Re: [PATCH v12 4/4] Documentation: add debugfs description for vfio

[Jason Gunthorpe <jgg@nvidia.com>]

On Fri, Jul 28, 2023 at 03:21:04PM +0800, liulongfang wrote:
> From: Longfang Liu <liulongfang@huawei.com>
> 
> 1.Add two debugfs document description file to help users understand
> how to use the accelerator live migration driver's debugfs.
> 2.Update the file paths that need to be maintained in MAINTAINERS
> 
> Signed-off-by: Longfang Liu <liulongfang@huawei.com>
> ---
>  .../ABI/testing/debugfs-hisi-migration        | 36 +++++++++++++++++++
>  Documentation/ABI/testing/debugfs-vfio        | 25 +++++++++++++
>  MAINTAINERS                                   |  2 ++
>  3 files changed, 63 insertions(+)
>  create mode 100644 Documentation/ABI/testing/debugfs-hisi-migration
>  create mode 100644 Documentation/ABI/testing/debugfs-vfio
> 
> diff --git a/Documentation/ABI/testing/debugfs-hisi-migration b/Documentation/ABI/testing/debugfs-hisi-migration
> new file mode 100644
> index 000000000000..791dd8a09575
> --- /dev/null
> +++ b/Documentation/ABI/testing/debugfs-hisi-migration
> @@ -0,0 +1,36 @@
> +What:		/sys/kernel/debug/vfio/<device>/migration/hisi_acc/data
> +Date:		Aug 2023
> +KernelVersion:  6.6
> +Contact:	Longfang Liu <liulongfang@huawei.com>
> +Description:	Read the live migration data of the vfio device.
> +		These data include device status data, queue configuration
> +		data and some task configuration data.
> +		The output format of the data is defined by the live
> +		migration driver.
> +
> +What:		/sys/kernel/debug/vfio/<device>/migration/hisi_acc/attr
> +Date:		Aug 2023
> +KernelVersion:  6.6
> +Contact:	Longfang Liu <liulongfang@huawei.com>
> +Description:	Read the live migration attributes of the vfio device.
> +		it include device status attributes and data length attributes
> +		The output format of the attributes is defined by the live
> +		migration driver.
> +
> +What:		/sys/kernel/debug/vfio/<device>/migration/hisi_acc/io_test
> +Date:		Aug 2023
> +KernelVersion:  6.6
> +Contact:	Longfang Liu <liulongfang@huawei.com>
> +Description:	Trigger the HiSilicon accelerator device to perform
> +		the io test through the read operation. If successful,
> +		it returns the execution result of mailbox. If fails,
> +		it returns error log result.
> +
> +What:		/sys/kernel/debug/vfio/<device>/migration/hisi_acc/save
> +Date:		Aug 2023
> +KernelVersion:  6.6
> +Contact:	Longfang Liu <liulongfang@huawei.com>
> +Description:	Trigger the Hisilicon accelerator device to perform
> +		the state saving operation of live migration through the read
> +		operation, and output the operation log results.

I still very much do not like this use of debugfs.

If you want to test migration then make a test program and use the
normal api

Creating some parallel backdoor to work the same API is just
unneeded complexity.

Jason