Re: [Qemu-devel] [PATCH 1/2] qxl: create slots on post_load in any state

[Gerd Hoffmann <kraxel@redhat.com>]

On 10/18/11 17:26, Alon Levy wrote:
> If we migrate when the device is not in a native state the guest
> still believes the slots are created, and will cause operations
> that reference the slots, causing a "panic: virtual address out of range"
> on the first of them. Easy to see by migrating in vga mode (with
> a driver loaded, for instance windows cmd window in full screen mode)
> and then exiting vga mode back to native mode will cause said panic.
>
> Fixed by doing the slot recreation unconditionally at post_load, and
> using the delta value. Next patch makes sure we actually migrate that
> delta.

I don't think we have to save the delta value.  The delta is used only 
in compat mode.  In compat mode the guest doesn't create memory slots, 
instead qxl does that (in qxl_set_mode).

I think you can just skip the slot re-creation in compat mode and let 
qxl_set_mode (which is called later in post_load) handle it.

cheers,
   Gerd