On Wed, 1 Nov 2000, Jeffrey B. Siegal wrote:
> Perhaps not, in theory. To really answer that you would have to look in
> detail at the particular achitecures in question. However, I suspect it
> could be very close. Certainly it would be close enough for a first
> step.
>
If I understand you correctly, you propose to take existing VGA emulation
and extend it to emulation of more advanced SVGA, including blt/3d
support using the host's accelerated driver (the later is not required to
have the same architecture, just to be accelerated). Perhaps the 3dfx
voodoo family (I mean old voodoo2/3) would suit the best for this purpose,
I believe it's the most documented SVGA hardware (correct me if I am
wrong), also it doesn't use extra features available in newest nvidia/ati
axels, so it can be considered as the "common denominator" of 3d
accelerators. Perhaps not so advanced as let's say GeForce, it would be
_heaps_ more advanced emulation than just plain VGA. You are right that it
would be really nice to use guests' OS native driver instead of rewriting
it.
> In practice it might turn out to be more efficient. See below.
>
> > The latter seems to be the (somewhat succesful)
> > approach that has been taken by vmware.
>
> Actually, in practice I am not very impressed with their approach. From
> what I've seen, their Windows drivers just aren't that good (and they
> don't support DirectX, at all).
>
I agree. vmware's video is not that advanced. definitely their weak point.
> It is a *lot* of work to do good Windows drivers, and this is a really
> good reason for using off-the shelf drivers if possible. They're better
> optimized and more complete. The end result would likely be
> considerably more efficient than lame drivers written for some
> plex86-only video device.
>
The only good reason of wrapping video at higher level (level of driver)
instead of at level of hardware I can think of, is to take the full usage
of features of this particular hardware, however you are right that it's
probably harder job.
Uhus
