYPERCALL

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This event is sent on a specific hypercall.

It is used by the code residing inside the introspected guest to call the
introspection tool and to report certain details about its operation.
For example, a classic antimalware remediation tool can report
what it has found during a scan.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/hypercalls.rst         | 35 +++++++++++++++
 Documentation/virt/kvm/kvmi.rst               | 36 +++++++++++++++-
 arch/x86/include/uapi/asm/kvmi.h              |  2 +
 arch/x86/kvm/kvmi.c                           | 33 ++++++++++++++
 arch/x86/kvm/x86.c                            | 18 ++++++--
 include/linux/kvmi_host.h                     |  2 +
 include/uapi/linux/kvm_para.h                 |  1 +
 include/uapi/linux/kvmi.h                     |  1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 43 +++++++++++++++++++
 virt/kvm/introspection/kvmi.c                 | 23 ++++++++++
 virt/kvm/introspection/kvmi_int.h             | 10 +++++
 virt/kvm/introspection/kvmi_msg.c             | 12 ++++++
 12 files changed, 211 insertions(+), 5 deletions(-)

diff --git a/Documentation/virt/kvm/hypercalls.rst b/Documentation/virt/kvm/hypercalls.rst
index 81294aaea07a..1a3cee369171 100644
--- a/Documentation/virt/kvm/hypercalls.rst
+++ b/Documentation/virt/kvm/hypercalls.rst
@@ -169,3 +169,38 @@ a0: destination APIC ID
 
 :Usage example: When sending a call-function IPI-many to vCPUs, yield if
 	        any of the IPI target vCPUs was preempted.
+
+9. KVM_HC_XEN_HVM_OP
+--------------------
+
+:Architecture: x86
+:Status: active
+:Purpose: To enable communication between a guest agent and a VMI application
+
+Usage:
+
+An event will be sent to the VMI application (see kvmi.rst) if the following
+registers, which differ between 32bit and 64bit, have the following values:
+
+       ========    =====     =====
+       32bit       64bit     value
+       ========    =====     =====
+       ebx (a0)    rdi       KVM_HC_XEN_HVM_OP_GUEST_REQUEST_VM_EVENT
+       ecx (a1)    rsi       0
+       ========    =====     =====
+
+This specification copies Xen's { __HYPERVISOR_hvm_op,
+HVMOP_guest_request_vm_event } hypercall and can originate from kernel or
+userspace.
+
+It returns 0 if successful, or a negative POSIX.1 error code if it fails. The
+absence of an active VMI application is not signaled in any way.
+
+The following registers are clobbered:
+
+  * 32bit: edx, esi, edi, ebp
+  * 64bit: rdx, r10, r8, r9
+
+In particular, for KVM_HC_XEN_HVM_OP_GUEST_REQUEST_VM_EVENT, the last two
+registers can be poisoned deliberately and cannot be used for passing
+information.
diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 76b22585feee..475b09924e06 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -543,7 +543,10 @@ command) before returning to guest.
 
 	struct kvmi_error_code
 
-Enables/disables vCPU introspection events.
+Enables/disables vCPU introspection events. This command can be used with
+the following events::
+
+	KVMI_EVENT_HYPERCALL
 
 When an event is enabled, the introspection tool is notified and
 must reply with: continue, retry, crash, etc. (see **Events** below).
@@ -781,3 +784,34 @@ This event is sent in response to a *KVMI_VCPU_PAUSE* command and
 cannot be disabled via *KVMI_VCPU_CONTROL_EVENTS*.
 Because it has a low priority, it will be sent after any other vCPU
 introspection event and when no vCPU introspection command is queued.
+
+3. KVMI_EVENT_HYPERCALL
+-----------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+	struct kvmi_event;
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+
+This event is sent on a specific user hypercall when the introspection has
+been enabled for this event (see *KVMI_VCPU_CONTROL_EVENTS*).
+
+The hypercall number must be ``KVM_HC_XEN_HVM_OP`` with the
+``KVM_HC_XEN_HVM_OP_GUEST_REQUEST_VM_EVENT`` sub-function
+(see hypercalls.txt).
+
+It is used by the code residing inside the introspected guest to call the
+introspection tool and to report certain details about its operation. For
+example, a classic antimalware remediation tool can report what it has
+found during a scan.
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 57c48ace417f..9882e68cab75 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -8,6 +8,8 @@
 
 #include <asm/kvm.h>
 
+#define KVM_HC_XEN_HVM_OP_GUEST_REQUEST_VM_EVENT 24
+
 struct kvmi_event_arch {
 	__u8 mode;		/* 2, 4 or 8 */
 	__u8 padding[7];
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index ede8c7cbdf1e..7930f6de1a40 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -208,3 +208,36 @@ int kvmi_arch_cmd_vcpu_get_cpuid(struct kvm_vcpu *vcpu,
 
 	return 0;
 }
+
+bool kvmi_arch_is_agent_hypercall(struct kvm_vcpu *vcpu)
+{
+	unsigned long subfunc1, subfunc2;
+	bool longmode = is_64_bit_mode(vcpu);
+
+	if (longmode) {
+		subfunc1 = kvm_rdi_read(vcpu);
+		subfunc2 = kvm_rsi_read(vcpu);
+	} else {
+		subfunc1 = kvm_rbx_read(vcpu);
+		subfunc1 &= 0xFFFFFFFF;
+		subfunc2 = kvm_rcx_read(vcpu);
+		subfunc2 &= 0xFFFFFFFF;
+	}
+
+	return (subfunc1 == KVM_HC_XEN_HVM_OP_GUEST_REQUEST_VM_EVENT
+		&& subfunc2 == 0);
+}
+
+void kvmi_arch_hypercall_event(struct kvm_vcpu *vcpu)
+{
+	u32 action;
+
+	action = kvmi_msg_send_hypercall(vcpu);
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action,
+						"HYPERCALL");
+	}
+}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 967c83791b37..bad66420f054 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7546,11 +7546,14 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
 {
 	unsigned long nr, a0, a1, a2, a3, ret;
 	int op_64_bit;
-
-	if (kvm_hv_hypercall_enabled(vcpu->kvm))
-		return kvm_hv_hypercall(vcpu);
+	bool kvmi_hc;
 
 	nr = kvm_rax_read(vcpu);
+	kvmi_hc = (u32)nr == KVM_HC_XEN_HVM_OP;
+
+	if (kvm_hv_hypercall_enabled(vcpu->kvm) && !kvmi_hc)
+		return kvm_hv_hypercall(vcpu);
+
 	a0 = kvm_rbx_read(vcpu);
 	a1 = kvm_rcx_read(vcpu);
 	a2 = kvm_rdx_read(vcpu);
@@ -7567,7 +7570,7 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
 		a3 &= 0xFFFFFFFF;
 	}
 
-	if (kvm_x86_ops->get_cpl(vcpu) != 0) {
+	if (kvm_x86_ops->get_cpl(vcpu) != 0 && !kvmi_hc) {
 		ret = -KVM_EPERM;
 		goto out;
 	}
@@ -7593,6 +7596,13 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
 		kvm_sched_yield(vcpu->kvm, a0);
 		ret = 0;
 		break;
+#ifdef CONFIG_KVM_INTROSPECTION
+	case KVM_HC_XEN_HVM_OP:
+		ret = 0;
+		if (!kvmi_hypercall_event(vcpu))
+			ret = -KVM_ENOSYS;
+		break;
+#endif /* CONFIG_KVM_INTROSPECTION */
 	default:
 		ret = -KVM_ENOSYS;
 		break;
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index fe071a92510c..ac78f2845e5f 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -75,6 +75,7 @@ int kvmi_ioctl_event(struct kvm *kvm, void __user *argp);
 int kvmi_ioctl_preunhook(struct kvm *kvm);
 
 void kvmi_handle_requests(struct kvm_vcpu *vcpu);
+bool kvmi_hypercall_event(struct kvm_vcpu *vcpu);
 
 #else
 
@@ -85,6 +86,7 @@ static inline void kvmi_destroy_vm(struct kvm *kvm) { }
 static inline void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu) { }
 
 static inline void kvmi_handle_requests(struct kvm_vcpu *vcpu) { }
+static inline bool kvmi_hypercall_event(struct kvm_vcpu *vcpu) { return false; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h
index 3ce388249682..53cebbe22099 100644
--- a/include/uapi/linux/kvm_para.h
+++ b/include/uapi/linux/kvm_para.h
@@ -33,6 +33,7 @@
 #define KVM_HC_CLOCK_PAIRING		9
 #define KVM_HC_SEND_IPI		10
 #define KVM_HC_SCHED_YIELD		11
+#define KVM_HC_XEN_HVM_OP		34 /* Xen's __HYPERVISOR_hvm_op */
 
 /*
  * hypercalls use architecture specific
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 3688fa26dbaf..19137bd4cafc 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -38,6 +38,7 @@ enum {
 enum {
 	KVMI_EVENT_UNHOOK     = 0,
 	KVMI_EVENT_PAUSE_VCPU = 1,
+	KVMI_EVENT_HYPERCALL  = 2,
 
 	KVMI_NUM_EVENTS
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 18ce7ddd9136..aefc83bc6955 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -49,6 +49,7 @@ struct vcpu_worker_data {
 
 enum {
 	GUEST_TEST_NOOP = 0,
+	GUEST_TEST_HYPERCALL,
 };
 
 #define GUEST_REQUEST_TEST()     GUEST_SYNC(0)
@@ -62,12 +63,23 @@ static int guest_test_id(void)
 	return READ_ONCE(test_id);
 }
 
+static void guest_hypercall_test(void)
+{
+	asm volatile("mov $34, %rax");
+	asm volatile("mov $24, %rdi");
+	asm volatile("mov $0, %rsi");
+	asm volatile(".byte 0x0f,0x01,0xc1");
+}
+
 static void guest_code(void)
 {
 	while (true) {
 		switch (guest_test_id()) {
 		case GUEST_TEST_NOOP:
 			break;
+		case GUEST_TEST_HYPERCALL:
+			guest_hypercall_test();
+			break;
 		}
 		GUEST_SIGNAL_TEST_DONE();
 	}
@@ -942,6 +954,36 @@ static void test_cmd_vcpu_get_cpuid(struct kvm_vm *vm)
 	      function, index, rpl.eax, rpl.ebx, rpl.ecx, rpl.edx);
 }
 
+static void test_event_hypercall(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = {
+		.vm = vm,
+		.vcpu_id = VCPU_ID,
+		.test_id = GUEST_TEST_HYPERCALL,
+	};
+	struct kvmi_msg_hdr hdr;
+	struct kvmi_event ev;
+	struct vcpu_reply rpl = {};
+	__u16 event_id = KVMI_EVENT_HYPERCALL;
+	pthread_t vcpu_thread;
+
+	enable_vcpu_event(vm, event_id);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	receive_event(&hdr, &ev, sizeof(ev), event_id);
+
+	DEBUG("Hypercall event, rip 0x%llx\n",
+		ev.arch.regs.rip);
+
+	reply_to_event(&hdr, &ev, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	disable_vcpu_event(vm, event_id);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -962,6 +1004,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_get_registers(vm);
 	test_cmd_vcpu_set_registers(vm);
 	test_cmd_vcpu_get_cpuid(vm);
+	test_event_hypercall(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index d1898bf8da1a..286cfc7ebf8a 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -78,6 +78,7 @@ static void setup_known_events(void)
 	set_bit(KVMI_EVENT_UNHOOK, Kvmi_known_vm_events);
 
 	bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
+	set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
 
 	bitmap_or(Kvmi_known_events, Kvmi_known_vm_events,
@@ -839,3 +840,25 @@ void kvmi_post_reply(struct kvm_vcpu *vcpu)
 		vcpui->have_delayed_regs = false;
 	}
 }
+
+bool kvmi_hypercall_event(struct kvm_vcpu *vcpu)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = false;
+
+	if (!kvmi_arch_is_agent_hypercall(vcpu))
+		return ret;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return ret;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_HYPERCALL)) {
+		kvmi_arch_hypercall_event(vcpu);
+		ret = true;
+	}
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index a28966912427..426b1e633528 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -23,6 +23,11 @@ extern DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 #define KVMI(kvm) ((kvm)->kvmi)
 #define VCPUI(vcpu) ((vcpu)->kvmi)
 
+static inline bool is_event_enabled(struct kvm_vcpu *vcpu, int event)
+{
+	return test_bit(event, VCPUI(vcpu)->ev_enable_mask);
+}
+
 /* kvmi_msg.c */
 bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd);
 void kvmi_sock_shutdown(struct kvm_introspection *kvmi);
@@ -30,6 +35,7 @@ void kvmi_sock_put(struct kvm_introspection *kvmi);
 bool kvmi_msg_process(struct kvm_introspection *kvmi);
 int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
 u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
+u32 kvmi_msg_send_hypercall(struct kvm_vcpu *vcpu);
 
 /* kvmi.c */
 void *kvmi_msg_alloc(void);
@@ -40,6 +46,8 @@ int kvmi_add_job(struct kvm_vcpu *vcpu,
 		 void *ctx, void (*free_fct)(void *ctx));
 void kvmi_run_jobs(struct kvm_vcpu *vcpu);
 void kvmi_post_reply(struct kvm_vcpu *vcpu);
+void kvmi_handle_common_event_actions(struct kvm *kvm,
+				      u32 action, const char *str);
 int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 				unsigned int event_id, bool enable);
 int kvmi_cmd_vcpu_control_events(struct kvm_vcpu *vcpu,
@@ -69,5 +77,7 @@ int kvmi_arch_cmd_vcpu_get_registers(struct kvm_vcpu *vcpu,
 int kvmi_arch_cmd_vcpu_get_cpuid(struct kvm_vcpu *vcpu,
 				 const struct kvmi_vcpu_get_cpuid *req,
 				 struct kvmi_vcpu_get_cpuid_reply *rpl);
+bool kvmi_arch_is_agent_hypercall(struct kvm_vcpu *vcpu);
+void kvmi_arch_hypercall_event(struct kvm_vcpu *vcpu);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index d3889ce6e41b..4b3625d89d52 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -837,3 +837,15 @@ u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu)
 
 	return action;
 }
+
+u32 kvmi_msg_send_hypercall(struct kvm_vcpu *vcpu)
+{
+	int err, action;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_HYPERCALL, NULL, 0,
+			      NULL, 0, &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	return action;
+}

[PATCH v8 61/81] KVM: introspection: add KVMI_EVENT_BREAKPOINT

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This event is sent when a breakpoint was reached.

The introspection tool can place breakpoints and use them as notification
for when the OS or an application has reached a certain state or is
trying to perform a certain operation (eg. create a process).

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 40 ++++++++++++++
 arch/x86/include/uapi/asm/kvmi.h              |  6 +++
 arch/x86/kvm/kvmi.c                           | 52 +++++++++++++++++++
 arch/x86/kvm/svm.c                            | 32 ++++++++++++
 arch/x86/kvm/vmx/vmx.c                        | 16 ++++--
 include/linux/kvmi_host.h                     |  4 ++
 include/uapi/linux/kvmi.h                     |  1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 46 ++++++++++++++++
 virt/kvm/introspection/kvmi.c                 | 30 ++++++++++-
 virt/kvm/introspection/kvmi_int.h             |  5 ++
 virt/kvm/introspection/kvmi_msg.c             | 17 ++++++
 11 files changed, 243 insertions(+), 6 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 475b09924e06..b62cfdd61f89 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -546,6 +546,7 @@ command) before returning to guest.
 Enables/disables vCPU introspection events. This command can be used with
 the following events::
 
+	KVMI_EVENT_BREAKPOINT
 	KVMI_EVENT_HYPERCALL
 
 When an event is enabled, the introspection tool is notified and
@@ -568,6 +569,9 @@ the *KVMI_VM_CONTROL_EVENTS* command.
 * -KVM_EINVAL - the event ID is unknown (use *KVMI_VM_CHECK_EVENT* first)
 * -KVM_EPERM - the access is disallowed (use *KVMI_VM_CHECK_EVENT* first)
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_EBUSY - the event can't be intercepted right now
+               (e.g. KVMI_EVENT_BREAKPOINT if the #BP event is already intercepted
+                by userspace)
 
 11. KVMI_VCPU_GET_REGISTERS
 ---------------------------
@@ -815,3 +819,39 @@ It is used by the code residing inside the introspected guest to call the
 introspection tool and to report certain details about its operation. For
 example, a classic antimalware remediation tool can report what it has
 found during a scan.
+
+4. KVMI_EVENT_BREAKPOINT
+------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH, RETRY
+:Parameters:
+
+::
+
+	struct kvmi_event;
+	struct kvmi_event_breakpoint {
+		__u64 gpa;
+		__u8 insn_len;
+		__u8 padding[7];
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+
+This event is sent when a breakpoint was reached and the introspection has
+been enabled for this event (see *KVMI_VCPU_CONTROL_EVENTS*).
+
+Some of these breakpoints could have been injected by the introspection tool,
+placed in the slack space of various functions and used as notification
+for when the OS or an application has reached a certain state or is
+trying to perform a certain operation (like creating a process).
+
+``kvmi_event`` and the guest physical address are sent to the introspection tool.
+
+The *RETRY* action is used by the introspection tool for its own breakpoints.
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 9882e68cab75..1605777256a3 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -59,4 +59,10 @@ struct kvmi_vcpu_get_cpuid_reply {
 	__u32 edx;
 };
 
+struct kvmi_event_breakpoint {
+	__u64 gpa;
+	__u8 insn_len;
+	__u8 padding[7];
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 7930f6de1a40..92314341b3a9 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -241,3 +241,55 @@ void kvmi_arch_hypercall_event(struct kvm_vcpu *vcpu)
 						"HYPERCALL");
 	}
 }
+
+static int kvmi_control_bp_intercept(struct kvm_vcpu *vcpu, bool enable)
+{
+	struct kvm_guest_debug dbg = {};
+	int err = 0;
+
+	if (enable)
+		dbg.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
+	err = kvm_arch_vcpu_set_guest_debug(vcpu, &dbg);
+
+	return err;
+}
+
+int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
+				    unsigned int event_id, bool enable)
+{
+	int err = 0;
+
+	switch (event_id) {
+	case KVMI_EVENT_BREAKPOINT:
+		err = kvmi_control_bp_intercept(vcpu, enable);
+		break;
+	default:
+		break;
+	}
+
+	return err;
+}
+
+void kvmi_arch_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len)
+{
+	u32 action;
+	u64 gpa;
+
+	gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, 0, NULL);
+
+	action = kvmi_msg_send_bp(vcpu, gpa, insn_len);
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		kvm_queue_exception(vcpu, BP_VECTOR);
+		break;
+	case KVMI_EVENT_ACTION_RETRY:
+		/* rip was most likely adjusted past the INT 3 instruction */
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action, "BP");
+	}
+}
+
+void kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
+{
+}
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 2be8f9313611..05c64318a8df 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2821,10 +2821,42 @@ static int db_interception(struct vcpu_svm *svm)
 	return 1;
 }
 
+static unsigned svm_get_instruction_len(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+	unsigned long next_rip = 0, rip = kvm_rip_read(vcpu);
+	unsigned insn_len;
+
+	if (static_cpu_has(X86_FEATURE_NRIPS))
+		next_rip = svm->vmcb->control.next_rip;
+
+	if (!next_rip) {
+		if (!kvm_emulate_instruction(vcpu, EMULTYPE_SKIP))
+			return 0;
+
+		next_rip = kvm_rip_read(vcpu);
+		kvm_rip_write(vcpu, rip);
+	}
+
+	insn_len = next_rip - rip;
+	if (insn_len > MAX_INST_SIZE) {
+		pr_err("%s: ip 0x%lx next 0x%lx\n",
+		       __func__, rip, next_rip);
+		return 0;
+	}
+
+	return insn_len;
+}
+
 static int bp_interception(struct vcpu_svm *svm)
 {
 	struct kvm_run *kvm_run = svm->vcpu.run;
 
+	if (!kvmi_breakpoint_event(&svm->vcpu, svm->vmcb->save.cs.base +
+					       svm->vmcb->save.rip,
+				   svm_get_instruction_len(&svm->vcpu)))
+		return 1;
+
 	kvm_run->exit_reason = KVM_EXIT_DEBUG;
 	kvm_run->debug.arch.pc = svm->vmcb->save.cs.base + svm->vmcb->save.rip;
 	kvm_run->debug.arch.exception = BP_VECTOR;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 13462ef2ce9e..4b7044193917 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4655,7 +4655,7 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct kvm_run *kvm_run = vcpu->run;
 	u32 intr_info, ex_no, error_code;
-	unsigned long cr2, rip, dr6;
+	unsigned long cr2, dr6;
 	u32 vect_info;
 
 	vect_info = vmx->idt_vectoring_info;
@@ -4733,7 +4733,10 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
 		kvm_run->debug.arch.dr6 = dr6 | DR6_FIXED_1;
 		kvm_run->debug.arch.dr7 = vmcs_readl(GUEST_DR7);
 		/* fall through */
-	case BP_VECTOR:
+	case BP_VECTOR: {
+		unsigned long gva = vmcs_readl(GUEST_CS_BASE) +
+			kvm_rip_read(vcpu);
+
 		/*
 		 * Update instruction length as we may reinject #BP from
 		 * user space while in guest debugging mode. Reading it for
@@ -4741,11 +4744,16 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
 		 */
 		vmx->vcpu.arch.event_exit_inst_len =
 			vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+
+		if (!kvmi_breakpoint_event(vcpu, gva,
+					   vmx->vcpu.arch.event_exit_inst_len))
+			return 1;
+
 		kvm_run->exit_reason = KVM_EXIT_DEBUG;
-		rip = kvm_rip_read(vcpu);
-		kvm_run->debug.arch.pc = vmcs_readl(GUEST_CS_BASE) + rip;
+		kvm_run->debug.arch.pc = gva;
 		kvm_run->debug.arch.exception = ex_no;
 		break;
+	}
 	default:
 		kvm_run->exit_reason = KVM_EXIT_EXCEPTION;
 		kvm_run->ex.exception = ex_no;
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index ac78f2845e5f..8f28065320d8 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -76,6 +76,7 @@ int kvmi_ioctl_preunhook(struct kvm *kvm);
 
 void kvmi_handle_requests(struct kvm_vcpu *vcpu);
 bool kvmi_hypercall_event(struct kvm_vcpu *vcpu);
+bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len);
 
 #else
 
@@ -87,6 +88,9 @@ static inline void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu) { }
 
 static inline void kvmi_handle_requests(struct kvm_vcpu *vcpu) { }
 static inline bool kvmi_hypercall_event(struct kvm_vcpu *vcpu) { return false; }
+static inline bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva,
+					 u8 insn_len)
+			{ return true; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 19137bd4cafc..f6792d41b02f 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -39,6 +39,7 @@ enum {
 	KVMI_EVENT_UNHOOK     = 0,
 	KVMI_EVENT_PAUSE_VCPU = 1,
 	KVMI_EVENT_HYPERCALL  = 2,
+	KVMI_EVENT_BREAKPOINT = 3,
 
 	KVMI_NUM_EVENTS
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index aefc83bc6955..dab015555f89 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -49,6 +49,7 @@ struct vcpu_worker_data {
 
 enum {
 	GUEST_TEST_NOOP = 0,
+	GUEST_TEST_BP,
 	GUEST_TEST_HYPERCALL,
 };
 
@@ -63,6 +64,11 @@ static int guest_test_id(void)
 	return READ_ONCE(test_id);
 }
 
+static void guest_bp_test(void)
+{
+	asm volatile("int3");
+}
+
 static void guest_hypercall_test(void)
 {
 	asm volatile("mov $34, %rax");
@@ -77,6 +83,9 @@ static void guest_code(void)
 		switch (guest_test_id()) {
 		case GUEST_TEST_NOOP:
 			break;
+		case GUEST_TEST_BP:
+			guest_bp_test();
+			break;
 		case GUEST_TEST_HYPERCALL:
 			guest_hypercall_test();
 			break;
@@ -984,6 +993,42 @@ static void test_event_hypercall(struct kvm_vm *vm)
 	disable_vcpu_event(vm, event_id);
 }
 
+static void test_event_breakpoint(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = {
+		.vm = vm,
+		.vcpu_id = VCPU_ID,
+		.test_id = GUEST_TEST_BP,
+	};
+	struct kvmi_msg_hdr hdr;
+	struct {
+		struct kvmi_event common;
+		struct kvmi_event_breakpoint bp;
+	} ev;
+	struct vcpu_reply rpl = {};
+	__u16 event_id = KVMI_EVENT_BREAKPOINT;
+	pthread_t vcpu_thread;
+
+	enable_vcpu_event(vm, event_id);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	receive_event(&hdr, &ev.common, sizeof(ev), event_id);
+
+	DEBUG("Breakpoint event, rip 0x%llx, len %u\n",
+		ev.common.arch.regs.rip, ev.bp.insn_len);
+
+	ev.common.arch.regs.rip += ev.bp.insn_len;
+	__set_registers(vm, &ev.common.arch.regs);
+
+	reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_RETRY,
+			&rpl, sizeof(rpl));
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	disable_vcpu_event(vm, event_id);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1005,6 +1050,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_set_registers(vm);
 	test_cmd_vcpu_get_cpuid(vm);
 	test_event_hypercall(vm);
+	test_event_breakpoint(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 286cfc7ebf8a..32516cc70928 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -78,6 +78,7 @@ static void setup_known_events(void)
 	set_bit(KVMI_EVENT_UNHOOK, Kvmi_known_vm_events);
 
 	bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
+	set_bit(KVMI_EVENT_BREAKPOINT, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
 
@@ -198,6 +199,8 @@ static void free_vcpui(struct kvm_vcpu *vcpu)
 
 	kfree(vcpui);
 	vcpu->kvmi = NULL;
+
+	kvmi_make_request(vcpu, false);
 }
 
 static void free_kvmi(struct kvm *kvm)
@@ -594,7 +597,7 @@ int kvmi_cmd_vcpu_control_events(struct kvm_vcpu *vcpu,
 	else
 		clear_bit(event_id, vcpui->ev_enable_mask);
 
-	return 0;
+	return kvmi_arch_cmd_control_intercept(vcpu, event_id, enable);
 }
 
 static unsigned long gfn_to_hva_safe(struct kvm *kvm, gfn_t gfn)
@@ -789,7 +792,7 @@ void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 
 	kvmi = kvmi_get(vcpu->kvm);
 	if (!kvmi)
-		return;
+		goto out;
 
 	for (;;) {
 		kvmi_run_jobs(vcpu);
@@ -801,6 +804,9 @@ void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 	}
 
 	kvmi_put(vcpu->kvm);
+
+out:
+	kvmi_arch_restore_interception(vcpu);
 }
 
 int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait)
@@ -862,3 +868,23 @@ bool kvmi_hypercall_event(struct kvm_vcpu *vcpu)
 
 	return ret;
 }
+
+bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = false;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return true;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_BREAKPOINT))
+		kvmi_arch_breakpoint_event(vcpu, gva, insn_len);
+	else
+		ret = true;
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
+EXPORT_SYMBOL(kvmi_breakpoint_event);
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 426b1e633528..0fc622b2c96d 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -36,6 +36,7 @@ bool kvmi_msg_process(struct kvm_introspection *kvmi);
 int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
 u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
 u32 kvmi_msg_send_hypercall(struct kvm_vcpu *vcpu);
+u32 kvmi_msg_send_bp(struct kvm_vcpu *vcpu, u64 gpa, u8 insn_len);
 
 /* kvmi.c */
 void *kvmi_msg_alloc(void);
@@ -64,6 +65,7 @@ int kvmi_cmd_vcpu_set_registers(struct kvm_vcpu *vcpu,
 				const struct kvm_regs *regs);
 
 /* arch */
+void kvmi_arch_restore_interception(struct kvm_vcpu *vcpu);
 int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
 				struct kvmi_vcpu_get_info_reply *rpl);
 void kvmi_arch_setup_event(struct kvm_vcpu *vcpu, struct kvmi_event *ev);
@@ -79,5 +81,8 @@ int kvmi_arch_cmd_vcpu_get_cpuid(struct kvm_vcpu *vcpu,
 				 struct kvmi_vcpu_get_cpuid_reply *rpl);
 bool kvmi_arch_is_agent_hypercall(struct kvm_vcpu *vcpu);
 void kvmi_arch_hypercall_event(struct kvm_vcpu *vcpu);
+void kvmi_arch_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len);
+int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
+				    unsigned int event_id, bool enable);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 4b3625d89d52..8e451ad534e4 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -849,3 +849,20 @@ u32 kvmi_msg_send_hypercall(struct kvm_vcpu *vcpu)
 
 	return action;
 }
+
+u32 kvmi_msg_send_bp(struct kvm_vcpu *vcpu, u64 gpa, u8 insn_len)
+{
+	struct kvmi_event_breakpoint e;
+	int err, action;
+
+	memset(&e, 0, sizeof(e));
+	e.gpa = gpa;
+	e.insn_len = insn_len;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_BREAKPOINT, &e, sizeof(e),
+			      NULL, 0, &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	return action;
+}

[PATCH v8 62/81] KVM: introspection: restore the state of #BP interception on unhook

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This commit also ensures that only the userspace or the introspection
tool can control the #BP interception exclusively at one time.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h   |  3 +
 arch/x86/include/asm/kvmi_host.h  | 22 +++++++
 arch/x86/kvm/kvmi.c               | 99 ++++++++++++++++++++++++++++++-
 arch/x86/kvm/x86.c                |  5 ++
 virt/kvm/introspection/kvmi.c     | 27 ++++++++-
 virt/kvm/introspection/kvmi_int.h |  6 +-
 6 files changed, 157 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c2176012676d..5f3b6f20718f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -832,6 +832,9 @@ struct kvm_vcpu_arch {
 
 	/* #PF translated error code from EPT/NPT exit reason */
 	u64 error_code;
+
+	/* Control the interception for KVM Introspection */
+	struct kvmi_interception *kvmi;
 };
 
 struct kvm_lpage_info {
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 360a57dd9019..c8b793915b84 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -2,10 +2,32 @@
 #ifndef _ASM_X86_KVMI_HOST_H
 #define _ASM_X86_KVMI_HOST_H
 
+struct kvmi_monitor_interception {
+	bool kvmi_intercepted;
+	bool kvm_intercepted;
+	bool (*monitor_fct)(struct kvm_vcpu *vcpu, bool enable);
+};
+
+struct kvmi_interception {
+	bool restore_interception;
+	struct kvmi_monitor_interception breakpoint;
+};
+
 struct kvm_vcpu_arch_introspection {
 };
 
 struct kvm_arch_introspection {
 };
 
+#ifdef CONFIG_KVM_INTROSPECTION
+
+bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg);
+
+#else /* CONFIG_KVM_INTROSPECTION */
+
+static inline bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg)
+	{ return false; }
+
+#endif /* CONFIG_KVM_INTROSPECTION */
+
 #endif /* _ASM_X86_KVMI_HOST_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 92314341b3a9..74fca566a44a 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -242,18 +242,71 @@ void kvmi_arch_hypercall_event(struct kvm_vcpu *vcpu)
 	}
 }
 
