Xen users - Aug 2007 - Advice on PCIe graphics card for Xen+X86_64 for X

Hello,

I used a ScienticLinux 5.0 distro (mimics RedHat 5.0 but merged the 
Server and Enterprise versions) in a x86_64 arch. I ran into a problem, 
because while I can have X in the normal kernel, the Xen kernel, when I 
boot in dom0 is in text mode and can''t load the Nvidia module. This is 
because Nvidia does not support Xen. There seems to be some patches for 
other distros (Suse, freeBSD) but I am afraid those might not work here 
... anyway I want to avoid this.

Also I was forced to install the OS in text mode, because the graphics 
card did not work out of the box with the distro. For what I want to do 
now, it is not essential to have a 3D graphics card. I want to have a 
dom0 for administration and to launch Linux as guests to create a 
virtual cluster (but where X should perform well in the guests).

The machine''s Motherboard is Intel S5000XVNSATA and I have  PCIe slots 
available. The question are:
1) Could someone please provide details about currently available 
graphic cards (PCIe) that work under Xen, kernel 2.1.18 (SL, RedHat) and 
x86_64 out of the box, so I could use X in both dom0 and domUs?

2) Is there a way that I could have both graphic cards installed so I 
could use the more powerful one when I boot with the normal kernel and 
the new one for Xen+X, when booting under the Xen kernel?

Regarding question 2), note that what I want to do is slightly different 
from what was discussed in the forum earlier. That is  only 1 card would 
be used for each booting configuration (but both would be physically in 
the system)

Thank you.

Regards,
Luis


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

On Mon, Aug 13, 2007 at 12:33:55PM +0100, Luis Torres
wrote:
> 
> I used a ScienticLinux 5.0 distro (mimics RedHat 5.0 but merged the 
> Server and Enterprise versions) in a x86_64 arch. I ran into a problem, 
> because while I can have X in the normal kernel, the Xen kernel, when I 
> boot in dom0 is in text mode and can''t load the Nvidia module.
This is
> because Nvidia does not support Xen. There seems to be some patches for 
> other distros (Suse, freeBSD) but I am afraid those might not work here 
> ... anyway I want to avoid this.
Havent tried with x86_64 but for i386 the patch at
http://fluxcoil.net/files/NVIDIA-Linux-x86-1.0-9746-pkg1_xendom0.patch
should do for any distro, kernel 2.6.18 running here.

> 2) Is there a way that I could have both graphic cards installed so I 
> could use the more powerful one when I boot with the normal kernel and 
> the new one for Xen+X, when booting under the Xen kernel?
Guess the intel-chipsets with 3d-functions should work best under xen,
i am not aware of external (not included into motherboard chipset) graphic
cards with intel-chips thou. And they are a bit slower than decent nvidia
and ati-chips, but its enough for compbiz and some games.

> Regarding question 2), note that what I want to do is slightly different 
> from what was discussed in the forum earlier. That is  only 1 card would 
> be used for each booting configuration (but both would be physically in 
> the system)
Read on people trying to dedicate pci-cards to domUs, but havent really
heard success-stories yet.


