Re: [Qemu-devel] [PATCH 2/2] qxl: change rom size to 8192

[Cole Robinson]

On 02/08/2013 04:36 AM, Gerd Hoffmann wrote:
>   Hi,
> 
>>> foo.img generated with stock qemu 1.3.1, migration fails with git
>>> head, still
>>> fails after reverting the seabios 1.7.2 update which supposedly
>>> causes other
>>> migrate issues (commit 3588185b8396eb97fd9efd41c2b97775465f67c4)
>>
>> So this is by design - that patch changes the rom size for revision 4 (which 
>> is the default for qemu 1.3.1) from 16384 bytes to 8192. This breaks 
>> migration from previously created revision 4 images... But it unbreaks 
>> migration from other revisions. Different things that could be done: do a 
>> special migration hook to copy from src 16384 byte rom bar to dst 8192 byte 
>> rom bar. Gerd, what do you think?
> 
> So the change making the rpm 16k was before 1.3, the fix thereafter, and
> now we have migration 1.2 -> 1.3 broken (maybe masked by -M 1.2
> defaulting to qxl rev 3), 1.3 -> 1.4 broken and 1.2 -> 1.4 working, correct?
> 
> So a compat property changing the rom size to 16k for pc-1.3 should do
> the trick I think.
> 

The example commands I gave were using -M pc-1.0, I can't tell if you're
solution factors that in.

Thanks,
Cole