KVM: SVM: do not generate "external interrupt exit" if other exit is pending

Nested SVM checks for external interrupt after injecting nested exception.
In case there is external interrupt pending the code generates "external
interrupt exit" and overwrites previous exit info. If previously injected
exception already generated exit it will be lost.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1a85fc5..c929d00 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1707,6 +1707,14 @@
 	if (!(svm->vcpu.arch.hflags & HF_HIF_MASK))
 		return false;
 
+	/*
+	 * if vmexit was already requested (by intercepted exception
+	 * for instance) do not overwrite it with "external interrupt"
+	 * vmexit.
+	 */
+	if (svm->nested.exit_required)
+		return false;
+
 	svm->vmcb->control.exit_code   = SVM_EXIT_INTR;
 	svm->vmcb->control.exit_info_1 = 0;
 	svm->vmcb->control.exit_info_2 = 0;