KVM: Fix interrupt unhalting a vcpu when it shouldn't

kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
if interrupt window is actually opened.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index aa528dbad070..de741043c5b1 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2270,6 +2270,15 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu)
                 vmcb->control.intercept_cr_write |= INTERCEPT_CR8_MASK;
 }
 
+static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
+{
+        struct vcpu_svm *svm = to_svm(vcpu);
+        struct vmcb *vmcb = svm->vmcb;
+        return (vmcb->save.rflags & X86_EFLAGS_IF) &&
+                !(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
+                (svm->vcpu.arch.hflags & HF_GIF_MASK);
+}
+
 static void svm_intr_assist(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
@@ -2649,6 +2658,7 @@ static struct kvm_x86_ops svm_x86_ops = {
         .exception_injected = svm_exception_injected,
         .inject_pending_irq = svm_intr_assist,
         .inject_pending_vectors = do_interrupt_requests,
+        .interrupt_allowed = svm_interrupt_allowed,
 
         .set_tss_addr = svm_set_tss_addr,
         .get_tdp_level = get_npt_level,