Re: [PATCH v3 05/21] block/vhost-user-blk-server: don't expose VHOST_USER_F_PROTOCOL_FEATURES

[Alex Bennée]

Jason Wang <jasowang@redhat.com> writes:

> 在 2022/7/27 03:21, Alex Bennée 写道:
>> This bit is unused in actual VirtIO feature negotiation and should
>> only appear in the vhost-user messages between master and slave.
>
>
> I might be wrong, but this is actually used between master and slave
> not the device and driver?

Argh you may be right. However got confused with grepping:

  static const VuDevIface vu_blk_iface = {
      .get_features          = vu_blk_get_features,
      .queue_set_started     = vu_blk_queue_set_started,
      .get_protocol_features = vu_blk_get_protocol_features,
      .get_config            = vu_blk_get_config,
      .set_config            = vu_blk_set_config,
      .process_msg           = vu_blk_process_msg,
  };

and this is all part of libvhostuser but vhost-user-blk-server is in the
main tree. I guess it isn't moved into tools/ because it also re-uses
bits of the block layer?

Anyway I shall drop this patch.

>
> Thanks
>
>
>>
>> [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>
>> ---
>>   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 ;
>>         if (!vexp->handler.writable) {
>>           features |= 1ull << VIRTIO_BLK_F_RO;


-- 
Alex Bennée