Re: [Qemu-devel] Re: [PATCH 2/3] qemu: make cirrus init value pci spec compliant

[Michael S. Tsirkin]

On Mon, Oct 12, 2009 at 05:43:39PM +0200, Gerd Hoffmann wrote:
> On 10/12/09 16:52, Gleb Natapov wrote:
>> On Mon, Oct 12, 2009 at 04:50:35PM +0200, Gerd Hoffmann wrote:
>>> pc.c does some magic here to map the complete bios into high memory
>>> and the legacy part at 0xe0000, thats why it is loaded in a
>>> different way. It gets loaded to IO_MEM_ROM memory though, so the
>>> guest should not be able to corrupt it.
>>>
>> But KVM doesn't support it (memory is always writable). And we want to reload
>> BIOS on reboot for migration purposes.
>
> Then it should be switched over to the new rom loader.  Also the logic  
> which does *not* reload stuff which goes to IO_MEM_ROM must be turned  
> off for kvm them.

I think it needs to be turned off anyway.  Since ROM is sent over for
migration, it might get out of sync with file even if it is read-only.

> cheers,
>   Gerd