Re: [PATCH] vfio/pci: Lock upstream bridge for vfio_pci_core_disable()

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Tue, 13 Jan 2026, Anthony Pighin (Nokia) wrote:

> Fix the following on VFIO detach:

Fix the following warning that occurs during VFIO detach:

> [  242.271584] pcieport 0000:00:00.0: unlocked secondary bus reset via:
>                pci_reset_bus_function+0x188/0x1b8
> 
> Commit 920f6468924f ("Warn on missing cfg_access_lock during secondary
> bus reset") added a warning if the PCI configuration space was not
> locked during a secondary bus reset request. That was in response to
> commit 7e89efc6e9e4 ("Lock upstream bridge for pci_reset_function()")
> such that remaining paths would be made more visible.
> 
> Address the vfio_pci_core_disable() path.

Similar comments as to the other patch.

Why these are not submitted in a series (they seem to fix very similar 
cases, just for different call chains)?

> Signed-off-by: Anthony Pighin <anthony.pighin@nokia.com>
> ---
>  drivers/vfio/pci/vfio_pci_core.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index 3a11e6f450f7..aa2c21020ea8 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -588,6 +588,7 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_enable);
>  
>  void vfio_pci_core_disable(struct vfio_pci_core_device *vdev)
>  {
> +	struct pci_dev *bridge;
>  	struct pci_dev *pdev = vdev->pdev;
>  	struct vfio_pci_dummy_resource *dummy_res, *tmp;
>  	struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
> @@ -694,12 +695,20 @@ void vfio_pci_core_disable(struct vfio_pci_core_device *vdev)
>  	 * We can not use the "try" reset interface here, which will
>  	 * overwrite the previously restored configuration information.
>  	 */
> -	if (vdev->reset_works && pci_dev_trylock(pdev)) {
> -		if (!__pci_reset_function_locked(pdev))
> -			vdev->needs_reset = false;
> -		pci_dev_unlock(pdev);
> +	if (vdev->reset_works) {
> +		bridge = pci_upstream_bridge(pdev);
> +		if (bridge && !pci_dev_trylock(bridge))
> +				goto out_restore_state;

Misaligned.

> +		if (pci_dev_trylock(pdev)) {
> +			if (!__pci_reset_function_locked(pdev))
> +				vdev->needs_reset = false;
> +			pci_dev_unlock(pdev);
> +		}
> +		if (bridge)
> +			pci_dev_unlock(bridge);
>  	}
>  
> +out_restore_state:
>  	pci_restore_state(pdev);
>  out:
>  	pci_disable_device(pdev);
> -- 
> 2.43.0
> 

-- 
 i.