10:23 a.m.
Changes since V2:
- VIR_STORAGE_FILE_AUTO_SAFE is not XML parsable
- Break out QED header defines by field and add link to QED spec
- Removed redundant overflow check in qedGetBackingStore
Changes since V1:
- Fix virStorageFileMatchesVersion() for formats without version info
- Allow backingStore format probing for QED images since it is safe
Qemu is about to gain support for a new disk image format: QED. Details on
this format (including specification) can be found here:
http://wiki.qemu.org/Features/QED. This short series of patches allows QED
images to be used with libvirt.
Adam Litke (4):
Allow probing of image formats without version information
QED: Basic support for QED images
storage_file: Add a new flag to mark backing files that are safe to
probe
Support for probing qed image metadata
src/conf/domain_conf.c | 4 ++
src/util/storage_file.c | 86 +++++++++++++++++++++++++++++++++++++++++++++-
src/util/storage_file.h | 2 +
3 files changed, 90 insertions(+), 2 deletions(-)
--
1.7.3.2.164.g6f10c
10:23 a.m.
New subject: [libvirt] [PATCH 1/4] Allow probing of image formats without version information
Disk image formats that wish to opt-out of version validation are supposed to
set versionOffset to -1 in their fileTypeInfo entry.
By unconditionally returning False for these formats,
virStorageFileMatchesVersion() incorrectly reports a version mismatch when the
test was actually skipped. The correct behavior is to return True so these
formats can be successfully probed using the magic bytes alone.
Signed-off-by: Adam Litke <agl(a)us.ibm.com>
Acked-by: Eric Blake <eblake(a)redhat.com>
---
src/util/storage_file.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/src/util/storage_file.c b/src/util/storage_file.c
index 4098383..f8ab168 100644
--- a/src/util/storage_file.c
+++ b/src/util/storage_file.c
@@ -478,7 +478,7 @@ virStorageFileMatchesVersion(int format,
/* Validate version number info */
if (fileTypeInfo[format].versionOffset == -1)
- return false;
+ return true;
if ((fileTypeInfo[format].versionOffset + 4) > buflen)
return false;
--
1.7.3.2.164.g6f10c
10:23 a.m.
New subject: [libvirt] [PATCH 2/4] QED: Basic support for QED images
Add an entry in fileTypeInfo for QED image files.
Signed-off-by: Adam Litke <agl(a)us.ibm.com>
Acked-by: Eric Blake <eblake(a)redhat.com>
Cc: Stefan Hajnoczi <stefan.hajnoczi(a)uk.ibm.com>
Cc: Anthony Liguori <aliguori(a)linux.vnet.ibm.com>
---
src/util/storage_file.c | 10 +++++++++-
src/util/storage_file.h | 1 +
2 files changed, 10 insertions(+), 1 deletions(-)
diff --git a/src/util/storage_file.c b/src/util/storage_file.c
index f8ab168..89c2cbe 100644
--- a/src/util/storage_file.c
+++ b/src/util/storage_file.c
@@ -43,7 +43,7 @@ VIR_ENUM_IMPL(virStorageFileFormat,
VIR_STORAGE_FILE_LAST,
"raw", "dir", "bochs",
"cloop", "cow", "dmg", "iso",
- "qcow", "qcow2", "vmdk", "vpc")
+ "qcow", "qcow2", "qed", "vmdk",
"vpc")
enum lv_endian {
LV_LITTLE_ENDIAN = 1, /* 1234 */
@@ -104,6 +104,8 @@ static int vmdk4GetBackingStore(char **, int *,
#define QCOW2_HDR_EXTENSION_END 0
#define QCOW2_HDR_EXTENSION_BACKING_FORMAT 0xE2792ACA
+#define QED_HDR_IMAGE_SIZE (4+4+4+4+8+8+8)
+
/* VMDK needs at least this to find backing store,
* other formats need less */
#define STORAGE_MAX_HEAD (20*512)
@@ -151,6 +153,12 @@ static struct FileTypeInfo const fileTypeInfo[] = {
LV_BIG_ENDIAN, 4, 2,
QCOWX_HDR_IMAGE_SIZE, 8, 1, QCOW2_HDR_CRYPT, qcow2GetBackingStore,
},
+ [VIR_STORAGE_FILE_QED] = {
+ /* http://wiki.qemu.org/Features/QED */
+ "QED\0", NULL,
+ LV_LITTLE_ENDIAN, -1, -1,
+ QED_HDR_IMAGE_SIZE, 8, 1, -1, NULL,
+ },
[VIR_STORAGE_FILE_VMDK] = {
"KDMV", NULL,
LV_LITTLE_ENDIAN, 4, 1,
diff --git a/src/util/storage_file.h b/src/util/storage_file.h
index a3703f5..c4d4650 100644
--- a/src/util/storage_file.h
+++ b/src/util/storage_file.h
@@ -38,6 +38,7 @@ enum virStorageFileFormat {
VIR_STORAGE_FILE_ISO,
VIR_STORAGE_FILE_QCOW,
VIR_STORAGE_FILE_QCOW2,
+ VIR_STORAGE_FILE_QED,
VIR_STORAGE_FILE_VMDK,
VIR_STORAGE_FILE_VPC,
VIR_STORAGE_FILE_LAST,
--
1.7.3.2.164.g6f10c
10:23 a.m.
