Re: [PATCH v7 4/5] Documentation: add debugfs description for hisi_acc_vfio_pci

[Alex Williamson]

On Fri, 20 Jan 2023 11:29:29 +0800
Longfang Liu <liulongfang@xxxxxxxxxx> wrote:

> Add a debugfs document description file to help users understand
> how to use the accelerator live migration driver's debugfs.
> 
> Signed-off-by: Longfang Liu <liulongfang@xxxxxxxxxx>
> ---
>  .../ABI/testing/debugfs-hisi-migration        | 32 +++++++++++++++++++
>  1 file changed, 32 insertions(+)
>  create mode 100644 Documentation/ABI/testing/debugfs-hisi-migration
> 
> diff --git a/Documentation/ABI/testing/debugfs-hisi-migration b/Documentation/ABI/testing/debugfs-hisi-migration
> new file mode 100644
> index 000000000000..d644a497c464
> --- /dev/null
> +++ b/Documentation/ABI/testing/debugfs-hisi-migration
> @@ -0,0 +1,32 @@
> +What:		/sys/kernel/debug/vfio_mig/<bdf>/state
> +Date:		Jan 2023
> +Contact:	linux-kernel@xxxxxxxxxxxxxxx
> +Description:	Read the live migration status of the VF device.
> +		The status of these live migrations includes:
> +		ERROR, RUNNING, STOP, STOP_COPY, RESUMING.

state is added by vfio-pci-core in this series, so the documentation
can't be limited to hisi_acc.

> +
> +What:		/sys/kernel/debug/vfio_mig/<bdf>/mig_data
> +Date:		Jan 2023
> +Contact:	linux-kernel@xxxxxxxxxxxxxxx
> +Description:	Read the live migration data of the VF device.
> +		The output format of the data is defined by the live
> +		migration driver.
> +
> +What:		/sys/kernel/debug/vfio_mig/<bdf>/mig_attr
> +Date:		Jan 2023
> +Contact:	linux-kernel@xxxxxxxxxxxxxxx
> +Description:	Read the live migration attributes of the VF device.
> +		The output format of the attributes is defined by the live
> +		migration driver.
> +
> +What:		/sys/kernel/debug/vfio_mig/<bdf>/debug
> +Date:		Jan 2023
> +Contact:	linux-kernel@xxxxxxxxxxxxxxx
> +Description:	This debug file supports "echo" command	write operations.
> +		The command is actually represented by an integer number, and the
> +		specific meaning is defined by the corresponding device driver.
> +		For example, three commands are defined in the HiSilicon accelerator
> +		live migration driver:
> +		0: State save
> +		1: State resume
> +		2: IO test

I think the goal here is to create some sort of standard interface for
migration, so these should also be documented for all devices, and any
device specific behavior noted.  Otherwise these should all be prefixed
hisi_acc_ to denote them as device specific implementations.  Thanks,

Alex