Re: [Qemu-devel] [PATCH] Make default invocation of block drivers safer

[Anthony Liguori]

On 07/14/2010 01:43 PM, Christoph Hellwig wrote:
> Err, strong NACK.  Please don't start messing with the contents of the
> data plane, we're getting into real trouble there.  It's perfectly
> valid for a guest to create an image inside an image, and with hardware
> support for nested virtualization I guess this use case will become
> rather common, just as it already is on S/390 with VM.
>    

Note, this is limited to raw.

If you use qcow2 in L0, the guest can do whatever it wants to do.

But if we autoprobe a raw image, we simply cannot let a guest turn the 
raw image into something else.

A user can still use raw images and let them contain anything, but they 
have to explicitly specify that it's a raw image.

Regards,

Anthony Liguori