Re: [PATCH v12 12/14] s390/vfio-ap: Set up for vfio-ap device migration

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] s390/vfio-ap: stale commit message in
  vfio_ap_setup_vfio_device_migration()
--

commit 91bb5c1f210ed8cb015ed15a312ace69b31f9fa7
Author: Anthony Krowiak <akrowiak@linux.ibm.com>

s390/vfio-ap: Set up for vfio-ap device migration

This commit adds vfio_ap_setup_vfio_device_migration() to configure
migration flags and callbacks on the vfio_device for non-SE guests and
calls it from vfio_ap_mdev_probe() prior to device registration.

> * The initial migration state of the vfio-ap device is set to RUNNING
>
> * The boolean flag indicating that all data sent from userspace during the
>   RESUMINMG phase has been received is initialized to false.

[ ... ]

> diff --git a/drivers/s390/crypto/vfio_ap_migration.c b/drivers/s390/crypto/vfio_ap_migration.c
> index 4af734aeee17e..924c25585987c 100644
> --- a/drivers/s390/crypto/vfio_ap_migration.c
> +++ b/drivers/s390/crypto/vfio_ap_migration.c
> @@ -217,6 +217,30 @@ static int vfio_ap_release_mig_file(struct inode *file_inode, struct file *filp)
>  	return 0;
>  }
>  
> +static const struct vfio_migration_ops vfio_ap_migration_ops;
> +
> +/**
> + * vfio_ap_setup_vfio_device_migration:
> + *
> + * Plug the object containing the function pointers to the migration callbacks
> + * used to facilitate migration into the vfio device and set the flags
> + * indicating migration states STOP, STOP_COPY and RESUMING are supported.
> + *
> + * @matrix_mdev: pointer to object containing the vfio device (vdev)
> + */
> +void vfio_ap_setup_vfio_device_migration(struct ap_matrix_mdev *matrix_mdev)
> +{
> +	/*
> +	 * Live guest migration is not supported for SE guests, so there is no
> +	 * need to initialize the migration capabilities.
> +	 */
> +	if (ap_is_se_guest())
> +		return;
> +
> +	matrix_mdev->vdev.migration_flags = VFIO_MIGRATION_STOP_COPY;
> +	matrix_mdev->vdev.mig_ops = &vfio_ap_migration_ops;
> +}

[Severity: Low]
This isn't a bug, but the last two bullet points of the commit message
describe initializing mig_state to VFIO_DEVICE_STATE_RUNNING and
resuming_mig_data_complete to false, which was already done in
vfio_ap_init_migration_data() in commit "s390/vfio-ap: Functions to
initialize/release vfio device migration data" rather than in this patch.

Also, placing vfio_ap_setup_vfio_device_migration() after the definition
of vfio_ap_migration_ops alongside vfio_ap_init_migration_data() would
avoid the forward declaration of vfio_ap_migration_ops.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261106152259.1360651-1-akrowiak@linux.ibm.com?part=12