From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752087Ab1JBJgc (ORCPT ); Sun, 2 Oct 2011 05:36:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:16091 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751456Ab1JBJg0 (ORCPT ); Sun, 2 Oct 2011 05:36:26 -0400 Date: Sun, 2 Oct 2011 11:37:33 +0200 From: "Michael S. Tsirkin" To: Amit Shah Cc: Rusty Russell , linux-kernel@vger.kernel.org Subject: Re: [PATCH 06/11] virtio: blk: Add freeze, restore handlers to support S4 Message-ID: <20111002093733.GE29706@redhat.com> References: <5160f2cf536e7c506a5e90b4cb95e0f2e41c53d9.1317309123.git.amit.shah@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5160f2cf536e7c506a5e90b4cb95e0f2e41c53d9.1317309123.git.amit.shah@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 29, 2011 at 08:56:02PM +0530, Amit Shah wrote: > Delete the vq on the freeze callback to prepare for hibernation. > Re-create the vq in the restore callback to resume normal function. > > Signed-off-by: Amit Shah > --- > drivers/block/virtio_blk.c | 17 +++++++++++++++++ > 1 files changed, 17 insertions(+), 0 deletions(-) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 509760b..9844d2c 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -549,6 +549,19 @@ static void __devexit virtblk_remove(struct virtio_device *vdev) > kfree(vblk); > } > > +#ifdef CONFIG_PM > +static int virtblk_freeze(struct virtio_device *vdev) > +{ > + vdev->config->del_vqs(vdev); What prevents the guest from trying to use the VQ while this is in progress? IF it does, what prevents a crash? > + return 0; > +} > + > +static int virtblk_restore(struct virtio_device *vdev) > +{ > + return init_vq(vdev->priv);; > +} > +#endif > + > static const struct virtio_device_id id_table[] = { > { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, > { 0 }, > @@ -574,6 +587,10 @@ static struct virtio_driver __refdata virtio_blk = { > .probe = virtblk_probe, > .remove = __devexit_p(virtblk_remove), > .config_changed = virtblk_config_changed, > +#ifdef CONFIG_PM > + .freeze = virtblk_freeze, > + .restore = virtblk_restore, > +#endif > }; > > static int __init init(void) > -- > 1.7.6.2