From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39920) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fdihQ-0000Rz-4S for qemu-devel@nongnu.org; Thu, 12 Jul 2018 17:00:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fdihL-0005LR-5L for qemu-devel@nongnu.org; Thu, 12 Jul 2018 17:00:28 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36186 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 1fdihL-0005KR-0j for qemu-devel@nongnu.org; Thu, 12 Jul 2018 17:00:23 -0400 Date: Fri, 13 Jul 2018 00:00:19 +0300 From: "Michael S. Tsirkin" Message-ID: <20180712235500-mutt-send-email-mst@kernel.org> References: <20180703095825.GC30904@rkaganb.sw.ru> <20180709130035.GA6271@rkaganb.sw.ru> <9136094e-a510-4201-7c71-d1c49226fa5f@oracle.com> <20180710045101-mutt-send-email-mst@kernel.org> <20180711115344.633eba9e.cohuck@redhat.com> <20180712133121.3b5f2bae.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [virtio-dev] Re: [PATCH v3 0/3] Use of unique identifier for pairing virtio and passthrough devices... List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Siwei Liu Cc: Cornelia Huck , si-wei liu , Roman Kagan , Venu Busireddy , Marcel Apfelbaum , virtio-dev@lists.oasis-open.org, qemu-devel@nongnu.org, "Samudrala, Sridhar" , Alexander Duyck , Netdev On Thu, Jul 12, 2018 at 01:52:53PM -0700, Siwei Liu wrote: > The definition is incomplete due to lack of spec. There's no "host" > part defined yet in the host-guest interface. If match by MAC is an > interface, the same must be done on the host(device) side as well, > which has been agreed not the way to go. However, I don't think that's > what the author intends to do by interpreting his QEMU patch - it > missed the other parts as well, such as the feature negotiation and > how it interacts with the paired device. > > What I said is that match by MAC is just a guest implementation that > one can change at any time. We now have the group ID on QEMU, why > still sticking to matching by MAC? It shoulnd't be a host-guest > interface in the first place anyway. I think that match by MAC is a simple portable way to match devices. E.g. it will work seamlessly with niche things like zPCI. However there are other niche use-cases that aren't addressed by match by MAC such as PF pass-through as a primary, and the pci bridge trick addresses that at cost of some portability. So I see no issues supporting both mechanisms, but others on the TC might feel differently. -- MST