From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH] virtio_net: add link status handling Date: Tue, 09 Dec 2008 15:32:14 -0600 Message-ID: <493EE3DE.7080702@codemonkey.ws> References: <1228817973.26198.1.camel@blaa> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Rusty Russell , netdev , kvm To: Mark McLoughlin Return-path: Received: from nf-out-0910.google.com ([64.233.182.188]:53799 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753999AbYLIVcV (ORCPT ); Tue, 9 Dec 2008 16:32:21 -0500 Received: by nf-out-0910.google.com with SMTP id d3so43883nfc.21 for ; Tue, 09 Dec 2008 13:32:19 -0800 (PST) In-Reply-To: <1228817973.26198.1.camel@blaa> Sender: netdev-owner@vger.kernel.org List-ID: Mark McLoughlin wrote: > Allow the host to inform us that the link is down by adding > a VIRTIO_NET_F_STATUS which indicates that device status is > available in virtio_net config. > > This is currently useful for simulating link down conditions > (e.g. using proposed qemu 'set_link' monitor command) but > would also be needed if we were to support device assignment > via virtio. It would be nice if the virtio-net card wrote some acknowledgement that it has received the link status down/up events. I'm thinking along the lines of doing live migration between two end points that are not on the same subnet. It would be nice to be able to signal link status down, have the guest acknowledge that it received it, do the live migration, then do link status up so the guest reconnects it's networking. Regards, Anthony Liguori