[PATCH] KVM: nVMX: Clear nested_run_pending if setting nested state fails

[Sean Christopherson]

VMX's nested_run_pending flag is subtly consumed when stuffing state to
enter guest mode, i.e. needs to be set according before KVM knows if
setting guest state is successful.  If setting guest state fails, clear
the flag as a nested run is obviously not pending.

Reported-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
 arch/x86/kvm/vmx/nested.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 04b40a98f60b..1a2a2f91b7e0 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5428,29 +5428,33 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
 		struct vmcs12 *shadow_vmcs12 = get_shadow_vmcs12(vcpu);
 
 		if (kvm_state->size < sizeof(kvm_state) + 2 * sizeof(*vmcs12))
-			return -EINVAL;
+			goto error_guest_mode;
 
 		if (copy_from_user(shadow_vmcs12,
 				   user_kvm_nested_state->data + VMCS12_SIZE,
 				   sizeof(*vmcs12)))
-			return -EFAULT;
+			goto error_guest_mode;
 
 		if (shadow_vmcs12->hdr.revision_id != VMCS12_REVISION ||
 		    !shadow_vmcs12->hdr.shadow_vmcs)
-			return -EINVAL;
+			goto error_guest_mode;
 	}
 
 	if (nested_vmx_check_controls(vcpu, vmcs12) ||
 	    nested_vmx_check_host_state(vcpu, vmcs12) ||
 	    nested_vmx_check_guest_state(vcpu, vmcs12, &exit_qual))
-		return -EINVAL;
+		goto error_guest_mode;
 
 	vmx->nested.dirty_vmcs12 = true;
 	ret = nested_vmx_enter_non_root_mode(vcpu, false);
 	if (ret)
-		return -EINVAL;
+		goto error_guest_mode;
 
 	return 0;
+
+error_guest_mode:
+	vmx->nested.nested_run_pending = 0;
+	return -EINVAL;
 }
 
 void nested_vmx_vcpu_setup(void)
-- 
2.21.0


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