Re: [PATCH] ioemu: drop unused 4MB video memory

[Samuel Thibault <samuel.thibault@eu.citrix.com>]

Hello,

Ian Jackson, le Mon 14 Jul 2008 10:35:15 +0100, a écrit :
> Samuel Thibault writes ("[Xen-devel] [PATCH] ioemu: drop unused 4MB video memory"):
> > ioemu: drop unused 4MB video memory
> > 
> > Since we only emulate the cirrus VGA video card which is only able to
> > expose 4MB video memory, we don't need more than that.
> 
> I see this has gone into xen-unstable and also the new qemu-xen tree[1].
> 
> But it would be nice to understand the compatibility properties:
>  * Evidently it breaks when tools have this change but qemu-dm
>    doesn't.

Yes.

> Is there a way to avoid this being a fatal error ?

Unfortunately VGA_RAM_SIZE is used in a lot of places of qemu so that'd
be a bit hard.

>  * I think I'm correct to assume that this change is harmless for
>    a new qemu-dm and old tools ?

Yes.

>  * What about save/restore ?

Ah, right, we need a compatibility version for that, I'll work on it.

Samuel