From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753449AbbDNBqR (ORCPT ); Mon, 13 Apr 2015 21:46:17 -0400 Received: from ozlabs.org ([103.22.144.67]:50724 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753315AbbDNBqK (ORCPT ); Mon, 13 Apr 2015 21:46:10 -0400 From: Rusty Russell To: "Michael S. Tsirkin" , linux-kernel@vger.kernel.org Cc: Cornelia Huck , Pawel Moll , virtio-dev@lists.oasis-open.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH v3 0/6] virtio_balloon: virtio 1 support In-Reply-To: <20150412170141-mutt-send-email-mst@redhat.com> References: <1427884468-23930-1-git-send-email-mst@redhat.com> <20150412170141-mutt-send-email-mst@redhat.com> User-Agent: Notmuch/0.17 (http://notmuchmail.org) Emacs/24.3.1 (x86_64-pc-linux-gnu) Date: Tue, 14 Apr 2015 10:42:56 +0930 Message-ID: <87h9sjtsvb.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Michael S. Tsirkin" writes: > On Wed, Apr 01, 2015 at 02:57:35PM +0200, Michael S. Tsirkin wrote: >> Virtio 1.0 doesn't include a modern balloon device. At some point we'll likely >> define an incompatible interface with a different ID and different >> semantics. But for now, it's not a big effort to support a transitional >> balloon device: this has the advantage of supporting existing drivers, >> transparently, as well as transports that don't allow mixing virtio 0 and >> virtio 1 devices. And balloon is an easy device to test, so it's also useful >> for people to test virtio core handling of transitional devices. >> >> The only interface issue is with the stats buffer, which has misaligned >> fields. We could leave it as is, but this sets a bad precedent that >> others might copy by mistake. >> >> As we need to change stats code to do byteswaps for virtio 1.0, it seems easy >> to fix by prepending a 6 byte reserved field. I also had to change config >> structure field types from __le32 to __u32 to match other devices. This means >> we need a couple of __force tags for legacy path but that seems minor. > > Rusty, what are your thoughts here? > How about merging this for 4.1? I disagree with making any changes, other than allowing it to be used with VIRTIO_F_VERSION_1. However it doesn't seem to bother anyone else, so I've applied it for 4.1. Thanks, Rusty.