From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45390) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fY6US-0004vP-Qo for qemu-devel@nongnu.org; Wed, 27 Jun 2018 05:11:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fY6UR-0000Th-Gp for qemu-devel@nongnu.org; Wed, 27 Jun 2018 05:11:52 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36416 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fY6UR-0000Ri-Am for qemu-devel@nongnu.org; Wed, 27 Jun 2018 05:11:51 -0400 Date: Wed, 27 Jun 2018 11:11:43 +0200 From: Cornelia Huck Message-ID: <20180627111143.32651114.cohuck@redhat.com> In-Reply-To: <20180626204312-mutt-send-email-mst@kernel.org> References: <20180621165913.7e3f4faa.cohuck@redhat.com> <20180621211712-mutt-send-email-mst@kernel.org> <20180622170955.298900c1.cohuck@redhat.com> <20180622214259-mutt-send-email-mst@kernel.org> <20180623003022-mutt-send-email-mst@kernel.org> <20180623012934-mutt-send-email-mst@kernel.org> <20180626170813.4db094a1.cohuck@redhat.com> <20180626204312-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [virtio-dev] Re: [PATCH] qemu: Introduce VIRTIO_NET_F_STANDBY feature bit to virtio_net List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Siwei Liu , "Samudrala, Sridhar" , Alexander Duyck , virtio-dev@lists.oasis-open.org, aaron.f.brown@intel.com, Jiri Pirko , Jakub Kicinski , Netdev , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, Joao Martins , Venu Busireddy , vijay.balakrishna@oracle.com On Tue, 26 Jun 2018 20:50:20 +0300 "Michael S. Tsirkin" wrote: > On Tue, Jun 26, 2018 at 05:08:13PM +0200, Cornelia Huck wrote: > > On Fri, 22 Jun 2018 17:05:04 -0700 > > Siwei Liu wrote: > > > > > On Fri, Jun 22, 2018 at 3:33 PM, Michael S. Tsirkin wrote: > > > > I suspect the diveregence will be lost on most users though > > > > simply because they don't even care about vfio. They just > > > > want things to go fast. > > > > > > Like Jason said, VF isn't faster than virtio-net in all cases. It > > > depends on the workload and performance metrics: throughput, latency, > > > or packet per second. > > > > So, will it be guest/admin-controllable then where the traffic flows > > through? Just because we do have a vf available after negotiation of > > the feature bit, it does not necessarily mean we want to use it? Do we > > (the guest) even want to make it visible in that case? > > I think these ideas belong to what Alex Duyck wanted to do: > some kind of advanced device that isn't tied to > any network interfaces and allows workload and performance > specific tuning. > > Way out of scope for a simple failover, and more importantly, > no one is looking at even enumerating the problems involved, > much less solving them. So, for simplicity's sake, we need to rely on the host admin configuring the vm for its guest's intended use case. Sounds fair, but probably needs a note somewhere.