From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: [PATCH] virtio-blk: allow toggling host cache between writeback and writethrough Date: Wed, 04 Jul 2012 18:26:57 +0200 Message-ID: <1341419217.18786.3.camel@lappy> References: <1341321577-24435-1-git-send-email-pbonzini@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, kvm@vger.kernel.org To: Paolo Bonzini Return-path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:65368 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932133Ab2GDQ0I (ORCPT ); Wed, 4 Jul 2012 12:26:08 -0400 In-Reply-To: <1341321577-24435-1-git-send-email-pbonzini@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, 2012-07-03 at 15:19 +0200, Paolo Bonzini wrote: > diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h > index e0edb40..18a1027 100644 > --- a/include/linux/virtio_blk.h > +++ b/include/linux/virtio_blk.h > @@ -37,8 +37,9 @@ > #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ > #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ > #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ > -#define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */ > +#define VIRTIO_BLK_F_WCE 9 /* Writeback mode enabled after reset */ > #define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ > +#define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */ Wouldn't this change break any usermode code that implements virtio-blk?