From patchwork Thu Sep 27 14:29:57 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [partial,RFC,1/2] qcow2: modify spec for deduplication Date: Thu, 27 Sep 2012 04:29:57 -0000 From: =?utf-8?q?Beno=C3=AEt_Canet?= X-Patchwork-Id: 187388 Message-Id: <1348756198-10845-2-git-send-email-benoit@irqsave.net> To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, pbonzini@redhat.com, stefanha@linux.vnet.ibm.com, =?UTF-8?q?Beno=C3=AEt=20Canet?= --- docs/specs/qcow2.txt | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/docs/specs/qcow2.txt b/docs/specs/qcow2.txt index 36a559d..e8bc189 100644 --- a/docs/specs/qcow2.txt +++ b/docs/specs/qcow2.txt @@ -80,7 +80,10 @@ in the description of a field. tables to repair refcounts before accessing the image. - Bits 1-63: Reserved (set to 0) + Bit 1: Deduplication bit. If this bit is set then + deduplication is used on this image. + + Bits 2-63: Reserved (set to 0) 80 - 87: compatible_features Bitmask of compatible features. An implementation can @@ -116,6 +119,7 @@ be stored. Each extension has a structure like the following: 0x00000000 - End of the header extension area 0xE2792ACA - Backing file format name 0x6803f857 - Feature name table + 0xCD8E819B - Deduplication table offset and length other - Unknown header extension, can be safely ignored