+/*
+ * Returns true if one side (kvm or kvmi) tries to enable/disable the breakpoint
+ * interception while the other side is still tracking it.
+ */
+bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg)
+{
+	struct kvmi_interception *arch_vcpui = READ_ONCE(vcpu->arch.kvmi);
+	u32 bp_mask = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
+	bool enable = false;
+
+	if ((dbg & bp_mask) == bp_mask)
+		enable = true;
+
+	return (arch_vcpui && arch_vcpui->breakpoint.monitor_fct(vcpu, enable));
+}
+EXPORT_SYMBOL(kvmi_monitor_bp_intercept);
+
+static bool monitor_bp_fct_kvmi(struct kvm_vcpu *vcpu, bool enable)
+{
+	if (enable) {
+		if (kvm_x86_ops->bp_intercepted(vcpu))
+			return true;
+	} else if (!vcpu->arch.kvmi->breakpoint.kvmi_intercepted)
+		return true;
+
+	vcpu->arch.kvmi->breakpoint.kvmi_intercepted = enable;
+
+	return false;
+}
+
+static bool monitor_bp_fct_kvm(struct kvm_vcpu *vcpu, bool enable)
+{
+	if (enable) {
+		if (kvm_x86_ops->bp_intercepted(vcpu))
+			return true;
+	} else if (!vcpu->arch.kvmi->breakpoint.kvm_intercepted)
+		return true;
+
+	vcpu->arch.kvmi->breakpoint.kvm_intercepted = enable;
+
+	return false;
+}
+
 static int kvmi_control_bp_intercept(struct kvm_vcpu *vcpu, bool enable)
 {
 	struct kvm_guest_debug dbg = {};
 	int err = 0;
 
+	vcpu->arch.kvmi->breakpoint.monitor_fct = monitor_bp_fct_kvmi;
 	if (enable)
 		dbg.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
 	err = kvm_arch_vcpu_set_guest_debug(vcpu, &dbg);
+	vcpu->arch.kvmi->breakpoint.monitor_fct = monitor_bp_fct_kvm;
 
 	return err;
 }
 
+static void kvmi_arch_disable_bp_intercept(struct kvm_vcpu *vcpu)
+{
+	kvmi_control_bp_intercept(vcpu, false);
+
+	vcpu->arch.kvmi->breakpoint.kvmi_intercepted = false;
+	vcpu->arch.kvmi->breakpoint.kvm_intercepted = false;
+}
+
 int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
 				    unsigned int event_id, bool enable)
 {
@@ -290,6 +343,50 @@ void kvmi_arch_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len)
 	}
 }
 
-void kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
+bool kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
 {
+	struct kvmi_interception *arch_vcpui = vcpu->arch.kvmi;
+
+	if (!arch_vcpui || !arch_vcpui->restore_interception)
+		return false;
+
+	kvmi_arch_disable_bp_intercept(vcpu);
+
+	return true;
+}
+
+bool kvmi_arch_vcpu_alloc(struct kvm_vcpu *vcpu)
+{
+	struct kvmi_interception *arch_vcpui;
+
+	arch_vcpui = kzalloc(sizeof(*arch_vcpui), GFP_KERNEL);
+	if (!arch_vcpui)
+		return false;
+
+	arch_vcpui->breakpoint.monitor_fct = monitor_bp_fct_kvm;
+
+	/* pair with kvmi_monitor_bp_intercept() */
+	smp_wmb();
+	WRITE_ONCE(vcpu->arch.kvmi, arch_vcpui);
+
+	return true;
+}
+
+void kvmi_arch_vcpu_free(struct kvm_vcpu *vcpu)
+{
+	kfree(vcpu->arch.kvmi);
+	WRITE_ONCE(vcpu->arch.kvmi, NULL);
+}
+
+bool kvmi_arch_vcpu_introspected(struct kvm_vcpu *vcpu)
+{
+	return !!READ_ONCE(vcpu->arch.kvmi);
+}
+
+void kvmi_arch_request_restore_interception(struct kvm_vcpu *vcpu)
+{
+	struct kvmi_interception *arch_vcpui = READ_ONCE(vcpu->arch.kvmi);
+
+	if (arch_vcpui)
+		arch_vcpui->restore_interception = true;
 }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bad66420f054..31273c4c7f8d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9169,6 +9169,11 @@ int kvm_arch_vcpu_set_guest_debug(struct kvm_vcpu *vcpu,
 			kvm_queue_exception(vcpu, BP_VECTOR);
 	}
 
+	if (kvmi_monitor_bp_intercept(vcpu, dbg->control)) {
+		r = -EBUSY;
+		goto out;
+	}
+
 	/*
 	 * Read rflags as long as potentially injected trace flags are still
 	 * filtered out.
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 32516cc70928..7ea0512bc580 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -167,7 +167,7 @@ static bool alloc_vcpui(struct kvm_vcpu *vcpu)
 
 	vcpu->kvmi = vcpui;
 
-	return true;
+	return kvmi_arch_vcpu_alloc(vcpu);
 }
 
 static int create_vcpui(struct kvm_vcpu *vcpu)
@@ -200,6 +200,7 @@ static void free_vcpui(struct kvm_vcpu *vcpu)
 	kfree(vcpui);
 	vcpu->kvmi = NULL;
 
+	kvmi_arch_request_restore_interception(vcpu);
 	kvmi_make_request(vcpu, false);
 }
 
@@ -219,6 +220,7 @@ void kvmi_vcpu_uninit(struct kvm_vcpu *vcpu)
 {
 	mutex_lock(&vcpu->kvm->kvmi_lock);
 	free_vcpui(vcpu);
+	kvmi_arch_vcpu_free(vcpu);
 	mutex_unlock(&vcpu->kvm->kvmi_lock);
 }
 
@@ -358,6 +360,21 @@ static int kvmi_recv_thread(void *arg)
 	return 0;
 }
 
+static bool ready_to_hook(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	if (kvm->kvmi)
+		return false;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		if (kvmi_arch_vcpu_introspected(vcpu))
+			return false;
+
+	return true;
+}
+
 int kvmi_hook(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 {
 	struct kvm_introspection *kvmi;
@@ -365,7 +382,7 @@ int kvmi_hook(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 
 	mutex_lock(&kvm->kvmi_lock);
 
-	if (kvm->kvmi) {
+	if (!ready_to_hook(kvm)) {
 		err = -EEXIST;
 		goto out;
 	}
@@ -806,7 +823,11 @@ void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 	kvmi_put(vcpu->kvm);
 
 out:
-	kvmi_arch_restore_interception(vcpu);
+	if (kvmi_arch_restore_interception(vcpu)) {
+		mutex_lock(&vcpu->kvm->kvmi_lock);
+		kvmi_arch_vcpu_free(vcpu);
+		mutex_unlock(&vcpu->kvm->kvmi_lock);
+	}
 }
 
 int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait)
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 0fc622b2c96d..7024bfa3df61 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -65,7 +65,11 @@ int kvmi_cmd_vcpu_set_registers(struct kvm_vcpu *vcpu,
 				const struct kvm_regs *regs);
 
 /* arch */
-void kvmi_arch_restore_interception(struct kvm_vcpu *vcpu);
+bool kvmi_arch_vcpu_alloc(struct kvm_vcpu *vcpu);
+void kvmi_arch_vcpu_free(struct kvm_vcpu *vcpu);
+bool kvmi_arch_vcpu_introspected(struct kvm_vcpu *vcpu);
+bool kvmi_arch_restore_interception(struct kvm_vcpu *vcpu);
+void kvmi_arch_request_restore_interception(struct kvm_vcpu *vcpu);
 int kvmi_arch_cmd_vcpu_get_info(struct kvm_vcpu *vcpu,
 				struct kvmi_vcpu_get_info_reply *rpl);
 void kvmi_arch_setup_event(struct kvm_vcpu *vcpu, struct kvmi_event *ev);

[PATCH v8 63/81] KVM: introspection: add KVMI_VCPU_CONTROL_CR and KVMI_EVENT_CR

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

Using the KVMI_VCPU_CONTROL_CR command, the introspection tool subscribes
to KVMI_EVENT_CR events that will be sent when CR{0,3,4} is going to
be changed.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  70 +++++++++++
 arch/x86/include/asm/kvmi_host.h              |  10 ++
 arch/x86/include/uapi/asm/kvmi.h              |  18 +++
 arch/x86/kvm/kvmi.c                           | 111 ++++++++++++++++++
 arch/x86/kvm/vmx/vmx.c                        |   6 +-
 arch/x86/kvm/x86.c                            |  12 +-
 include/uapi/linux/kvmi.h                     |   2 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  |  98 ++++++++++++++++
 virt/kvm/introspection/kvmi.c                 |   1 +
 virt/kvm/introspection/kvmi_int.h             |   7 ++
 virt/kvm/introspection/kvmi_msg.c             |  19 ++-
 11 files changed, 348 insertions(+), 6 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index b62cfdd61f89..c624ab59bd0e 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -547,6 +547,7 @@ Enables/disables vCPU introspection events. This command can be used with
 the following events::
 
 	KVMI_EVENT_BREAKPOINT
+	KVMI_EVENT_CR
 	KVMI_EVENT_HYPERCALL
 
 When an event is enabled, the introspection tool is notified and
@@ -680,6 +681,40 @@ Returns a CPUID leaf (as seen by the guest OS).
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 * -KVM_ENOENT - the selected leaf is not present or is invalid
 
+14. KVMI_VCPU_CONTROL_CR
+------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_control_cr {
+		__u16 cr;
+		__u8 enable;
+		__u8 padding1;
+		__u32 padding2;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Enables/disables introspection for a specific control register and must
+be used in addition to *KVMI_VCPU_CONTROL_EVENTS* with the *KVMI_EVENT_CR*
+ID set.
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the specified control register is not CR0, CR3 or CR4
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+
 Events
 ======
 
@@ -855,3 +890,38 @@ trying to perform a certain operation (like creating a process).
 ``kvmi_event`` and the guest physical address are sent to the introspection tool.
 
 The *RETRY* action is used by the introspection tool for its own breakpoints.
+
+5. KVMI_EVENT_CR
+----------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+	struct kvmi_event;
+	struct kvmi_event_cr {
+		__u16 cr;
+		__u16 padding[3];
+		__u64 old_value;
+		__u64 new_value;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+	struct kvmi_event_cr_reply {
+		__u64 new_val;
+	};
+
+This event is sent when a control register is going to be changed and the
+introspection has been enabled for this event and for this specific
+register (see **KVMI_VCPU_CONTROL_EVENTS**).
+
+``kvmi_event``, the control register number, the old value and the new value
+are sent to the introspection tool. The *CONTINUE* action will set the ``new_val``.
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index c8b793915b84..4ac209cb4ebf 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -2,6 +2,8 @@
 #ifndef _ASM_X86_KVMI_HOST_H
 #define _ASM_X86_KVMI_HOST_H
 
+#define KVMI_NUM_CR 5
+
 struct kvmi_monitor_interception {
 	bool kvmi_intercepted;
 	bool kvm_intercepted;
@@ -14,6 +16,7 @@ struct kvmi_interception {
 };
 
 struct kvm_vcpu_arch_introspection {
+	DECLARE_BITMAP(cr_mask, KVMI_NUM_CR);
 };
 
 struct kvm_arch_introspection {
@@ -22,11 +25,18 @@ struct kvm_arch_introspection {
 #ifdef CONFIG_KVM_INTROSPECTION
 
 bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg);
+bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
+		   unsigned long old_value, unsigned long *new_value);
+bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu);
 
 #else /* CONFIG_KVM_INTROSPECTION */
 
 static inline bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg)
 	{ return false; }
+static inline bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
+				 unsigned long old_value,
+				 unsigned long *new_value) { return true; }
+static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 1605777256a3..a3d29557cc15 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -65,4 +65,22 @@ struct kvmi_event_breakpoint {
 	__u8 padding[7];
 };
 
+struct kvmi_vcpu_control_cr {
+	__u16 cr;
+	__u8 enable;
+	__u8 padding1;
+	__u32 padding2;
+};
+
+struct kvmi_event_cr {
+	__u16 cr;
+	__u16 padding[3];
+	__u64 old_value;
+	__u64 new_value;
+};
+
+struct kvmi_event_cr_reply {
+	__u64 new_val;
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 74fca566a44a..2e00f0c530f2 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -390,3 +390,114 @@ void kvmi_arch_request_restore_interception(struct kvm_vcpu *vcpu)
 	if (arch_vcpui)
 		arch_vcpui->restore_interception = true;
 }
+
+int kvmi_arch_cmd_vcpu_control_cr(struct kvm_vcpu *vcpu,
+				  const struct kvmi_vcpu_control_cr *req)
+{
+	u32 cr = req->cr;
+
+	if (req->padding1 || req->padding2 || req->enable > 1)
+		return -KVM_EINVAL;
+
+	switch (cr) {
+	case 0:
+		break;
+	case 3:
+		kvm_x86_ops->control_cr3_intercept(vcpu, CR_TYPE_W,
+						   req->enable == 1);
+		break;
+	case 4:
+		break;
+	default:
+		return -KVM_EINVAL;
+	}
+
+	if (req->enable)
+		set_bit(cr, VCPUI(vcpu)->arch.cr_mask);
+	else
+		clear_bit(cr, VCPUI(vcpu)->arch.cr_mask);
+
+	return 0;
+}
+
+static u32 kvmi_send_cr(struct kvm_vcpu *vcpu, u32 cr, u64 old_value,
+			u64 new_value, u64 *ret_value)
+{
+	struct kvmi_event_cr e;
+	struct kvmi_event_cr_reply r;
+	int err, action;
+
+	memset(&e, 0, sizeof(e));
+	e.cr = cr;
+	e.old_value = old_value;
+	e.new_value = new_value;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_CR, &e, sizeof(e),
+			      &r, sizeof(r), &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	*ret_value = r.new_val;
+	return action;
+}
+
+static bool __kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
+			    unsigned long old_value, unsigned long *new_value)
+{
+	u64 ret_value = *new_value;
+	bool ret = false;
+	u32 action;
+
+	if (!test_bit(cr, VCPUI(vcpu)->arch.cr_mask))
+		return true;
+
+	action = kvmi_send_cr(vcpu, cr, old_value, *new_value, &ret_value);
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		*new_value = ret_value;
+		ret = true;
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action, "CR");
+	}
+
+	return ret;
+}
+
+bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
+		   unsigned long old_value, unsigned long *new_value)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = true;
+
+	if (old_value == *new_value)
+		return true;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return true;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_CR))
+		ret = __kvmi_cr_event(vcpu, cr, old_value, new_value);
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
+
+bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu)
+{
+	struct kvm_introspection *kvmi;
+	bool ret;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return false;
+
+	ret = test_bit(3, VCPUI(vcpu)->arch.cr_mask);
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
+EXPORT_SYMBOL(kvmi_cr3_intercepted);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 4b7044193917..ff705b4eee19 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4885,7 +4885,8 @@ static int handle_cr(struct kvm_vcpu *vcpu)
 			err = handle_set_cr0(vcpu, val);
 			return kvm_complete_insn_gp(vcpu, err);
 		case 3:
-			WARN_ON_ONCE(enable_unrestricted_guest);
+			WARN_ON_ONCE(enable_unrestricted_guest &&
+				     !kvmi_cr3_intercepted(vcpu));
 			err = kvm_set_cr3(vcpu, val);
 			return kvm_complete_insn_gp(vcpu, err);
 		case 4:
@@ -4918,7 +4919,8 @@ static int handle_cr(struct kvm_vcpu *vcpu)
 	case 1: /*mov from cr*/
 		switch (cr) {
 		case 3:
-			WARN_ON_ONCE(enable_unrestricted_guest);
+			WARN_ON_ONCE(enable_unrestricted_guest &&
+				     !kvmi_cr3_intercepted(vcpu));
 			val = kvm_read_cr3(vcpu);
 			kvm_register_write(vcpu, reg, val);
 			trace_kvm_cr_read(cr, val);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 31273c4c7f8d..5b88540384b4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -773,6 +773,9 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 	if (!(cr0 & X86_CR0_PG) && kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE))
 		return 1;
 
+	if (!kvmi_cr_event(vcpu, 0, old_cr0, &cr0))
+		return 1;
+
 	kvm_x86_ops->set_cr0(vcpu, cr0);
 
 	if ((cr0 ^ old_cr0) & X86_CR0_PG) {
@@ -950,6 +953,9 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 			return 1;
 	}
 
+	if (!kvmi_cr_event(vcpu, 4, old_cr4, &cr4))
+		return 1;
+
 	if (kvm_x86_ops->set_cr4(vcpu, cr4))
 		return 1;
 
@@ -966,6 +972,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cr4);
 
 int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
+	unsigned long old_cr3 = kvm_read_cr3(vcpu);
 	bool skip_tlb_flush = false;
 #ifdef CONFIG_X86_64
 	bool pcid_enabled = kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE);
@@ -976,7 +983,7 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 	}
 #endif
 
-	if (cr3 == kvm_read_cr3(vcpu) && !pdptrs_changed(vcpu)) {
+	if (cr3 == old_cr3 && !pdptrs_changed(vcpu)) {
 		if (!skip_tlb_flush) {
 			kvm_mmu_sync_roots(vcpu);
 			kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
@@ -991,6 +998,9 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 		 !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
 		return 1;
 
+	if (!kvmi_cr_event(vcpu, 3, old_cr3, &cr3))
+		return 1;
+
 	kvm_mmu_new_cr3(vcpu, cr3, skip_tlb_flush);
 	vcpu->arch.cr3 = cr3;
 	kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index f6792d41b02f..2826ac0f74e5 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -31,6 +31,7 @@ enum {
 	KVMI_VCPU_GET_REGISTERS  = 12,
 	KVMI_VCPU_SET_REGISTERS  = 13,
 	KVMI_VCPU_GET_CPUID      = 14,
+	KVMI_VCPU_CONTROL_CR     = 15,
 
 	KVMI_NUM_MESSAGES
 };
@@ -40,6 +41,7 @@ enum {
 	KVMI_EVENT_PAUSE_VCPU = 1,
 	KVMI_EVENT_HYPERCALL  = 2,
 	KVMI_EVENT_BREAKPOINT = 3,
+	KVMI_EVENT_CR         = 4,
 
 	KVMI_NUM_EVENTS
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index dab015555f89..9595e86cd79e 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -50,6 +50,7 @@ struct vcpu_worker_data {
 enum {
 	GUEST_TEST_NOOP = 0,
 	GUEST_TEST_BP,
+	GUEST_TEST_CR,
 	GUEST_TEST_HYPERCALL,
 };
 
@@ -69,6 +70,11 @@ static void guest_bp_test(void)
 	asm volatile("int3");
 }
 
+static void guest_cr_test(void)
+{
+	set_cr4(get_cr4() | X86_CR4_OSXSAVE);
+}
+
 static void guest_hypercall_test(void)
 {
 	asm volatile("mov $34, %rax");
@@ -86,6 +92,9 @@ static void guest_code(void)
 		case GUEST_TEST_BP:
 			guest_bp_test();
 			break;
+		case GUEST_TEST_CR:
+			guest_cr_test();
+			break;
 		case GUEST_TEST_HYPERCALL:
 			guest_hypercall_test();
 			break;
@@ -1029,6 +1038,94 @@ static void test_event_breakpoint(struct kvm_vm *vm)
 	disable_vcpu_event(vm, event_id);
 }
 
+static int cmd_control_cr(struct kvm_vm *vm, __u32 cr, bool enable)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_control_cr cmd;
+	} req = {};
+
+	req.cmd.cr = cr;
+	req.cmd.enable = enable ? 1 : 0;
+
+	return do_vcpu0_command(vm, KVMI_VCPU_CONTROL_CR, &req.hdr, sizeof(req),
+				NULL, 0);
+}
+
+static void enable_cr_events(struct kvm_vm *vm, __u32 cr)
+{
+	int r;
+
+	enable_vcpu_event(vm, KVMI_EVENT_CR);
+
+	r = cmd_control_cr(vm, cr, true);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_CONTROL_CR failed, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+}
+
+static void disable_cr_events(struct kvm_vm *vm, __u32 cr)
+{
+	int r;
+
+	r = cmd_control_cr(vm, cr, false);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_CONTROL_CR failed, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+
+	disable_vcpu_event(vm, KVMI_EVENT_CR);
+}
+
+static void test_cmd_vcpu_control_cr(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = {
+		.vm = vm,
+		.vcpu_id = VCPU_ID,
+		.test_id = GUEST_TEST_CR,
+	};
+	struct kvmi_msg_hdr hdr;
+	struct {
+		struct kvmi_event common;
+		struct kvmi_event_cr cr;
+	} ev;
+	struct {
+		struct vcpu_reply common;
+		struct kvmi_event_cr_reply cr;
+	} rpl = {};
+	__u16 event_id = KVMI_EVENT_CR;
+	__u32 cr_no = 4;
+	struct kvm_sregs sregs;
+	pthread_t vcpu_thread;
+
+	enable_cr_events(vm, cr_no);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	receive_event(&hdr, &ev.common, sizeof(ev), event_id);
+
+	DEBUG("CR%u, old 0x%llx, new 0x%llx\n",
+		ev.cr.cr, ev.cr.old_value, ev.cr.new_value);
+
+	TEST_ASSERT(ev.cr.cr == cr_no,
+		"Unexpected CR event, received CR%u, expected CR%u",
+		ev.cr.cr, cr_no);
+
+	rpl.cr.new_val = ev.cr.old_value;
+
+	reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl.common, sizeof(rpl));
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	disable_cr_events(vm, cr_no);
+
+	vcpu_sregs_get(vm, VCPU_ID, &sregs);
+	TEST_ASSERT(sregs.cr4 == ev.cr.old_value,
+		"Failed to block CR4 update, CR4 0x%x, expected 0x%x",
+		sregs.cr4, ev.cr.old_value);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1051,6 +1148,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_get_cpuid(vm);
 	test_event_hypercall(vm);
 	test_event_breakpoint(vm);
+	test_cmd_vcpu_control_cr(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 7ea0512bc580..6d421cf213d7 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -79,6 +79,7 @@ static void setup_known_events(void)
 
 	bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 	set_bit(KVMI_EVENT_BREAKPOINT, Kvmi_known_vcpu_events);
+	set_bit(KVMI_EVENT_CR, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
 
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 7024bfa3df61..588a386a3f37 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -33,6 +33,9 @@ bool kvmi_sock_get(struct kvm_introspection *kvmi, int fd);
 void kvmi_sock_shutdown(struct kvm_introspection *kvmi);
 void kvmi_sock_put(struct kvm_introspection *kvmi);
 bool kvmi_msg_process(struct kvm_introspection *kvmi);
+int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
+		    void *ev, size_t ev_size,
+		    void *rpl, size_t rpl_size, int *action);
 int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
 u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
 u32 kvmi_msg_send_hypercall(struct kvm_vcpu *vcpu);
@@ -49,6 +52,8 @@ void kvmi_run_jobs(struct kvm_vcpu *vcpu);
 void kvmi_post_reply(struct kvm_vcpu *vcpu);
 void kvmi_handle_common_event_actions(struct kvm *kvm,
 				      u32 action, const char *str);
+struct kvm_introspection * __must_check kvmi_get(struct kvm *kvm);
+void kvmi_put(struct kvm *kvm);
 int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 				unsigned int event_id, bool enable);
 int kvmi_cmd_vcpu_control_events(struct kvm_vcpu *vcpu,
@@ -88,5 +93,7 @@ void kvmi_arch_hypercall_event(struct kvm_vcpu *vcpu);
 void kvmi_arch_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len);
 int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
 				    unsigned int event_id, bool enable);
+int kvmi_arch_cmd_vcpu_control_cr(struct kvm_vcpu *vcpu,
+				  const struct kvmi_vcpu_control_cr *req);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 8e451ad534e4..789aa9f1912f 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -28,6 +28,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VM_GET_INFO]         = "KVMI_VM_GET_INFO",
 	[KVMI_VM_READ_PHYSICAL]    = "KVMI_VM_READ_PHYSICAL",
 	[KVMI_VM_WRITE_PHYSICAL]   = "KVMI_VM_WRITE_PHYSICAL",
+	[KVMI_VCPU_CONTROL_CR]     = "KVMI_VCPU_CONTROL_CR",
 	[KVMI_VCPU_CONTROL_EVENTS] = "KVMI_VCPU_CONTROL_EVENTS",
 	[KVMI_VCPU_GET_CPUID]      = "KVMI_VCPU_GET_CPUID",
 	[KVMI_VCPU_GET_INFO]       = "KVMI_VCPU_GET_INFO",
@@ -514,6 +515,17 @@ static int handle_get_cpuid(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, ec, &rpl, sizeof(rpl));
 }
 
+static int handle_vcpu_control_cr(const struct kvmi_vcpu_cmd_job *job,
+				  const struct kvmi_msg_hdr *msg,
+				  const void *req)
+{
+	int ec;
+
+	ec = kvmi_arch_cmd_vcpu_control_cr(job->vcpu, req);
+
+	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -523,6 +535,7 @@ static int handle_get_cpuid(const struct kvmi_vcpu_cmd_job *job,
 static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 			      const struct kvmi_msg_hdr *, const void *) = {
 	[KVMI_EVENT]               = handle_event_reply,
+	[KVMI_VCPU_CONTROL_CR]     = handle_vcpu_control_cr,
 	[KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events,
 	[KVMI_VCPU_GET_CPUID]      = handle_get_cpuid,
 	[KVMI_VCPU_GET_INFO]       = handle_get_vcpu_info,
@@ -784,9 +797,9 @@ static void kvmi_setup_vcpu_reply(struct kvm_vcpu_introspection *vcpui,
 	vcpui->waiting_for_reply = true;
 }
 
-static int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
-			   void *ev, size_t ev_size,
-			   void *rpl, size_t rpl_size, int *action)
+int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
+		    void *ev, size_t ev_size,
+		    void *rpl, size_t rpl_size, int *action)
 {
 	struct kvmi_msg_hdr hdr;
 	struct kvmi_event common;

[PATCH v8 64/81] KVM: introspection: restore the state of CR3 interception on unhook

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This commit also ensures that the introspection tool and the userspace
do not disable each other the CR3-write VM-exit.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvmi_host.h |  4 ++
 arch/x86/kvm/kvmi.c              | 64 ++++++++++++++++++++++++++++++--
 arch/x86/kvm/svm.c               |  5 +++
 arch/x86/kvm/vmx/vmx.c           |  5 +++
 4 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 4ac209cb4ebf..24f3f8fdee62 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -13,6 +13,7 @@ struct kvmi_monitor_interception {
 struct kvmi_interception {
 	bool restore_interception;
 	struct kvmi_monitor_interception breakpoint;
+	struct kvmi_monitor_interception cr3w;
 };
 
 struct kvm_vcpu_arch_introspection {
@@ -28,6 +29,7 @@ bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg);
 bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
 		   unsigned long old_value, unsigned long *new_value);
 bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu);
+bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable);
 
 #else /* CONFIG_KVM_INTROSPECTION */
 
@@ -37,6 +39,8 @@ static inline bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
 				 unsigned long old_value,
 				 unsigned long *new_value) { return true; }
 static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; }
+static inline bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu,
+						bool enable) { return false; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 2e00f0c530f2..281ebb47eaa2 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -307,6 +307,59 @@ static void kvmi_arch_disable_bp_intercept(struct kvm_vcpu *vcpu)
 	vcpu->arch.kvmi->breakpoint.kvm_intercepted = false;
 }
 
+static bool monitor_cr3w_fct_kvmi(struct kvm_vcpu *vcpu, bool enable)
+{
+	vcpu->arch.kvmi->cr3w.kvmi_intercepted = enable;
+
+	if (enable)
+		vcpu->arch.kvmi->cr3w.kvm_intercepted =
+			kvm_x86_ops->cr3_write_intercepted(vcpu);
+	else if (vcpu->arch.kvmi->cr3w.kvm_intercepted)
+		return true;
+
+	return false;
+}
+
+static bool monitor_cr3w_fct_kvm(struct kvm_vcpu *vcpu, bool enable)
+{
+	if (!vcpu->arch.kvmi->cr3w.kvmi_intercepted)
+		return false;
+
+	vcpu->arch.kvmi->cr3w.kvm_intercepted = enable;
+
+	if (!enable)
+		return true;
+
+	return false;
+}
+
+/*
+ * Returns true if one side (kvm or kvmi) tries to disable the CR3 write
+ * interception while the other side is still tracking it.
+ */
+bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable)
+{
+	struct kvmi_interception *arch_vcpui = READ_ONCE(vcpu->arch.kvmi);
+
+	return (arch_vcpui && arch_vcpui->cr3w.monitor_fct(vcpu, enable));
+}
+EXPORT_SYMBOL(kvmi_monitor_cr3w_intercept);
+
+static void kvmi_control_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable)
+{
+	vcpu->arch.kvmi->cr3w.monitor_fct = monitor_cr3w_fct_kvmi;
+	kvm_x86_ops->control_cr3_intercept(vcpu, CR_TYPE_W, enable);
+	vcpu->arch.kvmi->cr3w.monitor_fct = monitor_cr3w_fct_kvm;
+}
+
+static void kvmi_arch_disable_cr3w_intercept(struct kvm_vcpu *vcpu)
+{
+	kvmi_control_cr3w_intercept(vcpu, false);
+
+	vcpu->arch.kvmi->cr3w.kvmi_intercepted = false;
+	vcpu->arch.kvmi->cr3w.kvm_intercepted = false;
+}
+
 int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
 				    unsigned int event_id, bool enable)
 {
@@ -351,6 +404,7 @@ bool kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
 		return false;
 
 	kvmi_arch_disable_bp_intercept(vcpu);
+	kvmi_arch_disable_cr3w_intercept(vcpu);
 
 	return true;
 }
@@ -364,8 +418,13 @@ bool kvmi_arch_vcpu_alloc(struct kvm_vcpu *vcpu)
 		return false;
 
 	arch_vcpui->breakpoint.monitor_fct = monitor_bp_fct_kvm;
+	arch_vcpui->cr3w.monitor_fct = monitor_cr3w_fct_kvm;
 
-	/* pair with kvmi_monitor_bp_intercept() */
+	/*
+	 * paired with:
+	 *  - kvmi_monitor_bp_intercept()
+	 *  - kvmi_monitor_cr3w_intercept()
+	 */
 	smp_wmb();
 	WRITE_ONCE(vcpu->arch.kvmi, arch_vcpui);
 
@@ -403,8 +462,7 @@ int kvmi_arch_cmd_vcpu_control_cr(struct kvm_vcpu *vcpu,
 	case 0:
 		break;
 	case 3:
-		kvm_x86_ops->control_cr3_intercept(vcpu, CR_TYPE_W,
-						   req->enable == 1);
+		kvmi_control_cr3w_intercept(vcpu, req->enable == 1);
 		break;
 	case 4:
 		break;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 05c64318a8df..1021ff2f9e57 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7497,6 +7497,11 @@ static void svm_control_cr3_intercept(struct kvm_vcpu *vcpu, int type,
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
+#ifdef CONFIG_KVM_INTROSPECTION
+	if ((type & CR_TYPE_W) && kvmi_monitor_cr3w_intercept(vcpu, enable))
+		type &= ~CR_TYPE_W;
+#endif /* CONFIG_KVM_INTROSPECTION */
+
 	if (type & CR_TYPE_R)
 		enable ? set_cr_intercept(svm, INTERCEPT_CR3_READ) :
 			 clr_cr_intercept(svm, INTERCEPT_CR3_READ);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ff705b4eee19..f6180ecf15ba 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2940,6 +2940,11 @@ static void vmx_control_cr3_intercept(struct kvm_vcpu *vcpu, int type,
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	u32 cr3_exec_control = 0;
 
+#ifdef CONFIG_KVM_INTROSPECTION
+	if ((type & CR_TYPE_W) && kvmi_monitor_cr3w_intercept(vcpu, enable))
+		type &= ~CR_TYPE_W;
+#endif /* CONFIG_KVM_INTROSPECTION */
+
 	if (type & CR_TYPE_R)
 		cr3_exec_control |= CPU_BASED_CR3_STORE_EXITING;
 	if (type & CR_TYPE_W)

[PATCH v8 65/81] KVM: introspection: add KVMI_VCPU_INJECT_EXCEPTION + KVMI_EVENT_TRAP

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

The KVMI_VCPU_INJECT_EXCEPTION command is used by the introspection tool
to inject exceptions, for example, to get a page from swap.

