From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59446) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dLt2H-0004w7-0t for qemu-devel@nongnu.org; Fri, 16 Jun 2017 11:19:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dLt2C-00022z-2x for qemu-devel@nongnu.org; Fri, 16 Jun 2017 11:19:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59106) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dLt2B-00022n-Sn for qemu-devel@nongnu.org; Fri, 16 Jun 2017 11:19:40 -0400 Date: Fri, 16 Jun 2017 18:19:30 +0300 From: "Michael S. Tsirkin" Message-ID: <20170616181607-mutt-send-email-mst@kernel.org> References: <593F9187.6040800@intel.com> <9f196d71-f06b-7520-ca03-e94bf3b5a986@redhat.com> <593FB550.6090903@intel.com> <26250da7-b394-4964-8842-5c45bbe85e09@redhat.com> <6547dfcf-ea3a-f5f6-222d-40ff274654df@redhat.com> <20170614180459-mutt-send-email-mst@kernel.org> <59422E91.7080407@intel.com> <20170616061949-mutt-send-email-mst@kernel.org> <40a12829-6e84-e63e-ac47-6f09cc85c3cc@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <40a12829-6e84-e63e-ac47-6f09cc85c3cc@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [virtio-dev] Re: [virtio-dev] Re: [virtio-dev] Re: [PATCH v1] virtio-net: enable configurable tx queue size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Wang Cc: Wei Wang , "virtio-dev@lists.oasis-open.org" , "stefanha@gmail.com" , "qemu-devel@nongnu.org" , "jan.scheurich@ericsson.com" , "armbru@redhat.com" , "marcandre.lureau@gmail.com" , "pbonzini@redhat.com" , Maxime Coquelin On Fri, Jun 16, 2017 at 04:57:01PM +0800, Jason Wang wrote: >=20 >=20 > On 2017=E5=B9=B406=E6=9C=8816=E6=97=A5 11:22, Michael S. Tsirkin wrote: > > > I think the issues can be solved by VIRTIO_F_MAX_CHAIN_SIZE. > > >=20 > > > For now, how about splitting it into two series of patches: > > > 1) enable 1024 tx queue size for vhost-user, to let the users of vh= ost-user > > > to easily use 1024 queue size. > > Fine with me. 1) will get property from user but override it on > > !vhost-user. Do we need a protocol flag? It seems prudent but we get > > back to cross-version migration issues that a04re still pending solut= ion. > > Marc Andre, what's the status of that work? > >=20 > > > 2) enable VIRTIO_F_MAX_CHAIN_SIZE, to enhance robustness. > > Rather, to support it for more backends. >=20 > Ok, if we want to support different values of max chain size in the fut= ure. > It would be problematic for migration of cross backends, consider the c= ase > when migrating from 2048 (vhost-user) to 1024 (qemu/vhost-kernel). >=20 > Thanks That's already a problem, and it's growing with each new feature. Maxime looked at supporting vhost-user backends cross-version migration, I think we must merge some solution sooner rather than later, preferably by the next release. Maxime, any update here? Do we need a meeting to reach consensus? > >=20 > > > Best, > > > Wei > > --=20