Re: [Qemu-stable] [PATCH] vhost_net: initialize acked_features to a safe value during ack

[Andrey Korolyov]

On Wed, Sep 3, 2014 at 12:52 PM, Michael S. Tsirkin <address@hidden> wrote:
> On Wed, Sep 03, 2014 at 02:25:30PM +0800, Jason Wang wrote:
>> commit 2e6d46d77ed328d34a94688da8371bcbe243479b (vhost: add
>> vhost_get_features and vhost_ack_features) removes the step that
>> initializes the acked_features to backend_features. This will result an
>> unexpected value of acked_features which may fail the features setting of
>> vhost. This patch fixes it by recover this step.
>>
>> Cc: Nikolay Nikolaev <address@hidden>
>> Cc: Andrey Korolyov <address@hidden>
>> Cc: Michael S. Tsirkin <address@hidden>
>> Cc: Michael Roth <address@hidden>
>> Cc: address@hidden
>> Signed-off-by: Jason Wang <address@hidden>
>
> OK I get it and it's correct, but I think it's better to
> put the initialization in core vhost code.
> Patch sent, could you confirm that it works for you please?
>
>> ---
>>  hw/net/vhost_net.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>> index f87c798..b1d4b1f 100644
>> --- a/hw/net/vhost_net.c
>> +++ b/hw/net/vhost_net.c
>> @@ -115,6 +115,7 @@ unsigned vhost_net_get_features(struct vhost_net *net, 
>> unsigned features)
>>
>>  void vhost_net_ack_features(struct vhost_net *net, unsigned features)
>>  {
>> +    net->dev.acked_features = net->dev.backend_features;
>>      vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), 
>> features);
>>  }
>>
>> --
>> 1.8.3.1

Yes, this patch fixes both issues with vhost subsystem for me.