From: "Adalbert Lazăr" <alazar@bitdefender.com>
To: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Nicușor Cîțu" <ncitu@bitdefender.com>,
"Adalbert Lazăr" <alazar@bitdefender.com>
Subject: [PATCH v9 62/84] KVM: introspection: restore the state of #BP interception on unhook
Date: Wed, 22 Jul 2020 00:09:00 +0300 [thread overview]
Message-ID: <20200721210922.7646-63-alazar@bitdefender.com> (raw)
In-Reply-To: <20200721210922.7646-1-alazar@bitdefender.com>
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/kvmi_host.h | 18 ++++++
arch/x86/kvm/kvmi.c | 60 +++++++++++++++++++
arch/x86/kvm/x86.c | 5 ++
.../testing/selftests/kvm/x86_64/kvmi_test.c | 16 +++++
4 files changed, 99 insertions(+)
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index 6d274f173fb5..5f2a968831d3 100644
--- a/arch/x86/include/asm/kvmi_host.h
+++ b/arch/x86/include/asm/kvmi_host.h
@@ -4,8 +4,15 @@
#include <asm/kvmi.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 {
@@ -14,4 +21,15 @@ 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 ca2ce7498cfe..56c02dad3b57 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -243,18 +243,71 @@ 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)
{
@@ -293,6 +346,7 @@ void kvmi_arch_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len)
static void kvmi_arch_restore_interception(struct kvm_vcpu *vcpu)
{
+ kvmi_arch_disable_bp_intercept(vcpu);
}
bool kvmi_arch_clean_up_interception(struct kvm_vcpu *vcpu)
@@ -318,6 +372,12 @@ bool kvmi_arch_vcpu_alloc_interception(struct kvm_vcpu *vcpu)
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;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0d5ce07c4164..9c8b7a3c5758 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9325,6 +9325,11 @@ 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/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
index 3b921e3cf958..1418e31918be 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -58,6 +58,10 @@ enum {
#define HOST_SEND_TEST(uc) (uc.cmd == UCALL_SYNC && uc.args[1] == 0)
+static pthread_t start_vcpu_worker(struct vcpu_worker_data *data);
+static void stop_vcpu_worker(pthread_t vcpu_thread,
+ struct vcpu_worker_data *data);
+
static int guest_test_id(void)
{
GUEST_REQUEST_TEST();
@@ -171,8 +175,10 @@ static void allow_command(struct kvm_vm *vm, __s32 id)
static void hook_introspection(struct kvm_vm *vm)
{
+ struct vcpu_worker_data data = {.vm = vm, .vcpu_id = VCPU_ID };
__u32 allow = 1, disallow = 0, allow_inval = 2;
__u32 padding = 1, no_padding = 0;
+ pthread_t vcpu_thread;
__s32 all_IDs = -1;
set_command_perm(vm, all_IDs, allow, EFAULT);
@@ -180,6 +186,16 @@ static void hook_introspection(struct kvm_vm *vm)
do_hook_ioctl(vm, Kvm_socket, padding, EINVAL);
do_hook_ioctl(vm, -1, no_padding, EINVAL);
+
+ /*
+ * The last call failed "too late".
+ * We have to let the vCPU run and clean up its structures,
+ * otherwise the next call will fail with EEXIST.
+ */
+ vcpu_thread = start_vcpu_worker(&data);
+ sleep(1);
+ stop_vcpu_worker(vcpu_thread, &data);
+
do_hook_ioctl(vm, Kvm_socket, no_padding, 0);
do_hook_ioctl(vm, Kvm_socket, no_padding, EEXIST);
next prev parent reply other threads:[~2020-07-21 21:09 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 21:07 [PATCH v9 00/84] VM introspection Adalbert Lazăr
2020-07-21 21:07 ` [PATCH v9 01/84] signal: export kill_pid_info() Adalbert Lazăr
2020-07-22 6:36 ` Christoph Hellwig
2020-07-21 21:08 ` [PATCH v9 02/84] KVM: UAPI: add error codes used by the VM introspection code Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 03/84] KVM: add kvm_vcpu_kick_and_wait() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 04/84] KVM: add kvm_get_max_gfn() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 05/84] KVM: doc: fix the hypercall numbering Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 06/84] KVM: x86: add kvm_arch_vcpu_get_regs() and kvm_arch_vcpu_get_sregs() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 07/84] KVM: x86: add kvm_arch_vcpu_set_regs() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 08/84] KVM: x86: avoid injecting #PF when emulate the VMCALL instruction Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 09/84] KVM: x86: add .bp_intercepted() to struct kvm_x86_ops Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 10/84] KVM: x86: add .control_cr3_intercept() " Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 11/84] KVM: x86: add .cr3_write_intercepted() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 12/84] KVM: x86: add .desc_ctrl_supported() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 13/84] KVM: svm: add support for descriptor-table exits Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 14/84] KVM: x86: add .control_desc_intercept() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 15/84] KVM: x86: add .desc_intercepted() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 16/84] KVM: x86: export .msr_write_intercepted() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 17/84] KVM: x86: use MSR_TYPE_R, MSR_TYPE_W and MSR_TYPE_RW with AMD Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 18/84] KVM: svm: pass struct kvm_vcpu to set_msr_interception() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 19/84] KVM: vmx: pass struct kvm_vcpu to the intercept msr related functions Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 20/84] KVM: x86: add .control_msr_intercept() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 21/84] KVM: x86: vmx: use a symbolic constant when checking the exit qualifications Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 22/84] KVM: x86: save the error code during EPT/NPF exits handling Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 23/84] KVM: x86: add .fault_gla() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 24/84] KVM: x86: add .spt_fault() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 25/84] KVM: x86: add .gpt_translation_fault() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 26/84] KVM: x86: add .control_singlestep() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 27/84] KVM: x86: export kvm_arch_vcpu_set_guest_debug() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 28/84] KVM: x86: extend kvm_mmu_gva_to_gpa_system() with the 'access' parameter Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 29/84] KVM: x86: export kvm_inject_pending_exception() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 30/84] KVM: x86: export kvm_vcpu_ioctl_x86_get_xsave() Adalbert Lazăr
