From: "Adalbert Lazăr" <alazar@bitdefender.com>
To: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Nicușor Cîțu" <nicu.citu@icloud.com>,
"Adalbert Lazăr" <alazar@bitdefender.com>
Subject: [PATCH v11 59/81] KVM: introspection: restore the state of #BP interception on unhook
Date: Mon, 7 Dec 2020 22:46:00 +0200 [thread overview]
Message-ID: <20201207204622.15258-60-alazar@bitdefender.com> (raw)
In-Reply-To: <20201207204622.15258-1-alazar@bitdefender.com>
From: Nicușor Cîțu <nicu.citu@icloud.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 <nicu.citu@icloud.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 | 14 +++++
4 files changed, 97 insertions(+)
diff --git a/arch/x86/include/asm/kvmi_host.h b/arch/x86/include/asm/kvmi_host.h
index b776be4bb49f..e008662f91a5 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 {
@@ -16,4 +23,15 @@ 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 b4a7d581f68c..3fd73087276e 100644
--- a/arch/x86/kvm/kvmi.c
+++ b/arch/x86/kvm/kvmi.c
@@ -162,19 +162,72 @@ bool kvmi_arch_is_agent_hypercall(struct kvm_vcpu *vcpu)
&& subfunc2 == 0);
}
+/*
+ * 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)
{
@@ -213,6 +266,7 @@ 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)
@@ -238,6 +292,12 @@ 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 fcd02f6279b8..a012b040e3d1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9753,6 +9753,11 @@ 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 ccb9a3a997d8..143ee1a8f618 100644
--- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c
+++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c
@@ -63,6 +63,9 @@ enum {
#define HOST_SEND_TEST(uc) (uc.cmd == UCALL_SYNC && uc.args[1] == 0)
#define HOST_TEST_DONE(uc) (uc.cmd == UCALL_SYNC && uc.args[1] == 1)
+static pthread_t start_vcpu_worker(struct vcpu_worker_data *data);
+static void wait_vcpu_worker(pthread_t vcpu_thread);
+
static int guest_test_id(void)
{
GUEST_REQUEST_TEST();
@@ -172,13 +175,24 @@ 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;
+ pthread_t vcpu_thread;
__s32 all_IDs = -1;
set_command_perm(vm, all_IDs, allow, EFAULT);
set_event_perm(vm, all_IDs, allow, EFAULT);
do_hook_ioctl(vm, -1, 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);
+ wait_vcpu_worker(vcpu_thread);
+
do_hook_ioctl(vm, Kvm_socket, 0);
do_hook_ioctl(vm, Kvm_socket, EEXIST);
next prev parent reply other threads:[~2020-12-07 20:49 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 20:45 [PATCH v11 00/81] VM introspection Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 01/81] KVM: UAPI: add error codes used by the VM introspection code Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 02/81] KVM: add kvm_vcpu_kick_and_wait() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 03/81] KVM: add kvm_get_max_gfn() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 04/81] KVM: doc: fix the hypercalls numbering Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 05/81] KVM: x86: add kvm_arch_vcpu_get_regs() and kvm_arch_vcpu_get_sregs() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 06/81] KVM: x86: add kvm_arch_vcpu_set_regs() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 07/81] KVM: x86: avoid injecting #PF when emulate the VMCALL instruction Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 08/81] KVM: x86: add kvm_x86_ops.bp_intercepted() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 09/81] KVM: x86: add kvm_x86_ops.control_cr3_intercept() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 10/81] KVM: x86: add kvm_x86_ops.cr3_write_intercepted() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 11/81] KVM: x86: add kvm_x86_ops.desc_ctrl_supported() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 12/81] KVM: svm: add support for descriptor-table VM-exits Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 13/81] KVM: x86: add kvm_x86_ops.control_desc_intercept() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 14/81] KVM: x86: add kvm_x86_ops.desc_intercepted() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 15/81] KVM: x86: add kvm_x86_ops.msr_write_intercepted() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 16/81] KVM: x86: svm: use the vmx convention to control the MSR interception Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 17/81] KVM: x86: add kvm_x86_ops.control_msr_intercept() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 18/81] KVM: x86: vmx: use a symbolic constant when checking the exit qualifications Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 19/81] KVM: x86: save the error code during EPT/NPF exits handling Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 20/81] KVM: x86: add kvm_x86_ops.fault_gla() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 21/81] KVM: x86: add kvm_x86_ops.control_singlestep() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 22/81] KVM: x86: export kvm_arch_vcpu_set_guest_debug() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 23/81] KVM: x86: extend kvm_mmu_gva_to_gpa_system() with the 'access' parameter Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 24/81] KVM: x86: export kvm_inject_pending_exception() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 25/81] KVM: x86: export kvm_vcpu_ioctl_x86_get_xsave() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 26/81] KVM: x86: export kvm_vcpu_ioctl_x86_set_xsave() Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 27/81] KVM: x86: page track: provide all callbacks with the guest virtual address Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 28/81] KVM: x86: page track: add track_create_slot() callback Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 29/81] KVM: x86: page_track: add support for preread, prewrite and preexec Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 30/81] KVM: