On Tue, Apr 16, 2024 at 12:25 AM Jiri Pirko <jiri@xxxxxxxxxxx> wrote:
>
> From: Jiri Pirko <jiri@xxxxxxxxxx>
>
> Currently there is no way for user to set what features the driver
> should obey or not, it is hard wired in the code.
>
> In order to be able to debug the device behavior in case some feature is
> disabled, introduce a debugfs infrastructure with couple of files
> allowing user to see what features the device advertises and
> to set filter for features used by driver.
>
> Example:
> $cat /sys/bus/virtio/devices/virtio0/features
> 1110010111111111111101010000110010000000100000000000000000000000
> $ echo "5" >/sys/kernel/debug/virtio/virtio0/filter_feature_add
> $ cat /sys/kernel/debug/virtio/virtio0/filter_features
> 5
> $ echo "virtio0" > /sys/bus/virtio/drivers/virtio_net/unbind
> $ echo "virtio0" > /sys/bus/virtio/drivers/virtio_net/bind
> $ cat /sys/bus/virtio/devices/virtio0/features
> 1110000111111111111101010000110010000000100000000000000000000000
>
> Note that sysfs "features" know already exists, this patch does not
> touch it.
>
> Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxx>
> ---
Note that this can be done already with vp_vdpa feature provisioning:
commit c1ca352d371f724f7fb40f016abdb563aa85fe55
Author: Jason Wang <jasowang@xxxxxxxxxx>
Date: Tue Sep 27 15:48:10 2022 +0800
vp_vdpa: support feature provisioning
For example:
vdpa dev add name dev1 mgmtdev pci/0000:02:00.0 device_features 0x300020000
Thanks
