From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43446) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S4vlK-0006Z6-8H for qemu-devel@nongnu.org; Tue, 06 Mar 2012 09:53:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S4vlI-0001v8-Dz for qemu-devel@nongnu.org; Tue, 06 Mar 2012 09:53:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:31209) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S4vlI-0001uz-5v for qemu-devel@nongnu.org; Tue, 06 Mar 2012 09:53:12 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q26ErAP9015868 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 6 Mar 2012 09:53:10 -0500 Date: Tue, 6 Mar 2012 16:53:20 +0200 From: "Michael S. Tsirkin" Message-ID: <20120306145319.GE12096@redhat.com> References: <1331036527-7651-1-git-send-email-pbonzini@redhat.com> <1331036527-7651-4-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1331036527-7651-4-git-send-email-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [PATCH 3/3] virtio-blk: note optional features List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: amit.shah@redhat.com, uobergfe@redhat.com, owasserm@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com On Tue, Mar 06, 2012 at 01:22:07PM +0100, Paolo Bonzini wrote: > The guest must already be prepared to see SG_IO support > disappear from under its feet, for example if migration > refers to a block device on the source and file-based > storage on the destination; or more likely, if the source > kernel allows (gasp) SG_IO on a partition and the destination > does not. So, we can migrate safely even if the source > had VIRTIO_BLK_F_SCSI and the destination does not. > > Signed-off-by: Paolo Bonzini My first reaction is you want a new non guest visible flag to control whether SG_IO fails on host. guest visible ones must be consistent across migration. > --- > hw/virtio-blk.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c > index c95f8fc..9a4158a 100644 > --- a/hw/virtio-blk.c > +++ b/hw/virtio-blk.c > @@ -542,7 +542,7 @@ static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id) > if (version_id != 2) > return -EINVAL; > > - ret = virtio_load(&s->vdev, f, 0); > + ret = virtio_load(&s->vdev, f, VIRTIO_BLK_F_SCSI); > if (ret) { > return ret; > } > -- > 1.7.7.6