Christian

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Christian Horn wrote:
> On Mon, Aug 13, 2007 at 12:33:55PM +0100, Luis Torres wrote:
>   
>> I used a ScienticLinux 5.0 distro (mimics RedHat 5.0 but merged the 
>> Server and Enterprise versions) in a x86_64 arch. I ran into a problem,
>> because while I can have X in the normal kernel, the Xen kernel, when I
>> boot in dom0 is in text mode and can''t load the Nvidia module.
This is
>> because Nvidia does not support Xen. There seems to be some patches for
>> other distros (Suse, freeBSD) but I am afraid those might not work here
>> ... anyway I want to avoid this.
>>     
> Havent tried with x86_64 but for i386 the patch at
> http://fluxcoil.net/files/NVIDIA-Linux-x86-1.0-9746-pkg1_xendom0.patch
> should do for any distro, kernel 2.6.18 running here.
>
>
>   
I am not so sure. In the Suse mailing list someone reported compile 
errors in RedHat. Also even if it compiles  I am afraid side effects 
might result later. Otherwise Nvidia would simply make an official patch 
available. I want to do some work not games, so I am concerned. Thanks 
anyway.
>> 2) Is there a way that I could have both graphic cards installed so I 
>> could use the more powerful one when I boot with the normal kernel and 
>> the new one for Xen+X, when booting under the Xen kernel?
>>     
> Guess the intel-chipsets with 3d-functions should work best under xen,
> i am not aware of external (not included into motherboard chipset) graphic
> cards with intel-chips thou. And they are a bit slower than decent nvidia
> and ati-chips, but its enough for compbiz and some games.
>
>
>   
Well I agree. I also looked for intel-chipsets for PCIe and couldn''t 
find (only embedded in MB).
But for now I would be happy with a simple PCI Express x16 graphics card 
(not accelerated) which works well under Xen and the x86_64 
architecture, suitable for kernel 2.1.18. using drivers that come w/ the 
distro.
Likely there is people in the list using Xen+X86_64, with a PCIe 
graphics card and successfully using X.
I would appreciate if they say which card they use. Thanks.

Luis
>> Regarding question 2), note that what I want to do is slightly
different
>> from what was discussed in the forum earlier. That is  only 1 card
would
>> be used for each booting configuration (but both would be physically in
>> the system)
>>     
> Read on people trying to dedicate pci-cards to domUs, but havent really
> heard success-stories yet.
>
>
> Christian
>   


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

> I used a ScienticLinux 5.0 distro (mimics RedHat 5.0 but merged the
> Server and Enterprise versions) in a x86_64 arch. I ran into a problem,
> because while I can have X in the normal kernel, the Xen kernel, when I
> boot in dom0 is in text mode and can''t load the Nvidia module.
This is
> because Nvidia does not support Xen. There seems to be some patches for
> other distros (Suse, freeBSD) but I am afraid those might not work here
> ... anyway I want to avoid this.
>
> Also I was forced to install the OS in text mode, because the graphics
> card did not work out of the box with the distro. For what I want to do
> now, it is not essential to have a 3D graphics card. I want to have a
> dom0 for administration and to launch Linux as guests to create a
> virtual cluster (but where X should perform well in the guests).
>
> The machine''s Motherboard is Intel S5000XVNSATA and I have  PCIe
slots
> available. The question are:
> 1) Could someone please provide details about currently available
> graphic cards (PCIe) that work under Xen, kernel 2.1.18 (SL, RedHat) and
> x86_64 out of the box, so I could use X in both dom0 and domUs?
I''d have thought you could get your existing Nvidia card to work by
using the
open source "nv" driver that''s included with Xorg.  It
doesn''t support the
advanced features of the Nvidia cards, but it''ll do 2D for you.  Maybe
this
is enough?  I used nv for a long time on various machines a few years ago and 
found it worked just fine for me (I wasn''t using Xen on those machines
at the
time, though).

Regarding getting good X performance out of the guests themselves...  various 
people have played with passing through graphics devices directly to the 
guests so that they can have optimal graphics performance, but I don''t
know
how much success has been had there.

Using the standard virtual framebuffers / VNC that Xen supports, don''t
expect
to have brilliant guest graphics performance!  It''s server-oriented, so
the
graphical interface will work OK for administration and for office-type 
tasks, but don''t expect fast moving graphics / video to necessarily
work
well.

You could check out VMGL if you ever want to pass 3D operations from a guest 
to another VM / physical machine with decent performance though: 
http://www.cs.toronto.edu/~andreslc/xen-gl/
> 2) Is there a way that I could have both graphic cards installed so I
> could use the more powerful one when I boot with the normal kernel and
> the new one for Xen+X, when booting under the Xen kernel?
Well, I guess you probably could.  Easiest would be to hack your init scripts 
around a bit so that the X server got started with a different xorg.conf 
depending on what kernel you were booted into.

Actually, though, if you were going to do that you might as well just keep the 
Nvidia card there and hack your init scripts so that the xorg.conf either 
uses the binary "nvidia" driver or the open source "nv"
driver.

Cheers,
Mark

-- 
Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users