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

["Michał Winiarski" <michal.winiarski@intel.com>]

On Tue, Mar 17, 2026 at 08:43:40AM -0600, Alex Williamson wrote:
> 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>

Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>

And yes, we can take it through DRM.

Thanks,
-Michał