The exception is queued right before entering the guest unless there is
already an exception pending. The introspection tool is notified with
an KVMI_EVENT_TRAP event about the success of the injection.  In case
of failure, the introspecion tool is expected to try again later.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  74 ++++++++++++
 arch/x86/include/uapi/asm/kvmi.h              |  14 +++
 arch/x86/kvm/kvmi.c                           | 103 +++++++++++++++++
 arch/x86/kvm/x86.c                            |   3 +
 include/linux/kvmi_host.h                     |  12 ++
 include/uapi/linux/kvmi.h                     |  16 +--
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 109 +++++++++++++++++-
 virt/kvm/introspection/kvmi.c                 |  46 ++++++++
 virt/kvm/introspection/kvmi_int.h             |   8 ++
 virt/kvm/introspection/kvmi_msg.c             |  81 +++++++++----
 10 files changed, 433 insertions(+), 33 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index c624ab59bd0e..d6a09fac4f52 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -557,6 +557,7 @@ The following vCPU events do not need to be enabled or disabled,
 because these are sent as a result of certain commands::
 
 	KVMI_EVENT_PAUSE_VCPU
+	KVMI_EVENT_TRAP
 
 However, the events mentioned above can be disallowed.
 
@@ -715,6 +716,46 @@ ID set.
 * -KVM_EINVAL - the padding is not zero
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 
+15. KVMI_VCPU_INJECT_EXCEPTION
+------------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_inject_exception {
+		__u8 nr;
+		__u8 padding1;
+		__u16 padding2;
+		__u32 error_code;
+		__u64 address;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Injects a vCPU exception with or without an error code. In case of page fault
+exception, the guest virtual address has to be specified.
+
+The *KVMI_EVENT_TRAP* event will be sent with the effective injected expection.
+
+:Errors:
+
+* -KVM_EPERM  - the *KVMI_EVENT_TRAP* event is disallowed
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the specified exception number is invalid
+* -KVM_EINVAL - the specified address is invalid
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_EBUSY - another *KVMI_VCPU_INJECT_EXCEPTION*-*KVMI_EVENT_TRAP* pair
+               is in progress
+
 Events
 ======
 
@@ -925,3 +966,36 @@ register (see **KVMI_VCPU_CONTROL_EVENTS**).
 
 ``kvmi_event``, the control register number, the old value and the new value
 are sent to the introspection tool. The *CONTINUE* action will set the ``new_val``.
+
+6. KVMI_EVENT_TRAP
+------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+	struct kvmi_event;
+	struct kvmi_event_trap {
+		__u32 vector;
+		__u32 error_code;
+		__u64 cr2;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+
+This event is sent if a previous *KVMI_VCPU_INJECT_EXCEPTION* command
+took place. Because it has a high priority, it will be sent before any
+other vCPU introspection event.
+
+``kvmi_event``, exception/interrupt number (vector), exception code
+(``error_code``) and CR2 are sent to the introspection tool,
+which should check if its exception has been injected or overridden.
+
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index a3d29557cc15..073dbaac06b1 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -83,4 +83,18 @@ struct kvmi_event_cr_reply {
 	__u64 new_val;
 };
 
+struct kvmi_event_trap {
+	__u32 vector;
+	__u32 error_code;
+	__u64 cr2;
+};
+
+struct kvmi_vcpu_inject_exception {
+	__u8 nr;
+	__u8 padding1;
+	__u16 padding2;
+	__u32 error_code;
+	__u64 address;
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 281ebb47eaa2..9f8ef8a1a306 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -559,3 +559,106 @@ bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu)
 	return ret;
 }
 EXPORT_SYMBOL(kvmi_cr3_intercepted);
+
+int kvmi_arch_cmd_vcpu_inject_exception(struct kvm_vcpu *vcpu, u8 vector,
+					u32 error_code, u64 address)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+	bool has_error;
+
+	if (vcpui->exception.pending || vcpui->exception.send_event)
+		return -KVM_EBUSY;
+
+	vcpui->exception.pending = true;
+
+	has_error = x86_exception_has_error_code(vector);
+
+	vcpui->exception.nr = vector;
+	vcpui->exception.error_code = has_error ? error_code : 0;
+	vcpui->exception.error_code_valid = has_error;
+	vcpui->exception.address = address;
+
+	return 0;
+}
+
+static void kvmi_arch_queue_exception(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+	struct x86_exception e = {
+		.vector = vcpui->exception.nr,
+		.error_code_valid = vcpui->exception.error_code_valid,
+		.error_code = vcpui->exception.error_code,
+		.address = vcpui->exception.address,
+	};
+
+	if (e.vector == PF_VECTOR)
+		kvm_inject_page_fault(vcpu, &e);
+	else if (e.error_code_valid)
+		kvm_queue_exception_e(vcpu, e.vector, e.error_code);
+	else
+		kvm_queue_exception(vcpu, e.vector);
+}
+
+static void kvmi_arch_save_injected_event(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	vcpui->exception.error_code = 0;
+	vcpui->exception.error_code_valid = false;
+
+	vcpui->exception.address = vcpu->arch.cr2;
+	if (vcpu->arch.exception.injected) {
+		vcpui->exception.nr = vcpu->arch.exception.nr;
+		vcpui->exception.error_code_valid =
+			x86_exception_has_error_code(vcpu->arch.exception.nr);
+		vcpui->exception.error_code = vcpu->arch.exception.error_code;
+	} else if (vcpu->arch.interrupt.injected) {
+		vcpui->exception.nr = vcpu->arch.interrupt.nr;
+	}
+}
+
+void kvmi_arch_inject_exception(struct kvm_vcpu *vcpu)
+{
+	if (!kvm_event_needs_reinjection(vcpu)) {
+		kvmi_arch_queue_exception(vcpu);
+		kvm_inject_pending_exception(vcpu);
+	}
+
+	kvmi_arch_save_injected_event(vcpu);
+}
+
+static u32 kvmi_send_trap(struct kvm_vcpu *vcpu, u8 vector,
+			  u32 error_code, u64 cr2)
+{
+	struct kvmi_event_trap e;
+	int err, action;
+
+	memset(&e, 0, sizeof(e));
+	e.vector = vector;
+	e.error_code = error_code;
+	e.cr2 = cr2;
+
+	err = __kvmi_send_event(vcpu, KVMI_EVENT_TRAP, &e, sizeof(e),
+				NULL, 0, &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	return action;
+}
+
+void kvmi_arch_trap_event(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+	u32 action;
+
+	action = kvmi_send_trap(vcpu, vcpui->exception.nr,
+				vcpui->exception.error_code,
+				vcpui->exception.address);
+
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action, "TRAP");
+	}
+}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5b88540384b4..0e3704bed6c4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8408,6 +8408,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		goto cancel_injection;
 	}
 
+	if (!kvmi_enter_guest(vcpu))
+		req_immediate_exit = true;
+
 	if (req_immediate_exit) {
 		kvm_make_request(KVM_REQ_EVENT, vcpu);
 		kvm_x86_ops->request_immediate_exit(vcpu);
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 8f28065320d8..e64f2bbd033a 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -41,6 +41,15 @@ struct kvm_vcpu_introspection {
 
 	struct kvm_regs delayed_regs;
 	bool have_delayed_regs;
+
+	struct {
+		u8 nr;
+		u32 error_code;
+		bool error_code_valid;
+		u64 address;
+		bool pending;
+		bool send_event;
+	} exception;
 };
 
 struct kvm_introspection {
@@ -77,6 +86,7 @@ int kvmi_ioctl_preunhook(struct kvm *kvm);
 void kvmi_handle_requests(struct kvm_vcpu *vcpu);
 bool kvmi_hypercall_event(struct kvm_vcpu *vcpu);
 bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len);
+bool kvmi_enter_guest(struct kvm_vcpu *vcpu);
 
 #else
 
@@ -91,6 +101,8 @@ static inline bool kvmi_hypercall_event(struct kvm_vcpu *vcpu) { return false; }
 static inline bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva,
 					 u8 insn_len)
 			{ return true; }
+static inline bool kvmi_enter_guest(struct kvm_vcpu *vcpu)
+			{ return true; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 2826ac0f74e5..2603fa72154b 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -25,13 +25,14 @@ enum {
 	KVMI_VM_READ_PHYSICAL    = 7,
 	KVMI_VM_WRITE_PHYSICAL   = 8,
 
-	KVMI_VCPU_GET_INFO       = 9,
-	KVMI_VCPU_PAUSE          = 10,
-	KVMI_VCPU_CONTROL_EVENTS = 11,
-	KVMI_VCPU_GET_REGISTERS  = 12,
-	KVMI_VCPU_SET_REGISTERS  = 13,
-	KVMI_VCPU_GET_CPUID      = 14,
-	KVMI_VCPU_CONTROL_CR     = 15,
+	KVMI_VCPU_GET_INFO         = 9,
+	KVMI_VCPU_PAUSE            = 10,
+	KVMI_VCPU_CONTROL_EVENTS   = 11,
+	KVMI_VCPU_GET_REGISTERS    = 12,
+	KVMI_VCPU_SET_REGISTERS    = 13,
+	KVMI_VCPU_GET_CPUID        = 14,
+	KVMI_VCPU_CONTROL_CR       = 15,
+	KVMI_VCPU_INJECT_EXCEPTION = 16,
 
 	KVMI_NUM_MESSAGES
 };
@@ -42,6 +43,7 @@ enum {
 	KVMI_EVENT_HYPERCALL  = 2,
 	KVMI_EVENT_BREAKPOINT = 3,
 	KVMI_EVENT_CR         = 4,
+	KVMI_EVENT_TRAP       = 5,
 
 	KVMI_NUM_EVENTS
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 9595e86cd79e..6a6ad736db36 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -45,6 +45,8 @@ struct vcpu_worker_data {
 	int vcpu_id;
 	int test_id;
 	bool stop;
+	bool shutdown;
+	bool restart_on_shutdown;
 };
 
 enum {
@@ -603,11 +605,19 @@ static void *vcpu_worker(void *data)
 
 		vcpu_run(ctx->vm, ctx->vcpu_id);
 
-		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO
+			|| (run->exit_reason == KVM_EXIT_SHUTDOWN
+				&& ctx->shutdown),
 			"vcpu_run() failed, test_id %d, exit reason %u (%s)\n",
 			ctx->test_id, run->exit_reason,
 			exit_reason_str(run->exit_reason));
 
+		if (run->exit_reason == KVM_EXIT_SHUTDOWN) {
+			if (ctx->restart_on_shutdown)
+				continue;
+			break;
+		}
+
 		TEST_ASSERT(get_ucall(ctx->vm, ctx->vcpu_id, &uc),
 			"No guest request\n");
 
@@ -1126,6 +1136,102 @@ static void test_cmd_vcpu_control_cr(struct kvm_vm *vm)
 		sregs.cr4, ev.cr.old_value);
 }
 
+static void __inject_exception(struct kvm_vm *vm, int vector)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_inject_exception cmd;
+	} req = {};
+	__u16 vcpu_index = 0;
+	int r;
+
+	req.vcpu_hdr.vcpu = vcpu_index;
+	req.cmd.nr = vector;
+
+	r = do_command(KVMI_VCPU_INJECT_EXCEPTION,
+			&req.hdr, sizeof(req), NULL, 0);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_INJECT_EXCEPTION failed, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+}
+
+static void receive_exception_event(struct kvm_vm *vm, int vector)
+{
+	struct kvmi_msg_hdr hdr;
+	struct {
+		struct kvmi_event common;
+		struct kvmi_event_trap trap;
+	} ev;
+	struct vcpu_reply rpl = {};
+
+	receive_event(&hdr, &ev.common, sizeof(ev), KVMI_EVENT_TRAP);
+
+	DEBUG("Exception event: vector %u, error_code 0x%x, cr2 0x%llx\n",
+		ev.trap.vector, ev.trap.error_code, ev.trap.cr2);
+
+	TEST_ASSERT(ev.trap.vector == vector,
+		"Injected exception %u instead of %u\n",
+		ev.trap.vector, vector);
+
+	reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+}
+
+static void test_cmd_vcpu_inject_exception(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = {
+		.vm = vm,
+		.vcpu_id = VCPU_ID,
+		.shutdown = true,
+		.restart_on_shutdown = true,
+	};
+	struct kvmi_msg_hdr hdr;
+	struct {
+		struct kvmi_event common;
+		struct kvmi_event_breakpoint bp;
+	} ev;
+	struct vcpu_reply rpl = {};
+	pthread_t vcpu_thread;
+	__u8 ud_vector = 6;
+	__u8 bp_vector = 3;
+
+	if (!is_intel_cpu()) {
+		DEBUG("TODO: %s() - make it work with AMD\n", __func__);
+		return;
+	}
+
+	enable_vcpu_event(vm, KVMI_EVENT_BREAKPOINT);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	__inject_exception(vm, ud_vector);
+
+	/* confirm that our exception has been injected */
+	receive_exception_event(vm, ud_vector);
+
+	WRITE_ONCE(data.test_id, GUEST_TEST_BP);
+
+	receive_event(&hdr, &ev.common, sizeof(ev), KVMI_EVENT_BREAKPOINT);
+
+	__inject_exception(vm, ud_vector);
+
+	/* skip the breakpoint instruction, next time guest_bp_test() runs */
+	ev.common.arch.regs.rip += ev.bp.insn_len;
+	__set_registers(vm, &ev.common.arch.regs);
+
+	/* reinject the #BP exception */
+	reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+
+	/* confirm that our injection didn't override the #BP exception */
+	receive_exception_event(vm, bp_vector);
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	disable_vcpu_event(vm, KVMI_EVENT_BREAKPOINT);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1149,6 +1255,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_event_hypercall(vm);
 	test_event_breakpoint(vm);
 	test_cmd_vcpu_control_cr(vm);
+	test_cmd_vcpu_inject_exception(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 6d421cf213d7..0f2cec7e9c90 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -82,6 +82,7 @@ static void setup_known_events(void)
 	set_bit(KVMI_EVENT_CR, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
+	set_bit(KVMI_EVENT_TRAP, Kvmi_known_vcpu_events);
 
 	bitmap_or(Kvmi_known_events, Kvmi_known_vm_events,
 		  Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
@@ -803,6 +804,16 @@ static void kvmi_vcpu_pause_event(struct kvm_vcpu *vcpu)
 	}
 }
 
+void kvmi_send_pending_event(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	if (vcpui->exception.send_event) {
+		kvmi_arch_trap_event(vcpu);
+		vcpui->exception.send_event = false;
+	}
+}
+
 void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 {
 	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
@@ -812,6 +823,8 @@ void kvmi_handle_requests(struct kvm_vcpu *vcpu)
 	if (!kvmi)
 		goto out;
 
+	kvmi_send_pending_event(vcpu);
+
 	for (;;) {
 		kvmi_run_jobs(vcpu);
 
@@ -910,3 +923,36 @@ bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len)
 	return ret;
 }
 EXPORT_SYMBOL(kvmi_breakpoint_event);
+
+static bool kvmi_inject_pending_exception(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu);
+
+	if (!vcpui->exception.pending)
+		return false;
+
+	kvmi_arch_inject_exception(vcpu);
+
+	vcpui->exception.send_event = true;
+	kvm_make_request(KVM_REQ_INTROSPECTION, vcpu);
+
+	vcpui->exception.pending = false;
+
+	return true;
+}
+
+bool kvmi_enter_guest(struct kvm_vcpu *vcpu)
+{
+	struct kvm_introspection *kvmi;
+	bool r = true;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return true;
+
+	if (kvmi_inject_pending_exception(vcpu))
+		r = false;
+
+	kvmi_put(vcpu->kvm);
+	return r;
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 588a386a3f37..59a8b20af0fd 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -36,6 +36,9 @@ bool kvmi_msg_process(struct kvm_introspection *kvmi);
 int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
 		    void *ev, size_t ev_size,
 		    void *rpl, size_t rpl_size, int *action);
+int __kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
+		      void *ev, size_t ev_size,
+		      void *rpl, size_t rpl_size, int *action);
 int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
 u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
 u32 kvmi_msg_send_hypercall(struct kvm_vcpu *vcpu);
@@ -54,6 +57,7 @@ void kvmi_handle_common_event_actions(struct kvm *kvm,
 				      u32 action, const char *str);
 struct kvm_introspection * __must_check kvmi_get(struct kvm *kvm);
 void kvmi_put(struct kvm *kvm);
+void kvmi_send_pending_event(struct kvm_vcpu *vcpu);
 int kvmi_cmd_vm_control_events(struct kvm_introspection *kvmi,
 				unsigned int event_id, bool enable);
 int kvmi_cmd_vcpu_control_events(struct kvm_vcpu *vcpu,
@@ -95,5 +99,9 @@ int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
 				    unsigned int event_id, bool enable);
 int kvmi_arch_cmd_vcpu_control_cr(struct kvm_vcpu *vcpu,
 				  const struct kvmi_vcpu_control_cr *req);
+int kvmi_arch_cmd_vcpu_inject_exception(struct kvm_vcpu *vcpu, u8 vector,
+					u32 error_code, u64 address);
+void kvmi_arch_trap_event(struct kvm_vcpu *vcpu);
+void kvmi_arch_inject_exception(struct kvm_vcpu *vcpu);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 789aa9f1912f..830430777556 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -20,21 +20,22 @@ struct kvmi_vcpu_cmd_job {
 };
 
 static const char *const msg_IDs[] = {
-	[KVMI_EVENT]               = "KVMI_EVENT",
-	[KVMI_GET_VERSION]         = "KVMI_GET_VERSION",
-	[KVMI_VM_CHECK_COMMAND]    = "KVMI_VM_CHECK_COMMAND",
-	[KVMI_VM_CHECK_EVENT]      = "KVMI_VM_CHECK_EVENT",
-	[KVMI_VM_CONTROL_EVENTS]   = "KVMI_VM_CONTROL_EVENTS",
-	[KVMI_VM_GET_INFO]         = "KVMI_VM_GET_INFO",
-	[KVMI_VM_READ_PHYSICAL]    = "KVMI_VM_READ_PHYSICAL",
-	[KVMI_VM_WRITE_PHYSICAL]   = "KVMI_VM_WRITE_PHYSICAL",
-	[KVMI_VCPU_CONTROL_CR]     = "KVMI_VCPU_CONTROL_CR",
-	[KVMI_VCPU_CONTROL_EVENTS] = "KVMI_VCPU_CONTROL_EVENTS",
-	[KVMI_VCPU_GET_CPUID]      = "KVMI_VCPU_GET_CPUID",
-	[KVMI_VCPU_GET_INFO]       = "KVMI_VCPU_GET_INFO",
-	[KVMI_VCPU_GET_REGISTERS]  = "KVMI_VCPU_GET_REGISTERS",
-	[KVMI_VCPU_PAUSE]          = "KVMI_VCPU_PAUSE",
-	[KVMI_VCPU_SET_REGISTERS]  = "KVMI_VCPU_SET_REGISTERS",
+	[KVMI_EVENT]                 = "KVMI_EVENT",
+	[KVMI_GET_VERSION]           = "KVMI_GET_VERSION",
+	[KVMI_VM_CHECK_COMMAND]      = "KVMI_VM_CHECK_COMMAND",
+	[KVMI_VM_CHECK_EVENT]        = "KVMI_VM_CHECK_EVENT",
+	[KVMI_VM_CONTROL_EVENTS]     = "KVMI_VM_CONTROL_EVENTS",
+	[KVMI_VM_GET_INFO]           = "KVMI_VM_GET_INFO",
+	[KVMI_VM_READ_PHYSICAL]      = "KVMI_VM_READ_PHYSICAL",
+	[KVMI_VM_WRITE_PHYSICAL]     = "KVMI_VM_WRITE_PHYSICAL",
+	[KVMI_VCPU_CONTROL_CR]       = "KVMI_VCPU_CONTROL_CR",
+	[KVMI_VCPU_CONTROL_EVENTS]   = "KVMI_VCPU_CONTROL_EVENTS",
+	[KVMI_VCPU_GET_CPUID]        = "KVMI_VCPU_GET_CPUID",
+	[KVMI_VCPU_GET_INFO]         = "KVMI_VCPU_GET_INFO",
+	[KVMI_VCPU_GET_REGISTERS]    = "KVMI_VCPU_GET_REGISTERS",
+	[KVMI_VCPU_INJECT_EXCEPTION] = "KVMI_VCPU_INJECT_EXCEPTION",
+	[KVMI_VCPU_PAUSE]            = "KVMI_VCPU_PAUSE",
+	[KVMI_VCPU_SET_REGISTERS]    = "KVMI_VCPU_SET_REGISTERS",
 };
 
 static const char *id2str(u16 id)
@@ -526,6 +527,25 @@ static int handle_vcpu_control_cr(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
 }
 
+static int handle_vcpu_inject_exception(const struct kvmi_vcpu_cmd_job *job,
+					const struct kvmi_msg_hdr *msg,
+					const void *_req)
+{
+	const struct kvmi_vcpu_inject_exception *req = _req;
+	int ec;
+
+	if (!is_event_allowed(KVMI(job->vcpu->kvm), KVMI_EVENT_TRAP))
+		ec = -KVM_EPERM;
+	else if (req->padding1 || req->padding2)
+		ec = -KVM_EINVAL;
+	else
+		ec = kvmi_arch_cmd_vcpu_inject_exception(job->vcpu, req->nr,
+							 req->error_code,
+							 req->address);
+
+	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -534,13 +554,14 @@ static int handle_vcpu_control_cr(const struct kvmi_vcpu_cmd_job *job,
  */
 static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 			      const struct kvmi_msg_hdr *, const void *) = {
-	[KVMI_EVENT]               = handle_event_reply,
-	[KVMI_VCPU_CONTROL_CR]     = handle_vcpu_control_cr,
-	[KVMI_VCPU_CONTROL_EVENTS] = handle_vcpu_control_events,
-	[KVMI_VCPU_GET_CPUID]      = handle_get_cpuid,
-	[KVMI_VCPU_GET_INFO]       = handle_get_vcpu_info,
-	[KVMI_VCPU_GET_REGISTERS]  = handle_get_registers,
-	[KVMI_VCPU_SET_REGISTERS]  = handle_set_registers,
+	[KVMI_EVENT]                 = handle_event_reply,
+	[KVMI_VCPU_CONTROL_CR]       = handle_vcpu_control_cr,
+	[KVMI_VCPU_CONTROL_EVENTS]   = handle_vcpu_control_events,
+	[KVMI_VCPU_GET_CPUID]        = handle_get_cpuid,
+	[KVMI_VCPU_GET_INFO]         = handle_get_vcpu_info,
+	[KVMI_VCPU_GET_REGISTERS]    = handle_get_registers,
+	[KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception,
+	[KVMI_VCPU_SET_REGISTERS]    = handle_set_registers,
 };
 
 static bool is_vcpu_command(u16 id)
@@ -797,9 +818,9 @@ static void kvmi_setup_vcpu_reply(struct kvm_vcpu_introspection *vcpui,
 	vcpui->waiting_for_reply = true;
 }
 
-int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
-		    void *ev, size_t ev_size,
-		    void *rpl, size_t rpl_size, int *action)
+int __kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
+		      void *ev, size_t ev_size,
+		      void *rpl, size_t rpl_size, int *action)
 {
 	struct kvmi_msg_hdr hdr;
 	struct kvmi_event common;
@@ -839,6 +860,16 @@ int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
 	return err;
 }
 
+int kvmi_send_event(struct kvm_vcpu *vcpu, u32 ev_id,
+		    void *ev, size_t ev_size,
+		    void *rpl, size_t rpl_size, int *action)
+{
+	kvmi_send_pending_event(vcpu);
+
+	return __kvmi_send_event(vcpu, ev_id, ev, ev_size,
+				 rpl, rpl_size, action);
+}
+
 u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu)
 {
 	int err, action;

[PATCH v8 66/81] KVM: introspection: add KVMI_VM_GET_MAX_GFN

[Adalbert Lazăr]

From: Ștefan Șicleru <ssicleru@bitdefender.com>

The introspection tool will use this command to get the address range
for which it can set access restrictions.

Signed-off-by: Ștefan Șicleru <ssicleru@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 20 +++++++++++++++++++
 include/uapi/linux/kvmi.h                     |  6 ++++++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 12 +++++++++++
 virt/kvm/introspection/kvmi_msg.c             | 14 +++++++++++++
 4 files changed, 52 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index d6a09fac4f52..1c5e256975fe 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -756,6 +756,26 @@ The *KVMI_EVENT_TRAP* event will be sent with the effective injected expection.
 * -KVM_EBUSY - another *KVMI_VCPU_INJECT_EXCEPTION*-*KVMI_EVENT_TRAP* pair
                is in progress
 
+16. KVMI_VM_GET_MAX_GFN
+-----------------------
+
+:Architecture: all
+:Versions: >= 1
+:Parameters: none
+:Returns:
+
+::
+
+        struct kvmi_error_code;
+        struct kvmi_vm_get_max_gfn_reply {
+                __u64 gfn;
+        };
+
+Provides the maximum GFN allocated to the VM by walking through all
+memory slots allocated by KVM, considering all address spaces indicated
+by KVM_ADDRESS_SPACE_NUM. Stricly speaking, the returned value refers
+to the first inaccessible GFN, next to the maximum accessible GFN.
+
 Events
 ======
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 2603fa72154b..d33e8dae0084 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -34,6 +34,8 @@ enum {
 	KVMI_VCPU_CONTROL_CR       = 15,
 	KVMI_VCPU_INJECT_EXCEPTION = 16,
 
+	KVMI_VM_GET_MAX_GFN = 17,
+
 	KVMI_NUM_MESSAGES
 };
 
@@ -140,6 +142,10 @@ struct kvmi_vcpu_control_events {
 	__u32 padding2;
 };
 
+struct kvmi_vm_get_max_gfn_reply {
+	__u64 gfn;
+};
+
 struct kvmi_event {
 	__u16 size;
 	__u16 vcpu;
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 6a6ad736db36..66766d112006 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -1232,6 +1232,17 @@ static void test_cmd_vcpu_inject_exception(struct kvm_vm *vm)
 	disable_vcpu_event(vm, KVMI_EVENT_BREAKPOINT);
 }
 
+static void test_cmd_vm_get_max_gfn(void)
+{
+	struct kvmi_vm_get_max_gfn_reply rpl;
+	struct kvmi_msg_hdr req;
+
+	test_vm_command(KVMI_VM_GET_MAX_GFN, &req, sizeof(req),
+			&rpl, sizeof(rpl));
+
+	DEBUG("max_gfn: 0x%llx\n", rpl.gfn);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1256,6 +1267,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_event_breakpoint(vm);
 	test_cmd_vcpu_control_cr(vm);
 	test_cmd_vcpu_inject_exception(vm);
+	test_cmd_vm_get_max_gfn();
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 830430777556..8ae57c87256f 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -26,6 +26,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VM_CHECK_EVENT]        = "KVMI_VM_CHECK_EVENT",
 	[KVMI_VM_CONTROL_EVENTS]     = "KVMI_VM_CONTROL_EVENTS",
 	[KVMI_VM_GET_INFO]           = "KVMI_VM_GET_INFO",
+	[KVMI_VM_GET_MAX_GFN]        = "KVMI_VM_GET_MAX_GFN",
 	[KVMI_VM_READ_PHYSICAL]      = "KVMI_VM_READ_PHYSICAL",
 	[KVMI_VM_WRITE_PHYSICAL]     = "KVMI_VM_WRITE_PHYSICAL",
 	[KVMI_VCPU_CONTROL_CR]       = "KVMI_VCPU_CONTROL_CR",
@@ -348,6 +349,18 @@ static int handle_pause_vcpu(struct kvm_introspection *kvmi,
 	return kvmi_msg_vm_reply(kvmi, msg, err, NULL, 0);
 }
 
+static int handle_vm_get_max_gfn(struct kvm_introspection *kvmi,
+				 const struct kvmi_msg_hdr *msg,
+				 const void *req)
+{
+	struct kvmi_vm_get_max_gfn_reply rpl;
+
+	memset(&rpl, 0, sizeof(rpl));
+	rpl.gfn = kvm_get_max_gfn(kvmi->kvm);
+
+	return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl));
+}
+
 /*
  * These commands are executed by the receiving thread/worker.
  */
@@ -358,6 +371,7 @@ static int(*const msg_vm[])(struct kvm_introspection *,
 	[KVMI_VM_CHECK_EVENT]    = handle_check_event,
 	[KVMI_VM_CONTROL_EVENTS] = handle_vm_control_events,
 	[KVMI_VM_GET_INFO]       = handle_get_info,
+	[KVMI_VM_GET_MAX_GFN]    = handle_vm_get_max_gfn,
 	[KVMI_VM_READ_PHYSICAL]  = handle_read_physical,
 	[KVMI_VM_WRITE_PHYSICAL] = handle_write_physical,
 	[KVMI_VCPU_PAUSE]        = handle_pause_vcpu,

[PATCH v8 67/81] KVM: introspection: add KVMI_EVENT_XSETBV

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This event is sent when the extended control register XCR0 is going to
be changed.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 25 ++++++
 arch/x86/include/asm/kvmi_host.h              |  2 +
 arch/x86/kvm/kvmi.c                           | 39 +++++++++
 arch/x86/kvm/x86.c                            |  6 ++
 include/uapi/linux/kvmi.h                     |  1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 83 +++++++++++++++++++
 virt/kvm/introspection/kvmi.c                 |  1 +
 7 files changed, 157 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 1c5e256975fe..06ed05f4791b 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -549,6 +549,7 @@ the following events::
 	KVMI_EVENT_BREAKPOINT
 	KVMI_EVENT_CR
 	KVMI_EVENT_HYPERCALL
+	KVMI_EVENT_XSETBV
 
 When an event is enabled, the introspection tool is notified and
 must reply with: continue, retry, crash, etc. (see **Events** below).
@@ -1019,3 +1020,27 @@ other vCPU introspection event.
 (``error_code``) and CR2 are sent to the introspection tool,
 which should check if its exception has been injected or overridden.
 
