Re: [dpdk-stable] [PATCH v3] vhost: add header check in dequeue offload

["Wang, Xiao W" <xiao.w.wang@intel.com>]

Hi Maxime and David,

I see patch " vhost: fix offload flags in Rx path " http://patches.dpdk.org/project/dpdk/patch/20210503164344.27916-4-david.marchand@redhat.com/ has been merged, and the legacy implementation is kept. Do you think we still need to fix the header check for the legacy implementation?

BRs,
Xiao

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Tuesday, April 13, 2021 10:31 PM
> To: David Marchand <david.marchand@redhat.com>; Wang, Xiao W
> <xiao.w.wang@intel.com>
> Cc: Xia, Chenbo <chenbo.xia@intel.com>; Liu, Yong <yong.liu@intel.com>;
> dev <dev@dpdk.org>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; dpdk stable <stable@dpdk.org>;
> yangyi01@inspur.com
> Subject: Re: [PATCH v3] vhost: add header check in dequeue offload
> 
> 
> 
> On 4/12/21 11:33 AM, David Marchand wrote:
> > On Mon, Apr 12, 2021 at 11:09 AM Wang, Xiao W
> <xiao.w.wang@intel.com> wrote:
> >> Considering the major consumer of vhost API is virtual switch/router, I
> tend to keep the current implementation and apply this fix patch.
> >> Any comments?
> >
> > This is just a hack that bypasses the vswitch control.
> >
> > It happens to work when the vswitch does nothing.
> > If anything is done, like popping a vlan header, the vswitch needs to
> > update l3 offset.
> >
> >
> 
> I agree with David, current behavior is wrong.
> 
> Furthermore, when the lib is used via the Vhost PMD, the application
> should not have to handle it differently on whether it is Vhost PMD or
> any physical NIC PMD.