Re: [Qemu-devel] [PATCH v10 18/19] docs: Sysfs ABI for mediated device framework

[Jike Song]

On 10/27/2016 05:29 AM, Kirti Wankhede wrote:
> Added details of sysfs ABI for mediated device framework
> 
> Signed-off-by: Kirti Wankhede <address@hidden>
> Signed-off-by: Neo Jia <address@hidden>
> Change-Id: Icb0fd4ed58a2fa793fbcb1c3d5009a4403c1f3ac
> ---
>  Documentation/ABI/testing/sysfs-bus-vfio-mdev | 111 
> ++++++++++++++++++++++++++
>  1 file changed, 111 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-vfio-mdev
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-vfio-mdev 
> b/Documentation/ABI/testing/sysfs-bus-vfio-mdev
> new file mode 100644
> index 000000000000..452dbe39270e
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-vfio-mdev
> @@ -0,0 +1,111 @@
> +What:           /sys/.../<device>/mdev_supported_types/
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +                This directory contains list of directories of currently
> +             supported mediated device types and their details for
> +             <device>. Supported type attributes are defined by the
> +             vendor driver who registers with Mediated device framework.
> +             Each supported type is a directory whose name is created
> +             by adding the device driver string as a prefix to the
> +             string provided by the vendor driver.
> +
> +What:           /sys/.../<device>/mdev_supported_types/<type-id>/
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +                This directory gives details of supported type, like name,
> +             description, available_instances, device_api etc.
> +             'device_api' and 'available_instances' are mandatory
> +             attributes to be provided by vendor driver. 'name',
> +             'description' and other vendor driver specific attributes
> +             are optional.
> +

Hi Kirti,

Is there any checking in the mdev framework that mandatory attributes
are actually provided?

--
Thanks,
Jike

> +What:           /sys/.../mdev_supported_types/<type-id>/create
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             Writing UUID to this file will create mediated device of
> +             type <type-id> for parent device <device>. This is a
> +             write-only file.
> +             For example:
> +             # echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > \
> +                    /sys/devices/foo/mdev_supported_types/foo-1/create
> +
> +What:           /sys/.../mdev_supported_types/<type-id>/devices/
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             This directory contains symbolic links pointing to mdev
> +             devices sysfs entries which are created of this <type-id>.
> +
> +What:           /sys/.../mdev_supported_types/<type-id>/available_instances
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             Reading this attribute will show the number of mediated
> +             devices of type <type-id> that can be created. This is a
> +             readonly file.
> +Users:
> +             Userspace applications interested in creating mediated
> +             device of that type. Userspace application should check
> +             the number of available instances could be created before
> +             creating mediated device of this type.
> +
> +What:           /sys/.../mdev_supported_types/<type-id>/device_api
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             Reading this attribute will show VFIO device API supported
> +             by this type. For example, "vfio-pci" for a PCI device,
> +             "vfio-platform" for platform device.
> +
> +What:           /sys/.../mdev_supported_types/<type-id>/name
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             Reading this attribute will show human readable name of the
> +             mediated device that will get created of type <type-id>.
> +             This is optional attribute. For example: "Grid M60-0Q"
> +Users:
> +             Userspace applications interested in knowing the name of
> +             a particular <type-id> that can help in understanding the
> +             type of mediated device.
> +
> +What:           /sys/.../mdev_supported_types/<type-id>/description
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             Reading this attribute will show description of the type of
> +             mediated device that will get created of type <type-id>.
> +             This is optional attribute. For example:
> +             "2 heads, 512M FB, 2560x1600 maximum resolution"
> +Users:
> +             Userspace applications interested in knowing the details of
> +             a particular <type-id> that can help in understanding the
> +             features provided by that type of mediated device.
> +
> +What:           /sys/.../<device>/<UUID>/
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             This directory represents device directory of mediated
> +             device. It contains all the attributes related to mediated
> +             device.
> +
> +What:           /sys/.../<device>/<UUID>/mdev_type
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             This is symbolic link pointing to supported type, <type-id>
> +             directory of which this mediated device is created.
> +
> +What:           /sys/.../<device>/<UUID>/remove
> +Date:           October 2016
> +Contact:        Kirti Wankhede <address@hidden>
> +Description:
> +             Writing '1' to this file destroys the mediated device. The
> +             vendor driver can fail the remove() callback if that device
> +             is active and the vendor driver doesn't support hot unplug.
> +             Example:
> +             # echo 1 > /sys/bus/mdev/devices/<UUID>/remove
>