New subject: [libvirt] [PATCH 3/4] storage_file: Add a new flag to mark backing files that are safe to probe
Signed-off-by: Adam Litke <agl(a)us.ibm.com>
Acked-by: Eric Blake <eblake(a)redhat.com>
---
src/conf/domain_conf.c | 4 ++++
src/util/storage_file.h | 1 +
2 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 2d11785..a08c846 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -7825,6 +7825,10 @@ int virDomainDiskDefForeachPath(virDomainDiskDefPtr disk,
if (format == VIR_STORAGE_FILE_AUTO &&
!allowProbing)
format = VIR_STORAGE_FILE_RAW; /* Stops further recursion */
+
+ /* Allow probing for image formats that are safe */
+ if (format == VIR_STORAGE_FILE_AUTO_SAFE)
+ format = VIR_STORAGE_FILE_AUTO;
} while (nextpath);
ret = 0;
diff --git a/src/util/storage_file.h b/src/util/storage_file.h
index c4d4650..1eef4c5 100644
--- a/src/util/storage_file.h
+++ b/src/util/storage_file.h
@@ -28,6 +28,7 @@
# include <stdbool.h>
enum virStorageFileFormat {
+ VIR_STORAGE_FILE_AUTO_SAFE = -2,
VIR_STORAGE_FILE_AUTO = -1,
VIR_STORAGE_FILE_RAW = 0,
VIR_STORAGE_FILE_DIR,
--
1.7.3.2.164.g6f10c
10:23 a.m.
New subject: [libvirt] [PATCH 4/4] Support for probing qed image metadata
Implement getBackingStore() for QED images. The header format is defined in
the QED spec: http://wiki.qemu.org/Features/QED .
Signed-off-by: Adam Litke <agl(a)us.ibm.com>
Acked-by: Eric Blake <eblake(a)redhat.com>
Cc: Stefan Hajnoczi <stefan.hajnoczi(a)uk.ibm.com>
Cc: Anthony Liguori <aliguori(a)linux.vnet.ibm.com>
---
src/util/storage_file.c | 78 +++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 76 insertions(+), 2 deletions(-)
diff --git a/src/util/storage_file.c b/src/util/storage_file.c
index 89c2cbe..9d97066 100644
--- a/src/util/storage_file.c
+++ b/src/util/storage_file.c
@@ -89,6 +89,8 @@ static int qcow2GetBackingStore(char **, int *,
const unsigned char *, size_t);
static int vmdk4GetBackingStore(char **, int *,
const unsigned char *, size_t);
+static int
+qedGetBackingStore(char **, int *, const unsigned char *, size_t);
#define QCOWX_HDR_VERSION (4)
#define QCOWX_HDR_BACKING_FILE_OFFSET (QCOWX_HDR_VERSION+4)
@@ -104,7 +106,12 @@ static int vmdk4GetBackingStore(char **, int *,
#define QCOW2_HDR_EXTENSION_END 0
#define QCOW2_HDR_EXTENSION_BACKING_FORMAT 0xE2792ACA
-#define QED_HDR_IMAGE_SIZE (4+4+4+4+8+8+8)
+#define QED_HDR_FEATURES_OFFSET (4+4+4+4)
+#define QED_HDR_IMAGE_SIZE (QED_HDR_FEATURES_OFFSET+8+8+8+8)
+#define QED_HDR_BACKING_FILE_OFFSET (QED_HDR_IMAGE_SIZE+8)
+#define QED_HDR_BACKING_FILE_SIZE (QED_HDR_BACKING_FILE_OFFSET+4)
+#define QED_F_BACKING_FILE 0x01
+#define QED_F_BACKING_FORMAT_NO_PROBE 0x04
/* VMDK needs at least this to find backing store,
* other formats need less */
@@ -157,7 +164,7 @@ static struct FileTypeInfo const fileTypeInfo[] = {
/* http://wiki.qemu.org/Features/QED */
"QED\0", NULL,
LV_LITTLE_ENDIAN, -1, -1,
- QED_HDR_IMAGE_SIZE, 8, 1, -1, NULL,
+ QED_HDR_IMAGE_SIZE, 8, 1, -1, qedGetBackingStore,
},
[VIR_STORAGE_FILE_VMDK] = {
"KDMV", NULL,
@@ -417,6 +424,73 @@ cleanup:
return ret;
}
+static unsigned long
+qedGetHeaderUL(const unsigned char *loc)
+{
