Hi all, I''ve got a couple of questions regarding the current status of nvidia with Xen, since it is well known that nvidia doesn''t work as smooth at the moment with Xen (comparing to ati). My current goal is to use one nvidia gtx460 card and the onboard intel hd4000 on dom0, and then do passthrough for another nvidia gtx460 to a Windows domU. I know there are patches from Jean David Techer for Xen and nvidia vga passthrough. Are those patches and steps (such as dumping the VGA rom) needed if I only want to use the nvidia card on Dom0? I also understood that new(er) versions the proprietary nvidia drivers does not officially support non-quadro cards with Xen on both dom0 and domU. Are there any workaround for that? Thanks! Regards, Howell.
On Jan 12, 2013, at 11:17 PM, Howell Tam <pigeon@pigeond.net> wrote:> > > Hi all, > > > I''ve got a couple of questions regarding the current > status of nvidia with Xen, since it is well known that nvidia > doesn''t work as smooth at the moment with Xen (comparing to ati). > > > My current goal is to use one nvidia gtx460 card and the > onboard intel hd4000 on dom0, and then do passthrough for > another nvidia gtx460 to a Windows domU. > > > I know there are patches from Jean David Techer for Xen and > nvidia vga passthrough. Are those patches and steps (such as dumping the > VGA rom) needed if I only want to use the nvidia card on Dom0? > > > I also understood that new(er) versions the proprietary nvidia > drivers does not officially support non-quadro cards with Xen on > both dom0 and domU. Are there any workaround for that? > > > Thanks! > > > Regards, > Howell. > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xen.org > http://lists.xen.org/xen-usersHello Howell, Your GTX card will/should behave as if it were installed on any normal Linux system when used in your Dom0. No patches or special work is required to make hardware behave normally in Dom0 as a general rule... As far as I can recall, anyway :P The case where those patches comes into play is when using VGA Passthrough; this is a type of passthrough that goes above and beyond traditional PCI Passthrough. You use IOMMU/VT-d to expose the video card to your DomU, and in addition, the VGA BIOS of that card is also loaded into the HVM BIOS''s memory to allow the card to be controlled by the DomU at boot time. Simple PCI Passthrough of the device will give you the same, but only after you''ve loaded a driver in the VM to control the card, which is good enough for most purposes. It''s not necessary to use VGA Passthrough for most cases, and though it''s extremely cool, results are a little iffy from what I''ve seen recently. Basically, if anyone has reported any type of success with your card, I''d wager you''re good to go :) Cheers, Andrew Bobulsky
Hi Andrew,> Your GTX card will/should behave as if it were installed on any normal > Linux system when used in your Dom0. No patches or special work is > required to make hardware behave normally in Dom0 as a general rule... > As far as I can recall, anyway :PThanks for your reply. Weirdest thing then. I''ve been trying the latest Xen from hg, with kernel 3.2.36, nvidia driver 310.19. As soon as I start X, the Xorg process is stuck at 100% cpu, and nothing on the screen of course. This is Dom0, I haven''t even setup any DomU yet. Any ideas? Thanks again. Regards, Howell.
On 01/13/2013 04:48 PM, Howell Tam wrote:> > Hi Andrew, > >> Your GTX card will/should behave as if it were installed on any normal >> Linux system when used in your Dom0. No patches or special work is >> required to make hardware behave normally in Dom0 as a general rule... >> As far as I can recall, anyway :P > > Thanks for your reply. > > Weirdest thing then. I''ve been trying the latest Xen from hg, > with kernel 3.2.36, nvidia driver 310.19. As soon as I start X, the > Xorg process is stuck at 100% cpu, and nothing on the screen of course. > > This is Dom0, I haven''t even setup any DomU yet. > > Any ideas? > > Thanks again. > > Regards, > Howell. > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xen.org > http://lists.xen.org/xen-users >Try adding nopat as a cmdline argument to your dom0 kernel. here''s my grub entries as an example. kernel /xen-4.1.4.gz dom0_mem=2048M dom0_max_vcpus=2 dom0_vcpus_pin module /lfskernel-3.7.1 ro root=/dev/md0 nopat Regards. Steve.
Hi,> Try adding nopat as a cmdline argument to your dom0 kernel. > > here''s my grub entries as an example. > > kernel /xen-4.1.4.gz dom0_mem=2048M dom0_max_vcpus=2 dom0_vcpus_pin > module /lfskernel-3.7.1 ro root=/dev/md0 nopatThanks. I ended up going back to trying Xen 4.2 and I can get the nvidia drivers to work in Dom0, even without nopat, but with very bad 3d performance. And sometimes it still get the Xorg 100% cpu problem, and I can see the nvidia driver printing out a few Xid messages. After a bit of research i realized i''m hitting the PAT problem, which has been mentioned for quite a while. This affects all display cards, not just nvidia it seems. From what i understand now, PAT has been disabled now in the kernel by Konrad: http://lists.xen.org/archives/html/xen-devel/2012-02/msg01634.html which he had an attempt to fix the underlying problem: https://lkml.org/lkml/2012/2/10/228 Looking at the latest stable 3.7.2 kernel, PAT is still disabled in xen. Does anyone know the status of this? (Should I ask on xen-devel or Konrad?) And while I''m at this, what about the MTRR support in Xen? Thanks. Regards, Howell.