From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-3434-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id 703265818F0F for ; Tue, 6 Mar 2018 10:13:29 -0800 (PST) Date: Tue, 6 Mar 2018 20:13:14 +0200 From: "Michael S. Tsirkin" Message-ID: <20180306201252-mutt-send-email-mst@kernel.org> References: <7fc612d0-9610-9b07-d054-bb1438898f47@redhat.com> <20180302221831-mutt-send-email-mst@kernel.org> <258F88CA-D946-4804-A65D-2EA0790A66AF@redhat.com> <09cbf694-907e-dd68-60ff-eeb169925a5e@akamai.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <09cbf694-907e-dd68-60ff-eeb169925a5e@akamai.com> Subject: Re: [virtio-dev] [PATCH 4/4] virtio-net: add linkspeed and duplex settings to virtio-net To: Jason Baron Cc: Yan Vugenfirer , Jason Wang , qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org List-ID: On Tue, Mar 06, 2018 at 01:02:06PM -0500, Jason Baron wrote: > > > On 03/04/2018 08:05 AM, Yan Vugenfirer wrote: > > > > > >> On 2 Mar 2018, at 22:19, Michael S. Tsirkin >> > wrote: > >> > >> On Fri, Mar 02, 2018 at 03:14:01PM +0800, Jason Wang wrote: > >>> > >>> > >>> On 2018年03月02日 11:46, Jason Baron wrote: > >>>> Although linkspeed and duplex can be set in a linux guest via > >>>> 'ethtool -s', > >>>> this requires custom ethtool commands for virtio-net by default. > >>>> > >>>> Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows > >>>> the hypervisor to export a linkspeed and duplex setting. The user can > >>>> subsequently overwrite it later if desired via: 'ethtool -s'. > >>>> > >>>> Linkspeed and duplex settings can be set as: > >>>> '-device virtio-net,speed=10000,duplex=full' > >>> > >>> I was thinking whether or not it's better to decide the duplex by the > >>> type > >>> of backends. > >>> > >>> E.g userspace and vhost-kernel implement a in fact half duplex. But dpdk > >>> implement a full duplex. > >>> > >>> Thanks > >> > >> OTOH it's a priority for some people to be able to support migration > >> between different backend types. Breaking that won't be nice. > > > > I think that in this case we need a way to update the settings of link > > speed and link duplex (maybe add QMP command). Migration between > > different backend types should cause link down\link up events. And this > > is a time for a driver to re-read the settings and update the OS. > > > > Best regards, > > Yan. > > > > So the virtio_net driver in linux will re-read these settings on link up > events. So I could add a qmp command to set these (in addition to the > command-line) interface, if desired. Is there a consensus that we need > to add a qmp command here? Or can that be treated as a future item, if > somebody wants it? > > Thanks, > > -Jason We already have ability to take link down and up. I'd say it's a future item. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org