KVM: nSVM: Move SMI vmexit handling to svm_check_nested_events()

Unlike VMX, SVM allows a hypervisor to take a SMI vmexit without having
any special SMM-monitor enablement sequence.  Therefore, it has to be
handled like interrupts and NMIs.  Check for an unblocked SMI in
svm_check_nested_events() so that pending SMIs are correctly prioritized
over IRQs and NMIs when the latter events will trigger VM-Exit.

Note that there is no need to test explicitly for SMI vmexits, because
guests always runs outside SMM and therefore can never get an SMI while
they are blocked.

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

arch/x86/kvm/svm/svm.c

@@ -3778,14 +3778,6 @@ static bool svm_smi_allowed(struct kvm_vcpu *vcpu)
 	if (!gif_set(svm))
 		return false;
 
-	if (is_guest_mode(&svm->vcpu) &&
-	    svm->nested.intercept & (1ULL << INTERCEPT_SMI)) {
-		/* TODO: Might need to set exit_info_1 and exit_info_2 here */
-		svm->vmcb->control.exit_code = SVM_EXIT_SMI;
-		svm->nested.exit_required = true;
-		return false;
-	}
-
 	return !is_smm(vcpu);
 }