> -----Original Message-----
> From: brettm [mailto:brettm_nyc@xxxxxxxxxxx]
> Sent: 16 May 2006 18:11
> To: Petersson, Mats
> Subject: RE: [Xen-users] 3D acceleration
>
> What are the odds that Nvidia and ATI will knock out some Xen
> aware drivers then? Seems like the simplest solution. Is it
> just that the demand isn't there yet?
If you give me some odds, I'll bet against, yeah? ;-)
I think you hit the nail on the head, there's no demand yet. And by the
time Xen is mainstream enough to have huge demand, I bet the IOMMU
solution is already there, and we can fix it without help from nVidia
etc.
Note that MOST of the customers for virtualization are, currently at
least, servers, and those tend to be not very graphics intensive.
--
Mats
>
> -----Original Message-----
> From: Petersson, Mats [mailto:Mats.Petersson@xxxxxxx]
> Sent: Tuesday, May 16, 2006 5:18 AM
> To: brettm
> Subject: RE: [Xen-users] 3D acceleration
>
> > -----Original Message-----
> > From: brettm [mailto:brettm_nyc@xxxxxxxxxxx]
> > Sent: 15 May 2006 17:21
> > To: Petersson, Mats
> > Subject: RE: [Xen-users] 3D acceleration
> >
> > Ok, thanks so much for your reply. The way I understood
> the original
> > thread was that I would not need a Xen aware driver.
> > That's really the crux of my problem. And I want to run
> Windows with
> > 3D acceleration under Xen.
> > Unfortunately, it appears I misunderstood the original post :( I'm
> > new to all of this, but the more I read, the more I think
> I'm going to
> > have to wait *at least* a year to see this. Oh well. Thanks again!
>
> To be able to run a "native" driver, you'd have to have
> hardware that supports IO virtualizaton, aka IOMMU. It is
> possible to make a small IOMMU-like functionality with the
> GART (Graphics Aperture Routing Table,
> IIRC) in AMD64. Intel doesn't have the same feature, so it
> wouldn't work there. This OF COURSE, means that you have to
> have a SVM-enabled processor, which will be another little
> while before they are available.
>
>
> But currently, I there's no IOMMU capability for Xen with
> HVM(SVM/VT), so it's not possible to do this at the moment.
>
> The idea, of course, is that the IOMMU will be programmed to
> have a the memory-mapped IO-space "moved" so that it matches
> the offset of the guest address, so when the guest driver
> says "here's a bitmap, at address x", the DMA access from the
> card to read the bitmap will automagically read x + 128MB (to
> use the example below). That way there's no need for the
> driver to know that the memory is different from what we said.
>
> --
> Mats
>
> >
> > -b
> >
> > -----Original Message-----
> > From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
> > [mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of
> Petersson,
> > Mats
> > Sent: Monday, May 15, 2006 8:41 AM
> > To: brettm; xen-users@xxxxxxxxxxxxxxxxxxx
> > Subject: RE: [Xen-users] 3D acceleration
> >
> > > -----Original Message-----
> > > From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
> > > [mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of brettm
> > > Sent: 15 May 2006 00:43
> > > To: xen-users@xxxxxxxxxxxxxxxxxxx
> > > Subject: Re: [Xen-users] 3D acceleration
> > >
> > > Is it possible to use my motherboard's integrated
> graphics for dom0
> > > and my x1900 video card for a guest? If so, how would I
> > set this up?
> >
> > Aside from the obvious problem of having a graphics driver that
> > actually understands Xen, yes, I believe this could be possible.
> > Although it doesn't work under fully-virtualized guests (VT/SVM),
> > since there would be the added complication of the machine physical
> > address and the guest physical address (i.e. we tell the guest that
> > it's memory is 256MB starting at address zero, when it's really
> > starting at 128MB), and any direct memory access from the
> card would
> > be offset by 128MB in the example...
> >
> > But if you have Xen-aware/Xen-compatible graphics driver,
> and you're
> > using Xen-linux rather than for example Windows or a
> unmodified Linux,
> > you should be able to give the graphics card PCI address to
> the guest
> > - I don't know the details of it, but I believe there's
> more than one
> > example of how to "hide" from Dom0 and "give" a device to DomU.
> >
> > Of course, this also assumes that your MB graphics and plug-in
> > graphics cards are actually able to work at the same time.
> I've seen
> > more than one design where essentially they are mutually
> exclusive due
> > to sharing the same point-to-point bus, and the one device is just
> > disabled when you use the other [usually a BIOS setting that says
> > whether you want built-in or plugged in graphics, and it's
> an EXCLUSE
> > OR of those choices.]
> >
> > --
> > Mats
> > >
> > >
> > > On Feb 24, 2006, at 4:46 AM, Petersson, Mats wrote:
> > >
> > >
> > >
> > > There's been more than one discussion thread on this
> > subject, and the
> > > summary answer is:
> > > - It's possible to do with a para-virtualized driver in
> the guest -
> > > that is, a driver that takes the calls for graphics commands and
> > > passes them to Dom0, where a "real" graphics driver executes the
> > > actual intention of the call.
> > >
> > > It is not trivial to write such a driver, but it's
> nowhere near as
> > > hard as it would be to try to get a very advanced native
> driver to
> > > work in a guest environment.
> > >
> > > Of course, if you have two different graphics cards in
> the machine,
> > > Dom0 can be given one card, and one of the guest domains
> > can be given
> > > the other card, thus you can use the native driver
> straight off (at
> > > least in fully virtualized mode).
> > >
> > > Can you do this one card? Just have dom0 not have a video
> > card, and
> > > pass the only video card to domU? That's how I run all
> my servers
> > > anyway, and it'd be awesome to use hardware acceleration on
> > a "desktop
> > > domU"...
> > >
> > > --
> > > Luke
> > > _______________________________________________
> > > Xen-users mailing list
> > > Xen-users@xxxxxxxxxxxxxxxxxxx
> > > http://lists.xensource.com/xen-users
> > >
> > >
> > > _______________________________________________
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> > > Xen-users@xxxxxxxxxxxxxxxxxxx
> > > http://lists.xensource.com/xen-users
> > >
> > >
> >
> >
> > _______________________________________________
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> > http://lists.xensource.com/xen-users
> >
> >
>
>
>
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