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Tsirkin" To: Eugenio Perez Martin Cc: Jason Wang , qemu-devel@nongnu.org, Liuxiangdong , Stefan Hajnoczi , Harpreet Singh Anand , Gautam Dawar , Zhu Lingshan , Cindy Lu , Si-Wei Liu , "Dr. David Alan Gilbert" , Laurent Vivier , Eli Cohen , Stefano Garzarella , Juan Quintela , Parav Pandit Subject: Re: [RFC PATCH for 8.0 10/13] virtio-net: Migrate vhost inflight descriptors Message-ID: <20230116155949-mutt-send-email-mst@kernel.org> References: <20221205170436.2977336-1-eperezma@redhat.com> <20221205170436.2977336-11-eperezma@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=170.10.133.124; envelope-from=mst@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Dec 07, 2022 at 09:56:20AM +0100, Eugenio Perez Martin wrote: > > A dumb question, any reason we need bother with virtio-net? It looks > > to me it's not a must and would complicate migration compatibility. > > > > I guess virtio-blk is the better place. > > > > I'm fine to start with -blk, but if -net devices are processing > buffers out of order we have chances of losing descriptors too. > > We can wait for more feedback to prioritize correctly this though. > > Thanks! Traditionally vhost serialized everything when dropping the VQ. Would be interesting to hear from hardware vendors on whether it's hard or easy to do in hardware. But I suspect all devices will want the capability eventually because why not, if we have the code let's just do it everywhere. -- MST