[patch 115/123] KVM: VMX: Trap and invalid MWAIT/MONITOR instruction

From: Greg KH
Date: Fri Mar 12 2010 - 19:26:28 EST


2.6.33-stable review patch. If anyone has any objections, please let me know.

-----------------

From: Sheng Yang <sheng@xxxxxxxxxxxxxxx>

commit 59708670b639bff00f92e519df1ae14da240e919 upstream.

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.

Signed-off-by: Sheng Yang <sheng@xxxxxxxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
arch/x86/include/asm/vmx.h | 1 +
arch/x86/kvm/vmx.c | 10 ++++++++++
2 files changed, 11 insertions(+)

--- 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
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1224,6 +1224,8 @@ static __init int setup_vmcs_config(stru
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
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[])(st
[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 =


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