KVM: SVM: Fix wrong interrupt injection in enable_irq_windows

The nested_svm_intr() function does not execute the vmexit
anymore. Therefore we may still be in the nested state after
that function ran. This patch changes the nested_svm_intr()
function to return wether the irq window could be enabled.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index a8ec53fe74f..294bbca3417 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1432,16 +1432,17 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
         return vmexit;
 }
 
-static inline int nested_svm_intr(struct vcpu_svm *svm)
+/* This function returns true if it is save to enable the irq window */
+static inline bool nested_svm_intr(struct vcpu_svm *svm)
 {
         if (!is_nested(svm))
-                return 0;
+                return true;
 
         if (!(svm->vcpu.arch.hflags & HF_VINTR_MASK))
-                return 0;
+                return true;
 
         if (!(svm->vcpu.arch.hflags & HF_HIF_MASK))
-                return 0;
+                return false;
 
         svm->vmcb->control.exit_code = SVM_EXIT_INTR;
 
@@ -1454,10 +1455,10 @@ static inline int nested_svm_intr(struct vcpu_svm *svm)
                  */
                 svm->nested.exit_required = true;
                 trace_kvm_nested_intr_vmexit(svm->vmcb->save.rip);
-                return 1;
+                return false;
         }
 
-        return 0;
+        return true;
 }
 
 static void *nested_svm_map(struct vcpu_svm *svm, u64 gpa, struct page **_page)
@@ -2629,13 +2630,11 @@ static void enable_irq_window(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
 
-        nested_svm_intr(svm);
-
         /* In case GIF=0 we can't rely on the CPU to tell us when
          * GIF becomes 1, because that's a separate STGI/VMRUN intercept.
          * The next time we get that intercept, this function will be
          * called again though and we'll get the vintr intercept. */
-        if (gif_set(svm)) {
+        if (gif_set(svm) && nested_svm_intr(svm)) {
                 svm_set_vintr(svm);
                 svm_inject_irq(svm, 0x0);
         }