Re: [Qemu-devel] [PULL v2 33/37] block: vhdx - add .bdrv_create() support

[Alexander Graf]

> Am 04.03.2014 um 03:58 schrieb Jeff Cody <address@hidden>:
> 
>> On Fri, Feb 21, 2014 at 01:06:43PM +0100, Alexander Graf wrote:
>> 
>>> On 08.11.2013, at 11:12, Stefan Hajnoczi <address@hidden> wrote:
>>> 
>>> From: Jeff Cody <address@hidden>
>>> 
>>> This adds support for VHDX image creation, for images of type "Fixed"
>>> and "Dynamic".  "Differencing" types (i.e., VHDX images with backing
>>> files) are currently not supported.
>>> 
>>> Options for image creation include:
>>>   * log size:
>>>       The size of the journaling log for VHDX.  Minimum is 1MB,
>>>       and it must be a multiple of 1MB. Invalid log sizes will be
>>>       silently fixed by rounding up to the nearest MB.
>>> 
>>>       Default is 1MB.
>>> 
>>>   * block size:
>>>       This is the size of a payload block.  The range is 1MB to 256MB,
>>>       inclusive, and must be a multiple of 1MB as well.  Invalid sizes
>>>       and multiples will be silently fixed.  If '0' is passed, then
>>>       a sane size is chosen (depending on virtual image size).
>>> 
>>>       Default is 0 (Auto-select).
>>> 
>>>   * subformat:
>>>       - "dynamic"
>>>           An image without data pre-allocated.
>>>       - "fixed"
>>>           An image with data pre-allocated.
>>> 
>>>       Default is "dynamic"
>>> 
>>> When creating the image file, the lettered sections are created:
>>> 
>>> -----------------------------------------------------------------.
>>> |   (A)    |   (B)    |    (C)    |     (D)       |     (E)
>>> |  File ID |  Header1 |  Header 2 |  Region Tbl 1 |  Region Tbl 2
>>> |          |          |           |               |
>>> .-----------------------------------------------------------------.
>>> 0         64KB      128KB       192KB           256KB          320KB
>>> 
>>> .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
>>> |     (F)     |     (G)       |    (H)    |
>>> | Journal Log |  BAT / Bitmap |  Metadata |  .... data ......
>>> |             |               |           |
>>> .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
>>> 1MB         (var.)          (var.)      (var.)
>>> 
>>> Signed-off-by: Jeff Cody <address@hidden>
>>> Signed-off-by: Stefan Hajnoczi <address@hidden>
>>> ---
>>> block/vhdx.c | 558 
>>> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>> block/vhdx.h |  15 +-
>>> 2 files changed, 572 insertions(+), 1 deletion(-)
>> 
>> [..…]
>> 
>>> /* Header for the region table block */
>>> +#define VHDX_REGION_SIGNATURE  0x69676572  /* "regi" in ASCII */
>>> typedef struct QEMU_PACKED VHDXRegionTableHeader {
>>>    uint32_t    signature;              /* "regi" in ASCII */
>>>    uint32_t    checksum;               /* CRC-32C hash of the 64KB table */
>>> @@ -238,6 +247,7 @@ typedef uint64_t VHDXBatEntry;
>>> #define VHDX_METADATA_MAX_ENTRIES 2047  /* not including the header */
>>> #define VHDX_METADATA_TABLE_MAX_SIZE \
>>>    (VHDX_METADATA_ENTRY_SIZE * (VHDX_METADATA_MAX_ENTRIES+1))
>>> +#define VHDX_METADATA_SIGNATURE 0x617461646174656D  /* "metadata" in ASCII 
>>> */
>> 
>> This is missing a "ULL" tag. There are a few places where compilation of 
>> vhdx spawns warnings on 32bit hosts - I haven't checked all of them.
>> 
>> 02/21 12:22:14 ERROR|     utils:0144| [stderr] block/vhdx.c: In function 
>> 'vhdx_open':
>> 02/21 12:22:14 ERROR|     utils:0144| [stderr] block/vhdx.c:957: warning: 
>> integer constant is too large for 'long' type
>> 02/21 12:22:14 ERROR|     utils:0144| [stderr] block/vhdx.c: In function 
>> 'vhdx_block_translate':
>> 02/21 12:22:14 ERROR|     utils:0144| [stderr] block/vhdx.c:1027: warning: 
>> integer constant is too large for 'long' type
>> 02/21 12:22:14 ERROR|     utils:0144| [stderr] block/vhdx.c: In function 
>> 'vhdx_create_new_metadata':
>> 02/21 12:22:14 ERROR|     utils:0144| [stderr] block/vhdx.c:1455: warning: 
>> integer constant is too large for 'long' type
>> 02/21 12:22:14 ERROR|     utils:0144| [stderr] block/vhdx.c: In function 
>> 'vhdx_create':
>> 02/21 12:22:14 ERROR|     utils:0144| [stderr] block/vhdx.c:1812: warning: 
>> integer constant is too large for 'long' type
> 
> Hi Alex,
> 
> I've compiled this using both i686/i386 Fedora 20 and OpenSuse 13.1
> hosts, and I did not run into these warnings.  Could you tell me what
> host and compiler you are using for compilation, so I can reproduce
> and verify the fix?

In this particular case I was running ppc32 openSUSE 11.1. i'm surprised you 
don't see it on newer versions though.

Alex

> 
> 
> Thanks,
> Jeff