[PATCH v2 08/10] KVM: nVMX: Cast exit_reason to u16 to check for nested EXTERNAL_INTERRUPT

From: Sean Christopherson
Date: Wed Apr 15 2020 - 14:00:15 EST


Explicitly check only the basic exit reason when emulating an external
interrupt VM-Exit in nested_vmx_vmexit(). Checking the full exit reason
doesn't currently cause problems, but only because the only exit reason
modifier support by KVM is FAILED_VMENTRY, which is mutually exclusive
with EXTERNAL_INTERRUPT. Future modifiers, e.g. ENCLAVE_MODE, will
coexist with EXTERNAL_INTERRUPT.

Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 67d27bc40143..23d84d063197 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4406,7 +4406,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;

if (likely(!vmx->fail)) {
- if (exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT &&
+ if ((u16)exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT &&
nested_exit_intr_ack_set(vcpu)) {
int irq = kvm_cpu_get_interrupt(vcpu);
WARN_ON(irq < 0);
--
2.26.0