Re: [Qemu-devel] [Qemu-ppc] [PATCH 2/2] spapr: Add support for -vga option

[Benjamin Herrenschmidt]

On Wed, 2012-06-27 at 17:25 -0500, Anthony Liguori wrote:

> If a user asks for something and we can't make it work, we should fail.

Note that QEMU's cirrus works fine with the new kernel cirrusdrmfb, so
I say we should allow it (needs to be able to the powerpc device .mak
as well tho.

It shouldn't be primary because old RHEL's iirc used to have cirrusfb
enabled and that would blow due to guest kernel bugs among others.

I haven't had a chance to try whatever userspace DDX the Xorg folks have
come up with to use on top of cirrusdrmfb, so that might need a bit of
fixing but there's no reason not to allow -vga cirrus at this point.

Note to Matthew: cirrusdrmfb is a LOT SLOWER than offb for a similar
SW only dumb framebuffer, probably has to do with the way it does the
"dirty" stuff, not sure ...

Why not draw directly into the emulated vram ?

Cheers,
Ben.