kvm: nVMX: Set nested_run_pending in vmx_set_nested_state after checks complete

nested_run_pending=1 implies we have successfully entered guest mode.
Move setting from external state in vmx_set_nested_state() until after
all other checks are complete.

Based on a patch by Aaron Lewis.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/nested.c

@@ -5420,9 +5420,6 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
 	if (!(kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE))
 		return 0;
 
-	vmx->nested.nested_run_pending =
-		!!(kvm_state->flags & KVM_STATE_NESTED_RUN_PENDING);
-
 	if (nested_cpu_has_shadow_vmcs(vmcs12) &&
 	    vmcs12->vmcs_link_pointer != -1ull) {
 		struct vmcs12 *shadow_vmcs12 = get_shadow_vmcs12(vcpu);
@@ -5446,9 +5443,14 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 
 	vmx->nested.dirty_vmcs12 = true;
+	vmx->nested.nested_run_pending =
+		!!(kvm_state->flags & KVM_STATE_NESTED_RUN_PENDING);
+
 	ret = nested_vmx_enter_non_root_mode(vcpu, false);
-	if (ret)
+	if (ret) {
+		vmx->nested.nested_run_pending = 0;
 		return -EINVAL;
+	}
 
 	return 0;
 }