From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-4725-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 [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id AE7E9985C74 for ; Mon, 23 Jul 2018 09:22:42 +0000 (UTC) Date: Mon, 23 Jul 2018 12:22:38 +0300 From: "Michael S. Tsirkin" Message-ID: <20180723122205-mutt-send-email-mst@kernel.org> References: <1532035780-38883-1-git-send-email-sridhar.samudrala@intel.com> <20180720094450.2f2978f9.cohuck@redhat.com> <20180722182834-mutt-send-email-mst@kernel.org> <20180723110311.5a36f56a.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180723110311.5a36f56a.cohuck@redhat.com> Subject: Re: [virtio-dev] [PATCH] content: Introduce VIRTIO_NET_F_STANDBY feature To: Cornelia Huck Cc: Sridhar Samudrala , virtio-dev@lists.oasis-open.org List-ID: On Mon, Jul 23, 2018 at 11:03:11AM +0200, Cornelia Huck wrote: > On Sun, 22 Jul 2018 18:37:42 +0300 > "Michael S. Tsirkin" wrote: > > > On Fri, Jul 20, 2018 at 09:44:50AM +0200, Cornelia Huck wrote: > > > On Thu, 19 Jul 2018 14:29:40 -0700 > > > Sridhar Samudrala wrote: > > > > > > > VIRTIO_NET_F_STANDBY feature enables hypervisor to indicate virtio_net > > > > driver to act as a standby for another device with the same MAC address. > > > > > > > > Signed-off-by: Sridhar Samudrala > > > --- > > > > content.tex | 10 ++++++++++ > > > > 1 file changed, 10 insertions(+) > > > > > @@ -2636,6 +2639,13 @@ If the driver negotiates VIRTIO_NET_F_MTU, it MUST NOT transmit packets of > > > > size exceeding the value of \field{mtu} (plus low level ethernet header length) > > > > with \field{gso_type} NONE or ECN. > > > > > > > > +A driver SHOULD negotiate VIRTIO_NET_F_STANDBY feature if the device offers it. > > > > > > I'm not sure that this is the right section of the spec. Maybe we need > > > a new normative driver section for "cross-device features" (better > > > names wanted :), and the same for devices? > > > > You mean if we ever extend this to non-network devices? > > This is a network specific feature bit so what makes > > it a cross-device feature? > > No, the network device location is alright. But it is in a section that > deals with how the config space etc. is handled, and I'm not sure > whether it fits well with the other statements in there. Not a major > gripe, though. > > > > > > > + > > > > +If the driver negotiates VIRTIO_NET_F_STANDBY, it should act as a standby > > > for > > > > +another device with the same MAC address when available. The hypervisor can > > > > +hot-plug a primary device with same MAC address if the feature is successfully > > > > +negotiated with the driver. > > > > > > I don't think you should add implementation details like hotplugging > > > into the spec. > > > > > > What about: > > > > > > "If the driver negotiates VIRTIO_NET_F_STANDBY, the device MAY act as a > > > standby device for another device with the same MAC address, the > > > 'failover device'. > > > > I find the name "failover device" confusing. Linux came up with > > names primary and standby. > > "...the device MAY act as a standby device for a primary device with > the same MAC address." > > ? Right. But I agree we need a section that defines failover operation. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org