+7. KVMI_EVENT_XSETBV
+--------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+	struct kvmi_event;
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+
+This event is sent when the extended control register XCR0 is going
+to be changed and the introspection has been enabled for this event
+(see *KVMI_VCPU_CONTROL_EVENTS*).
+
+``kvmi_event`` is sent to the introspection tool.
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 24f3f8fdee62..b3fa950362db 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -30,6 +30,7 @@ bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
 		   unsigned long old_value, unsigned long *new_value);
 bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu);
 bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable);
+void kvmi_xsetbv_event(struct kvm_vcpu *vcpu);
 
 #else /* CONFIG_KVM_INTROSPECTION */
 
@@ -41,6 +42,7 @@ static inline bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
 static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; }
 static inline bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu,
 						bool enable) { return false; }
+static inline void kvmi_xsetbv_event(struct kvm_vcpu *vcpu) { }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 9f8ef8a1a306..f947f18e9d72 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -662,3 +662,42 @@ void kvmi_arch_trap_event(struct kvm_vcpu *vcpu)
 		kvmi_handle_common_event_actions(vcpu->kvm, action, "TRAP");
 	}
 }
+
+static u32 kvmi_send_xsetbv(struct kvm_vcpu *vcpu)
+{
+	int err, action;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_XSETBV, NULL, 0,
+			      NULL, 0, &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	return action;
+}
+
+static void __kvmi_xsetbv_event(struct kvm_vcpu *vcpu)
+{
+	u32 action;
+
+	action = kvmi_send_xsetbv(vcpu);
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action, "XSETBV");
+	}
+}
+
+void kvmi_xsetbv_event(struct kvm_vcpu *vcpu)
+{
+	struct kvm_introspection *kvmi;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_XSETBV))
+		__kvmi_xsetbv_event(vcpu);
+
+	kvmi_put(vcpu->kvm);
+}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0e3704bed6c4..ab0ad3b6ebc2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -865,6 +865,12 @@ static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
 	}
 	vcpu->arch.xcr0 = xcr0;
 
+#ifdef CONFIG_KVM_INTROSPECTION
+	if (index == 0 && xcr0 != old_xcr0)
+		kvmi_xsetbv_event(vcpu);
+#endif /* CONFIG_KVM_INTROSPECTION */
+
+
 	if ((xcr0 ^ old_xcr0) & XFEATURE_MASK_EXTEND)
 		kvm_update_cpuid(vcpu);
 	return 0;
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index d33e8dae0084..ecf140ba3cab 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -46,6 +46,7 @@ enum {
 	KVMI_EVENT_BREAKPOINT = 3,
 	KVMI_EVENT_CR         = 4,
 	KVMI_EVENT_TRAP       = 5,
+	KVMI_EVENT_XSETBV     = 6,
 
 	KVMI_NUM_EVENTS
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 66766d112006..3a45834e9235 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -22,6 +22,8 @@
 
 #define VCPU_ID         5
 
+#define X86_FEATURE_XSAVE	(1<<26)
+
 static int socket_pair[2];
 #define Kvm_socket       socket_pair[0]
 #define Userspace_socket socket_pair[1]
@@ -54,6 +56,7 @@ enum {
 	GUEST_TEST_BP,
 	GUEST_TEST_CR,
 	GUEST_TEST_HYPERCALL,
+	GUEST_TEST_XSETBV,
 };
 
 #define GUEST_REQUEST_TEST()     GUEST_SYNC(0)
@@ -85,6 +88,45 @@ static void guest_hypercall_test(void)
 	asm volatile(".byte 0x0f,0x01,0xc1");
 }
 
+/* from fpu/internal.h */
+static u64 xgetbv(u32 index)
+{
+	u32 eax, edx;
+
+	asm volatile(".byte 0x0f,0x01,0xd0" /* xgetbv */
+		     : "=a" (eax), "=d" (edx)
+		     : "c" (index));
+	return eax + ((u64)edx << 32);
+}
+
+/* from fpu/internal.h */
+static void xsetbv(u32 index, u64 value)
+{
+	u32 eax = value;
+	u32 edx = value >> 32;
+
+	asm volatile(".byte 0x0f,0x01,0xd1" /* xsetbv */
+		     : : "a" (eax), "d" (edx), "c" (index));
+}
+
+static void guest_xsetbv_test(void)
+{
+	const int SSE_BIT = 1 << 1;
+	const int AVX_BIT = 1 << 2;
+	u64 xcr0;
+
+	/* avoid #UD */
+	set_cr4(get_cr4() | X86_CR4_OSXSAVE);
+
+	xcr0 = xgetbv(0);
+	if (xcr0 & AVX_BIT)
+		xcr0 &= ~AVX_BIT;
+	else
+		xcr0 |= (AVX_BIT | SSE_BIT);
+
+	xsetbv(0, xcr0);
+}
+
 static void guest_code(void)
 {
 	while (true) {
@@ -100,6 +142,9 @@ static void guest_code(void)
 		case GUEST_TEST_HYPERCALL:
 			guest_hypercall_test();
 			break;
+		case GUEST_TEST_XSETBV:
+			guest_xsetbv_test();
+			break;
 		}
 		GUEST_SIGNAL_TEST_DONE();
 	}
@@ -1243,6 +1288,43 @@ static void test_cmd_vm_get_max_gfn(void)
 	DEBUG("max_gfn: 0x%llx\n", rpl.gfn);
 }
 
+static void test_event_xsetbv(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = {
+		.vm = vm,
+		.vcpu_id = VCPU_ID,
+		.test_id = GUEST_TEST_XSETBV,
+	};
+	__u16 event_id = KVMI_EVENT_XSETBV;
+	struct kvm_cpuid_entry2 *entry;
+	struct vcpu_reply rpl = {};
+	struct kvmi_msg_hdr hdr;
+	pthread_t vcpu_thread;
+	struct kvmi_event ev;
+
+	entry = kvm_get_supported_cpuid_entry(1);
+	if (!(entry->ecx & X86_FEATURE_XSAVE)) {
+		DEBUG("XSAVE is not supported, ecx 0x%x, skipping xsetbv test\n",
+			entry->ecx);
+		return;
+	}
+
+	enable_vcpu_event(vm, event_id);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	receive_event(&hdr, &ev, sizeof(ev), event_id);
+
+	DEBUG("XSETBV event, rip 0x%llx\n", ev.arch.regs.rip);
+
+	reply_to_event(&hdr, &ev, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	disable_vcpu_event(vm, event_id);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1268,6 +1350,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_control_cr(vm);
 	test_cmd_vcpu_inject_exception(vm);
 	test_cmd_vm_get_max_gfn();
+	test_event_xsetbv(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 0f2cec7e9c90..d358686fce76 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -83,6 +83,7 @@ static void setup_known_events(void)
 	set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_TRAP, Kvmi_known_vcpu_events);
+	set_bit(KVMI_EVENT_XSETBV, Kvmi_known_vcpu_events);
 
 	bitmap_or(Kvmi_known_events, Kvmi_known_vm_events,
 		  Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);

[PATCH v8 68/81] KVM: introspection: add KVMI_VCPU_GET_XSAVE

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This vCPU command is used to get the XSAVE area.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 31 +++++++++++++++++++
 arch/x86/include/uapi/asm/kvmi.h              |  4 +++
 arch/x86/kvm/kvmi.c                           | 21 +++++++++++++
 include/uapi/linux/kvmi.h                     |  2 ++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 21 +++++++++++++
 virt/kvm/introspection/kvmi_int.h             |  3 ++
 virt/kvm/introspection/kvmi_msg.c             | 17 ++++++++++
 7 files changed, 99 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 06ed05f4791b..e1be8d63bfcd 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -777,6 +777,37 @@ memory slots allocated by KVM, considering all address spaces indicated
 by KVM_ADDRESS_SPACE_NUM. Stricly speaking, the returned value refers
 to the first inaccessible GFN, next to the maximum accessible GFN.
 
+17. KVMI_VCPU_GET_XSAVE
+-----------------------
+
+:Architecture: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_vcpu_get_xsave_reply {
+		__u32 region[0];
+	};
+
+Returns a buffer containing the XSAVE area. Currently, the size of
+``kvm_xsave`` is used, but it could change. The userspace should get
+the buffer size from the message size (kvmi_msg_hdr.size).
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_ENOMEM - there is not enough memory to allocate the reply
+
 Events
 ======
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 073dbaac06b1..39812e93c9c1 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -97,4 +97,8 @@ struct kvmi_vcpu_inject_exception {
 	__u64 address;
 };
 
+struct kvmi_vcpu_get_xsave_reply {
+	__u32 region[0];
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index f947f18e9d72..348583d8237f 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -701,3 +701,24 @@ void kvmi_xsetbv_event(struct kvm_vcpu *vcpu)
 
 	kvmi_put(vcpu->kvm);
 }
+
+int kvmi_arch_cmd_vcpu_get_xsave(struct kvm_vcpu *vcpu,
+				 struct kvmi_vcpu_get_xsave_reply **dest,
+				 size_t *dest_size)
+{
+	struct kvmi_vcpu_get_xsave_reply *rpl = NULL;
+	size_t rpl_size = sizeof(*rpl) + sizeof(struct kvm_xsave);
+	struct kvm_xsave *area;
+
+	rpl = kvmi_msg_alloc_check(rpl_size);
+	if (!rpl)
+		return -KVM_ENOMEM;
+
+	area = (struct kvm_xsave *) rpl->region;
+	kvm_vcpu_ioctl_x86_get_xsave(vcpu, area);
+
+	*dest = rpl;
+	*dest_size = rpl_size;
+
+	return 0;
+}
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index ecf140ba3cab..b3008f96dd06 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -36,6 +36,8 @@ enum {
 
 	KVMI_VM_GET_MAX_GFN = 17,
 
+	KVMI_VCPU_GET_XSAVE = 18,
+
 	KVMI_NUM_MESSAGES
 };
 
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 3a45834e9235..4aa033a2b18b 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -1325,6 +1325,26 @@ static void test_event_xsetbv(struct kvm_vm *vm)
 	disable_vcpu_event(vm, event_id);
 }
 
+static void test_cmd_vcpu_get_xsave(struct kvm_vm *vm)
+{
+	struct kvm_cpuid_entry2 *entry;
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+	} req = {};
+	struct kvm_xsave rpl;
+
+	entry = kvm_get_supported_cpuid_entry(1);
+	if (!(entry->ecx & X86_FEATURE_XSAVE)) {
+		DEBUG("XSAVE is not supported, ecx 0x%x, skipping xsave test\n",
+			entry->ecx);
+		return;
+	}
+
+	test_vcpu0_command(vm, KVMI_VCPU_GET_XSAVE, &req.hdr, sizeof(req),
+			   &rpl, sizeof(rpl));
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1351,6 +1371,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_inject_exception(vm);
 	test_cmd_vm_get_max_gfn();
 	test_event_xsetbv(vm);
+	test_cmd_vcpu_get_xsave(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 59a8b20af0fd..907751bbf596 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -103,5 +103,8 @@ int kvmi_arch_cmd_vcpu_inject_exception(struct kvm_vcpu *vcpu, u8 vector,
 					u32 error_code, u64 address);
 void kvmi_arch_trap_event(struct kvm_vcpu *vcpu);
 void kvmi_arch_inject_exception(struct kvm_vcpu *vcpu);
+int kvmi_arch_cmd_vcpu_get_xsave(struct kvm_vcpu *vcpu,
+				 struct kvmi_vcpu_get_xsave_reply **dest,
+				 size_t *dest_size);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 8ae57c87256f..9bc648b2eb08 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -34,6 +34,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VCPU_GET_CPUID]        = "KVMI_VCPU_GET_CPUID",
 	[KVMI_VCPU_GET_INFO]         = "KVMI_VCPU_GET_INFO",
 	[KVMI_VCPU_GET_REGISTERS]    = "KVMI_VCPU_GET_REGISTERS",
+	[KVMI_VCPU_GET_XSAVE]        = "KVMI_VCPU_GET_XSAVE",
 	[KVMI_VCPU_INJECT_EXCEPTION] = "KVMI_VCPU_INJECT_EXCEPTION",
 	[KVMI_VCPU_PAUSE]            = "KVMI_VCPU_PAUSE",
 	[KVMI_VCPU_SET_REGISTERS]    = "KVMI_VCPU_SET_REGISTERS",
@@ -560,6 +561,21 @@ static int handle_vcpu_inject_exception(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
 }
 
+static int handle_vcpu_get_xsave(const struct kvmi_vcpu_cmd_job *job,
+				 const struct kvmi_msg_hdr *msg,
+				 const void *req)
+{
+	struct kvmi_vcpu_get_xsave_reply *rpl = NULL;
+	size_t rpl_size = 0;
+	int err, ec;
+
+	ec = kvmi_arch_cmd_vcpu_get_xsave(job->vcpu, &rpl, &rpl_size);
+
+	err = kvmi_msg_vcpu_reply(job, msg, ec, rpl, rpl_size);
+	kvmi_msg_free(rpl);
+	return err;
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -574,6 +590,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 	[KVMI_VCPU_GET_CPUID]        = handle_get_cpuid,
 	[KVMI_VCPU_GET_INFO]         = handle_get_vcpu_info,
 	[KVMI_VCPU_GET_REGISTERS]    = handle_get_registers,
+	[KVMI_VCPU_GET_XSAVE]        = handle_vcpu_get_xsave,
 	[KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception,
 	[KVMI_VCPU_SET_REGISTERS]    = handle_set_registers,
 };

[PATCH v8 69/81] KVM: introspection: add KVMI_VCPU_GET_MTRR_TYPE

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This command returns the memory type for a guest physical address.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 32 +++++++++++++++++++
 arch/x86/include/uapi/asm/kvmi.h              |  9 ++++++
 arch/x86/kvm/kvmi.c                           |  7 ++++
 include/uapi/linux/kvmi.h                     |  3 +-
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 19 +++++++++++
 virt/kvm/introspection/kvmi_int.h             |  1 +
 virt/kvm/introspection/kvmi_msg.c             | 17 ++++++++++
 7 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index e1be8d63bfcd..9d37030213a6 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -808,6 +808,38 @@ the buffer size from the message size (kvmi_msg_hdr.size).
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 * -KVM_ENOMEM - there is not enough memory to allocate the reply
 
+18. KVMI_VCPU_GET_MTRR_TYPE
+---------------------------
+
+:Architecture: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_get_mtrr_type {
+		__u64 gpa;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_vcpu_get_mtrr_type_reply {
+		__u8 type;
+		__u8 padding[7];
+	};
+
+Returns the guest memory type for a specific physical address.
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+
 Events
 ======
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 39812e93c9c1..d622c89a4f2c 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -101,4 +101,13 @@ struct kvmi_vcpu_get_xsave_reply {
 	__u32 region[0];
 };
 
+struct kvmi_vcpu_get_mtrr_type {
+	__u64 gpa;
+};
+
+struct kvmi_vcpu_get_mtrr_type_reply {
+	__u8 type;
+	__u8 padding[7];
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 348583d8237f..3de7e98fa426 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -722,3 +722,10 @@ int kvmi_arch_cmd_vcpu_get_xsave(struct kvm_vcpu *vcpu,
 
 	return 0;
 }
+
+int kvmi_arch_cmd_vcpu_get_mtrr_type(struct kvm_vcpu *vcpu, u64 gpa, u8 *type)
+{
+	*type = kvm_mtrr_get_guest_memory_type(vcpu, gpa_to_gfn(gpa));
+
+	return 0;
+}
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index b3008f96dd06..0827bd90691b 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -36,7 +36,8 @@ enum {
 
 	KVMI_VM_GET_MAX_GFN = 17,
 
-	KVMI_VCPU_GET_XSAVE = 18,
+	KVMI_VCPU_GET_XSAVE     = 18,
+	KVMI_VCPU_GET_MTRR_TYPE = 19,
 
 	KVMI_NUM_MESSAGES
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 4aa033a2b18b..b984c3704baf 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -1345,6 +1345,24 @@ static void test_cmd_vcpu_get_xsave(struct kvm_vm *vm)
 			   &rpl, sizeof(rpl));
 }
 
+static void test_cmd_vcpu_get_mtrr_type(struct kvm_vm *vm)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_get_mtrr_type cmd;
+	} req = {};
+	struct kvmi_vcpu_get_mtrr_type_reply rpl;
+
+	req.cmd.gpa = test_gpa;
+
+	test_vcpu0_command(vm, KVMI_VCPU_GET_MTRR_TYPE,
+			   &req.hdr, sizeof(req),
+			   &rpl, sizeof(rpl));
+
+	DEBUG("mtrr_type: gpa 0x%lx type 0x%x\n", test_gpa, rpl.type);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1372,6 +1390,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vm_get_max_gfn();
 	test_event_xsetbv(vm);
 	test_cmd_vcpu_get_xsave(vm);
+	test_cmd_vcpu_get_mtrr_type(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 907751bbf596..72c9d3a1a4b6 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -106,5 +106,6 @@ void kvmi_arch_inject_exception(struct kvm_vcpu *vcpu);
 int kvmi_arch_cmd_vcpu_get_xsave(struct kvm_vcpu *vcpu,
 				 struct kvmi_vcpu_get_xsave_reply **dest,
 				 size_t *dest_size);
+int kvmi_arch_cmd_vcpu_get_mtrr_type(struct kvm_vcpu *vcpu, u64 gpa, u8 *type);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 9bc648b2eb08..78ae52f05c29 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -33,6 +33,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VCPU_CONTROL_EVENTS]   = "KVMI_VCPU_CONTROL_EVENTS",
 	[KVMI_VCPU_GET_CPUID]        = "KVMI_VCPU_GET_CPUID",
 	[KVMI_VCPU_GET_INFO]         = "KVMI_VCPU_GET_INFO",
+	[KVMI_VCPU_GET_MTRR_TYPE]    = "KVMI_VCPU_GET_MTRR_TYPE",
 	[KVMI_VCPU_GET_REGISTERS]    = "KVMI_VCPU_GET_REGISTERS",
 	[KVMI_VCPU_GET_XSAVE]        = "KVMI_VCPU_GET_XSAVE",
 	[KVMI_VCPU_INJECT_EXCEPTION] = "KVMI_VCPU_INJECT_EXCEPTION",
@@ -576,6 +577,21 @@ static int handle_vcpu_get_xsave(const struct kvmi_vcpu_cmd_job *job,
 	return err;
 }
 
+static int handle_vcpu_get_mtrr_type(const struct kvmi_vcpu_cmd_job *job,
+				     const struct kvmi_msg_hdr *msg,
+				     const void *_req)
+{
+	const struct kvmi_vcpu_get_mtrr_type *req = _req;
+	struct kvmi_vcpu_get_mtrr_type_reply rpl;
+	int ec;
+
+	memset(&rpl, 0, sizeof(rpl));
+
+	ec = kvmi_arch_cmd_vcpu_get_mtrr_type(job->vcpu, req->gpa, &rpl.type);
+
+	return kvmi_msg_vcpu_reply(job, msg, ec, &rpl, sizeof(rpl));
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -589,6 +605,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 	[KVMI_VCPU_CONTROL_EVENTS]   = handle_vcpu_control_events,
 	[KVMI_VCPU_GET_CPUID]        = handle_get_cpuid,
 	[KVMI_VCPU_GET_INFO]         = handle_get_vcpu_info,
+	[KVMI_VCPU_GET_MTRR_TYPE]    = handle_vcpu_get_mtrr_type,
 	[KVMI_VCPU_GET_REGISTERS]    = handle_get_registers,
 	[KVMI_VCPU_GET_XSAVE]        = handle_vcpu_get_xsave,
 	[KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception,

[PATCH v8 70/81] KVM: introspection: add KVMI_EVENT_DESCRIPTOR

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This event is sent when IDTR, GDTR, LDTR or TR are accessed.

These could be used to implement a tiny agent which runs in the context
of an introspected guest and uses virtualized exceptions (#VE) and
alternate EPT views (VMFUNC #0) to filter converted VMEXITS. The events
of interested will be suppressed (after some appropriate guest-side
handling) while the rest will be sent to the introspector via a VMCALL.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 41 ++++++++++
 arch/x86/include/asm/kvmi_host.h              |  3 +
 arch/x86/include/uapi/asm/kvmi.h              | 11 +++
 arch/x86/kvm/kvmi.c                           | 75 +++++++++++++++++++
 arch/x86/kvm/svm.c                            | 33 ++++++++
 arch/x86/kvm/vmx/vmx.c                        | 23 ++++++
 include/uapi/linux/kvmi.h                     |  1 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 75 +++++++++++++++++++
 virt/kvm/introspection/kvmi.c                 |  1 +
 9 files changed, 263 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 9d37030213a6..6f6551230e11 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -548,6 +548,7 @@ the following events::
 
 	KVMI_EVENT_BREAKPOINT
 	KVMI_EVENT_CR
+	KVMI_EVENT_DESCRIPTOR
 	KVMI_EVENT_HYPERCALL
 	KVMI_EVENT_XSETBV
 
@@ -572,6 +573,8 @@ the *KVMI_VM_CONTROL_EVENTS* command.
 * -KVM_EINVAL - the event ID is unknown (use *KVMI_VM_CHECK_EVENT* first)
 * -KVM_EPERM - the access is disallowed (use *KVMI_VM_CHECK_EVENT* first)
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_EOPNOTSUPP - the event can't be intercepted in the current setup
+                    (e.g. KVMI_EVENT_DESCRIPTOR with AMD)
 * -KVM_EBUSY - the event can't be intercepted right now
                (e.g. KVMI_EVENT_BREAKPOINT if the #BP event is already intercepted
                 by userspace)
@@ -1107,3 +1110,41 @@ to be changed and the introspection has been enabled for this event
 (see *KVMI_VCPU_CONTROL_EVENTS*).
 
 ``kvmi_event`` is sent to the introspection tool.
+
+8. KVMI_EVENT_DESCRIPTOR
+------------------------
+
+:Architecture: x86
+:Versions: >= 1
+:Actions: CONTINUE, RETRY, CRASH
+:Parameters:
+
+::
+
+	struct kvmi_event;
+	struct kvmi_event_descriptor {
+		__u8 descriptor;
+		__u8 write;
+		__u8 padding[6];
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+
+This event is sent when a descriptor table register is accessed and the
+introspection has been enabled for this event (see **KVMI_VCPU_CONTROL_EVENTS**).
+
+``kvmi_event`` and ``kvmi_event_descriptor`` are sent to the introspection tool.
+
+``descriptor`` can be one of::
+
+	KVMI_DESC_IDTR
+	KVMI_DESC_GDTR
+	KVMI_DESC_LDTR
+	KVMI_DESC_TR
+
+``write`` is 1 if the descriptor was written, 0 otherwise.
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index b3fa950362db..7633501031d2 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -31,6 +31,7 @@ bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
 bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu);
 bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable);
 void kvmi_xsetbv_event(struct kvm_vcpu *vcpu);
+bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write);
 
 #else /* CONFIG_KVM_INTROSPECTION */
 
@@ -43,6 +44,8 @@ static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; }
 static inline bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu,
 						bool enable) { return false; }
 static inline void kvmi_xsetbv_event(struct kvm_vcpu *vcpu) { }
+static inline bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor,
+					 bool write) { return true; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index d622c89a4f2c..691a501200b3 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -110,4 +110,15 @@ struct kvmi_vcpu_get_mtrr_type_reply {
 	__u8 padding[7];
 };
 
+#define KVMI_DESC_IDTR  1
+#define KVMI_DESC_GDTR  2
+#define KVMI_DESC_LDTR  3
+#define KVMI_DESC_TR    4
+
+struct kvmi_event_descriptor {
+	__u8 descriptor;
+	__u8 write;
+	__u8 padding[6];
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 3de7e98fa426..093ff0da88ff 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -360,6 +360,21 @@ static void kvmi_arch_disable_cr3w_intercept(struct kvm_vcpu *vcpu)
 	vcpu->arch.kvmi->cr3w.kvm_intercepted = false;
 }
 
+static int kvmi_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
+{
+	if (!kvm_x86_ops->desc_ctrl_supported())
+		return -KVM_EOPNOTSUPP;
+
+	kvm_x86_ops->control_desc_intercept(vcpu, enable);
+
+	return 0;
+}
+
+static void kvmi_arch_disable_desc_intercept(struct kvm_vcpu *vcpu)
+{
+	kvmi_control_desc_intercept(vcpu, false);
+}
+
 int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
 				    unsigned int event_id, bool enable)
 {
@@ -369,6 +384,9 @@ int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
 	case KVMI_EVENT_BREAKPOINT:
 		err = kvmi_control_bp_intercept(vcpu, enable);
 		break;
+	case KVMI_EVENT_DESCRIPTOR:
+		err = kvmi_control_desc_intercept(vcpu, enable);
+		break;
 	default:
 		break;
 	}
@@ -405,6 +423,7 @@ bool kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
 
 	kvmi_arch_disable_bp_intercept(vcpu);
 	kvmi_arch_disable_cr3w_intercept(vcpu);
+	kvmi_arch_disable_desc_intercept(vcpu);
 
 	return true;
 }
@@ -729,3 +748,59 @@ int kvmi_arch_cmd_vcpu_get_mtrr_type(struct kvm_vcpu *vcpu, u64 gpa, u8 *type)
 
 	return 0;
 }
+
+static u32 kvmi_msg_send_descriptor(struct kvm_vcpu *vcpu, u8 descriptor,
+				    bool write)
+{
+	struct kvmi_event_descriptor e;
+	int err, action;
+
+	memset(&e, 0, sizeof(e));
+	e.descriptor = descriptor;
+	e.write = write ? 1 : 0;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_DESCRIPTOR, &e, sizeof(e),
+			      NULL, 0, &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	return action;
+}
+
+static bool __kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor,
+				    bool write)
+{
+	bool ret = false;
+	u32 action;
+
+	action = kvmi_msg_send_descriptor(vcpu, descriptor, write);
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		ret = true;
+		break;
+	case KVMI_EVENT_ACTION_RETRY:
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action, "DESC");
+	}
+
+	return ret;
+}
+
+bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = true;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return true;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_DESCRIPTOR))
+		ret = __kvmi_descriptor_event(vcpu, descriptor, write);
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
+EXPORT_SYMBOL(kvmi_descriptor_event);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1021ff2f9e57..b377acc3410c 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4854,6 +4854,39 @@ static int descriptor_access_interception(struct vcpu_svm *svm)
 {
 	struct kvm_vcpu *vcpu = &svm->vcpu;
 
+#ifdef CONFIG_KVM_INTROSPECTION
+	struct vmcb_control_area *c = &svm->vmcb->control;
+	bool cont;
+
+	switch (c->exit_code) {
+	case SVM_EXIT_IDTR_READ:
+	case SVM_EXIT_IDTR_WRITE:
+		cont = kvmi_descriptor_event(vcpu, KVMI_DESC_IDTR,
+				      c->exit_code == SVM_EXIT_IDTR_WRITE);
+		break;
+	case SVM_EXIT_GDTR_READ:
+	case SVM_EXIT_GDTR_WRITE:
+		cont = kvmi_descriptor_event(vcpu, KVMI_DESC_GDTR,
+				      c->exit_code == SVM_EXIT_GDTR_WRITE);
+		break;
+	case SVM_EXIT_LDTR_READ:
+	case SVM_EXIT_LDTR_WRITE:
+		cont = kvmi_descriptor_event(vcpu, KVMI_DESC_LDTR,
+				      c->exit_code == SVM_EXIT_LDTR_WRITE);
+		break;
+	case SVM_EXIT_TR_READ:
+	case SVM_EXIT_TR_WRITE:
+		cont = kvmi_descriptor_event(vcpu, KVMI_DESC_TR,
+				      c->exit_code == SVM_EXIT_TR_WRITE);
+		break;
+	default:
+		cont = true;
+		break;
+	}
+	if (!cont)
+		return 1;
+#endif /* CONFIG_KVM_INTROSPECTION */
+
 	return kvm_emulate_instruction(vcpu, 0);
 }
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f6180ecf15ba..c54c01e088b6 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4866,7 +4866,30 @@ static int handle_set_cr4(struct kvm_vcpu *vcpu, unsigned long val)
 
 static int handle_desc(struct kvm_vcpu *vcpu)
 {
+#ifdef CONFIG_KVM_INTROSPECTION
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	u32 exit_reason = vmx->exit_reason;
+	u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
+	u8 store = (vmx_instruction_info >> 29) & 0x1;
+	u8 descriptor = 0;
+
+	if (exit_reason == EXIT_REASON_GDTR_IDTR) {
+		if ((vmx_instruction_info >> 28) & 0x1)
+			descriptor = KVMI_DESC_IDTR;
+		else
+			descriptor = KVMI_DESC_GDTR;
+	} else {
+		if ((vmx_instruction_info >> 28) & 0x1)
+			descriptor = KVMI_DESC_TR;
+		else
+			descriptor = KVMI_DESC_LDTR;
+	}
+
+	if (!kvmi_descriptor_event(vcpu, descriptor, store))
+		return 1;
+#else
 	WARN_ON(!(vcpu->arch.cr4 & X86_CR4_UMIP));
+#endif /* CONFIG_KVM_INTROSPECTION */
 	return kvm_emulate_instruction(vcpu, 0);
 }
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 0827bd90691b..2ccc4045137f 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -50,6 +50,7 @@ enum {
 	KVMI_EVENT_CR         = 4,
 	KVMI_EVENT_TRAP       = 5,
 	KVMI_EVENT_XSETBV     = 6,
+	KVMI_EVENT_DESCRIPTOR = 7,
 
 	KVMI_NUM_EVENTS
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index b984c3704baf..4f2de304a6f8 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -55,6 +55,7 @@ enum {
 	GUEST_TEST_NOOP = 0,
 	GUEST_TEST_BP,
 	GUEST_TEST_CR,
+	GUEST_TEST_DESCRIPTOR,
 	GUEST_TEST_HYPERCALL,
 	GUEST_TEST_XSETBV,
 };
@@ -80,6 +81,14 @@ static void guest_cr_test(void)
 	set_cr4(get_cr4() | X86_CR4_OSXSAVE);
 }
 
+static void guest_descriptor_test(void)
+{
+	void *ptr;
+
+	asm volatile("sgdt %0" :: "m"(ptr));
+	asm volatile("lgdt %0" :: "m"(ptr));
+}
+
 static void guest_hypercall_test(void)
 {
 	asm volatile("mov $34, %rax");
@@ -139,6 +148,9 @@ static void guest_code(void)
 		case GUEST_TEST_CR:
 			guest_cr_test();
 			break;
+		case GUEST_TEST_DESCRIPTOR:
+			guest_descriptor_test();
+			break;
 		case GUEST_TEST_HYPERCALL:
 			guest_hypercall_test();
 			break;
@@ -1363,6 +1375,68 @@ static void test_cmd_vcpu_get_mtrr_type(struct kvm_vm *vm)
 	DEBUG("mtrr_type: gpa 0x%lx type 0x%x\n", test_gpa, rpl.type);
 }
 
+static void test_desc_read_access(__u16 event_id)
+{
+	struct kvmi_msg_hdr hdr;
+	struct {
+		struct kvmi_event common;
+		struct kvmi_event_descriptor desc;
+	} ev;
+	struct vcpu_reply rpl = {};
+
+	receive_event(&hdr, &ev.common, sizeof(ev), event_id);
+
+	DEBUG("Descriptor event (read), descriptor %u, write %u\n",
+		ev.desc.descriptor, ev.desc.write);
+
+	TEST_ASSERT(ev.desc.write == 0,
+		"Received a write descriptor access\n");
+
+	reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+}
+
+static void test_desc_write_access(__u16 event_id)
+{
+	struct kvmi_msg_hdr hdr;
+	struct {
+		struct kvmi_event common;
+		struct kvmi_event_descriptor desc;
+	} ev;
+	struct vcpu_reply rpl = {};
+
+	receive_event(&hdr, &ev.common, sizeof(ev), event_id);
+
+	DEBUG("Descriptor event (write), descriptor %u, write %u\n",
+		ev.desc.descriptor, ev.desc.write);
+
+	TEST_ASSERT(ev.desc.write == 1,
+		"Received a read descriptor access\n");
+
+	reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+}
+
+static void test_event_descriptor(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = {
+		.vm = vm,
+		.vcpu_id = VCPU_ID,
+		.test_id = GUEST_TEST_DESCRIPTOR,
+	};
+	__u16 event_id = KVMI_EVENT_DESCRIPTOR;
+	pthread_t vcpu_thread;
+
+	enable_vcpu_event(vm, event_id);
+	vcpu_thread = start_vcpu_worker(&data);
+
+	test_desc_read_access(event_id);
+	test_desc_write_access(event_id);
+
+	stop_vcpu_worker(vcpu_thread, &data);
+	disable_vcpu_event(vm, event_id);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1391,6 +1465,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_event_xsetbv(vm);
 	test_cmd_vcpu_get_xsave(vm);
 	test_cmd_vcpu_get_mtrr_type(vm);
+	test_event_descriptor(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index d358686fce76..db79744e5d2f 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -80,6 +80,7 @@ static void setup_known_events(void)
 	bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 	set_bit(KVMI_EVENT_BREAKPOINT, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_CR, Kvmi_known_vcpu_events);
+	set_bit(KVMI_EVENT_DESCRIPTOR, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_TRAP, Kvmi_known_vcpu_events);

