[PATCH v2] kvm: vmx: Properly handle machine check during VM-entry

[Jim Mattson <jmattson@google.com>]

When bit 31 of the exit reason is set to indicate a VM-entry failure,
only the exit reason and exit qualification fields are set. All other
VM-exit information fields, including "VM-exit interruption
information," are unmodified.

Fixes: 00eba012d53e6 ("KVM: VMX: Refactor vmx_complete_atomic_exit()")
Signed-off-by: Jim Mattson <jmattson@google.com>
---
 arch/x86/kvm/vmx.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c6f4ad44aa95..7c7ebefa8d15 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8614,17 +8614,19 @@ static void vmx_apicv_post_state_restore(struct kvm_vcpu *vcpu)
 
 static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
 {
-	u32 exit_intr_info;
+	u32 exit_intr_info = 0;
 
 	if (!(vmx->exit_reason == EXIT_REASON_MCE_DURING_VMENTRY
 	      || vmx->exit_reason == EXIT_REASON_EXCEPTION_NMI))
 		return;
 
-	vmx->exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
-	exit_intr_info = vmx->exit_intr_info;
+	if (vmx->exit_reason != EXIT_REASON_MCE_DURING_VMENTRY)
+		exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
+	vmx->exit_intr_info = exit_intr_info;
 
 	/* Handle machine checks before interrupts are enabled */
-	if (is_machine_check(exit_intr_info))
+	if (vmx->exit_reason == EXIT_REASON_MCE_DURING_VMENTRY ||
+	    is_machine_check(exit_intr_info))
 		kvm_machine_check();
 
 	/* We need to handle NMIs before interrupts are enabled */
-- 
2.13.0.303.g4ebf302169-goog