KVM: VMX: do not check bit 12 of EPT violation exit qualification when undefined

Bit 12 is undefined in any of the following cases:
- If the "NMI exiting" VM-execution control is 1 and the "virtual NMIs"
  VM-execution control is 0.
- If the VM exit sets the valid bit in the IDT-vectoring information field

Signed-off-by: Gleb Natapov <gleb@redhat.com>
[Add parentheses around & within && - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a1216de9ffda..3b8e7459dd4d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5345,7 +5345,9 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
          * There are errata that may cause this bit to not be set:
          * AAK134, BY25.
          */
-        if (exit_qualification & INTR_INFO_UNBLOCK_NMI)
+        if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) &&
+                        cpu_has_virtual_nmis() &&
+                        (exit_qualification & INTR_INFO_UNBLOCK_NMI))
                 vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI);
 
         gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);