[PATCH v8 71/81] KVM: introspection: restore the state of descriptor-table register interception on unhook

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This commit also ensures that the introspection tool and the userspace
do not disable each other the descriptor access VM-exit.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvmi_host.h |  4 +++
 arch/x86/kvm/kvmi.c              | 45 ++++++++++++++++++++++++++++++++
 arch/x86/kvm/svm.c               |  3 +++
 arch/x86/kvm/vmx/vmx.c           |  3 +++
 4 files changed, 55 insertions(+)

diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 7633501031d2..3c4bba88b50d 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -14,6 +14,7 @@ struct kvmi_interception {
 	bool restore_interception;
 	struct kvmi_monitor_interception breakpoint;
 	struct kvmi_monitor_interception cr3w;
+	struct kvmi_monitor_interception descriptor;
 };
 
 struct kvm_vcpu_arch_introspection {
@@ -31,6 +32,7 @@ bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
 bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu);
 bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable);
 void kvmi_xsetbv_event(struct kvm_vcpu *vcpu);
+bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu, bool enable);
 bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write);
 
 #else /* CONFIG_KVM_INTROSPECTION */
@@ -44,6 +46,8 @@ static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; }
 static inline bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu,
 						bool enable) { return false; }
 static inline void kvmi_xsetbv_event(struct kvm_vcpu *vcpu) { }
+static inline bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu,
+					       bool enable) { return false; }
 static inline bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor,
 					 bool write) { return true; }
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 093ff0da88ff..11178bd75cb4 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -360,12 +360,52 @@ static void kvmi_arch_disable_cr3w_intercept(struct kvm_vcpu *vcpu)
 	vcpu->arch.kvmi->cr3w.kvm_intercepted = false;
 }
 
+/*
+ * Returns true if one side (kvm or kvmi) tries to disable the descriptor
+ * interception while the other side is still tracking it.
+ */
+bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
+{
+	struct kvmi_interception *arch_vcpui = READ_ONCE(vcpu->arch.kvmi);
+
+	return (arch_vcpui && arch_vcpui->descriptor.monitor_fct(vcpu, enable));
+}
+EXPORT_SYMBOL(kvmi_monitor_desc_intercept);
+
+static bool monitor_desc_fct_kvmi(struct kvm_vcpu *vcpu, bool enable)
+{
+	vcpu->arch.kvmi->descriptor.kvmi_intercepted = enable;
+
+	if (enable)
+		vcpu->arch.kvmi->descriptor.kvm_intercepted =
+			kvm_x86_ops->desc_intercepted(vcpu);
+	else if (vcpu->arch.kvmi->descriptor.kvm_intercepted)
+		return true;
+
+	return false;
+}
+
+static bool monitor_desc_fct_kvm(struct kvm_vcpu *vcpu, bool enable)
+{
+	if (!vcpu->arch.kvmi->descriptor.kvmi_intercepted)
+		return false;
+
+	vcpu->arch.kvmi->descriptor.kvm_intercepted = enable;
+
+	if (!enable)
+		return true;
+
+	return false;
+}
+
 static int kvmi_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
 {
 	if (!kvm_x86_ops->desc_ctrl_supported())
 		return -KVM_EOPNOTSUPP;
 
+	vcpu->arch.kvmi->descriptor.monitor_fct = monitor_desc_fct_kvmi;
 	kvm_x86_ops->control_desc_intercept(vcpu, enable);
+	vcpu->arch.kvmi->descriptor.monitor_fct = monitor_desc_fct_kvm;
 
 	return 0;
 }
@@ -373,6 +413,9 @@ static int kvmi_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
 static void kvmi_arch_disable_desc_intercept(struct kvm_vcpu *vcpu)
 {
 	kvmi_control_desc_intercept(vcpu, false);
+
+	vcpu->arch.kvmi->descriptor.kvmi_intercepted = false;
+	vcpu->arch.kvmi->descriptor.kvm_intercepted = false;
 }
 
 int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
@@ -438,11 +481,13 @@ bool kvmi_arch_vcpu_alloc(struct kvm_vcpu *vcpu)
 
 	arch_vcpui->breakpoint.monitor_fct = monitor_bp_fct_kvm;
 	arch_vcpui->cr3w.monitor_fct = monitor_cr3w_fct_kvm;
+	arch_vcpui->descriptor.monitor_fct = monitor_desc_fct_kvm;
 
 	/*
 	 * paired with:
 	 *  - kvmi_monitor_bp_intercept()
 	 *  - kvmi_monitor_cr3w_intercept()
+	 *  - kvmi_monitor_desc_intercept()
 	 */
 	smp_wmb();
 	WRITE_ONCE(vcpu->arch.kvmi, arch_vcpui);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b377acc3410c..0fdc4556057e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7547,6 +7547,9 @@ static void svm_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
+	if (kvmi_monitor_desc_intercept(vcpu, enable))
+		return;
+
 	if (enable) {
 		set_intercept(svm, INTERCEPT_STORE_IDTR);
 		set_intercept(svm, INTERCEPT_STORE_GDTR);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c54c01e088b6..8745d696f592 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3044,6 +3044,9 @@ static void vmx_control_desc_intercept(struct kvm_vcpu *vcpu, bool enable)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
+	if (kvmi_monitor_desc_intercept(vcpu, enable))
+		return;
+
 	if (enable)
 		secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_DESC);
 	else

[PATCH v8 72/81] KVM: introspection: add KVMI_VCPU_CONTROL_MSR and KVMI_EVENT_MSR

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This command is used to enable/disable introspection for a specific
MSR. The KVMI_EVENT_MSR event is sent when the tracked MSR is going to
be changed. The introspection tool can respond by allowing the guest to
continue with normal execution or by discarding the change.

This is meant to prevent malicious changes to MSRs
such as MSR_IA32_SYSENTER_EIP.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  75 +++++++++
 arch/x86/include/asm/kvmi_host.h              |  12 ++
 arch/x86/include/uapi/asm/kvmi.h              |  18 ++
 arch/x86/kvm/kvmi.c                           | 157 ++++++++++++++++++
 arch/x86/kvm/x86.c                            |   3 +
 include/uapi/linux/kvmi.h                     |   2 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 102 ++++++++++++
 virt/kvm/introspection/kvmi.c                 |   1 +
 virt/kvm/introspection/kvmi_int.h             |   2 +
 virt/kvm/introspection/kvmi_msg.c             |  13 ++
 10 files changed, 385 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 6f6551230e11..3b9db943a549 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -550,6 +550,7 @@ the following events::
 	KVMI_EVENT_CR
 	KVMI_EVENT_DESCRIPTOR
 	KVMI_EVENT_HYPERCALL
+	KVMI_EVENT_MSR
 	KVMI_EVENT_XSETBV
 
 When an event is enabled, the introspection tool is notified and
@@ -843,6 +844,45 @@ Returns the guest memory type for a specific physical address.
 * -KVM_EINVAL - the padding is not zero
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 
+19. KVMI_VCPU_CONTROL_MSR
+-------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_control_msr {
+		__u8 enable;
+		__u8 padding1;
+		__u16 padding2;
+		__u32 msr;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Enables/disables introspection for a specific MSR and must be used
+in addition to *KVMI_VCPU_CONTROL_EVENTS* with the *KVMI_EVENT_MSR* ID set.
+
+Currently, only MSRs within the following two ranges are supported. Trying
+to control events for any other register will fail with -KVM_EINVAL::
+
+	0          ... 0x00001fff
+	0xc0000000 ... 0xc0001fff
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EINVAL - the specified MSR is invalid
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+
 Events
 ======
 
@@ -1148,3 +1188,38 @@ introspection has been enabled for this event (see **KVMI_VCPU_CONTROL_EVENTS**)
 	KVMI_DESC_TR
 
 ``write`` is 1 if the descriptor was written, 0 otherwise.
+
+9. KVMI_EVENT_MSR
+-----------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+	struct kvmi_event;
+	struct kvmi_event_msr {
+		__u32 msr;
+		__u32 padding;
+		__u64 old_value;
+		__u64 new_value;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+	struct kvmi_event_msr_reply {
+		__u64 new_val;
+	};
+
+This event is sent when a model specific register is going to be changed
+and the introspection has been enabled for this event and for this specific
+register (see **KVMI_VCPU_CONTROL_EVENTS**).
+
+``kvmi_event``, the MSR number, the old value and the new value are
+sent to the introspection tool. The *CONTINUE* action will set the ``new_val``.
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 3c4bba88b50d..a9326c8e8252 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -2,7 +2,10 @@
 #ifndef _ASM_X86_KVMI_HOST_H
 #define _ASM_X86_KVMI_HOST_H
 
+struct msr_data;
+
 #define KVMI_NUM_CR 5
+#define KVMI_NUM_MSR 0x2000
 
 struct kvmi_monitor_interception {
 	bool kvmi_intercepted;
@@ -15,6 +18,12 @@ struct kvmi_interception {
 	struct kvmi_monitor_interception breakpoint;
 	struct kvmi_monitor_interception cr3w;
 	struct kvmi_monitor_interception descriptor;
+	struct {
+		struct {
+			DECLARE_BITMAP(low, KVMI_NUM_MSR);
+			DECLARE_BITMAP(high, KVMI_NUM_MSR);
+		} kvmi_mask;
+	} msrw;
 };
 
 struct kvm_vcpu_arch_introspection {
@@ -34,6 +43,7 @@ bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu, bool enable);
 void kvmi_xsetbv_event(struct kvm_vcpu *vcpu);
 bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu, bool enable);
 bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write);
+bool kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr);
 
 #else /* CONFIG_KVM_INTROSPECTION */
 
@@ -50,6 +60,8 @@ static inline bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu,
 					       bool enable) { return false; }
 static inline bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor,
 					 bool write) { return true; }
+static inline bool kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr)
+				{ return true; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index 691a501200b3..e4d591912f37 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -121,4 +121,22 @@ struct kvmi_event_descriptor {
 	__u8 padding[6];
 };
 
+struct kvmi_vcpu_control_msr {
+	__u8 enable;
+	__u8 padding1;
+	__u16 padding2;
+	__u32 msr;
+};
+
+struct kvmi_event_msr {
+	__u32 msr;
+	__u32 padding;
+	__u64 old_value;
+	__u64 new_value;
+};
+
+struct kvmi_event_msr_reply {
+	__u64 new_val;
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 11178bd75cb4..b57b4320a19f 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -418,6 +418,76 @@ static void kvmi_arch_disable_desc_intercept(struct kvm_vcpu *vcpu)
 	vcpu->arch.kvmi->descriptor.kvm_intercepted = false;
 }
 
+static bool kvmi_msr_valid(unsigned int msr)
+{
+	return msr <= 0x1fff || (msr >= 0xc0000000 && msr <= 0xc0001fff);
+}
+
+static unsigned long *msr_mask(struct kvm_vcpu *vcpu, unsigned int *msr)
+{
+	switch (*msr) {
+	case 0 ... 0x1fff:
+		return vcpu->arch.kvmi->msrw.kvmi_mask.low;
+	case 0xc0000000 ... 0xc0001fff:
+		*msr &= 0x1fff;
+		return vcpu->arch.kvmi->msrw.kvmi_mask.high;
+	}
+
+	return NULL;
+}
+
+static bool test_msr_mask(struct kvm_vcpu *vcpu, unsigned int msr)
+{
+	unsigned long *mask = msr_mask(vcpu, &msr);
+
+	if (!mask)
+		return false;
+
+	return !!test_bit(msr, mask);
+}
+
+static bool msr_control(struct kvm_vcpu *vcpu, unsigned int msr, bool enable)
+{
+	unsigned long *mask = msr_mask(vcpu, &msr);
+
+	if (!mask)
+		return false;
+
+	if (enable)
+		set_bit(msr, mask);
+	else
+		clear_bit(msr, mask);
+
+	return true;
+}
+
+static unsigned int msr_mask_to_base(struct kvm_vcpu *vcpu, unsigned long *mask)
+{
+	if (mask == vcpu->arch.kvmi->msrw.kvmi_mask.high)
+		return 0xc0000000;
+
+	return 0;
+}
+
+static void kvmi_arch_disable_msr_intercept(struct kvm_vcpu *vcpu,
+					    unsigned long *mask)
+{
+	unsigned int msr_base = msr_mask_to_base(vcpu, mask);
+	int offset = -1;
+
+	for (;;) {
+		offset = find_next_bit(mask, KVMI_NUM_MSR, offset + 1);
+
+		if (offset >= KVMI_NUM_MSR)
+			break;
+
+		kvm_x86_ops->control_msr_intercept(vcpu, msr_base + offset,
+						   MSR_TYPE_W, false);
+	}
+
+	bitmap_zero(mask, KVMI_NUM_MSR);
+}
+
 int kvmi_arch_cmd_control_intercept(struct kvm_vcpu *vcpu,
 				    unsigned int event_id, bool enable)
 {
@@ -467,6 +537,8 @@ bool kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
 	kvmi_arch_disable_bp_intercept(vcpu);
 	kvmi_arch_disable_cr3w_intercept(vcpu);
 	kvmi_arch_disable_desc_intercept(vcpu);
+	kvmi_arch_disable_msr_intercept(vcpu, arch_vcpui->msrw.kvmi_mask.low);
+	kvmi_arch_disable_msr_intercept(vcpu, arch_vcpui->msrw.kvmi_mask.high);
 
 	return true;
 }
@@ -849,3 +921,88 @@ bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write)
 	return ret;
 }
 EXPORT_SYMBOL(kvmi_descriptor_event);
+
+int kvmi_arch_cmd_vcpu_control_msr(struct kvm_vcpu *vcpu,
+				   const struct kvmi_vcpu_control_msr *req)
+{
+	if (req->padding1 || req->padding2)
+		return -KVM_EINVAL;
+
+	if (!kvmi_msr_valid(req->msr))
+		return -KVM_EINVAL;
+
+	kvm_x86_ops->control_msr_intercept(vcpu, req->msr, MSR_TYPE_W,
+					   req->enable);
+	msr_control(vcpu, req->msr, req->enable);
+
+	return 0;
+}
+
+static u32 kvmi_send_msr(struct kvm_vcpu *vcpu, u32 msr, u64 old_value,
+			 u64 new_value, u64 *ret_value)
+{
+	struct kvmi_event_msr e;
+	struct kvmi_event_msr_reply r;
+	int err, action;
+
+	memset(&e, 0, sizeof(e));
+	e.msr = msr;
+	e.old_value = old_value;
+	e.new_value = new_value;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_MSR, &e, sizeof(e),
+			      &r, sizeof(r), &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	*ret_value = r.new_val;
+	return action;
+}
+
+static bool __kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr)
+{
+	struct msr_data old_msr = {
+		.host_initiated = true,
+		.index = msr->index,
+	};
+	bool ret = false;
+	u64 ret_value = msr->data;
+	u32 action;
+
+	if (!test_msr_mask(vcpu, msr->index))
+		return true;
+	if (kvm_x86_ops->get_msr(vcpu, &old_msr))
+		return true;
+	if (old_msr.data == msr->data)
+		return true;
+
+	action = kvmi_send_msr(vcpu, msr->index, old_msr.data, msr->data,
+			       &ret_value);
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		msr->data = ret_value;
+		ret = true;
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action, "MSR");
+	}
+
+	return ret;
+}
+
+bool kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = true;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return true;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_MSR))
+		ret = __kvmi_msr_event(vcpu, msr);
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ab0ad3b6ebc2..ce2f9d47d6f6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1490,6 +1490,9 @@ static int __kvm_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data,
 	msr.index = index;
 	msr.host_initiated = host_initiated;
 
+	if (!host_initiated && !kvmi_msr_event(vcpu, &msr))
+		return 1;
+
 	return kvm_x86_ops->set_msr(vcpu, &msr);
 }
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 2ccc4045137f..04e6971ea0af 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -38,6 +38,7 @@ enum {
 
 	KVMI_VCPU_GET_XSAVE     = 18,
 	KVMI_VCPU_GET_MTRR_TYPE = 19,
+	KVMI_VCPU_CONTROL_MSR   = 20,
 
 	KVMI_NUM_MESSAGES
 };
@@ -51,6 +52,7 @@ enum {
 	KVMI_EVENT_TRAP       = 5,
 	KVMI_EVENT_XSETBV     = 6,
 	KVMI_EVENT_DESCRIPTOR = 7,
+	KVMI_EVENT_MSR        = 8,
 
 	KVMI_NUM_EVENTS
 };
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 4f2de304a6f8..955ef55e1346 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -57,6 +57,7 @@ enum {
 	GUEST_TEST_CR,
 	GUEST_TEST_DESCRIPTOR,
 	GUEST_TEST_HYPERCALL,
+	GUEST_TEST_MSR,
 	GUEST_TEST_XSETBV,
 };
 
@@ -97,6 +98,15 @@ static void guest_hypercall_test(void)
 	asm volatile(".byte 0x0f,0x01,0xc1");
 }
 
+static void guest_msr_test(void)
+{
+	uint64_t msr;
+
+	msr = rdmsr(MSR_MISC_FEATURES_ENABLES);
+	msr |= 1; /* MSR_MISC_FEATURES_ENABLES_CPUID_FAULT */
+	wrmsr(MSR_MISC_FEATURES_ENABLES, msr);
+}
+
 /* from fpu/internal.h */
 static u64 xgetbv(u32 index)
 {
@@ -154,6 +164,9 @@ static void guest_code(void)
 		case GUEST_TEST_HYPERCALL:
 			guest_hypercall_test();
 			break;
+		case GUEST_TEST_MSR:
+			guest_msr_test();
+			break;
 		case GUEST_TEST_XSETBV:
 			guest_xsetbv_test();
 			break;
@@ -1437,6 +1450,94 @@ static void test_event_descriptor(struct kvm_vm *vm)
 	disable_vcpu_event(vm, event_id);
 }
 
+static int cmd_control_msr(struct kvm_vm *vm, __u32 msr, bool enable)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_control_msr cmd;
+	} req = {};
+
+	req.cmd.msr = msr;
+	req.cmd.enable = enable ? 1 : 0;
+
+	return do_vcpu0_command(vm, KVMI_VCPU_CONTROL_MSR,
+				&req.hdr, sizeof(req), NULL, 0);
+}
+
+static void enable_msr_events(struct kvm_vm *vm, __u32 msr)
+{
+	int r;
+
+	enable_vcpu_event(vm, KVMI_EVENT_MSR);
+
+	r = cmd_control_msr(vm, msr, true);
+	TEST_ASSERT(r == 0,
+		"KVMI_EVENT_MSR failed, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+}
+
+static void disable_msr_events(struct kvm_vm *vm, __u32 msr)
+{
+	int r;
+
+	r = cmd_control_msr(vm, msr, false);
+	TEST_ASSERT(r == 0,
+		"KVMI_EVENT_MSR failed, error %d(%s)\n",
+		-r, kvm_strerror(-r));
+
+	disable_vcpu_event(vm, KVMI_EVENT_MSR);
+}
+
+static void test_cmd_vcpu_control_msr(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = {
+		.vm = vm,
+		.vcpu_id = VCPU_ID,
+		.test_id = GUEST_TEST_MSR,
+	};
+	struct kvmi_msg_hdr hdr;
+	struct {
+		struct kvmi_event common;
+		struct kvmi_event_msr msr;
+	} ev;
+	struct {
+		struct vcpu_reply common;
+		struct kvmi_event_msr_reply msr;
+	} rpl = {};
+	__u16 event_id = KVMI_EVENT_MSR;
+	__u32 msr = MSR_MISC_FEATURES_ENABLES;
+	uint64_t msr_data;
+	pthread_t vcpu_thread;
+
+	enable_msr_events(vm, msr);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	receive_event(&hdr, &ev.common, sizeof(ev), event_id);
+
+	DEBUG("MSR 0x%x, old 0x%llx, new 0x%llx\n",
+		ev.msr.msr, ev.msr.old_value, ev.msr.new_value);
+
+	TEST_ASSERT(ev.msr.msr == msr,
+		"Unexpected MSR event, received MSR 0x%x, expected MSR 0x%x",
+		ev.msr.msr, msr);
+
+	rpl.msr.new_val = ev.msr.old_value;
+
+	reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl.common, sizeof(rpl));
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	disable_msr_events(vm, msr);
+
+	msr_data = vcpu_get_msr(vm, VCPU_ID, msr);
+	TEST_ASSERT(msr_data == ev.msr.old_value,
+		"Failed to block MSR 0x%x update, value 0x%x, expected 0x%x",
+		msr, msr_data, ev.msr.old_value);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1466,6 +1567,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_get_xsave(vm);
 	test_cmd_vcpu_get_mtrr_type(vm);
 	test_event_descriptor(vm);
+	test_cmd_vcpu_control_msr(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index db79744e5d2f..a858aba1672d 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -82,6 +82,7 @@ static void setup_known_events(void)
 	set_bit(KVMI_EVENT_CR, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_DESCRIPTOR, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events);
+	set_bit(KVMI_EVENT_MSR, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_TRAP, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_XSETBV, Kvmi_known_vcpu_events);
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 72c9d3a1a4b6..ba4bdfaef20d 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -107,5 +107,7 @@ int kvmi_arch_cmd_vcpu_get_xsave(struct kvm_vcpu *vcpu,
 				 struct kvmi_vcpu_get_xsave_reply **dest,
 				 size_t *dest_size);
 int kvmi_arch_cmd_vcpu_get_mtrr_type(struct kvm_vcpu *vcpu, u64 gpa, u8 *type);
+int kvmi_arch_cmd_vcpu_control_msr(struct kvm_vcpu *vcpu,
+				   const struct kvmi_vcpu_control_msr *req);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 78ae52f05c29..191b60c290ee 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -31,6 +31,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VM_WRITE_PHYSICAL]     = "KVMI_VM_WRITE_PHYSICAL",
 	[KVMI_VCPU_CONTROL_CR]       = "KVMI_VCPU_CONTROL_CR",
 	[KVMI_VCPU_CONTROL_EVENTS]   = "KVMI_VCPU_CONTROL_EVENTS",
+	[KVMI_VCPU_CONTROL_MSR]      = "KVMI_VCPU_CONTROL_MSR",
 	[KVMI_VCPU_GET_CPUID]        = "KVMI_VCPU_GET_CPUID",
 	[KVMI_VCPU_GET_INFO]         = "KVMI_VCPU_GET_INFO",
 	[KVMI_VCPU_GET_MTRR_TYPE]    = "KVMI_VCPU_GET_MTRR_TYPE",
@@ -592,6 +593,17 @@ static int handle_vcpu_get_mtrr_type(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, ec, &rpl, sizeof(rpl));
 }
 
+static int handle_vcpu_control_msr(const struct kvmi_vcpu_cmd_job *job,
+				   const struct kvmi_msg_hdr *msg,
+				   const void *req)
+{
+	int ec;
+
+	ec = kvmi_arch_cmd_vcpu_control_msr(job->vcpu, req);
+
+	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -603,6 +615,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 	[KVMI_EVENT]                 = handle_event_reply,
 	[KVMI_VCPU_CONTROL_CR]       = handle_vcpu_control_cr,
 	[KVMI_VCPU_CONTROL_EVENTS]   = handle_vcpu_control_events,
+	[KVMI_VCPU_CONTROL_MSR]      = handle_vcpu_control_msr,
 	[KVMI_VCPU_GET_CPUID]        = handle_get_cpuid,
 	[KVMI_VCPU_GET_INFO]         = handle_get_vcpu_info,
 	[KVMI_VCPU_GET_MTRR_TYPE]    = handle_vcpu_get_mtrr_type,

[PATCH v8 73/81] KVM: introspection: restore the state of MSR interception on unhook

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This commit also ensures that the introspection tool and the userspace
do not disable each other the MSR access VM-exit.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvmi_host.h |  12 +++
 arch/x86/kvm/kvmi.c              | 133 +++++++++++++++++++++++++++----
 arch/x86/kvm/svm.c               |  11 +++
 arch/x86/kvm/vmx/vmx.c           |  11 +++
 4 files changed, 150 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index a9326c8e8252..e6bb2d6f19d0 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -23,6 +23,12 @@ struct kvmi_interception {
 			DECLARE_BITMAP(low, KVMI_NUM_MSR);
 			DECLARE_BITMAP(high, KVMI_NUM_MSR);
 		} kvmi_mask;
+		struct {
+			DECLARE_BITMAP(low, KVMI_NUM_MSR);
+			DECLARE_BITMAP(high, KVMI_NUM_MSR);
+		} kvm_mask;
+		bool (*monitor_fct)(struct kvm_vcpu *vcpu, u32 msr,
+				    bool enable);
 	} msrw;
 };
 
@@ -44,6 +50,8 @@ void kvmi_xsetbv_event(struct kvm_vcpu *vcpu);
 bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu, bool enable);
 bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write);
 bool kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr);
+bool kvmi_monitor_msrw_intercept(struct kvm_vcpu *vcpu, u32 msr, bool enable);
+bool kvmi_msrw_intercept_originator(struct kvm_vcpu *vcpu);
 
 #else /* CONFIG_KVM_INTROSPECTION */
 
@@ -62,6 +70,10 @@ static inline bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor,
 					 bool write) { return true; }
 static inline bool kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr)
 				{ return true; }
+static inline bool kvmi_monitor_msrw_intercept(struct kvm_vcpu *vcpu, u32 msr,
+					       bool enable) { return false; }
+static inline bool kvmi_msrw_intercept_originator(struct kvm_vcpu *vcpu)
+				{ return false; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index b57b4320a19f..ccb11e553bde 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -423,22 +423,25 @@ static bool kvmi_msr_valid(unsigned int msr)
 	return msr <= 0x1fff || (msr >= 0xc0000000 && msr <= 0xc0001fff);
 }
 
-static unsigned long *msr_mask(struct kvm_vcpu *vcpu, unsigned int *msr)
+static unsigned long *msr_mask(struct kvm_vcpu *vcpu, unsigned int *msr,
+			       bool kvmi)
 {
 	switch (*msr) {
 	case 0 ... 0x1fff:
-		return vcpu->arch.kvmi->msrw.kvmi_mask.low;
+		return kvmi ? vcpu->arch.kvmi->msrw.kvmi_mask.low :
+			      vcpu->arch.kvmi->msrw.kvm_mask.low;
 	case 0xc0000000 ... 0xc0001fff:
 		*msr &= 0x1fff;
-		return vcpu->arch.kvmi->msrw.kvmi_mask.high;
+		return kvmi ? vcpu->arch.kvmi->msrw.kvmi_mask.high :
+			      vcpu->arch.kvmi->msrw.kvm_mask.high;
 	}
 
 	return NULL;
 }
 
-static bool test_msr_mask(struct kvm_vcpu *vcpu, unsigned int msr)
+static bool test_msr_mask(struct kvm_vcpu *vcpu, unsigned int msr, bool kvmi)
 {
-	unsigned long *mask = msr_mask(vcpu, &msr);
+	unsigned long *mask = msr_mask(vcpu, &msr, kvmi);
 
 	if (!mask)
 		return false;
@@ -446,9 +449,27 @@ static bool test_msr_mask(struct kvm_vcpu *vcpu, unsigned int msr)
 	return !!test_bit(msr, mask);
 }
 
-static bool msr_control(struct kvm_vcpu *vcpu, unsigned int msr, bool enable)
+/*
+ * Returns true if one side (kvm or kvmi) tries to disable the MSR write
+ * interception while the other side is still tracking it.
+ */
+bool kvmi_monitor_msrw_intercept(struct kvm_vcpu *vcpu, u32 msr, bool enable)
 {
-	unsigned long *mask = msr_mask(vcpu, &msr);
+	struct kvmi_interception *arch_vcpui;
+
+	if (!vcpu)
+		return false;
+
+	arch_vcpui = READ_ONCE(vcpu->arch.kvmi);
+
+	return (arch_vcpui && arch_vcpui->msrw.monitor_fct(vcpu, msr, enable));
+}
+EXPORT_SYMBOL(kvmi_monitor_msrw_intercept);
+
+static bool msr_control(struct kvm_vcpu *vcpu, unsigned int msr, bool enable,
+		       bool kvmi)
+{
+	unsigned long *mask = msr_mask(vcpu, &msr, kvmi);
 
 	if (!mask)
 		return false;
@@ -461,6 +482,63 @@ static bool msr_control(struct kvm_vcpu *vcpu, unsigned int msr, bool enable)
 	return true;
 }
 
+static bool msr_intercepted_by_kvmi(struct kvm_vcpu *vcpu, u32 msr)
+{
+	return test_msr_mask(vcpu, msr, true);
+}
+
+static bool msr_intercepted_by_kvm(struct kvm_vcpu *vcpu, u32 msr)
+{
+	return test_msr_mask(vcpu, msr, false);
+}
+
+static void record_msr_intercept_status_for_kvmi(struct kvm_vcpu *vcpu, u32 msr,
+						 bool enable)
+{
+	msr_control(vcpu, msr, enable, true);
+}
+
+static void record_msr_intercept_status_for_kvm(struct kvm_vcpu *vcpu, u32 msr,
+						bool enable)
+{
+	msr_control(vcpu, msr, enable, false);
+}
+
+static bool monitor_msrw_fct_kvmi(struct kvm_vcpu *vcpu, u32 msr, bool enable)
+{
+	bool ret = false;
+
+	if (enable) {
+		if (kvm_x86_ops->msr_write_intercepted(vcpu, msr))
+			record_msr_intercept_status_for_kvm(vcpu, msr, true);
+	} else {
+		if (unlikely(!msr_intercepted_by_kvmi(vcpu, msr)))
+			ret = true;
+
+		if (msr_intercepted_by_kvm(vcpu, msr))
+			ret = true;
+	}
+
+	record_msr_intercept_status_for_kvmi(vcpu, msr, enable);
+
+	return ret;
+}
+
+static bool monitor_msrw_fct_kvm(struct kvm_vcpu *vcpu, u32 msr, bool enable)
+{
+	bool ret = false;
+
+	if (!(msr_intercepted_by_kvmi(vcpu, msr)))
+		return false;
+
+	if (!enable)
+		ret = true;
+
+	record_msr_intercept_status_for_kvm(vcpu, msr, enable);
+
+	return ret;
+}
+
 static unsigned int msr_mask_to_base(struct kvm_vcpu *vcpu, unsigned long *mask)
 {
 	if (mask == vcpu->arch.kvmi->msrw.kvmi_mask.high)
@@ -469,8 +547,16 @@ static unsigned int msr_mask_to_base(struct kvm_vcpu *vcpu, unsigned long *mask)
 	return 0;
 }
 
-static void kvmi_arch_disable_msr_intercept(struct kvm_vcpu *vcpu,
-					    unsigned long *mask)
+static void kvmi_control_msrw_intercept(struct kvm_vcpu *vcpu, u32 msr,
+					bool enable)
+{
+	vcpu->arch.kvmi->msrw.monitor_fct = monitor_msrw_fct_kvmi;
+	kvm_x86_ops->control_msr_intercept(vcpu, msr, MSR_TYPE_W, enable);
+	vcpu->arch.kvmi->msrw.monitor_fct = monitor_msrw_fct_kvm;
+}
+
+static void kvmi_arch_disable_msrw_intercept(struct kvm_vcpu *vcpu,
+					     unsigned long *mask)
 {
 	unsigned int msr_base = msr_mask_to_base(vcpu, mask);
 	int offset = -1;
@@ -481,8 +567,7 @@ static void kvmi_arch_disable_msr_intercept(struct kvm_vcpu *vcpu,
 		if (offset >= KVMI_NUM_MSR)
 			break;
 
