From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60121) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SyUAj-0008Ql-Nv for qemu-devel@nongnu.org; Mon, 06 Aug 2012 16:45:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SyUAi-0004Wi-J0 for qemu-devel@nongnu.org; Mon, 06 Aug 2012 16:45:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42917) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SyUAi-0004VG-BS for qemu-devel@nongnu.org; Mon, 06 Aug 2012 16:45:04 -0400 From: Kevin Wolf Date: Mon, 6 Aug 2012 22:44:45 +0200 Message-Id: <1344285891-6578-7-git-send-email-kwolf@redhat.com> In-Reply-To: <1344285891-6578-1-git-send-email-kwolf@redhat.com> References: <1344285891-6578-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH 06/12] docs: add lazy refcounts bit to qcow2 specification List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony@codemonkey.ws Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Stefan Hajnoczi The lazy refcounts bit indicates that this image can take advantage of the dirty bit and that refcount updates can be postponed. Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- docs/specs/qcow2.txt | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/docs/specs/qcow2.txt b/docs/specs/qcow2.txt index 339cdc1..36a559d 100644 --- a/docs/specs/qcow2.txt +++ b/docs/specs/qcow2.txt @@ -86,7 +86,12 @@ in the description of a field. Bitmask of compatible features. An implementation can safely ignore any unknown bits that are set. - Bits 0-63: Reserved (set to 0) + Bit 0: Lazy refcounts bit. If this bit is set then + lazy refcount updates can be used. This means + marking the image file dirty and postponing + refcount metadata updates. + + Bits 1-63: Reserved (set to 0) 88 - 95: autoclear_features Bitmask of auto-clear features. An implementation may only -- 1.7.6.5