Re: [PATCH v1 1/5] block/vhost-user-blk-server: don't expose VHOST_USER_F_PROTOCOL_FEATURES

[Kevin Wolf]

Am 27.07.2022 um 17:56 hat Alex Bennée geschrieben:
> This bit is unused in actual VirtIO feature negotiation and should
> only appear in the vhost-user messages between master and slave.
> 
> [AJB: experiment, this doesn't break the tests but I'm not super
> confident of the range of tests]
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Message-Id: <20220726192150.2435175-6-alex.bennee@linaro.org>
> ---
>  block/export/vhost-user-blk-server.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/block/export/vhost-user-blk-server.c 
> b/block/export/vhost-user-blk-server.c
> index 3409d9e02e..d31436006d 100644
> --- a/block/export/vhost-user-blk-server.c
> +++ b/block/export/vhost-user-blk-server.c
> @@ -125,8 +125,7 @@ static uint64_t vu_blk_get_features(VuDev *dev)
>                 1ull << VIRTIO_BLK_F_MQ |
>                 1ull << VIRTIO_F_VERSION_1 |
>                 1ull << VIRTIO_RING_F_INDIRECT_DESC |
> -               1ull << VIRTIO_RING_F_EVENT_IDX |
> -               1ull << VHOST_USER_F_PROTOCOL_FEATURES;
> +               1ull << VIRTIO_RING_F_EVENT_IDX ;

I didn't see this series yet when I replied to the other series this is
split off from, but of course, my comments are still relevant for this
one.

I asked for a changed commit message (the "experiment" part should
probably go away if we're merging it; instead, it should explain that
in vu_get_features_exec(), libvhost-user adds the vhost-user protocol
level VHOST_USER_F_PROTOCOL_FEATURES flag anyway and the device is the
wrong layer to add it, but the behaviour doesn't change with this patch)
and noted the extra space before the semicolon.

Kevin