-		kvm_x86_ops->control_msr_intercept(vcpu, msr_base + offset,
-						   MSR_TYPE_W, false);
+		kvmi_control_msrw_intercept(vcpu, msr_base + offset, false);
 	}
 
 	bitmap_zero(mask, KVMI_NUM_MSR);
@@ -537,8 +622,8 @@ bool kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
 	kvmi_arch_disable_bp_intercept(vcpu);
 	kvmi_arch_disable_cr3w_intercept(vcpu);
 	kvmi_arch_disable_desc_intercept(vcpu);
-	kvmi_arch_disable_msr_intercept(vcpu, arch_vcpui->msrw.kvmi_mask.low);
-	kvmi_arch_disable_msr_intercept(vcpu, arch_vcpui->msrw.kvmi_mask.high);
+	kvmi_arch_disable_msrw_intercept(vcpu, arch_vcpui->msrw.kvmi_mask.low);
+	kvmi_arch_disable_msrw_intercept(vcpu, arch_vcpui->msrw.kvmi_mask.high);
 
 	return true;
 }
@@ -554,12 +639,14 @@ bool kvmi_arch_vcpu_alloc(struct kvm_vcpu *vcpu)
 	arch_vcpui->breakpoint.monitor_fct = monitor_bp_fct_kvm;
 	arch_vcpui->cr3w.monitor_fct = monitor_cr3w_fct_kvm;
 	arch_vcpui->descriptor.monitor_fct = monitor_desc_fct_kvm;
+	arch_vcpui->msrw.monitor_fct = monitor_msrw_fct_kvm;
 
 	/*
 	 * paired with:
 	 *  - kvmi_monitor_bp_intercept()
 	 *  - kvmi_monitor_cr3w_intercept()
 	 *  - kvmi_monitor_desc_intercept()
+	 *  - kvmi_monitor_msrw_intercept()
 	 */
 	smp_wmb();
 	WRITE_ONCE(vcpu->arch.kvmi, arch_vcpui);
@@ -922,6 +1009,20 @@ bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write)
 }
 EXPORT_SYMBOL(kvmi_descriptor_event);
 
+bool kvmi_msrw_intercept_originator(struct kvm_vcpu *vcpu)
+{
+	struct kvmi_interception *arch_vcpui;
+
+	if (!vcpu)
+		return false;
+
+	arch_vcpui = READ_ONCE(vcpu->arch.kvmi);
+
+	return (arch_vcpui &&
+		arch_vcpui->msrw.monitor_fct == monitor_msrw_fct_kvmi);
+}
+EXPORT_SYMBOL(kvmi_msrw_intercept_originator);
+
 int kvmi_arch_cmd_vcpu_control_msr(struct kvm_vcpu *vcpu,
 				   const struct kvmi_vcpu_control_msr *req)
 {
@@ -931,9 +1032,7 @@ int kvmi_arch_cmd_vcpu_control_msr(struct kvm_vcpu *vcpu,
 	if (!kvmi_msr_valid(req->msr))
 		return -KVM_EINVAL;
 
-	kvm_x86_ops->control_msr_intercept(vcpu, req->msr, MSR_TYPE_W,
-					   req->enable);
-	msr_control(vcpu, req->msr, req->enable);
+	kvmi_control_msrw_intercept(vcpu, req->msr, req->enable);
 
 	return 0;
 }
@@ -969,7 +1068,7 @@ static bool __kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr)
 	u64 ret_value = msr->data;
 	u32 action;
 
-	if (!test_msr_mask(vcpu, msr->index))
+	if (!test_msr_mask(vcpu, msr->index, true))
 		return true;
 	if (kvm_x86_ops->get_msr(vcpu, &old_msr))
 		return true;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 0fdc4556057e..0df26556f317 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1088,6 +1088,17 @@ static void set_msr_interception(struct kvm_vcpu *vcpu,
 	unsigned long tmp;
 	u32 offset;
 
+#ifdef CONFIG_KVM_INTROSPECTION
+	if ((type & MSR_TYPE_W) &&
+	    kvmi_monitor_msrw_intercept(vcpu, msr, !value))
+		type &= ~MSR_TYPE_W;
+
+	/*
+	 * Avoid the below warning for kvmi intercepted msrs.
+	 */
+	if (!kvmi_msrw_intercept_originator(vcpu))
+#endif /* CONFIG_KVM_INTROSPECTION */
+
 	/*
 	 * If this warning triggers extend the direct_access_msrs list at the
 	 * beginning of the file
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 8745d696f592..fd748c165e78 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3662,6 +3662,12 @@ static __always_inline void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu,
 	if (!cpu_has_vmx_msr_bitmap())
 		return;
 
+#ifdef CONFIG_KVM_INTROSPECTION
+	if ((type & MSR_TYPE_W) &&
+	    kvmi_monitor_msrw_intercept(vcpu, msr, false))
+		type &= ~MSR_TYPE_W;
+#endif /* CONFIG_KVM_INTROSPECTION */
+
 	if (static_branch_unlikely(&enable_evmcs))
 		evmcs_touch_msr_bitmap();
 
@@ -3701,6 +3707,11 @@ static __always_inline void vmx_enable_intercept_for_msr(struct kvm_vcpu *vcpu,
 	if (!cpu_has_vmx_msr_bitmap())
 		return;
 
+#ifdef CONFIG_KVM_INTROSPECTION
+	if (type & MSR_TYPE_W)
+		kvmi_monitor_msrw_intercept(vcpu, msr, true);
+#endif /* CONFIG_KVM_INTROSPECTION */
+
 	if (static_branch_unlikely(&enable_evmcs))
 		evmcs_touch_msr_bitmap();
 

[PATCH v8 74/81] KVM: introspection: add KVMI_VM_SET_PAGE_ACCESS

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This command sets the spte access bits (rwx) for an array of guest
physical addresses (through the page tracking subsystem).

These GPAs, with the requested access bits, are also kept in a radix
tree in order to filter out the #PF events which are of no interest to
the introspection tool.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  59 ++++++++
 arch/x86/include/asm/kvm_host.h               |   2 +
 arch/x86/include/asm/kvmi_host.h              |   8 ++
 arch/x86/kvm/kvmi.c                           |  73 ++++++++++
 include/linux/kvmi_host.h                     |   3 +
 include/uapi/linux/kvmi.h                     |  23 +++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  |  53 +++++++
 virt/kvm/introspection/kvmi.c                 | 135 +++++++++++++++++-
 virt/kvm/introspection/kvmi_int.h             |  14 ++
 virt/kvm/introspection/kvmi_msg.c             |  31 ++--
 10 files changed, 391 insertions(+), 10 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 3b9db943a549..fe6c71f84dd7 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -883,6 +883,65 @@ to control events for any other register will fail with -KVM_EINVAL::
 * -KVM_EINVAL - the padding is not zero
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 
+20. KVMI_VM_SET_PAGE_ACCESS
+---------------------------
+
+:Architectures: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vm_set_page_access {
+		__u16 count;
+		__u16 padding1;
+		__u32 padding2;
+		struct kvmi_page_access_entry entries[0];
+	};
+
+where::
+
+	struct kvmi_page_access_entry {
+		__u64 gpa;
+		__u8 access;
+		__u8 padding1;
+		__u16 padding2;
+		__u32 padding3;
+	};
+
+
+:Returns:
+
+::
+
+	struct kvmi_error_code
+
+Sets the spte access bits (rwx) for an array of ``count`` guest physical
+addresses.
+
+The valid access bits are::
+
+	KVMI_PAGE_ACCESS_R
+	KVMI_PAGE_ACCESS_W
+	KVMI_PAGE_ACCESS_X
+
+
+The command will fail with -KVM_EINVAL if any of the specified combination
+of access bits is not supported.
+
+The command will try to apply all changes and return the first error if
+some failed. The introspection tool should handle the rollback.
+
+In order to 'forget' an address, all three bits ('rwx') must be set.
+
+:Errors:
+
+* -KVM_EINVAL - the specified access bits combination is invalid
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EINVAL - the message size is invalid
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+* -KVM_ENOMEM - there is not enough memory to add the page tracking structures
+
 Events
 ======
 
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5f3b6f20718f..08f82e7d462b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -45,6 +45,8 @@
 #define KVM_PRIVATE_MEM_SLOTS 3
 #define KVM_MEM_SLOTS_NUM (KVM_USER_MEM_SLOTS + KVM_PRIVATE_MEM_SLOTS)
 
+#include <asm/kvmi_host.h>
+
 #define KVM_HALT_POLL_NS_DEFAULT 200000
 
 #define KVM_IRQCHIP_NUM_PINS  KVM_IOAPIC_NUM_PINS
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index e6bb2d6f19d0..446f6c3ddf4e 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -2,6 +2,8 @@
 #ifndef _ASM_X86_KVMI_HOST_H
 #define _ASM_X86_KVMI_HOST_H
 
+#include <asm/kvm_page_track.h>
+
 struct msr_data;
 
 #define KVMI_NUM_CR 5
@@ -39,6 +41,12 @@ struct kvm_vcpu_arch_introspection {
 struct kvm_arch_introspection {
 };
 
+#define SLOTS_SIZE BITS_TO_LONGS(KVM_MEM_SLOTS_NUM)
+
+struct kvmi_arch_mem_access {
+	unsigned long active[KVM_PAGE_TRACK_MAX][SLOTS_SIZE];
+};
+
 #ifdef CONFIG_KVM_INTROSPECTION
 
 bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg);
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index ccb11e553bde..328783d9e341 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -1105,3 +1105,76 @@ bool kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr)
 
 	return ret;
 }
+
+static const struct {
+	unsigned int allow_bit;
+	enum kvm_page_track_mode track_mode;
+} track_modes[] = {
+	{ KVMI_PAGE_ACCESS_R, KVM_PAGE_TRACK_PREREAD },
+	{ KVMI_PAGE_ACCESS_W, KVM_PAGE_TRACK_PREWRITE },
+	{ KVMI_PAGE_ACCESS_X, KVM_PAGE_TRACK_PREEXEC },
+};
+
+void kvmi_arch_update_page_tracking(struct kvm *kvm,
+				    struct kvm_memory_slot *slot,
+				    struct kvmi_mem_access *m)
+{
+	struct kvmi_arch_mem_access *arch = &m->arch;
+	int i;
+
+	if (!slot) {
+		slot = gfn_to_memslot(kvm, m->gfn);
+		if (!slot)
+			return;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(track_modes); i++) {
+		unsigned int allow_bit = track_modes[i].allow_bit;
+		enum kvm_page_track_mode mode = track_modes[i].track_mode;
+		bool slot_tracked = test_bit(slot->id, arch->active[mode]);
+
+		if (m->access & allow_bit) {
+			if (slot_tracked) {
+				kvm_slot_page_track_remove_page(kvm, slot,
+								m->gfn, mode);
+				clear_bit(slot->id, arch->active[mode]);
+			}
+		} else if (!slot_tracked) {
+			kvm_slot_page_track_add_page(kvm, slot, m->gfn, mode);
+			set_bit(slot->id, arch->active[mode]);
+		}
+	}
+}
+
+int kvmi_arch_cmd_set_page_access(struct kvm_introspection *kvmi,
+				  const struct kvmi_msg_hdr *msg,
+				  const struct kvmi_vm_set_page_access *req)
+{
+	const struct kvmi_page_access_entry *entry = req->entries;
+	const struct kvmi_page_access_entry *end = req->entries + req->count;
+	u8 unknown_bits = ~(KVMI_PAGE_ACCESS_R | KVMI_PAGE_ACCESS_W
+			    | KVMI_PAGE_ACCESS_X);
+	int ec = 0;
+
+	if (req->padding1 || req->padding2)
+		return -KVM_EINVAL;
+
+	if (msg->size != struct_size(req, entries, req->count))
+		return -KVM_EINVAL;
+
+	for (; entry < end; entry++) {
+		int r;
+
+		if ((entry->access & unknown_bits) || entry->padding1
+				|| entry->padding2 || entry->padding3)
+			r = -KVM_EINVAL;
+		else
+			r = kvmi_cmd_set_page_access(kvmi, entry->gpa,
+						      entry->access);
+		if (r && !ec)
+			ec = r;
+	}
+
+	return ec;
+}
+
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index e64f2bbd033a..c9dd2d57033b 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -67,6 +67,9 @@ struct kvm_introspection {
 	DECLARE_BITMAP(vm_event_enable_mask, KVMI_NUM_EVENTS);
 
 	atomic_t ev_seq;
+
+	struct radix_tree_root access_tree;
+	rwlock_t access_tree_lock;
 };
 
 #ifdef CONFIG_KVM_INTROSPECTION
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 04e6971ea0af..da0ce3e41cdd 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -40,6 +40,8 @@ enum {
 	KVMI_VCPU_GET_MTRR_TYPE = 19,
 	KVMI_VCPU_CONTROL_MSR   = 20,
 
+	KVMI_VM_SET_PAGE_ACCESS = 21,
+
 	KVMI_NUM_MESSAGES
 };
 
@@ -63,6 +65,12 @@ enum {
 	KVMI_EVENT_ACTION_CRASH    = 2,
 };
 
+enum {
+	KVMI_PAGE_ACCESS_R = 1 << 0,
+	KVMI_PAGE_ACCESS_W = 1 << 1,
+	KVMI_PAGE_ACCESS_X = 1 << 2,
+};
+
 struct kvmi_msg_hdr {
 	__u16 id;
 	__u16 size;
@@ -153,6 +161,21 @@ struct kvmi_vm_get_max_gfn_reply {
 	__u64 gfn;
 };
 
+struct kvmi_page_access_entry {
+	__u64 gpa;
+	__u8 access;
+	__u8 padding1;
+	__u16 padding2;
+	__u32 padding3;
+};
+
+struct kvmi_vm_set_page_access {
+	__u16 count;
+	__u16 padding1;
+	__u32 padding2;
+	struct kvmi_page_access_entry entries[0];
+};
+
 struct kvmi_event {
 	__u16 size;
 	__u16 vcpu;
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 955ef55e1346..c2ab28f6427f 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -1538,6 +1538,58 @@ static void test_cmd_vcpu_control_msr(struct kvm_vm *vm)
 		msr, msr_data, ev.msr.old_value);
 }
 
+static int cmd_set_page_access(__u16 count, __u64 *gpa, __u8 *access)
+{
+	struct kvmi_page_access_entry *entry, *end;
+	struct kvmi_vm_set_page_access *cmd;
+	struct kvmi_msg_hdr *req;
+	size_t req_size;
+	int r;
+
+	req_size = sizeof(*req) + sizeof(*cmd) + count * sizeof(*entry);
+
+	req = calloc(1, req_size);
+
+	TEST_ASSERT(req, "Insufficient Memory\n");
+
+	cmd = (struct kvmi_vm_set_page_access *)(req + 1);
+	cmd->count = count;
+
+	entry = cmd->entries;
+	end = cmd->entries + count;
+	for (; entry < end; entry++) {
+		entry->gpa = *gpa++;
+		entry->access = *access++;
+	}
+
+	r = do_command(KVMI_VM_SET_PAGE_ACCESS, req, req_size, NULL, 0);
+
+	free(req);
+	return r;
+}
+
+static void set_page_access(__u64 gpa, __u8 access)
+{
+	int r;
+
+	r = cmd_set_page_access(1, &gpa, &access);
+	TEST_ASSERT(r == 0,
+		"KVMI_VM_SET_PAGE_ACCESS failed, gpa 0x%llx, access 0x%x, error %d (%s)\n",
+		gpa, access, -r, kvm_strerror(-r));
+}
+
+static void test_cmd_vm_set_page_access(struct kvm_vm *vm)
+{
+	__u8 full_access = KVMI_PAGE_ACCESS_R | KVMI_PAGE_ACCESS_W
+			| KVMI_PAGE_ACCESS_X;
+	__u8 no_access = 0;
+	__u64 gpa = 0;
+
+	set_page_access(gpa, no_access);
+
+	set_page_access(gpa, full_access);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1568,6 +1620,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_get_mtrr_type(vm);
 	test_event_descriptor(vm);
 	test_cmd_vcpu_control_msr(vm);
+	test_cmd_vm_set_page_access(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index a858aba1672d..2629d3d1f68c 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -20,6 +20,11 @@ DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 
 static struct kmem_cache *msg_cache;
 static struct kmem_cache *job_cache;
+static struct kmem_cache *radix_cache;
+
+static const u8 full_access  =	KVMI_PAGE_ACCESS_R |
+				KVMI_PAGE_ACCESS_W |
+				KVMI_PAGE_ACCESS_X;
 
 void *kvmi_msg_alloc(void)
 {
@@ -45,6 +50,8 @@ static void kvmi_cache_destroy(void)
 	msg_cache = NULL;
 	kmem_cache_destroy(job_cache);
 	job_cache = NULL;
+	kmem_cache_destroy(radix_cache);
+	radix_cache = NULL;
 }
 
 static int kvmi_cache_create(void)
@@ -54,8 +61,11 @@ static int kvmi_cache_create(void)
 	job_cache = kmem_cache_create("kvmi_job",
 				      sizeof(struct kvmi_job),
 				      0, SLAB_ACCOUNT, NULL);
+	radix_cache = kmem_cache_create("kvmi_radix_tree",
+					sizeof(struct kvmi_mem_access),
+					0, SLAB_ACCOUNT, NULL);
 
-	if (!msg_cache || !job_cache) {
+	if (!msg_cache || !job_cache || !radix_cache) {
 		kvmi_cache_destroy();
 
 		return -1;
@@ -209,11 +219,37 @@ static void free_vcpui(struct kvm_vcpu *vcpu)
 	kvmi_make_request(vcpu, false);
 }
 
+static void kvmi_clear_mem_access(struct kvm *kvm)
+{
+	struct kvm_introspection *kvmi = KVMI(kvm);
+	struct radix_tree_iter iter;
+	void **slot;
+	int idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+
+	radix_tree_for_each_slot(slot, &kvmi->access_tree, &iter, 0) {
+		struct kvmi_mem_access *m = *slot;
+
+		m->access = full_access;
+		kvmi_arch_update_page_tracking(kvm, NULL, m);
+
+		radix_tree_iter_delete(&kvmi->access_tree, &iter, slot);
+		kmem_cache_free(radix_cache, m);
+	}
+
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+}
+
 static void free_kvmi(struct kvm *kvm)
 {
 	struct kvm_vcpu *vcpu;
 	int i;
 
+	kvmi_clear_mem_access(kvm);
+
 	kvm_for_each_vcpu(i, vcpu, kvm)
 		free_vcpui(vcpu);
 
@@ -248,6 +284,10 @@ alloc_kvmi(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 
 	atomic_set(&kvmi->ev_seq, 0);
 
+	INIT_RADIX_TREE(&kvmi->access_tree,
+			GFP_KERNEL & ~__GFP_DIRECT_RECLAIM);
+	rwlock_init(&kvmi->access_tree_lock);
+
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		int err = create_vcpui(vcpu);
 
@@ -959,3 +999,96 @@ bool kvmi_enter_guest(struct kvm_vcpu *vcpu)
 	kvmi_put(vcpu->kvm);
 	return r;
 }
+
+static struct kvmi_mem_access *
+__kvmi_get_gfn_access(struct kvm_introspection *kvmi, const gfn_t gfn)
+{
+	return radix_tree_lookup(&kvmi->access_tree, gfn);
+}
+
+static void kvmi_update_mem_access(struct kvm *kvm, struct kvmi_mem_access *m)
+{
+	struct kvm_introspection *kvmi = KVMI(kvm);
+
+	kvmi_arch_update_page_tracking(kvm, NULL, m);
+
+	if (m->access == full_access) {
+		radix_tree_delete(&kvmi->access_tree, m->gfn);
+		kmem_cache_free(radix_cache, m);
+	}
+}
+
+static bool kvmi_insert_mem_access(struct kvm *kvm, struct kvmi_mem_access *m)
+{
+	struct kvm_introspection *kvmi = KVMI(kvm);
+
+	if (!kvm_is_visible_gfn(kvm, m->gfn))
+		return false;
+
+	if (m->access == full_access)
+		return false;
+
+	radix_tree_insert(&kvmi->access_tree, m->gfn, m);
+	kvmi_arch_update_page_tracking(kvm, NULL, m);
+
+	return true;
+}
+
+static void kvmi_set_mem_access(struct kvm *kvm, struct kvmi_mem_access *m,
+				bool *done)
+{
+	struct kvm_introspection *kvmi = KVMI(kvm);
+	struct kvmi_mem_access *found;
+	int idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+	write_lock(&kvmi->access_tree_lock);
+
+	found = __kvmi_get_gfn_access(kvmi, m->gfn);
+	if (found) {
+		found->access = m->access;
+		kvmi_update_mem_access(kvm, found);
+	} else {
+		if (kvmi_insert_mem_access(kvm, m))
+			*done = true;
+	}
+
+	write_unlock(&kvmi->access_tree_lock);
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+}
+
+static int kvmi_set_gfn_access(struct kvm *kvm, gfn_t gfn, u8 access)
+{
+	struct kvmi_mem_access *m;
+	bool done = false;
+	int err = 0;
+
+	m = kmem_cache_zalloc(radix_cache, GFP_KERNEL);
+	if (!m)
+		return -KVM_ENOMEM;
+
+	m->gfn = gfn;
+	m->access = access;
+
+	if (radix_tree_preload(GFP_KERNEL))
+		err = -KVM_ENOMEM;
+	else
+		kvmi_set_mem_access(kvm, m, &done);
+
+	radix_tree_preload_end();
+
+	if (!done)
+		kmem_cache_free(radix_cache, m);
+
+	return err;
+}
+
+int kvmi_cmd_set_page_access(struct kvm_introspection *kvmi, u64 gpa, u8 access)
+{
+	gfn_t gfn = gpa_to_gfn(gpa);
+
+	return kvmi_set_gfn_access(kvmi->kvm, gfn, access);
+}
+
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index ba4bdfaef20d..237bb083cf01 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -23,6 +23,12 @@ extern DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 #define KVMI(kvm) ((kvm)->kvmi)
 #define VCPUI(vcpu) ((vcpu)->kvmi)
 
+struct kvmi_mem_access {
+	gfn_t gfn;
+	u8 access;
+	struct kvmi_arch_mem_access arch;
+};
+
 static inline bool is_event_enabled(struct kvm_vcpu *vcpu, int event)
 {
 	return test_bit(event, VCPUI(vcpu)->ev_enable_mask);
@@ -72,6 +78,8 @@ int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, size_t size,
 int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait);
 int kvmi_cmd_vcpu_set_registers(struct kvm_vcpu *vcpu,
 				const struct kvm_regs *regs);
+int kvmi_cmd_set_page_access(struct kvm_introspection *kvmi, u64 gpa,
+			     u8 access);
 
 /* arch */
 bool kvmi_arch_vcpu_alloc(struct kvm_vcpu *vcpu);
@@ -109,5 +117,11 @@ int kvmi_arch_cmd_vcpu_get_xsave(struct kvm_vcpu *vcpu,
 int kvmi_arch_cmd_vcpu_get_mtrr_type(struct kvm_vcpu *vcpu, u64 gpa, u8 *type);
 int kvmi_arch_cmd_vcpu_control_msr(struct kvm_vcpu *vcpu,
 				   const struct kvmi_vcpu_control_msr *req);
+void kvmi_arch_update_page_tracking(struct kvm *kvm,
+				    struct kvm_memory_slot *slot,
+				    struct kvmi_mem_access *m);
+int kvmi_arch_cmd_set_page_access(struct kvm_introspection *kvmi,
+				  const struct kvmi_msg_hdr *msg,
+				  const struct kvmi_vm_set_page_access *req);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 191b60c290ee..973ed9d92bfb 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -28,6 +28,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VM_GET_INFO]           = "KVMI_VM_GET_INFO",
 	[KVMI_VM_GET_MAX_GFN]        = "KVMI_VM_GET_MAX_GFN",
 	[KVMI_VM_READ_PHYSICAL]      = "KVMI_VM_READ_PHYSICAL",
+	[KVMI_VM_SET_PAGE_ACCESS]    = "KVMI_VM_SET_PAGE_ACCESS",
 	[KVMI_VM_WRITE_PHYSICAL]     = "KVMI_VM_WRITE_PHYSICAL",
 	[KVMI_VCPU_CONTROL_CR]       = "KVMI_VCPU_CONTROL_CR",
 	[KVMI_VCPU_CONTROL_EVENTS]   = "KVMI_VCPU_CONTROL_EVENTS",
@@ -364,20 +365,32 @@ static int handle_vm_get_max_gfn(struct kvm_introspection *kvmi,
 	return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl));
 }
 
+static int handle_set_page_access(struct kvm_introspection *kvmi,
+				  const struct kvmi_msg_hdr *msg,
+				  const void *req)
+{
+	int ec;
+
+	ec = kvmi_arch_cmd_set_page_access(kvmi, msg, req);
+
+	return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed by the receiving thread/worker.
  */
 static int(*const msg_vm[])(struct kvm_introspection *,
 			    const struct kvmi_msg_hdr *, const void *) = {
-	[KVMI_GET_VERSION]       = handle_get_version,
-	[KVMI_VM_CHECK_COMMAND]  = handle_check_command,
-	[KVMI_VM_CHECK_EVENT]    = handle_check_event,
-	[KVMI_VM_CONTROL_EVENTS] = handle_vm_control_events,
-	[KVMI_VM_GET_INFO]       = handle_get_info,
-	[KVMI_VM_GET_MAX_GFN]    = handle_vm_get_max_gfn,
-	[KVMI_VM_READ_PHYSICAL]  = handle_read_physical,
-	[KVMI_VM_WRITE_PHYSICAL] = handle_write_physical,
-	[KVMI_VCPU_PAUSE]        = handle_pause_vcpu,
+	[KVMI_GET_VERSION]        = handle_get_version,
+	[KVMI_VM_CHECK_COMMAND]   = handle_check_command,
+	[KVMI_VM_CHECK_EVENT]     = handle_check_event,
+	[KVMI_VM_CONTROL_EVENTS]  = handle_vm_control_events,
+	[KVMI_VM_GET_INFO]        = handle_get_info,
+	[KVMI_VM_GET_MAX_GFN]     = handle_vm_get_max_gfn,
+	[KVMI_VM_READ_PHYSICAL]   = handle_read_physical,
+	[KVMI_VM_SET_PAGE_ACCESS] = handle_set_page_access,
+	[KVMI_VM_WRITE_PHYSICAL]  = handle_write_physical,
+	[KVMI_VCPU_PAUSE]         = handle_pause_vcpu,
 };
 
 static bool is_vm_command(u16 id)

[PATCH v8 75/81] KVM: introspection: add KVMI_EVENT_PF

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

This event is sent when a #PF occurs due to a failed permission check
in the shadow page tables, for a page in which the introspection tool
has shown interest.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               |  50 +++++
 arch/x86/include/asm/kvmi_host.h              |   1 +
 arch/x86/kvm/kvmi.c                           |  27 +++
 include/uapi/linux/kvmi.h                     |  10 +
 .../testing/selftests/kvm/x86_64/kvmi_test.c  |  74 +++++++
 virt/kvm/introspection/kvmi.c                 | 205 ++++++++++++++++++
 virt/kvm/introspection/kvmi_int.h             |   4 +
 virt/kvm/introspection/kvmi_msg.c             |  18 ++
 8 files changed, 389 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index fe6c71f84dd7..3952aef9af9c 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -551,6 +551,7 @@ the following events::
 	KVMI_EVENT_DESCRIPTOR
 	KVMI_EVENT_HYPERCALL
 	KVMI_EVENT_MSR
+	KVMI_EVENT_PF
 	KVMI_EVENT_XSETBV
 
 When an event is enabled, the introspection tool is notified and
@@ -1282,3 +1283,52 @@ register (see **KVMI_VCPU_CONTROL_EVENTS**).
 