+ return ( ((unsigned long)loc[3] << 24)
+ | ((unsigned long)loc[2] << 16)
+ | ((unsigned long)loc[1] << 8)
+ | ((unsigned long)loc[0] << 0));
+}
+
+static unsigned long long
+qedGetHeaderULL(const unsigned char *loc)
+{
+ return ( ((unsigned long)loc[7] << 56)
+ | ((unsigned long)loc[6] << 48)
+ | ((unsigned long)loc[5] << 40)
+ | ((unsigned long)loc[4] << 32)
+ | ((unsigned long)loc[3] << 24)
+ | ((unsigned long)loc[2] << 16)
+ | ((unsigned long)loc[1] << 8)
+ | ((unsigned long)loc[0] << 0));
+}
+
+static int
+qedGetBackingStore(char **res,
+ int *format,
+ const unsigned char *buf,
+ size_t buf_size)
+{
+ unsigned long long flags;
+ unsigned long offset, size;
+
+ *res = NULL;
+ /* Check if this image has a backing file */
+ if (buf_size < QED_HDR_FEATURES_OFFSET+8)
+ return BACKING_STORE_INVALID;
+ flags = qedGetHeaderULL(buf + QED_HDR_FEATURES_OFFSET);
+ if (!(flags & QED_F_BACKING_FILE))
+ return BACKING_STORE_OK;
+
+ /* Parse the backing file */
+ if (buf_size < QED_HDR_BACKING_FILE_OFFSET+8)
+ return BACKING_STORE_INVALID;
+ offset = qedGetHeaderUL(buf + QED_HDR_BACKING_FILE_OFFSET);
+ if (offset > buf_size)
+ return BACKING_STORE_INVALID;
+ size = qedGetHeaderUL(buf + QED_HDR_BACKING_FILE_SIZE);
+ if (size == 0)
+ return BACKING_STORE_OK;
+ if (offset + size > buf_size || offset + size < offset)
+ return BACKING_STORE_INVALID;
+ if (VIR_ALLOC_N(*res, size + 1) < 0) {
+ virReportOOMError();
+ return BACKING_STORE_ERROR;
+ }
+ memcpy(*res, buf + offset, size);
+ (*res)[size] = '\0';
+
+ if (format) {
+ if (flags & QED_F_BACKING_FORMAT_NO_PROBE)
+ *format = VIR_STORAGE_FILE_RAW;
+ else
+ *format = VIR_STORAGE_FILE_AUTO_SAFE;
+ }
+
+ return BACKING_STORE_OK;
+}
+
/**
* Return an absolute path corresponding to PATH, which is absolute or relative
* to the directory containing BASE_FILE, or NULL on error
--
1.7.3.2.164.g6f10c
10:41 a.m.
On 11/22/2010 09:23 AM, Adam Litke wrote:
Changes since V2:
- VIR_STORAGE_FILE_AUTO_SAFE is not XML parsable
- Break out QED header defines by field and add link to QED spec
- Removed redundant overflow check in qedGetBackingStore
I had already applied your v1 series last week after folding in my
suggested tweaks; would you mind rebasing this to provide just the
subsequent patch(es) on top of what is already applied?
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org
10:45 a.m.
Sure, no problem.
On Mon, 2010-11-22 at 09:41 -0700, Eric Blake wrote:
On 11/22/2010 09:23 AM, Adam Litke wrote:
> Changes since V2:
> - VIR_STORAGE_FILE_AUTO_SAFE is not XML parsable
> - Break out QED header defines by field and add link to QED spec
> - Removed redundant overflow check in qedGetBackingStore
I had already applied your v1 series last week after folding in my
suggested tweaks; would you mind rebasing this to provide just the
subsequent patch(es) on top of what is already applied?
--
Thanks,
Adam
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days inactive
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6 comments
2 participants
participants (2)
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Adam Litke -
Eric Blake