2020-07-22 1:31 ` kernel test robot
2020-07-21 21:08 ` [PATCH v9 31/84] KVM: x86: export kvm_vcpu_ioctl_x86_set_xsave() Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 32/84] KVM: x86: page track: provide all callbacks with the guest virtual address Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 33/84] KVM: x86: page track: add track_create_slot() callback Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 34/84] KVM: x86: page_track: add support for preread, prewrite and preexec Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 35/84] KVM: x86: wire in the preread/prewrite/preexec page trackers Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 36/84] KVM: x86: disable gpa_available optimization for fetch and page-walk SPT violations Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 37/84] KVM: introduce VM introspection Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 38/84] KVM: introspection: add hook/unhook ioctls Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 39/84] KVM: introspection: add permission access ioctls Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 40/84] KVM: introspection: add the read/dispatch message function Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 41/84] KVM: introspection: add KVMI_GET_VERSION Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 42/84] KVM: introspection: add KVMI_VM_CHECK_COMMAND and KVMI_VM_CHECK_EVENT Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 43/84] KVM: introspection: add KVMI_VM_GET_INFO Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 44/84] KVM: introspection: add KVMI_EVENT_UNHOOK Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 45/84] KVM: introspection: add KVMI_VM_CONTROL_EVENTS Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 46/84] KVM: introspection: add KVMI_VM_READ_PHYSICAL/KVMI_VM_WRITE_PHYSICAL Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 47/84] KVM: introspection: add vCPU related data Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 48/84] KVM: introspection: add a jobs list to every introspected vCPU Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 49/84] KVM: introspection: handle vCPU introspection requests Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 50/84] KVM: introspection: handle vCPU commands Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 51/84] KVM: introspection: add KVMI_VCPU_GET_INFO Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 52/84] KVM: introspection: add KVMI_VCPU_PAUSE Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 53/84] KVM: introspection: add KVMI_EVENT_PAUSE_VCPU Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 54/84] KVM: introspection: add the crash action handling on the event reply Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 55/84] KVM: introspection: add KVMI_VCPU_CONTROL_EVENTS Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 56/84] KVM: introspection: add KVMI_VCPU_GET_REGISTERS Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 57/84] KVM: introspection: add KVMI_VCPU_SET_REGISTERS Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 58/84] KVM: introspection: add KVMI_VCPU_GET_CPUID Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 59/84] KVM: introspection: add KVMI_EVENT_HYPERCALL Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 60/84] KVM: introspection: add KVMI_EVENT_BREAKPOINT Adalbert Lazăr
2020-07-21 21:08 ` [PATCH v9 61/84] KVM: introspection: add cleanup support for vCPUs Adalbert Lazăr
2020-07-21 21:09 ` Adalbert Lazăr [this message]
2020-07-21 21:09 ` [PATCH v9 63/84] KVM: introspection: add KVMI_VM_CONTROL_CLEANUP Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 64/84] KVM: introspection: add KVMI_VCPU_CONTROL_CR and KVMI_EVENT_CR Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 65/84] KVM: introspection: restore the state of CR3 interception on unhook Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 66/84] KVM: introspection: add KVMI_VCPU_INJECT_EXCEPTION + KVMI_EVENT_TRAP Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 67/84] KVM: introspection: add KVMI_VM_GET_MAX_GFN Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 68/84] KVM: introspection: add KVMI_EVENT_XSETBV Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 69/84] KVM: introspection: add KVMI_VCPU_GET_XCR Adalbert Lazăr
2020-07-22 8:25 ` kernel test robot
2020-07-21 21:09 ` [PATCH v9 70/84] KVM: introspection: add KVMI_VCPU_GET_XSAVE Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 71/84] KVM: introspection: add KVMI_VCPU_SET_XSAVE Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 72/84] KVM: introspection: add KVMI_VCPU_GET_MTRR_TYPE Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 73/84] KVM: introspection: add KVMI_EVENT_DESCRIPTOR Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 74/84] KVM: introspection: restore the state of descriptor-table register interception on unhook Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 75/84] KVM: introspection: add KVMI_VCPU_CONTROL_MSR and KVMI_EVENT_MSR Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 76/84] KVM: introspection: restore the state of MSR interception on unhook Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 77/84] KVM: introspection: add KVMI_VM_SET_PAGE_ACCESS Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 78/84] KVM: introspection: add KVMI_EVENT_PF Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 79/84] KVM: introspection: extend KVMI_GET_VERSION with struct kvmi_features Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 80/84] KVM: introspection: add KVMI_VCPU_CONTROL_SINGLESTEP Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 81/84] KVM: introspection: add KVMI_EVENT_SINGLESTEP Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 82/84] KVM: introspection: add KVMI_VCPU_TRANSLATE_GVA Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 83/84] KVM: introspection: emulate a guest page table walk on SPT violations due to A/D bit updates Adalbert Lazăr
2020-07-21 21:09 ` [PATCH v9 84/84] KVM: x86: call the page tracking code on emulation failure Adalbert Lazăr
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