Re: [Qemu-devel] [PATCH v2 1/4] vmdk: fix L1 and L2 table size in vmdk3 open

[Paolo Bonzini]

Il 19/08/2013 04:18, Fam Zheng ha scritto:
> On Sun, 08/18 17:19, Paolo Bonzini wrote:
>> Il 13/08/2013 03:21, Fam Zheng ha scritto:
>>> VMDK3 header has the field l1dir_size, but vmdk_open_vmdk3 hardcoded the
>>> value. This patch honors the header field.
>>>
>>> And the L2 table size is 4096 according to VMDK spec[1], instead of
>>> 1 << 9 (512).
>>
>> I'm not sure from the VMDK spec that _only_ 4096 is supported for VMDK3
>> files.  The way I read it, VMDK3 files in hosted products are supposed
>> to have 2K grain tables (as specified by vmdk_open_vmdk3).
> 
> I presume "COWD" is only specified in "ESXi Host Sparse Extents"
> section, which is also in practice the only known use case to me. There
> it says "Grain tables have 4096 entries."
> 
> I think you meant 2KB grain table specified in section "Hosted Sparse
> Extent Metadata", with 512 entries. If so, it should be for VMDK4 with
> "KDMV" magic bytes, so doesn't affect "COWD".

Ok, thanks for explaining.

Paolo