On Tue, 19 Apr 2011, Prasad Joshi wrote:
On Tue, Apr 19, 2011 at 10:07 PM, Pekka Enberg <penberg@xxxxxxxxxx> wrote:
This patch extends the QCOW1 format to also support QCOW2 images as specified
by the following document:
http://people.gnome.org/~markmc/qcow-image-format.html
Cc: Asias He <asias.hejun@xxxxxxxxx>
Cc: Cyrill Gorcunov <gorcunov@xxxxxxxxx>
Cc: Prasad Joshi <prasadjoshi124@xxxxxxxxx>
Cc: Sasha Levin <levinsasha928@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxx>
---
tools/kvm/include/kvm/qcow.h | 42 ++++++++++-
tools/kvm/qcow.c | 177 +++++++++++++++++++++++++++++++++---------
2 files changed, 181 insertions(+), 38 deletions(-)
diff --git a/tools/kvm/include/kvm/qcow.h b/tools/kvm/include/kvm/qcow.h
index 4be2597..afd776d 100644
--- a/tools/kvm/include/kvm/qcow.h
+++ b/tools/kvm/include/kvm/qcow.h
@@ -4,9 +4,17 @@
#include <linux/types.h>
#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
+
#define QCOW1_VERSION 1
+#define QCOW2_VERSION 2
+
+#define QCOW1_OFLAG_COMPRESSED (1LL << 63)
+
+#define QCOW1_OFLAG_MASK QCOW1_OFLAG_COMPRESSED
-#define QCOW_OFLAG_COMPRESSED (1LL << 63)
+#define QCOW2_OFLAG_COPIED (1LL << 63)
+#define QCOW2_OFLAG_COMPRESSED (1LL << 62)
+#define QCOW2_OFLAG_MASK (QCOW2_OFLAG_COPIED|QCOW2_OFLAG_COMPRESSED)
struct qcow_table {
u32 table_size;
@@ -19,7 +27,16 @@ struct qcow {
int fd;
};
-struct qcow1_header {
+struct qcow_header {
+ u64 size; /* in bytes */
+ u64 l1_table_offset;
+ u32 l1_size;
+ u8 cluster_bits;
+ u8 l2_bits;
+ uint64_t oflag_mask;
+};
+
+struct qcow1_header_disk {
u32 magic;
u32 version;
@@ -36,6 +53,27 @@ struct qcow1_header {
u64 l1_table_offset;
};
+struct qcow2_header_disk {
+ u32 magic;
+ u32 version;
+
+ u64 backing_file_offset;
+ u32 backing_file_size;
+
+ u32 cluster_bits;
+ u64 size; /* in bytes */
+ u32 crypt_method;
+
+ u32 l1_size;
+ u64 l1_table_offset;
+
+ u64 refcount_table_offset;
+ u32 refcount_table_clusters;
+
+ u32 nb_snapshots;
+ u64 snapshots_offset;
+};
IMHO, as we start adding other features of QCOW, the two structures qcow2_header_disk and qcow_header might eventually become the same.
No, the point of 'struct qcow2_header_disk' is to map to the on-disk
representation. 'struct qcow_header' is the in-memory version of the data.
+ disk_image = disk_image__new(fd, h->size, &qcow1_disk_ops);
qcow1_disk_ops can be changed to qcow_disk_ops.
Sure, there's more qcow1 prefixes that need fixing now as well.