 ``kvmi_event``, the MSR number, the old value and the new value are
 sent to the introspection tool. The *CONTINUE* action will set the ``new_val``.
+
+10. KVMI_EVENT_PF
+-----------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH, RETRY
+:Parameters:
+
+::
+
+	struct kvmi_event;
+	struct kvmi_event_pf {
+		__u64 gva;
+		__u64 gpa;
+		__u8 access;
+		__u8 padding1;
+		__u16 padding2;
+		__u32 padding3;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+
+This event is sent when a hypervisor page fault occurs due to a failed
+permission check in the shadow page tables, the introspection has been
+enabled for this event (see *KVMI_VPUC_CONTROL_EVENTS*) and the event was
+generated for a page in which the introspection tool has shown interest
+(ie. has previously touched it by adjusting the spte permissions).
+
+The shadow page tables can be used by the introspection tool to guarantee
+the purpose of code areas inside the guest (code, rodata, stack, heap
+etc.) Each attempt at an operation unfitting for a certain memory
+range (eg. execute code in heap) triggers a page fault and gives the
+introspection tool the chance to audit the code attempting the operation.
+
+``kvmi_event``, guest virtual address (or 0xffffffff/UNMAPPED_GVA),
+guest physical address and the access flags (eg. KVMI_PAGE_ACCESS_R)
+are sent to the introspection tool.
+
+The *CONTINUE* action will continue the page fault handling via emulation.
+
+The *RETRY* action is used by the introspection tool to retry the
+execution of the current instruction, usually because it changed the
+instruction pointer or the page restrictions.
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 446f6c3ddf4e..8d0c3ed3021b 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -39,6 +39,7 @@ struct kvm_vcpu_arch_introspection {
 };
 
 struct kvm_arch_introspection {
+	struct kvm_page_track_notifier_node kptn_node;
 };
 
 #define SLOTS_SIZE BITS_TO_LONGS(KVM_MEM_SLOTS_NUM)
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 328783d9e341..06829e1c5737 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -1178,3 +1178,30 @@ int kvmi_arch_cmd_set_page_access(struct kvm_introspection *kvmi,
 	return ec;
 }
 
+bool kvmi_arch_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			u8 access)
+{
+	bool ret = false;
+	u32 action;
+
+	action = kvmi_msg_send_pf(vcpu, gpa, gva, access);
+
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		ret = true;
+		break;
+	case KVMI_EVENT_ACTION_RETRY:
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action, "PF");
+	}
+
+	return ret;
+}
+
+bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu)
+{
+	return kvm_x86_ops->spt_fault(vcpu) &&
+	      !kvm_x86_ops->gpt_translation_fault(vcpu);
+}
+
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index da0ce3e41cdd..df192936b017 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -55,6 +55,7 @@ enum {
 	KVMI_EVENT_XSETBV     = 6,
 	KVMI_EVENT_DESCRIPTOR = 7,
 	KVMI_EVENT_MSR        = 8,
+	KVMI_EVENT_PF         = 9,
 
 	KVMI_NUM_EVENTS
 };
@@ -191,4 +192,13 @@ struct kvmi_event_reply {
 	__u32 padding2;
 };
 
+struct kvmi_event_pf {
+	__u64 gva;
+	__u64 gpa;
+	__u8 access;
+	__u8 padding1;
+	__u16 padding2;
+	__u32 padding3;
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index c2ab28f6427f..48cb546234c0 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -42,6 +42,11 @@ struct vcpu_reply {
 	struct kvmi_event_reply reply;
 };
 
+struct pf_ev {
+	struct kvmi_event common;
+	struct kvmi_event_pf pf;
+};
+
 struct vcpu_worker_data {
 	struct kvm_vm *vm;
 	int vcpu_id;
@@ -51,6 +56,10 @@ struct vcpu_worker_data {
 	bool restart_on_shutdown;
 };
 
+typedef void (*fct_pf_event)(struct kvm_vm *vm, struct kvmi_msg_hdr *hdr,
+				struct pf_ev *ev,
+				struct vcpu_reply *rpl);
+
 enum {
 	GUEST_TEST_NOOP = 0,
 	GUEST_TEST_BP,
@@ -58,6 +67,7 @@ enum {
 	GUEST_TEST_DESCRIPTOR,
 	GUEST_TEST_HYPERCALL,
 	GUEST_TEST_MSR,
+	GUEST_TEST_PF,
 	GUEST_TEST_XSETBV,
 };
 
@@ -107,6 +117,11 @@ static void guest_msr_test(void)
 	wrmsr(MSR_MISC_FEATURES_ENABLES, msr);
 }
 
+static void guest_pf_test(void)
+{
+	*((uint8_t *)test_gva) = READ_ONCE(test_write_pattern);
+}
+
 /* from fpu/internal.h */
 static u64 xgetbv(u32 index)
 {
@@ -167,6 +182,9 @@ static void guest_code(void)
 		case GUEST_TEST_MSR:
 			guest_msr_test();
 			break;
+		case GUEST_TEST_PF:
+			guest_pf_test();
+			break;
 		case GUEST_TEST_XSETBV:
 			guest_xsetbv_test();
 			break;
@@ -1590,6 +1608,61 @@ static void test_cmd_vm_set_page_access(struct kvm_vm *vm)
 	set_page_access(gpa, full_access);
 }
 
+static void test_pf(struct kvm_vm *vm, fct_pf_event cbk)
+{
+	__u16 event_id = KVMI_EVENT_PF;
+	struct vcpu_worker_data data = {
+		.vm = vm,
+		.vcpu_id = VCPU_ID,
+		.test_id = GUEST_TEST_PF,
+	};
+	struct kvmi_msg_hdr hdr;
+	struct vcpu_reply rpl = {};
+	pthread_t vcpu_thread;
+	struct pf_ev ev;
+
+	set_page_access(test_gpa, KVMI_PAGE_ACCESS_R);
+
+	enable_vcpu_event(vm, event_id);
+
+	new_test_write_pattern(vm);
+
+	vcpu_thread = start_vcpu_worker(&data);
+
+	receive_event(&hdr, &ev.common, sizeof(ev), event_id);
+
+	DEBUG("PF event, gpa 0x%llx, gva 0x%llx, access 0x%x\n",
+		ev.pf.gpa, ev.pf.gva, ev.pf.access);
+
+	TEST_ASSERT(ev.pf.gpa == test_gpa && ev.pf.gva == test_gva,
+		"Unexpected #PF event, gpa 0x%llx (expended 0x%llx), gva 0x%llx (expected 0x%llx)\n",
+		ev.pf.gpa, test_gpa, ev.pf.gva, test_gva);
+
+	cbk(vm, &hdr, &ev, &rpl);
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	TEST_ASSERT(*((uint8_t *)test_hva) == test_write_pattern,
+		"Write failed, expected 0x%x, result 0x%x\n",
+		test_write_pattern, *((uint8_t *)test_hva));
+
+	disable_vcpu_event(vm, event_id);
+}
+
+static void cbk_test_event_pf(struct kvm_vm *vm, struct kvmi_msg_hdr *hdr,
+				struct pf_ev *ev, struct vcpu_reply *rpl)
+{
+	set_page_access(test_gpa, KVMI_PAGE_ACCESS_R | KVMI_PAGE_ACCESS_W);
+
+	reply_to_event(hdr, &ev->common, KVMI_EVENT_ACTION_RETRY,
+			rpl, sizeof(*rpl));
+}
+
+static void test_event_pf(struct kvm_vm *vm)
+{
+	test_pf(vm, cbk_test_event_pf);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1621,6 +1694,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_event_descriptor(vm);
 	test_cmd_vcpu_control_msr(vm);
 	test_cmd_vm_set_page_access(vm);
+	test_event_pf(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 2629d3d1f68c..e13b55856e9c 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -18,6 +18,21 @@ DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS);
 DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS);
 DECLARE_BITMAP(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS);
 
+static bool kvmi_track_preread(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			       int bytes,
+			       struct kvm_page_track_notifier_node *node);
+static bool kvmi_track_prewrite(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+				const u8 *new, int bytes,
+				struct kvm_page_track_notifier_node *node);
+static bool kvmi_track_preexec(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			       struct kvm_page_track_notifier_node *node);
+static void kvmi_track_create_slot(struct kvm *kvm,
+				   struct kvm_memory_slot *slot,
+				   unsigned long npages,
+				   struct kvm_page_track_notifier_node *node);
+static void kvmi_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
+				  struct kvm_page_track_notifier_node *node);
+
 static struct kmem_cache *msg_cache;
 static struct kmem_cache *job_cache;
 static struct kmem_cache *radix_cache;
@@ -94,6 +109,7 @@ static void setup_known_events(void)
 	set_bit(KVMI_EVENT_HYPERCALL, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_MSR, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
+	set_bit(KVMI_EVENT_PF, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_TRAP, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_XSETBV, Kvmi_known_vcpu_events);
 
@@ -288,6 +304,12 @@ alloc_kvmi(struct kvm *kvm, const struct kvm_introspection_hook *hook)
 			GFP_KERNEL & ~__GFP_DIRECT_RECLAIM);
 	rwlock_init(&kvmi->access_tree_lock);
 
+	kvmi->arch.kptn_node.track_preread = kvmi_track_preread;
+	kvmi->arch.kptn_node.track_prewrite = kvmi_track_prewrite;
+	kvmi->arch.kptn_node.track_preexec = kvmi_track_preexec;
+	kvmi->arch.kptn_node.track_create_slot = kvmi_track_create_slot;
+	kvmi->arch.kptn_node.track_flush_slot = kvmi_track_flush_slot;
+
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		int err = create_vcpui(vcpu);
 
@@ -319,6 +341,8 @@ static void __kvmi_unhook(struct kvm *kvm)
 	struct kvm_introspection *kvmi = KVMI(kvm);
 
 	wait_for_completion_killable(&kvm->kvmi_complete);
+
+	kvm_page_track_unregister_notifier(kvm, &kvmi->arch.kptn_node);
 	kvmi_sock_put(kvmi);
 }
 
@@ -366,6 +390,8 @@ static int __kvmi_hook(struct kvm *kvm,
 	if (!kvmi_sock_get(kvmi, hook->fd))
 		return -EINVAL;
 
+	kvm_page_track_register_notifier(kvm, &kvmi->arch.kptn_node);
+
 	return 0;
 }
 
@@ -1092,3 +1118,182 @@ int kvmi_cmd_set_page_access(struct kvm_introspection *kvmi, u64 gpa, u8 access)
 	return kvmi_set_gfn_access(kvmi->kvm, gfn, access);
 }
 
+static int kvmi_get_gfn_access(struct kvm_introspection *kvmi, const gfn_t gfn,
+			       u8 *access)
+{
+	struct kvmi_mem_access *m;
+
+	read_lock(&kvmi->access_tree_lock);
+	m = __kvmi_get_gfn_access(kvmi, gfn);
+	if (m)
+		*access = m->access;
+	read_unlock(&kvmi->access_tree_lock);
+
+	return m ? 0 : -1;
+}
+
+static bool kvmi_restricted_access(struct kvm_introspection *kvmi, gpa_t gpa,
+				   u8 access)
+{
+	u8 allowed_access;
+	int err;
+
+	err = kvmi_get_gfn_access(kvmi, gpa_to_gfn(gpa), &allowed_access);
+	if (err)
+		return false;
+
+	/*
+	 * We want to be notified only for violations involving access
+	 * bits that we've specifically cleared
+	 */
+	if (access & (~allowed_access))
+		return true;
+
+	return false;
+}
+
+static bool is_pf_of_interest(struct kvm_vcpu *vcpu, gpa_t gpa, u8 access)
+{
+	struct kvm *kvm = vcpu->kvm;
+
+	if (!kvmi_arch_pf_of_interest(vcpu))
+		return false;
+
+	return kvmi_restricted_access(KVMI(kvm), gpa, access);
+}
+
+static bool kvmi_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			  int access)
+{
+	if (!is_pf_of_interest(vcpu, gpa, access))
+		return true;
+
+	return kvmi_arch_pf_event(vcpu, gpa, gva, access);
+}
+
+static bool kvmi_track_preread(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			       int bytes,
+			       struct kvm_page_track_notifier_node *node)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = true;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return true;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_PF))
+		ret = kvmi_pf_event(vcpu, gpa, gva, KVMI_PAGE_ACCESS_R);
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
+
+static bool kvmi_track_prewrite(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+				const u8 *new, int bytes,
+				struct kvm_page_track_notifier_node *node)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = true;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return true;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_PF))
+		ret = kvmi_pf_event(vcpu, gpa, gva, KVMI_PAGE_ACCESS_W);
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
+
+static bool kvmi_track_preexec(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			       struct kvm_page_track_notifier_node *node)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = true;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return true;
+
+	if (is_event_enabled(vcpu, KVMI_EVENT_PF))
+		ret = kvmi_pf_event(vcpu, gpa, gva, KVMI_PAGE_ACCESS_X);
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
+
+static void kvmi_track_create_slot(struct kvm *kvm,
+				   struct kvm_memory_slot *slot,
+				   unsigned long npages,
+				   struct kvm_page_track_notifier_node *node)
+{
+	struct kvm_introspection *kvmi;
+	gfn_t start = slot->base_gfn;
+	const gfn_t end = start + npages;
+	int idx;
+
+	kvmi = kvmi_get(kvm);
+	if (!kvmi)
+		return;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+	read_lock(&kvmi->access_tree_lock);
+
+	while (start < end) {
+		struct kvmi_mem_access *m;
+
+		m = __kvmi_get_gfn_access(kvmi, start);
+		if (m)
+			kvmi_arch_update_page_tracking(kvm, slot, m);
+		start++;
+	}
+
+	read_unlock(&kvmi->access_tree_lock);
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+
+	kvmi_put(kvm);
+}
+
+static void kvmi_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
+				  struct kvm_page_track_notifier_node *node)
+{
+	struct kvm_introspection *kvmi;
+	gfn_t start = slot->base_gfn;
+	const gfn_t end = start + slot->npages;
+	int idx;
+
+	kvmi = kvmi_get(kvm);
+	if (!kvmi)
+		return;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+	write_lock(&kvmi->access_tree_lock);
+
+	while (start < end) {
+		struct kvmi_mem_access *m;
+
+		m = __kvmi_get_gfn_access(kvmi, start);
+		if (m) {
+			u8 prev_access = m->access;
+
+			m->access = full_access;
+			kvmi_arch_update_page_tracking(kvm, slot, m);
+			m->access = prev_access;
+		}
+		start++;
+	}
+
+	write_unlock(&kvmi->access_tree_lock);
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+
+	kvmi_put(kvm);
+}
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 237bb083cf01..639d14811933 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -49,6 +49,7 @@ int kvmi_msg_send_unhook(struct kvm_introspection *kvmi);
 u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu);
 u32 kvmi_msg_send_hypercall(struct kvm_vcpu *vcpu);
 u32 kvmi_msg_send_bp(struct kvm_vcpu *vcpu, u64 gpa, u8 insn_len);
+u32 kvmi_msg_send_pf(struct kvm_vcpu *vcpu, u64 gpa, u64 gva, u8 access);
 
 /* kvmi.c */
 void *kvmi_msg_alloc(void);
@@ -123,5 +124,8 @@ void kvmi_arch_update_page_tracking(struct kvm *kvm,
 int kvmi_arch_cmd_set_page_access(struct kvm_introspection *kvmi,
 				  const struct kvmi_msg_hdr *msg,
 				  const struct kvmi_vm_set_page_access *req);
+bool kvmi_arch_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+			u8 access);
+bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 973ed9d92bfb..10d4e40387ef 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -984,3 +984,21 @@ u32 kvmi_msg_send_bp(struct kvm_vcpu *vcpu, u64 gpa, u8 insn_len)
 
 	return action;
 }
+
+u32 kvmi_msg_send_pf(struct kvm_vcpu *vcpu, u64 gpa, u64 gva, u8 access)
+{
+	struct kvmi_event_pf e;
+	int err, action;
+
+	memset(&e, 0, sizeof(e));
+	e.gpa = gpa;
+	e.gva = gva;
+	e.access = access;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_PF, &e, sizeof(e),
+			      NULL, 0, &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	return action;
+}

[PATCH v8 76/81] KVM: introspection: extend KVMI_GET_VERSION with struct kvmi_features

[Adalbert Lazăr]

This is used by the introspection tool to check the hardware support
for single step.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst                | 13 ++++++++++++-
 arch/x86/include/uapi/asm/kvmi.h               |  5 +++++
 arch/x86/kvm/kvmi.c                            |  5 +++++
 include/uapi/linux/kvmi.h                      |  1 +
 tools/testing/selftests/kvm/x86_64/kvmi_test.c |  5 +++++
 virt/kvm/introspection/kvmi_int.h              |  1 +
 virt/kvm/introspection/kvmi_msg.c              |  2 ++
 7 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 3952aef9af9c..b211ae0ed86a 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -254,9 +254,20 @@ The vCPU commands start with::
 	struct kvmi_get_version_reply {
 		__u32 version;
 		__u32 padding;
+		struct kvmi_features features;
 	};
 
-Returns the introspection API version.
+For x86
+
+::
+
+	struct kvmi_features {
+		__u8 singlestep;
+		__u8 padding[7];
+	};
+
+Returns the introspection API version and some of the features supported
+by the hardware.
 
 This command is always allowed and successful (if the introspection is
 built in kernel).
diff --git a/arch/x86/include/uapi/asm/kvmi.h b/arch/x86/include/uapi/asm/kvmi.h
index e4d591912f37..0bdf70cc8fc7 100644
--- a/arch/x86/include/uapi/asm/kvmi.h
+++ b/arch/x86/include/uapi/asm/kvmi.h
@@ -139,4 +139,9 @@ struct kvmi_event_msr_reply {
 	__u64 new_val;
 };
 
+struct kvmi_features {
+	__u8 singlestep;
+	__u8 padding[7];
+};
+
 #endif /* _UAPI_ASM_X86_KVMI_H */
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 06829e1c5737..d7e1c0690c43 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -1199,6 +1199,11 @@ bool kvmi_arch_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 	return ret;
 }
 
+void kvmi_arch_features(struct kvmi_features *feat)
+{
+	feat->singlestep = !!kvm_x86_ops->control_singlestep;
+}
+
 bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu)
 {
 	return kvm_x86_ops->spt_fault(vcpu) &&
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index df192936b017..caf166e7ddff 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -97,6 +97,7 @@ struct kvmi_error_code {
 struct kvmi_get_version_reply {
 	__u32 version;
 	__u32 padding;
+	struct kvmi_features features;
 };
 
 struct kvmi_vm_check_command {
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 48cb546234c0..d4cfe595821d 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -56,6 +56,8 @@ struct vcpu_worker_data {
 	bool restart_on_shutdown;
 };
 
+static struct kvmi_features features;
+
 typedef void (*fct_pf_event)(struct kvm_vm *vm, struct kvmi_msg_hdr *hdr,
 				struct pf_ev *ev,
 				struct vcpu_reply *rpl);
@@ -372,7 +374,10 @@ static void test_cmd_get_version(void)
 		    "Unexpected KVMI version %d, expecting %d\n",
 		    rpl.version, KVMI_VERSION);
 
+	features = rpl.features;
+
 	DEBUG("KVMI version: %u\n", rpl.version);
+	DEBUG("\tsinglestep: %u\n", features.singlestep);
 }
 
 static int cmd_check_command(__u16 id)
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 639d14811933..e0cb58c60697 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -127,5 +127,6 @@ int kvmi_arch_cmd_set_page_access(struct kvm_introspection *kvmi,
 bool kvmi_arch_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			u8 access);
 bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu);
+void kvmi_arch_features(struct kvmi_features *feat);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 10d4e40387ef..71a67154542f 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -182,6 +182,8 @@ static int handle_get_version(struct kvm_introspection *kvmi,
 	memset(&rpl, 0, sizeof(rpl));
 	rpl.version = KVMI_VERSION;
 
+	kvmi_arch_features(&rpl.features);
+
 	return kvmi_msg_vm_reply(kvmi, msg, 0, &rpl, sizeof(rpl));
 }
 

[PATCH v8 77/81] KVM: introspection: add KVMI_VCPU_CONTROL_SINGLESTEP

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This command is useful for debuggers.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 32 +++++++
 arch/x86/kvm/kvmi.c                           | 18 ++++
 arch/x86/kvm/x86.c                            |  7 ++
 include/linux/kvmi_host.h                     |  7 ++
 include/uapi/linux/kvmi.h                     |  7 ++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 23 +++++
 virt/kvm/introspection/kvmi.c                 | 23 +++++
 virt/kvm/introspection/kvmi_int.h             |  2 +
 virt/kvm/introspection/kvmi_msg.c             | 94 ++++++++++++-------
 9 files changed, 181 insertions(+), 32 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index b211ae0ed86a..5e013ee4a79b 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -954,6 +954,38 @@ In order to 'forget' an address, all three bits ('rwx') must be set.
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 * -KVM_ENOMEM - there is not enough memory to add the page tracking structures
 
+20. KVMI_VCPU_CONTROL_SINGLESTEP
+--------------------------------
+
+:Architectures: x86 (vmx)
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_control_singlestep {
+		__u8 enable;
+		__u8 padding[7];
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+
+Enables/disables singlestep for the selected vCPU.
+
+The introspection tool should use *KVMI_GET_VERSION*, to check
+if the hardware supports singlestep (see **KVMI_GET_VERSION**).
+
+:Errors:
+
+* -KVM_EOPNOTSUPP - the hardware doesn't support singlestep
+* -KVM_EINVAL - the padding is not zero
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+
 Events
 ======
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index d7e1c0690c43..729f91a66405 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -1210,3 +1210,21 @@ bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu)
 	      !kvm_x86_ops->gpt_translation_fault(vcpu);
 }
 
+bool kvmi_arch_start_singlestep(struct kvm_vcpu *vcpu)
+{
+	if (!kvm_x86_ops->control_singlestep)
+		return false;
+
+	kvm_x86_ops->control_singlestep(vcpu, true);
+	return true;
+}
+
+bool kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu)
+{
+	if (!kvm_x86_ops->control_singlestep)
+		return false;
+
+	kvm_x86_ops->control_singlestep(vcpu, false);
+	return true;
+}
+
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ce2f9d47d6f6..12e9b4689025 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7738,6 +7738,13 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
 {
 	int r;
 
+	if (kvmi_vcpu_running_singlestep(vcpu))
+		/*
+		 * We cannot inject events during single-stepping.
+		 * Try again later.
+		 */
+		return -1;
+
 	/* try to reinject previous events if any */
 
 	if (vcpu->arch.exception.injected)
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index c9dd2d57033b..23784611996e 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -50,6 +50,10 @@ struct kvm_vcpu_introspection {
 		bool pending;
 		bool send_event;
 	} exception;
+
+	struct {
+		bool loop;
+	} singlestep;
 };
 
 struct kvm_introspection {
@@ -90,6 +94,7 @@ void kvmi_handle_requests(struct kvm_vcpu *vcpu);
 bool kvmi_hypercall_event(struct kvm_vcpu *vcpu);
 bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len);
 bool kvmi_enter_guest(struct kvm_vcpu *vcpu);
+bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu);
 
 #else
 
@@ -106,6 +111,8 @@ static inline bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva,
 			{ return true; }
 static inline bool kvmi_enter_guest(struct kvm_vcpu *vcpu)
 			{ return true; }
+static inline bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu)
+			{ return false; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index caf166e7ddff..97c4ef67bfe4 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -42,6 +42,8 @@ enum {
 
 	KVMI_VM_SET_PAGE_ACCESS = 21,
 
+	KVMI_VCPU_CONTROL_SINGLESTEP = 22,
+
 	KVMI_NUM_MESSAGES
 };
 
@@ -178,6 +180,11 @@ struct kvmi_vm_set_page_access {
 	struct kvmi_page_access_entry entries[0];
 };
 
+struct kvmi_vcpu_control_singlestep {
+	__u8 enable;
+	__u8 padding[7];
+};
+
 struct kvmi_event {
 	__u16 size;
 	__u16 vcpu;
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index d4cfe595821d..27642000c4e4 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -1668,6 +1668,28 @@ static void test_event_pf(struct kvm_vm *vm)
 	test_pf(vm, cbk_test_event_pf);
 }
 
+static void test_cmd_vcpu_control_singlestep(struct kvm_vm *vm)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_control_singlestep cmd;
+	} req = {};
+
+	if (!features.singlestep) {
+		DEBUG("Skip %s()\n", __func__);
+		return;
+	}
+
+	req.cmd.enable = true;
+	test_vcpu0_command(vm, KVMI_VCPU_CONTROL_SINGLESTEP,
+			   &req.hdr, sizeof(req), NULL, 0);
+
+	req.cmd.enable = false;
+	test_vcpu0_command(vm, KVMI_VCPU_CONTROL_SINGLESTEP,
+			   &req.hdr, sizeof(req), NULL, 0);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1700,6 +1722,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vcpu_control_msr(vm);
 	test_cmd_vm_set_page_access(vm);
 	test_event_pf(vm);
+	test_cmd_vcpu_control_singlestep(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index e13b55856e9c..90e6c2d3dd4f 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -401,6 +401,9 @@ static void kvmi_job_release_vcpu(struct kvm_vcpu *vcpu, void *ctx)
 
 	atomic_set(&vcpui->pause_requests, 0);
 	vcpui->waiting_for_reply = false;
+
+	if (vcpui->singlestep.loop)
+		kvmi_arch_stop_singlestep(vcpu);
 }
 
 static void kvmi_release_vcpus(struct kvm *kvm)
@@ -1019,6 +1022,9 @@ bool kvmi_enter_guest(struct kvm_vcpu *vcpu)
 	if (!kvmi)
 		return true;
 
+	if (VCPUI(vcpu)->singlestep.loop)
+		kvmi_arch_start_singlestep(vcpu);
+
 	if (kvmi_inject_pending_exception(vcpu))
 		r = false;
 
@@ -1297,3 +1303,20 @@ static void kvmi_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot,
 
 	kvmi_put(kvm);
 }
+
+bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu)
+{
+	struct kvm_introspection *kvmi;
+	bool ret;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return false;
+
+	ret = VCPUI(vcpu)->singlestep.loop;
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
+EXPORT_SYMBOL(kvmi_vcpu_running_singlestep);
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index e0cb58c60697..820081f8e3f1 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -128,5 +128,7 @@ bool kvmi_arch_pf_event(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
 			u8 access);
 bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu);
 void kvmi_arch_features(struct kvmi_features *feat);
+bool kvmi_arch_start_singlestep(struct kvm_vcpu *vcpu);
+bool kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 71a67154542f..14c063869c29 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -20,27 +20,28 @@ struct kvmi_vcpu_cmd_job {
 };
 
 static const char *const msg_IDs[] = {
-	[KVMI_EVENT]                 = "KVMI_EVENT",
-	[KVMI_GET_VERSION]           = "KVMI_GET_VERSION",
-	[KVMI_VM_CHECK_COMMAND]      = "KVMI_VM_CHECK_COMMAND",
-	[KVMI_VM_CHECK_EVENT]        = "KVMI_VM_CHECK_EVENT",
-	[KVMI_VM_CONTROL_EVENTS]     = "KVMI_VM_CONTROL_EVENTS",
-	[KVMI_VM_GET_INFO]           = "KVMI_VM_GET_INFO",
-	[KVMI_VM_GET_MAX_GFN]        = "KVMI_VM_GET_MAX_GFN",
-	[KVMI_VM_READ_PHYSICAL]      = "KVMI_VM_READ_PHYSICAL",
-	[KVMI_VM_SET_PAGE_ACCESS]    = "KVMI_VM_SET_PAGE_ACCESS",
-	[KVMI_VM_WRITE_PHYSICAL]     = "KVMI_VM_WRITE_PHYSICAL",
-	[KVMI_VCPU_CONTROL_CR]       = "KVMI_VCPU_CONTROL_CR",
-	[KVMI_VCPU_CONTROL_EVENTS]   = "KVMI_VCPU_CONTROL_EVENTS",
-	[KVMI_VCPU_CONTROL_MSR]      = "KVMI_VCPU_CONTROL_MSR",
-	[KVMI_VCPU_GET_CPUID]        = "KVMI_VCPU_GET_CPUID",
-	[KVMI_VCPU_GET_INFO]         = "KVMI_VCPU_GET_INFO",
-	[KVMI_VCPU_GET_MTRR_TYPE]    = "KVMI_VCPU_GET_MTRR_TYPE",
-	[KVMI_VCPU_GET_REGISTERS]    = "KVMI_VCPU_GET_REGISTERS",
-	[KVMI_VCPU_GET_XSAVE]        = "KVMI_VCPU_GET_XSAVE",
-	[KVMI_VCPU_INJECT_EXCEPTION] = "KVMI_VCPU_INJECT_EXCEPTION",
-	[KVMI_VCPU_PAUSE]            = "KVMI_VCPU_PAUSE",
-	[KVMI_VCPU_SET_REGISTERS]    = "KVMI_VCPU_SET_REGISTERS",
+	[KVMI_EVENT]                   = "KVMI_EVENT",
+	[KVMI_GET_VERSION]             = "KVMI_GET_VERSION",
+	[KVMI_VM_CHECK_COMMAND]        = "KVMI_VM_CHECK_COMMAND",
+	[KVMI_VM_CHECK_EVENT]          = "KVMI_VM_CHECK_EVENT",
+	[KVMI_VM_CONTROL_EVENTS]       = "KVMI_VM_CONTROL_EVENTS",
+	[KVMI_VM_GET_INFO]             = "KVMI_VM_GET_INFO",
+	[KVMI_VM_GET_MAX_GFN]          = "KVMI_VM_GET_MAX_GFN",
+	[KVMI_VM_READ_PHYSICAL]        = "KVMI_VM_READ_PHYSICAL",
+	[KVMI_VM_SET_PAGE_ACCESS]      = "KVMI_VM_SET_PAGE_ACCESS",
+	[KVMI_VM_WRITE_PHYSICAL]       = "KVMI_VM_WRITE_PHYSICAL",
+	[KVMI_VCPU_CONTROL_CR]         = "KVMI_VCPU_CONTROL_CR",
+	[KVMI_VCPU_CONTROL_EVENTS]     = "KVMI_VCPU_CONTROL_EVENTS",
+	[KVMI_VCPU_CONTROL_MSR]        = "KVMI_VCPU_CONTROL_MSR",
+	[KVMI_VCPU_CONTROL_SINGLESTEP] = "KVMI_VCPU_CONTROL_SINGLESTEP",
+	[KVMI_VCPU_GET_CPUID]          = "KVMI_VCPU_GET_CPUID",
+	[KVMI_VCPU_GET_INFO]           = "KVMI_VCPU_GET_INFO",
+	[KVMI_VCPU_GET_MTRR_TYPE]      = "KVMI_VCPU_GET_MTRR_TYPE",
+	[KVMI_VCPU_GET_REGISTERS]      = "KVMI_VCPU_GET_REGISTERS",
+	[KVMI_VCPU_GET_XSAVE]          = "KVMI_VCPU_GET_XSAVE",
+	[KVMI_VCPU_INJECT_EXCEPTION]   = "KVMI_VCPU_INJECT_EXCEPTION",
+	[KVMI_VCPU_PAUSE]              = "KVMI_VCPU_PAUSE",
+	[KVMI_VCPU_SET_REGISTERS]      = "KVMI_VCPU_SET_REGISTERS",
 };
 
 static const char *id2str(u16 id)
@@ -619,6 +620,34 @@ static int handle_vcpu_control_msr(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
 }
 
+static int handle_vcpu_control_singlestep(const struct kvmi_vcpu_cmd_job *job,
+					  const struct kvmi_msg_hdr *msg,
+					  const void *_req)
+{
+	const struct kvmi_vcpu_control_singlestep *req = _req;
+	struct kvm_vcpu *vcpu = job->vcpu;
+	int ec = -KVM_EINVAL;
+	bool done;
+	int i;
+
+	for (i = 0; i < sizeof(req->padding); i++)
+		if (req->padding[i])
+			goto reply;
+
+	if (req->enable)
+		done = kvmi_arch_start_singlestep(vcpu);
+	else
+		done = kvmi_arch_stop_singlestep(vcpu);
+
+	if (done) {
+		ec = 0;
+		VCPUI(vcpu)->singlestep.loop = !!req->enable;
+	}
+
+reply:
+	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -627,17 +656,18 @@ static int handle_vcpu_control_msr(const struct kvmi_vcpu_cmd_job *job,
  */
 static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 			      const struct kvmi_msg_hdr *, const void *) = {
-	[KVMI_EVENT]                 = handle_event_reply,
-	[KVMI_VCPU_CONTROL_CR]       = handle_vcpu_control_cr,
-	[KVMI_VCPU_CONTROL_EVENTS]   = handle_vcpu_control_events,
-	[KVMI_VCPU_CONTROL_MSR]      = handle_vcpu_control_msr,
-	[KVMI_VCPU_GET_CPUID]        = handle_get_cpuid,
-	[KVMI_VCPU_GET_INFO]         = handle_get_vcpu_info,
-	[KVMI_VCPU_GET_MTRR_TYPE]    = handle_vcpu_get_mtrr_type,
-	[KVMI_VCPU_GET_REGISTERS]    = handle_get_registers,
-	[KVMI_VCPU_GET_XSAVE]        = handle_vcpu_get_xsave,
-	[KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception,
-	[KVMI_VCPU_SET_REGISTERS]    = handle_set_registers,
+	[KVMI_EVENT]                   = handle_event_reply,
+	[KVMI_VCPU_CONTROL_CR]         = handle_vcpu_control_cr,
+	[KVMI_VCPU_CONTROL_EVENTS]     = handle_vcpu_control_events,
+	[KVMI_VCPU_CONTROL_MSR]        = handle_vcpu_control_msr,
+	[KVMI_VCPU_CONTROL_SINGLESTEP] = handle_vcpu_control_singlestep,
+	[KVMI_VCPU_GET_CPUID]          = handle_get_cpuid,
+	[KVMI_VCPU_GET_INFO]           = handle_get_vcpu_info,
+	[KVMI_VCPU_GET_MTRR_TYPE]      = handle_vcpu_get_mtrr_type,
+	[KVMI_VCPU_GET_REGISTERS]      = handle_get_registers,
+	[KVMI_VCPU_GET_XSAVE]          = handle_vcpu_get_xsave,
+	[KVMI_VCPU_INJECT_EXCEPTION]   = handle_vcpu_inject_exception,
+	[KVMI_VCPU_SET_REGISTERS]      = handle_set_registers,
 };
 
 static bool is_vcpu_command(u16 id)

[PATCH v8 78/81] KVM: introspection: add KVMI_EVENT_SINGLESTEP

[Adalbert Lazăr]

From: Nicușor Cîțu <ncitu@bitdefender.com>

This event is sent when the current instruction has been single stepped
with or without success.

