Re: [RFC PATCH v3 19/20] vfio/pci: Add VFIO_DEVICE_FEATURE_PCI_ERROR_RECOVERY

[sashiko-bot@kernel.org]

> Userspace needs a way to enable host recovery and find out whether it is
> still running, succeeded, reset the device or failed.
> 
> Add a device feature that registers a recovery eventfd and reports
> status flags and a sequence number. SET with eventfd -1 disables
> recovery. GET is available while hardware access is blocked. The
> sequence number lets userspace detect recovery that finished before it
> read the notification.
> 
> Reject SET if access is blocked, recovery has failed or a recorded host
> recovery is still running. This also applies if userspace had not
> enabled recovery when the event started, so a late subscription cannot
> report part of an older event as a new one. Updating the eventfd resets
> status for the current open. The existing error eventfd is unchanged.
> 
> Add the recovery eventfd and signal it when recovery starts, completes
> or fails. Release it during close. Signal under access_lock so SET cannot
> replace the eventfd and reset status before notification.
> 
> Userspace must probe each device and restore guest state after a reset.
> 
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261112141632.918954-1-skolothumtho@nvidia.com?part=19