Re: [Qemu-devel] Re: QEMU-KVM and video performance

Jamie Lokier
2010-04-21T18:39:48Z

Avi Kivity wrote:
> Writes to vga in 16-color mode don't change set a memory location to a
> value, instead they change multiple memory locations.

While code is just writing to the VGA memory, not reading(*) and not
touching the VGA I/O register that control the write latches, is it
possible in principle to swizzle the format around in memory to make
regular writes work?

(*) Reading should be ok for some settings of the write latches, I
think.

I wonder if guests of interest behave like that.

> >Is this a case where TCG would run significantly faster for code blocks
> >that have been detected to access the VGA memory?
>
> Yes.

$ date
Wed Apr 21 19:37:38 2015
$ modprobe ktcg
;-)

-- Jamie