Re: [Qemu-devel] [PATCH] vhdx: Return true for bdrv_has_zero_init

[Kevin Wolf <kwolf@redhat.com>]

Am 05.12.2014 um 11:26 hat Kevin Wolf geschrieben:
> Like for most other image formats, vhdx images read as all zero in qemu
> after their creation (we're taking advantage from the fact that qemu has
> just created the image, because PAYLOAD_BLOCK_NOT_PRESENT actually means
> undefined rather than zeroed according to the spec).
> 
> This fixes that 'qemu-img convert' to vhdx fully populates the image.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Jeff, another thing that Max found while we looked at the spec is that
the 1.0 spec defines PAYLOAD_BLOCK_UNMAPPED as 3, but we define it as 5.
It appears that the 0.95 spec actually had it that way.

Should we handle both 3 and 5 as unmapped?

Kevin