KVM: SVM: introduce nested_run_pending

We want to inject vmexits immediately from svm_check_nested_events,
so that the interrupt/NMI window requests happen in inject_pending_event
right after it returns.

This however has the same issue as in vmx_check_nested_events, so
introduce a nested_run_pending flag with the exact same purpose
of delaying vmexit injection after the vmentry.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/svm.h

@@ -97,6 +97,10 @@ struct nested_state {
 	/* A VMEXIT is required but not yet emulated */
 	bool exit_required;
 
+	/* A VMRUN has started but has not yet been performed, so
+	 * we cannot inject a nested vmexit yet.  */
+	bool nested_run_pending;
+
 	/* cache for intercepts of the guest */
 	u32 intercept_cr;
 	u32 intercept_dr;