Re: [RFC PATCH v2] s390/vfio-ap: Notify userspace that guest's AP config changed when mdev removed

From: Vasily Gorbik
Date: Tue Mar 04 2025 - 16:00:42 EST


On Tue, Mar 04, 2025 at 03:11:12PM -0500, Anthony Krowiak wrote:
> On 3/4/25 3:08 PM, Rorie Reyes wrote:
> > The guest's AP configuration is cleared when the mdev is removed, so
> > userspace must be notified that the AP configuration has changed. To this
> > end, this patch:
> >
> > * Removes call to 'signal_guest_ap_cfg_changed()' function from the
> > 'vfio_ap_mdev_unset_kvm()' function because it has no affect given it is
> > called after the mdev fd is closed.
> >
> > * Adds call to 'signal_guest_ap_cfg_changed()' function to the
> > 'vfio_ap_mdev_request()' function to notify userspace that the guest's
> > AP configuration has changed before signaling the request to remove the
> > mdev.
> >
> > Minor change - Fixed an indentation issue in function
> > 'signal_guest_ap_cfg_changed()'
> >
> > Fixes: 07d89045bffe ("s390/vfio-ap: Signal eventfd when guest AP configuration is changed")
> > Signed-off-by: Rorie Reyes <rreyes@xxxxxxxxxxxxx>
> > ---
> > This patch is based on the s390/features branch
> >
> > V1 -> V2:
> > - replaced get_update_locks_for_kvm() with get_update_locks_for_mdev
> > - removed else statements that were unnecessary
> > - Addressed review comments for commit messages/details
> > ---
> > drivers/s390/crypto/vfio_ap_ops.c | 15 ++++++++++++---
> > 1 file changed, 12 insertions(+), 3 deletions(-)

> > @@ -2068,6 +2074,9 @@ static void vfio_ap_mdev_request(struct vfio_device *vdev, unsigned int count)
> > dev_notice(dev,
> > "No device request registered, blocked until released by user\n");
> > }
> > +
> > + release_update_locks_for_mdev(matrix_mdev);
> > +
>
> Get rid of empty line; other than that, LGTM
> Reviewed-by: Anthony Krowiak <akrowiak@xxxxxxxxxxxxx>

Removed the empty line and applied, thank you!