Signed-off-by: Nicușor Cîțu <ncitu@bitdefender.com>
Co-developed-by: Adalbert Lazăr <alazar@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 32 ++++++++
 arch/x86/kvm/vmx/vmx.c                        |  6 ++
 include/linux/kvmi_host.h                     |  4 +
 include/uapi/linux/kvmi.h                     |  6 ++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 80 ++++++++++++++++---
 virt/kvm/introspection/kvmi.c                 | 61 ++++++++++++++
 virt/kvm/introspection/kvmi_msg.c             |  5 ++
 7 files changed, 185 insertions(+), 9 deletions(-)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index 5e013ee4a79b..c761438801dd 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -572,6 +572,7 @@ The following vCPU events do not need to be enabled or disabled,
 because these are sent as a result of certain commands::
 
 	KVMI_EVENT_PAUSE_VCPU
+	KVMI_EVENT_SINGLESTEP
 	KVMI_EVENT_TRAP
 
 However, the events mentioned above can be disallowed.
@@ -980,8 +981,12 @@ Enables/disables singlestep for the selected vCPU.
 The introspection tool should use *KVMI_GET_VERSION*, to check
 if the hardware supports singlestep (see **KVMI_GET_VERSION**).
 
+After every instruction, a *KVMI_EVENT_SINGLESTEP* event is sent
+to the introspection tool.
+
 :Errors:
 
+* -KVM_EPERM  - the *KVMI_EVENT_SINGLESTEP* event is disallowed
 * -KVM_EOPNOTSUPP - the hardware doesn't support singlestep
 * -KVM_EINVAL - the padding is not zero
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
@@ -1375,3 +1380,30 @@ The *CONTINUE* action will continue the page fault handling via emulation.
 The *RETRY* action is used by the introspection tool to retry the
 execution of the current instruction, usually because it changed the
 instruction pointer or the page restrictions.
+
+11. KVMI_EVENT_SINGLESTEP
+-------------------------
+
+:Architectures: x86
+:Versions: >= 1
+:Actions: CONTINUE, CRASH
+:Parameters:
+
+::
+
+	struct kvmi_event;
+
+:Returns:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_event_reply;
+	struct kvmi_event_singlestep {
+		__u8 failed;
+		__u8 padding[7];
+	};
+
+This event is sent when the current instruction has been executed or
+failed and the singlestep has been enabled for the selected vCPU
+(see **KVMI_VCPU_CONTROL_SINGLESTEP**).
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index fd748c165e78..baae118f1cdc 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5464,6 +5464,7 @@ static int handle_invalid_op(struct kvm_vcpu *vcpu)
 
 static int handle_monitor_trap(struct kvm_vcpu *vcpu)
 {
+	kvmi_singlestep_done(vcpu);
 	return 1;
 }
 
@@ -6025,6 +6026,11 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu,
 		return 1;
 	}
 
+	if (kvmi_vcpu_running_singlestep(vcpu) &&
+	    exit_reason != EXIT_REASON_EPT_VIOLATION &&
+	    exit_reason != EXIT_REASON_MONITOR_TRAP_FLAG)
+		kvmi_singlestep_failed(vcpu);
+
 	if (exit_reason >= kvm_vmx_max_exit_handlers)
 		goto unexpected_vmexit;
 #ifdef CONFIG_RETPOLINE
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 23784611996e..58a30c087d63 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -95,6 +95,8 @@ bool kvmi_hypercall_event(struct kvm_vcpu *vcpu);
 bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len);
 bool kvmi_enter_guest(struct kvm_vcpu *vcpu);
 bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu);
+void kvmi_singlestep_done(struct kvm_vcpu *vcpu);
+void kvmi_singlestep_failed(struct kvm_vcpu *vcpu);
 
 #else
 
@@ -113,6 +115,8 @@ static inline bool kvmi_enter_guest(struct kvm_vcpu *vcpu)
 			{ return true; }
 static inline bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu)
 			{ return false; }
+static inline void kvmi_singlestep_done(struct kvm_vcpu *vcpu) { }
+static inline void kvmi_singlestep_failed(struct kvm_vcpu *vcpu) { }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index 97c4ef67bfe4..d69735918fd6 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -58,6 +58,7 @@ enum {
 	KVMI_EVENT_DESCRIPTOR = 7,
 	KVMI_EVENT_MSR        = 8,
 	KVMI_EVENT_PF         = 9,
+	KVMI_EVENT_SINGLESTEP = 10,
 
 	KVMI_NUM_EVENTS
 };
@@ -209,4 +210,9 @@ struct kvmi_event_pf {
 	__u32 padding3;
 };
 
+struct kvmi_event_singlestep {
+	__u8 failed;
+	__u8 padding[7];
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 27642000c4e4..24dfcba113cd 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -745,6 +745,14 @@ static void stop_vcpu_worker(pthread_t vcpu_thread,
 	wait_vcpu_worker(vcpu_thread);
 }
 
+static int __do_vcpu_command(struct kvm_vm *vm, int cmd_id,
+			     struct kvmi_msg_hdr *req, size_t req_size,
+			     void *rpl, size_t rpl_size)
+{
+	send_message(cmd_id, req, req_size);
+	return receive_cmd_reply(req, rpl, rpl_size);
+}
+
 static int do_vcpu_command(struct kvm_vm *vm, int cmd_id,
 			   struct kvmi_msg_hdr *req, size_t req_size,
 			   void *rpl, size_t rpl_size)
@@ -755,13 +763,24 @@ static int do_vcpu_command(struct kvm_vm *vm, int cmd_id,
 
 	vcpu_thread = start_vcpu_worker(&data);
 
-	send_message(cmd_id, req, req_size);
-	r = receive_cmd_reply(req, rpl, rpl_size);
+	r = __do_vcpu_command(vm, cmd_id, req, req_size, rpl, rpl_size);
 
 	stop_vcpu_worker(vcpu_thread, &data);
 	return r;
 }
 
+static int __do_vcpu0_command(struct kvm_vm *vm, int cmd_id,
+			      struct kvmi_msg_hdr *req, size_t req_size,
+			      void *rpl, size_t rpl_size)
+{
+	struct kvmi_vcpu_hdr *vcpu_hdr = (struct kvmi_vcpu_hdr *)req;
+
+	vcpu_hdr->vcpu = 0;
+
+	send_message(cmd_id, req, req_size);
+	return receive_cmd_reply(req, rpl, rpl_size);
+}
+
 static int do_vcpu0_command(struct kvm_vm *vm, int cmd_id,
 			    struct kvmi_msg_hdr *req, size_t req_size,
 			    void *rpl, size_t rpl_size)
@@ -1668,26 +1687,69 @@ static void test_event_pf(struct kvm_vm *vm)
 	test_pf(vm, cbk_test_event_pf);
 }
 
-static void test_cmd_vcpu_control_singlestep(struct kvm_vm *vm)
+static void control_singlestep(struct kvm_vm *vm, bool enable)
 {
 	struct {
 		struct kvmi_msg_hdr hdr;
 		struct kvmi_vcpu_hdr vcpu_hdr;
 		struct kvmi_vcpu_control_singlestep cmd;
 	} req = {};
+	int r;
+
+	req.cmd.enable = enable;
+	r = __do_vcpu0_command(vm, KVMI_VCPU_CONTROL_SINGLESTEP,
+			       &req.hdr, sizeof(req), NULL, 0);
+	TEST_ASSERT(r == 0,
+		"KVMI_VCPU_CONTROL_SINGLESTEP failed, error %d (%s)\n",
+		-r, kvm_strerror(-r));
+}
+
+static void enable_singlestep(struct kvm_vm *vm)
+{
+	control_singlestep(vm, true);
+}
+
+static void disable_singlestep(struct kvm_vm *vm)
+{
+	control_singlestep(vm, false);
+}
+
+static void test_cmd_vcpu_control_singlestep(struct kvm_vm *vm)
+{
+	struct vcpu_worker_data data = { .vm = vm, .vcpu_id = VCPU_ID };
+	struct {
+		struct kvmi_event common;
+		struct kvmi_event_singlestep singlestep;
+	} ev;
+	__u16 event_id = KVMI_EVENT_SINGLESTEP;
+	struct vcpu_reply rpl = {};
+	struct kvmi_msg_hdr hdr;
+	pthread_t vcpu_thread;
 
 	if (!features.singlestep) {
 		DEBUG("Skip %s()\n", __func__);
 		return;
 	}
 
-	req.cmd.enable = true;
-	test_vcpu0_command(vm, KVMI_VCPU_CONTROL_SINGLESTEP,
-			   &req.hdr, sizeof(req), NULL, 0);
+	enable_vcpu_event(vm, event_id);
 
-	req.cmd.enable = false;
-	test_vcpu0_command(vm, KVMI_VCPU_CONTROL_SINGLESTEP,
-			   &req.hdr, sizeof(req), NULL, 0);
+	vcpu_thread = start_vcpu_worker(&data);
+
+	enable_singlestep(vm);
+
+	receive_event(&hdr, &ev.common, sizeof(ev), event_id);
+
+	DEBUG("SINGLESTEP event, rip 0x%llx success %d\n",
+		ev.common.arch.regs.rip, !ev.singlestep.failed);
+
+	disable_singlestep(vm);
+
+	reply_to_event(&hdr, &ev.common, KVMI_EVENT_ACTION_CONTINUE,
+			&rpl, sizeof(rpl));
+
+	stop_vcpu_worker(vcpu_thread, &data);
+
+	disable_vcpu_event(vm, KVMI_EVENT_SINGLESTEP);
 }
 
 static void test_introspection(struct kvm_vm *vm)
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 90e6c2d3dd4f..8a73fac287b4 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -110,6 +110,7 @@ static void setup_known_events(void)
 	set_bit(KVMI_EVENT_MSR, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PAUSE_VCPU, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_PF, Kvmi_known_vcpu_events);
+	set_bit(KVMI_EVENT_SINGLESTEP, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_TRAP, Kvmi_known_vcpu_events);
 	set_bit(KVMI_EVENT_XSETBV, Kvmi_known_vcpu_events);
 
@@ -1320,3 +1321,63 @@ bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu)
 	return ret;
 }
 EXPORT_SYMBOL(kvmi_vcpu_running_singlestep);
+
+static u32 kvmi_send_singlestep(struct kvm_vcpu *vcpu, bool success)
+{
+	struct kvmi_event_singlestep e;
+	int err, action;
+
+	memset(&e, 0, sizeof(e));
+	e.failed = success ? 0 : 1;
+
+	err = kvmi_send_event(vcpu, KVMI_EVENT_SINGLESTEP, &e, sizeof(e),
+			      NULL, 0, &action);
+	if (err)
+		return KVMI_EVENT_ACTION_CONTINUE;
+
+	return action;
+}
+
+static void kvmi_singlestep_event(struct kvm_vcpu *vcpu, bool success)
+{
+	u32 action;
+
+	action = kvmi_send_singlestep(vcpu, success);
+	switch (action) {
+	case KVMI_EVENT_ACTION_CONTINUE:
+		break;
+	default:
+		kvmi_handle_common_event_actions(vcpu->kvm, action,
+						"SINGLESTEP");
+	}
+}
+
+static void kvmi_handle_singlestep_exit(struct kvm_vcpu *vcpu, bool success)
+{
+	struct kvm_vcpu_introspection *vcpui;
+	struct kvm_introspection *kvmi;
+	struct kvm *kvm = vcpu->kvm;
+
+	kvmi = kvmi_get(kvm);
+	if (!kvmi)
+		return;
+
+	vcpui = VCPUI(vcpu);
+
+	if (vcpui->singlestep.loop)
+		kvmi_singlestep_event(vcpu, success);
+
+	kvmi_put(kvm);
+}
+
+void kvmi_singlestep_done(struct kvm_vcpu *vcpu)
+{
+	kvmi_handle_singlestep_exit(vcpu, true);
+}
+EXPORT_SYMBOL(kvmi_singlestep_done);
+
+void kvmi_singlestep_failed(struct kvm_vcpu *vcpu)
+{
+	kvmi_handle_singlestep_exit(vcpu, false);
+}
+EXPORT_SYMBOL(kvmi_singlestep_failed);
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 14c063869c29..43762e4b7c5c 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -630,6 +630,11 @@ static int handle_vcpu_control_singlestep(const struct kvmi_vcpu_cmd_job *job,
 	bool done;
 	int i;
 
+	if (!is_event_allowed(KVMI(vcpu->kvm), KVMI_EVENT_SINGLESTEP)) {
+		ec = -KVM_EPERM;
+		goto reply;
+	}
+
 	for (i = 0; i < sizeof(req->padding); i++)
 		if (req->padding[i])
 			goto reply;

[PATCH v8 79/81] KVM: introspection: add KVMI_VCPU_TRANSLATE_GVA

[Adalbert Lazăr]

This helps the introspection tool with the GVA to GPA translations
without the need to monitor the guest page tables.

Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 Documentation/virt/kvm/kvmi.rst               | 31 +++++++++++++++++++
 arch/x86/kvm/kvmi.c                           |  4 +++
 include/uapi/linux/kvmi.h                     |  9 ++++++
 .../testing/selftests/kvm/x86_64/kvmi_test.c  | 31 +++++++++++++++++++
 virt/kvm/introspection/kvmi_int.h             |  1 +
 virt/kvm/introspection/kvmi_msg.c             | 16 ++++++++++
 6 files changed, 92 insertions(+)

diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst
index c761438801dd..c45643ebec3b 100644
--- a/Documentation/virt/kvm/kvmi.rst
+++ b/Documentation/virt/kvm/kvmi.rst
@@ -991,6 +991,37 @@ to the introspection tool.
 * -KVM_EINVAL - the padding is not zero
 * -KVM_EAGAIN - the selected vCPU can't be introspected yet
 
+21. KVMI_VCPU_TRANSLATE_GVA
+---------------------------
+
+:Architecture: all
+:Versions: >= 1
+:Parameters:
+
+::
+
+	struct kvmi_vcpu_hdr;
+	struct kvmi_vcpu_translate_gva {
+		__u64 gva;
+	};
+
+:Returns:
+
+::
+
+	struct kvmi_error_code;
+	struct kvmi_vcpu_translate_gva_reply {
+		__u64 gpa;
+	};
+
+Translates a guest virtual address to a guest physical address or ~0 if
+the address cannot be translated.
+
+:Errors:
+
+* -KVM_EINVAL - the selected vCPU is invalid
+* -KVM_EAGAIN - the selected vCPU can't be introspected yet
+
 Events
 ======
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index 729f91a66405..d339a879ba0b 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -1228,3 +1228,7 @@ bool kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu)
 	return true;
 }
 
+gpa_t kvmi_arch_cmd_translate_gva(struct kvm_vcpu *vcpu, gva_t gva)
+{
+	return kvm_mmu_gva_to_gpa_system(vcpu, gva, 0, NULL);
+}
diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h
index d69735918fd6..52e305a76c3b 100644
--- a/include/uapi/linux/kvmi.h
+++ b/include/uapi/linux/kvmi.h
@@ -43,6 +43,7 @@ enum {
 	KVMI_VM_SET_PAGE_ACCESS = 21,
 
 	KVMI_VCPU_CONTROL_SINGLESTEP = 22,
+	KVMI_VCPU_TRANSLATE_GVA      = 23,
 
 	KVMI_NUM_MESSAGES
 };
@@ -215,4 +216,12 @@ struct kvmi_event_singlestep {
 	__u8 padding[7];
 };
 
+struct kvmi_vcpu_translate_gva {
+	__u64 gva;
+};
+
+struct kvmi_vcpu_translate_gva_reply {
+	__u64 gpa;
+};
+
 #endif /* _UAPI__LINUX_KVMI_H */
diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 24dfcba113cd..cb4973141051 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -1752,6 +1752,36 @@ static void test_cmd_vcpu_control_singlestep(struct kvm_vm *vm)
 	disable_vcpu_event(vm, KVMI_EVENT_SINGLESTEP);
 }
 
+static void cmd_translate_gva(struct kvm_vm *vm, vm_vaddr_t gva,
+			      vm_paddr_t expected_gpa)
+{
+	struct {
+		struct kvmi_msg_hdr hdr;
+		struct kvmi_vcpu_hdr vcpu_hdr;
+		struct kvmi_vcpu_translate_gva cmd;
+	} req = { 0 };
+	struct kvmi_vcpu_translate_gva_reply rpl;
+
+	req.cmd.gva = gva;
+
+	test_vcpu0_command(vm, KVMI_VCPU_TRANSLATE_GVA, &req.hdr, sizeof(req),
+			  &rpl, sizeof(rpl));
+
+	TEST_ASSERT(rpl.gpa == expected_gpa,
+		    "Translation failed for gva 0x%llx -> gpa 0x%llx instead of 0x%llx\n",
+		    gva, rpl.gpa, expected_gpa);
+}
+
+static void test_cmd_translate_gva(struct kvm_vm *vm)
+{
+	cmd_translate_gva(vm, test_gva, test_gpa);
+	DEBUG("Tested gva 0x%lx to gpa 0x%lx\n", test_gva, test_gpa);
+
+	cmd_translate_gva(vm, -1, ~0);
+	DEBUG("Tested gva 0x%lx to gpa 0x%lx\n",
+		(vm_vaddr_t)-1, (vm_paddr_t)-1);
+}
+
 static void test_introspection(struct kvm_vm *vm)
 {
 	srandom(time(0));
@@ -1785,6 +1815,7 @@ static void test_introspection(struct kvm_vm *vm)
 	test_cmd_vm_set_page_access(vm);
 	test_event_pf(vm);
 	test_cmd_vcpu_control_singlestep(vm);
+	test_cmd_translate_gva(vm);
 
 	unhook_introspection(vm);
 }
diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h
index 820081f8e3f1..88fe3d67d580 100644
--- a/virt/kvm/introspection/kvmi_int.h
+++ b/virt/kvm/introspection/kvmi_int.h
@@ -130,5 +130,6 @@ bool kvmi_arch_pf_of_interest(struct kvm_vcpu *vcpu);
 void kvmi_arch_features(struct kvmi_features *feat);
 bool kvmi_arch_start_singlestep(struct kvm_vcpu *vcpu);
 bool kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu);
+gpa_t kvmi_arch_cmd_translate_gva(struct kvm_vcpu *vcpu, gva_t gva);
 
 #endif
diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c
index 43762e4b7c5c..c7af2b5701eb 100644
--- a/virt/kvm/introspection/kvmi_msg.c
+++ b/virt/kvm/introspection/kvmi_msg.c
@@ -42,6 +42,7 @@ static const char *const msg_IDs[] = {
 	[KVMI_VCPU_INJECT_EXCEPTION]   = "KVMI_VCPU_INJECT_EXCEPTION",
 	[KVMI_VCPU_PAUSE]              = "KVMI_VCPU_PAUSE",
 	[KVMI_VCPU_SET_REGISTERS]      = "KVMI_VCPU_SET_REGISTERS",
+	[KVMI_VCPU_TRANSLATE_GVA]      = "KVMI_VCPU_TRANSLATE_GVA",
 };
 
 static const char *id2str(u16 id)
@@ -653,6 +654,20 @@ static int handle_vcpu_control_singlestep(const struct kvmi_vcpu_cmd_job *job,
 	return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0);
 }
 
+static int handle_vcpu_translate_gva(const struct kvmi_vcpu_cmd_job *job,
+				     const struct kvmi_msg_hdr *msg,
+				     const void *_req)
+{
+	const struct kvmi_vcpu_translate_gva *req = _req;
+	struct kvmi_vcpu_translate_gva_reply rpl;
+
+	memset(&rpl, 0, sizeof(rpl));
+
+	rpl.gpa = kvmi_arch_cmd_translate_gva(job->vcpu, req->gva);
+
+	return kvmi_msg_vcpu_reply(job, msg, 0, &rpl, sizeof(rpl));
+}
+
 /*
  * These commands are executed from the vCPU thread. The receiving thread
  * passes the messages using a newly allocated 'struct kvmi_vcpu_cmd_job'
@@ -673,6 +688,7 @@ static int(*const msg_vcpu[])(const struct kvmi_vcpu_cmd_job *,
 	[KVMI_VCPU_GET_XSAVE]          = handle_vcpu_get_xsave,
 	[KVMI_VCPU_INJECT_EXCEPTION]   = handle_vcpu_inject_exception,
 	[KVMI_VCPU_SET_REGISTERS]      = handle_set_registers,
+	[KVMI_VCPU_TRANSLATE_GVA]      = handle_vcpu_translate_gva,
 };
 
 static bool is_vcpu_command(u16 id)

[PATCH v8 80/81] KVM: introspection: emulate a guest page table walk on SPT violations due to A/D bit updates

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

On SPT page faults caused by guest page table walks, use the existing
guest page table walk code to make the necessary adjustments to the A/D
bits and return to guest. This effectively bypasses the x86 emulator
who was making the wrong modifications leading one OS (Windows 8.1 x64)
to triple-fault very early in the boot process with the introspection
enabled.

With introspection disabled, these faults are handled by simply removing
the protection from the affected guest page and returning to guest.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/include/asm/kvmi_host.h |  2 ++
 arch/x86/kvm/kvmi.c              | 33 ++++++++++++++++++++++++++++++++
 arch/x86/kvm/mmu/mmu.c           | 11 +++++++++--
 include/linux/kvmi_host.h        |  3 +++
 virt/kvm/introspection/kvmi.c    | 26 +++++++++++++++++++++++++
 5 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 8d0c3ed3021b..9c9d6a018206 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -61,6 +61,7 @@ bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor, bool write);
 bool kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr);
 bool kvmi_monitor_msrw_intercept(struct kvm_vcpu *vcpu, u32 msr, bool enable);
 bool kvmi_msrw_intercept_originator(struct kvm_vcpu *vcpu);
+bool kvmi_update_ad_flags(struct kvm_vcpu *vcpu);
 
 #else /* CONFIG_KVM_INTROSPECTION */
 
@@ -83,6 +84,7 @@ static inline bool kvmi_monitor_msrw_intercept(struct kvm_vcpu *vcpu, u32 msr,
 					       bool enable) { return false; }
 static inline bool kvmi_msrw_intercept_originator(struct kvm_vcpu *vcpu)
 				{ return false; }
+bool kvmi_update_ad_flags(struct kvm_vcpu *vcpu) { return false; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c
index d339a879ba0b..f649630b089e 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -1232,3 +1232,36 @@ gpa_t kvmi_arch_cmd_translate_gva(struct kvm_vcpu *vcpu, gva_t gva)
 {
 	return kvm_mmu_gva_to_gpa_system(vcpu, gva, 0, NULL);
 }
+
+bool kvmi_update_ad_flags(struct kvm_vcpu *vcpu)
+{
+	struct kvm_introspection *kvmi;
+	bool ret = false;
+	gva_t gva;
+	gpa_t gpa;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return false;
+
+	gva = kvm_x86_ops->fault_gla(vcpu);
+	if (gva == ~0ull) {
+		kvmi_warn_once(kvmi, "%s: cannot perform translation\n",
+			       __func__);
+		goto out;
+	}
+
+	gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, PFERR_WRITE_MASK, NULL);
+	if (gpa == UNMAPPED_GVA) {
+		struct x86_exception exception = { };
+
+		gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, 0, &exception);
+	}
+
+	ret = (gpa != UNMAPPED_GVA);
+
+out:
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 35be9f2a2fc7..19a61136e1f1 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5574,8 +5574,15 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
 	 */
 	if (vcpu->arch.mmu->direct_map &&
 	    (error_code & PFERR_NESTED_GUEST_PAGE) == PFERR_NESTED_GUEST_PAGE) {
-		kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(cr2_or_gpa));
-		return 1;
+		gfn_t gfn = gpa_to_gfn(cr2_or_gpa);
+
+		if (kvmi_tracked_gfn(vcpu, gfn)) {
+			if (kvmi_update_ad_flags(vcpu))
+				return 1;
+		} else {
+			kvm_mmu_unprotect_page(vcpu->kvm, gfn);
+			return 1;
+		}
 	}
 
 	/*
diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h
index 58a30c087d63..a301148c8857 100644
--- a/include/linux/kvmi_host.h
+++ b/include/linux/kvmi_host.h
@@ -97,6 +97,7 @@ bool kvmi_enter_guest(struct kvm_vcpu *vcpu);
 bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu);
 void kvmi_singlestep_done(struct kvm_vcpu *vcpu);
 void kvmi_singlestep_failed(struct kvm_vcpu *vcpu);
+bool kvmi_tracked_gfn(struct kvm_vcpu *vcpu, gfn_t gfn);
 
 #else
 
@@ -117,6 +118,8 @@ static inline bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu)
 			{ return false; }
 static inline void kvmi_singlestep_done(struct kvm_vcpu *vcpu) { }
 static inline void kvmi_singlestep_failed(struct kvm_vcpu *vcpu) { }
+static inline bool kvmi_tracked_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
+			{ return false; }
 
 #endif /* CONFIG_KVM_INTROSPECTION */
 
diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c
index 8a73fac287b4..9176ae147d2a 100644
--- a/virt/kvm/introspection/kvmi.c
+++ b/virt/kvm/introspection/kvmi.c
@@ -1381,3 +1381,29 @@ void kvmi_singlestep_failed(struct kvm_vcpu *vcpu)
 	kvmi_handle_singlestep_exit(vcpu, false);
 }
 EXPORT_SYMBOL(kvmi_singlestep_failed);
+
+static bool __kvmi_tracked_gfn(struct kvm_introspection *kvmi, gfn_t gfn)
+{
+	u8 ignored_access;
+
+	if (kvmi_get_gfn_access(kvmi, gfn, &ignored_access))
+		return false;
+
+	return true;
+}
+
+bool kvmi_tracked_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+	struct kvm_introspection *kvmi;
+	bool ret;
+
+	kvmi = kvmi_get(vcpu->kvm);
+	if (!kvmi)
+		return false;
+
+	ret = __kvmi_tracked_gfn(kvmi, gfn);
+
+	kvmi_put(vcpu->kvm);
+
+	return ret;
+}

Re: [PATCH v8 80/81] KVM: introspection: emulate a guest page table walk on SPT violations due to A/D bit updates

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 8540 bytes --]

Hi "Adalbert,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on linus/master v5.6]
[cannot apply to kvm/linux-next vhost/linux-next next-20200330]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Adalbert-Laz-r/VM-introspection/20200330-234749
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: x86_64-lkp (attached as .config)
compiler: gcc-7 (Debian 7.4.0-6) 7.4.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   ld: arch/x86/../../virt/kvm/coalesced_mmio.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/../../virt/kvm/eventfd.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/../../virt/kvm/irqchip.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/../../virt/kvm/vfio.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/../../virt/kvm/async_pf.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/x86.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/emulate.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/i8259.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/irq.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/lapic.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/i8254.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/ioapic.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/irq_comm.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/cpuid.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/pmu.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/mtrr.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/hyperv.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/debugfs.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/mmu/mmu.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/mmu/page_track.o: in function `kvmi_update_ad_flags':
>> arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/vmx/vmx.o: in function `kvmi_update_ad_flags':
   arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/vmx/pmu_intel.o: in function `kvmi_update_ad_flags':
   arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/vmx/vmcs12.o: in function `kvmi_update_ad_flags':
   arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/vmx/evmcs.o: in function `kvmi_update_ad_flags':
   arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here
   ld: arch/x86/kvm/vmx/nested.o: in function `kvmi_update_ad_flags':
   arch/x86/include/asm/kvmi_host.h:87: multiple definition of `kvmi_update_ad_flags'; arch/x86/../../virt/kvm/kvm_main.o:arch/x86/include/asm/kvmi_host.h:87: first defined here

vim +87 arch/x86/include/asm/kvmi_host.h

    67	
    68	static inline bool kvmi_monitor_bp_intercept(struct kvm_vcpu *vcpu, u32 dbg)
    69		{ return false; }
    70	static inline bool kvmi_cr_event(struct kvm_vcpu *vcpu, unsigned int cr,
    71					 unsigned long old_value,
    72					 unsigned long *new_value) { return true; }
    73	static inline bool kvmi_cr3_intercepted(struct kvm_vcpu *vcpu) { return false; }
    74	static inline bool kvmi_monitor_cr3w_intercept(struct kvm_vcpu *vcpu,
    75							bool enable) { return false; }
    76	static inline void kvmi_xsetbv_event(struct kvm_vcpu *vcpu) { }
    77	static inline bool kvmi_monitor_desc_intercept(struct kvm_vcpu *vcpu,
    78						       bool enable) { return false; }
    79	static inline bool kvmi_descriptor_event(struct kvm_vcpu *vcpu, u8 descriptor,
    80						 bool write) { return true; }
    81	static inline bool kvmi_msr_event(struct kvm_vcpu *vcpu, struct msr_data *msr)
    82					{ return true; }
    83	static inline bool kvmi_monitor_msrw_intercept(struct kvm_vcpu *vcpu, u32 msr,
    84						       bool enable) { return false; }
    85	static inline bool kvmi_msrw_intercept_originator(struct kvm_vcpu *vcpu)
    86					{ return false; }
  > 87	bool kvmi_update_ad_flags(struct kvm_vcpu *vcpu) { return false; }
    88	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 28889 bytes --]

[PATCH v8 81/81] KVM: x86: call the page tracking code on emulation failure

[Adalbert Lazăr]

From: Mihai Donțu <mdontu@bitdefender.com>

The information we can provide this way is incomplete, but current users
of the page tracking code can work with it.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Signed-off-by: Adalbert Lazăr <alazar@bitdefender.com>
---
 arch/x86/kvm/x86.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 12e9b4689025..de90335d2e01 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6793,6 +6793,51 @@ static bool is_vmware_backdoor_opcode(struct x86_emulate_ctxt *ctxt)
 	return false;
 }
 
+/*
+ * With introspection enabled, emulation failures translate in events being
+ * missed because the read/write callbacks are not invoked. All we have is
+ * the fetch event (kvm_page_track_preexec). Below we use the EPT/NPT VMEXIT
+ * information to generate the events, but without providing accurate
+ * data and size (the emulator would have computed those). If an instruction
+ * would happen to read and write in the same page, the second event will
+ * initially be missed and we rely on the page tracking mechanism to bring
+ * us back here to send it.
+ */
+static bool kvm_page_track_emulation_failure(struct kvm_vcpu *vcpu, gpa_t gpa)
+{
+	u64 error_code = vcpu->arch.error_code;
+	u8 data = 0;
+	gva_t gva;
+	bool ret;
+
+	/* MMIO emulation failures should be treated the normal way */
+	if (unlikely(error_code & PFERR_RSVD_MASK))
+		return true;
+
+	/* EPT/NTP must be enabled */
+	if (unlikely(!vcpu->arch.mmu->direct_map))
+		return true;
+
+	/*
+	 * The A/D bit emulation should make this test unneeded, but just
+	 * in case
+	 */
+	if (unlikely((error_code & PFERR_NESTED_GUEST_PAGE) ==
+		     PFERR_NESTED_GUEST_PAGE))
+		return true;
+
+	gva = kvm_x86_ops->fault_gla(vcpu);
+
+	if (error_code & PFERR_WRITE_MASK)
+		ret = kvm_page_track_prewrite(vcpu, gpa, gva, &data, 0);
+	else if (error_code & PFERR_USER_MASK)
+		ret = kvm_page_track_preread(vcpu, gpa, gva, 0);
+	else
+		ret = true;
+
+	return ret;
+}
+
 int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 			    int emulation_type, void *insn, int insn_len)
 {
@@ -6842,6 +6887,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 				kvm_queue_exception(vcpu, UD_VECTOR);
 				return 1;
 			}
+			if (!kvm_page_track_emulation_failure(vcpu, cr2_or_gpa))
+				return 1;
 			if (reexecute_instruction(vcpu, cr2_or_gpa,
 						  write_fault_to_spt,
 						  emulation_type))
@@ -6900,6 +6947,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 		return 1;
 
 	if (r == EMULATION_FAILED) {
+		if (!kvm_page_track_emulation_failure(vcpu, cr2_or_gpa))
+			return 1;
 		if (reexecute_instruction(vcpu, cr2_or_gpa, write_fault_to_spt,
 					emulation_type))
 			return 1;