KVM: VMX: Trap and invalid MWAIT/MONITOR instruction

We don't support these instructions, but guest can execute them even if the
feature('monitor') haven't been exposed in CPUID. So we would trap and inject
a #UD if guest try this way.

Cc: stable@kernel.org
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 2b49454..8f6b011 100644 (file)
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -251,6 +251,7 @@ enum vmcs_field {
 #define EXIT_REASON_MSR_READ            31
 #define EXIT_REASON_MSR_WRITE           32
 #define EXIT_REASON_MWAIT_INSTRUCTION   36
+#define EXIT_REASON_MONITOR_INSTRUCTION 39
 #define EXIT_REASON_PAUSE_INSTRUCTION   40
 #define EXIT_REASON_MCE_DURING_VMENTRY  41
 #define EXIT_REASON_TPR_BELOW_THRESHOLD 43

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index d4918d6..8a8e139 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1224,6 +1224,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
              CPU_BASED_USE_IO_BITMAPS |
              CPU_BASED_MOV_DR_EXITING |
              CPU_BASED_USE_TSC_OFFSETING |
+             CPU_BASED_MWAIT_EXITING |
+             CPU_BASED_MONITOR_EXITING |
              CPU_BASED_INVLPG_EXITING;
        opt = CPU_BASED_TPR_SHADOW |
              CPU_BASED_USE_MSR_BITMAPS |
@@ -3416,6 +3418,12 @@ static int handle_pause(struct kvm_vcpu *vcpu)
        return 1;
 }
 
+static int handle_invalid_op(struct kvm_vcpu *vcpu)
+{
+       kvm_queue_exception(vcpu, UD_VECTOR);
+       return 1;
+}
+
 /*
  * The exit handlers return 1 if the exit was handled fully and guest execution
  * may resume.  Otherwise they set the kvm_run parameter to indicate what needs
@@ -3453,6 +3461,8 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
        [EXIT_REASON_EPT_VIOLATION]           = handle_ept_violation,
        [EXIT_REASON_EPT_MISCONFIG]           = handle_ept_misconfig,
        [EXIT_REASON_PAUSE_INSTRUCTION]       = handle_pause,
+       [EXIT_REASON_MWAIT_INSTRUCTION]       = handle_invalid_op,
+       [EXIT_REASON_MONITOR_INSTRUCTION]     = handle_invalid_op,
 };
 
 static const int kvm_vmx_max_exit_handlers =