Re: [PATCH v2 2/2] vfio/xe: Notify PF about VF FLR in reset_prepare

[Alex Williamson <alex@shazbot.org>]

On Mon, 9 Mar 2026 16:24:49 +0100
"Piórkowski, Piotr" <piotr.piorkowski@intel.com> wrote:

> From: Piotr Piórkowski <piotr.piorkowski@intel.com>
> 
> Hook into the PCI error handler reset_prepare() callback to notify
> the PF about an upcoming VF FLR before reset_done() is executed.
> This enables early FLR_PREPARE signaling and ensures that the PF is
> aware of the reset before the completion wait begins.
> 
> Signed-off-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
> Cc: Michał Winiarski <michal.winiarski@intel.com>
> ---
>  drivers/vfio/pci/xe/main.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/vfio/pci/xe/main.c b/drivers/vfio/pci/xe/main.c
> index fff95b2d5dde..88acfcf840fc 100644
> --- a/drivers/vfio/pci/xe/main.c
> +++ b/drivers/vfio/pci/xe/main.c
> @@ -85,6 +85,19 @@ static void xe_vfio_pci_state_mutex_unlock(struct xe_vfio_pci_core_device *xe_vd
>  	spin_unlock(&xe_vdev->reset_lock);
>  }
>  
> +static void xe_vfio_pci_reset_prepare(struct pci_dev *pdev)
> +{
> +	struct xe_vfio_pci_core_device *xe_vdev = pci_get_drvdata(pdev);
> +	int ret;
> +
> +	if (!pdev->is_virtfn)
> +		return;
> +
> +	ret = xe_sriov_vfio_flr_prepare(xe_vdev->xe, xe_vdev->vfid);
> +	if (ret)
> +		dev_err(&pdev->dev, "Failed to prepare FLR: %d\n", ret);
> +}
> +
>  static void xe_vfio_pci_reset_done(struct pci_dev *pdev)
>  {
>  	struct xe_vfio_pci_core_device *xe_vdev = pci_get_drvdata(pdev);
> @@ -127,6 +140,7 @@ static void xe_vfio_pci_reset_done(struct pci_dev *pdev)
>  }
>  
>  static const struct pci_error_handlers xe_vfio_pci_err_handlers = {
> +	.reset_prepare = xe_vfio_pci_reset_prepare,
>  	.reset_done = xe_vfio_pci_reset_done,
>  	.error_detected = vfio_pci_core_aer_err_detected,
>  };

Looks ok to me, should really have Michał's ack as well.  Will this go
in through drm?

Reviewed-by: Alex Williamson <alex@shazbot.org>