x86: wire in the preread/prewrite/preexec page trackers Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 31/81] KVM: x86: disable gpa_available optimization for fetch and page-walk SPT violations Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 32/81] KVM: introduce VM introspection Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 33/81] KVM: introspection: add hook/unhook ioctls Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 34/81] KVM: introspection: add permission access ioctls Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 35/81] KVM: introspection: add the read/dispatch message function Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 36/81] KVM: introspection: add KVMI_GET_VERSION Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 37/81] KVM: introspection: add KVMI_VM_CHECK_COMMAND and KVMI_VM_CHECK_EVENT Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 38/81] KVM: introspection: add KVMI_VM_GET_INFO Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 39/81] KVM: introspection: add KVM_INTROSPECTION_PREUNHOOK Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 40/81] KVM: introspection: add KVMI_VM_EVENT_UNHOOK Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 41/81] KVM: introspection: add KVMI_VM_CONTROL_EVENTS Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 42/81] KVM: introspection: add KVMI_VM_READ_PHYSICAL/KVMI_VM_WRITE_PHYSICAL Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 43/81] KVM: introspection: add vCPU related data Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 44/81] KVM: introspection: add a jobs list to every introspected vCPU Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 45/81] KVM: introspection: handle vCPU introspection requests Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 46/81] KVM: introspection: handle vCPU commands Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 47/81] KVM: introspection: add KVMI_VCPU_GET_INFO Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 48/81] KVM: introspection: add KVMI_VM_PAUSE_VCPU Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 49/81] KVM: introspection: add support for vCPU events Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 50/81] KVM: introspection: add KVMI_VCPU_EVENT_PAUSE Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 51/81] KVM: introspection: add the crash action handling on the event reply Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 52/81] KVM: introspection: add KVMI_VCPU_CONTROL_EVENTS Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 53/81] KVM: introspection: add KVMI_VCPU_GET_REGISTERS Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 54/81] KVM: introspection: add KVMI_VCPU_SET_REGISTERS Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 55/81] KVM: introspection: add KVMI_VCPU_GET_CPUID Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 56/81] KVM: introspection: add KVMI_VCPU_EVENT_HYPERCALL Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 57/81] KVM: introspection: add KVMI_VCPU_EVENT_BREAKPOINT Adalbert Lazăr
2020-12-07 20:45 ` [PATCH v11 58/81] KVM: introspection: add cleanup support for vCPUs Adalbert Lazăr
2020-12-07 20:46 ` Adalbert Lazăr [this message]
2020-12-07 20:46 ` [PATCH v11 60/81] KVM: introspection: add KVMI_VM_CONTROL_CLEANUP Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 61/81] KVM: introspection: add KVMI_VCPU_CONTROL_CR and KVMI_VCPU_EVENT_CR Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 62/81] KVM: introspection: restore the state of CR3 interception on unhook Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 63/81] KVM: introspection: add KVMI_VCPU_INJECT_EXCEPTION + KVMI_VCPU_EVENT_TRAP Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 64/81] KVM: introspection: add KVMI_VM_GET_MAX_GFN Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 65/81] KVM: introspection: add KVMI_VCPU_EVENT_XSETBV Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 66/81] KVM: introspection: add KVMI_VCPU_GET_XCR Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 67/81] KVM: introspection: add KVMI_VCPU_GET_XSAVE Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 68/81] KVM: introspection: add KVMI_VCPU_SET_XSAVE Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 69/81] KVM: introspection: add KVMI_VCPU_GET_MTRR_TYPE Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 70/81] KVM: introspection: add KVMI_VCPU_EVENT_DESCRIPTOR Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 71/81] KVM: introspection: restore the state of descriptor-table register interception on unhook Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 72/81] KVM: introspection: add KVMI_VCPU_CONTROL_MSR and KVMI_VCPU_EVENT_MSR Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 73/81] KVM: introspection: restore the state of MSR interception on unhook Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 74/81] KVM: introspection: add KVMI_VM_SET_PAGE_ACCESS Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 75/81] KVM: introspection: add KVMI_VCPU_EVENT_PF Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 76/81] KVM: introspection: extend KVMI_GET_VERSION with struct kvmi_features Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 77/81] KVM: introspection: add KVMI_VCPU_CONTROL_SINGLESTEP Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 78/81] KVM: introspection: add KVMI_VCPU_EVENT_SINGLESTEP Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 79/81] KVM: introspection: add KVMI_VCPU_TRANSLATE_GVA Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 80/81] KVM: introspection: emulate a guest page table walk on SPT violations due to A/D bit updates Adalbert Lazăr
2020-12-07 20:46 ` [PATCH v11 81/81] KVM: x86: call the page tracking code on emulation failure Adalbert Lazăr
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