Re: [PULL 52/53] vhost_net: add an assertion for TAP client backends

[Ani Sinha]

> On 28-Jun-2023, at 11:58 AM, Cédric Le Goater <c...@redhat.com> wrote:
> 
> Hello,
> 
> On 6/26/23 14:30, Michael S. Tsirkin wrote:
>> From: Ani Sinha <anisi...@redhat.com>
>> An assertion was missing for tap vhost backends that enforces a non-null
>> reference from get_vhost_net(). Both vhost-net-user and vhost-net-vdpa
>> enforces this. Enforce the same for tap. Unit tests pass with this change.
>> Signed-off-by: Ani Sinha <anisi...@redhat.com>
>> Message-Id: <20230619041501.111655-1-anisi...@redhat.com>
>> Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
>> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
>> Reviewed-by: Laurent Vivier <lviv...@redhat.com>
>> ---
>>  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 c4eecc6f36..6db23ca323 100644
>> --- a/hw/net/vhost_net.c
>> +++ b/hw/net/vhost_net.c
>> @@ -507,6 +507,7 @@ VHostNetState *get_vhost_net(NetClientState *nc)
>>      switch (nc->info->type) {
>>      case NET_CLIENT_DRIVER_TAP:
>>          vhost_net = tap_get_vhost_net(nc);
>> +        assert(vhost_net);
>>          break;
>>  #ifdef CONFIG_VHOST_NET_USER
>>      case NET_CLIENT_DRIVER_VHOST_USER:
> 
> A system of mine without vhost_net (old host kernel) is reaching this assert

We need to understand why this assertion is being hit. It could be a bug 
somewhere else.
What is the backtrace? What is the repro case?

> and works perfectly fine without. Should it be considered as a regression ?
> 
> Thanks,
> 
> C.
>