Hi,
Then our big problem is migration between read of the 1st register and
of the 2nd register, no?
"big"? The window is quite small, and I think we have a bunch of
simliar issues elsewhere in qemu. They are hardly avoidable for new ->
old migration when adding new features to emulated devices.
Well, maybe sections can fix it, but probably only in case the old qemu
is new enougth that it can handle sections too.
Furthermore, older vga bios, seing VBE_DISPI_ID5, what are they going to
do?
Work as they did before ;)
So when migrating from new to old qemu: Before reset
vgabios will have the video memory size saved somewhere. After reset
ID will reset to ID0, and in case you are running vgabios 0.6c vesa
gfx modes will stop working.
I see this part, but I still think that we have a window where we can be
in very bad shape, no? I guess that we don't support anything different
that vgabios, so ....
See above. Worst case is that vesa graphics modes stop working, even if
you hit the race window (vgabios will think you have 0 MB video ram then
and refuse all gfx modes).
cheers,
Gerd
