From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark McLoughlin Subject: Re: [PATCH 1/1] qemu-kvm: virtio-net: Re-instate GSO code removed upstream Date: Wed, 30 Sep 2009 14:59:20 +0100 Message-ID: <1254319160.3105.67.camel@blaa> References: <1241459088.26045.1.camel@lappy> <1241513785-28738-1-git-send-email-markmc@redhat.com> <1254257151.29022.11.camel@blaa> <20090930135144.GA29956@infradead.org> <4AC36355.8040908@redhat.com> Reply-To: Mark McLoughlin Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Christoph Hellwig , kvm@vger.kernel.org, qemu-devel@nongnu.org To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32348 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752299AbZI3OAy (ORCPT ); Wed, 30 Sep 2009 10:00:54 -0400 In-Reply-To: <4AC36355.8040908@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, 2009-09-30 at 15:55 +0200, Avi Kivity wrote: > On 09/30/2009 03:51 PM, Christoph Hellwig wrote: > > I might sound like a broken record, but why isn't the full GSO support > > for virtio-net upstream in qemu? > > > > IIRC the current hacks are not upstream quality. > > The problem (again IIRC) is that the guest and host negotiate a > protocol, but the qemu vlan model doesn't have a guest and a host, it > has peers (possibly more than two), so a lot of translation has to take > place if you have one peer supporting a guest feature and another not. Right. > IMO the best way out is to drop the vlan model. It has its uses, but > they can all be implemented in other ways, and are all have minor usage > compared to the business of getting data into and out of a guest. I think we should keep the vlan stuff, just de-emphasise it. I'm planning on adding -hostnet and -nic arguments, which would not use vlans by default but rather connect the nic directly to the host side. The QemuOpts conversion of -net which is waiting to be merged is the first stage of that. Cheers, Mark.