RE: [Qemu-devel] re: native gfx card support

RE: [Qemu-devel] re: native gfx card support

[Natalia Portillo]

Hi!

> Basically the main thing I know about gfx support is that it 
> should be way faster to support native cards (I've got a 
> GeForce 4 MX 64MB DDR in my 1 Ghz iMac, for instance) instead 
> of emulating a card.  That's why I was curious if qemu will 
> do this, as VPC7 will supposedly do.  I'm not trying to rush 
> the qemu devs or anything, I have no idea how long things 
> like that would take to implement.

Is a good idea but with a very difficult problem.
For making this VPC7 will use a kernel driver.
If qemu wants to make the same will have to write a driver for Linux,
another for Win32, another for MacOS X, another for FreeBSD, another for
<put here your favourite HOST system>.

Is the eternal question: Performance vs. Portability

[Qemu-devel] re: native gfx card support

[Fred Hope]

 >> Have you tried the cirrus emulation ? <<

If you mean running qemu with the -cirrusvga flag, then yes.  I don't 
know much about what cirrusvga is, or how it improves qemu's graphics 
support, I just read some how-to's for qemu and it said to use that 
flag, so I did.

Basically the main thing I know about gfx support is that it should be 
way faster to support native cards (I've got a GeForce 4 MX 64MB DDR in 
my 1 Ghz iMac, for instance) instead of emulating a card.  That's why I 
was curious if qemu will do this, as VPC7 will supposedly do.  I'm not 
trying to rush the qemu devs or anything, I have no idea how long things 
like that would take to implement.

Fred Hope

Re: [Qemu-devel] re: native gfx card support

[Leigh Dyer]

On Tue, 2004-07-06 at 22:56 -0700, Fred Hope wrote:
>  >> Have you tried the cirrus emulation ? <<
> 
> If you mean running qemu with the -cirrusvga flag, then yes.  I don't 
> know much about what cirrusvga is, or how it improves qemu's graphics 
> support, I just read some how-to's for qemu and it said to use that 
> flag, so I did.
> 
The cirrusvga flag causes Qemu to emulate a Cirrus Logic PCI video card,
rather than just a generic VESA-compatible card. The main reason for
this (if my understanding's correct) is that it makes getting decent
video running on Windows much easier - both 98 and 2000 ship with
drivers for the Cirrus card, but no generic VESA driver. In theory I
guess the emulated card could prove to be a bit faster in future too, by
moving some drawing operations from the guest to the host.

> Basically the main thing I know about gfx support is that it should be 
> way faster to support native cards (I've got a GeForce 4 MX 64MB DDR in 
> my 1 Ghz iMac, for instance) instead of emulating a card.  That's why I 
> was curious if qemu will do this, as VPC7 will supposedly do.  I'm not 
> trying to rush the qemu devs or anything, I have no idea how long things 
> like that would take to implement.

Do you have a link that describes this native video card support? If it
can take your system's primary video card and make it avaiable directly
to the emulated system, then I can't see how it'd work. However, being
able to use a second video card that's in your host system but not used
by the host OS sounds like more of a possiblity. Depending on how
development of the PCI proxy patch goes, I guess it might eventually be
possible to do this in Qemu.

Thanks
Leigh