> From: Yishai Hadas <yishaih@xxxxxxxxxx>
> Sent: Monday, June 6, 2022 4:56 PM
>
> vfio core checks whether the driver sets some migration op (e.g.
> set_state/get_state) and accordingly calls its op.
>
> However, currently mlx5 driver sets the above ops without regards to its
> migration caps.
>
> This might lead to unexpected usage/Oops if user space may call to the
> above ops even if the driver doesn't support migration. As for example,
> the migration state_mutex is not initialized in that case.
>
> The cleanest way to manage that seems to split the migration ops from
> the main device ops, this will let the driver setting them separately
> from the main ops when it's applicable.
>
> As part of that, changed HISI driver to match this scheme.
>
> This scheme may enable down the road to come with some extra group of
> ops (e.g. DMA log) that can be set without regards to the other options
> based on driver caps.
>
> Fixes: 6fadb021266d ("vfio/mlx5: Implement vfio_pci driver for mlx5 devices")
> Signed-off-by: Yishai Hadas <yishaih@xxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>, with one nit:
> @@ -1534,8 +1534,8 @@ vfio_ioctl_device_feature_mig_device_state(struct
> vfio_device *device,
> struct file *filp = NULL;
> int ret;
>
> - if (!device->ops->migration_set_state ||
> - !device->ops->migration_get_state)
> + if (!device->mig_ops->migration_set_state ||
> + !device->mig_ops->migration_get_state)
> return -ENOTTY;
...
> @@ -1582,8 +1583,8 @@ static int
> vfio_ioctl_device_feature_migration(struct vfio_device *device,
> };
> int ret;
>
> - if (!device->ops->migration_set_state ||
> - !device->ops->migration_get_state)
> + if (!device->mig_ops->migration_set_state ||
> + !device->mig_ops->migration_get_state)
> return -ENOTTY;
>
Above checks can be done once when the device is registered then
here replaced with a single check on device->mig_ops.
