On 2018-06-06 16:46, Michael S. Tsirkin wrote:
> On Wed, Jun 06, 2018 at 01:44:02PM +0200, Max Reitz wrote:
>> Because it's a hack, right.  Storing binary data in a qcow2 file,
>> completely ignoring it in qemu (and being completely unusable to any
>> potential other users of the qcow2 format[1]) and only interpreting it
>> somewhere up the stack is a hack.
> 
> It's just a first step and it ensures compatibility with old QEMU
> versions. But down the road I think we will start warning
> user if the machine type does not match, and possibly even
> get the type from there if user didn't supply it.

If it's a first step we should have an idea on what the following steps
should be.

I don't want people to convince me that adding a blob to qcow2 is a good
idea because "we are only going to store two or three values!" and then
that blob grows out of control because "well, now we have it anyway".

Max