From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34535) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fW4C4-0003pJ-0g for qemu-devel@nongnu.org; Thu, 21 Jun 2018 14:20:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fW4C0-00044K-SS for qemu-devel@nongnu.org; Thu, 21 Jun 2018 14:20:27 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60962 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 1fW4C0-00043S-OH for qemu-devel@nongnu.org; Thu, 21 Jun 2018 14:20:24 -0400 Date: Thu, 21 Jun 2018 21:20:13 +0300 From: "Michael S. Tsirkin" Message-ID: <20180621211712-mutt-send-email-mst@kernel.org> References: <20180615134815.6613620e.cohuck@redhat.com> <20180619125453.2d2dfb2d.cohuck@redhat.com> <20180619233001-mutt-send-email-mst@kernel.org> <20180620115359.1a3bf6fb.cohuck@redhat.com> <20180620170904-mutt-send-email-mst@kernel.org> <20180620180619.6b4ee52d.cohuck@redhat.com> <20180620224535-mutt-send-email-mst@kernel.org> <20180621165913.7e3f4faa.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180621165913.7e3f4faa.cohuck@redhat.com> 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: Cornelia Huck 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 Thu, Jun 21, 2018 at 04:59:13PM +0200, Cornelia Huck wrote: > On Wed, 20 Jun 2018 22:48:58 +0300 > "Michael S. Tsirkin" wrote: > > > On Wed, Jun 20, 2018 at 06:06:19PM +0200, Cornelia Huck wrote: > > > In any case, I'm not sure anymore why we'd want the extra uuid. > > > > It's mostly so we can have e.g. multiple devices with same MAC > > (which some people seem to want in order to then use > > then with different containers). > > > > But it is also handy for when you assign a PF, since then you > > can't set the MAC. > > > > OK, so what about the following: > > - introduce a new feature bit, VIRTIO_NET_F_STANDBY_UUID that indicates > that we have a new uuid field in the virtio-net config space > - in QEMU, add a property for virtio-net that allows to specify a uuid, > offer VIRTIO_NET_F_STANDBY_UUID if set > - when configuring, set the property to the group UUID of the vfio-pci > device > - in the guest, use the uuid from the virtio-net device's config space > if applicable; else, fall back to matching by MAC as done today > > That should work for all virtio transports. True. I'm a bit unhappy that it's virtio net specific though since down the road I expect we'll have a very similar feature for scsi (and maybe others). But we do not have a way to have fields that are portable both across devices and transports, and I think it would be a useful addition. How would this work though? Any idea? -- MST