Re: Re: [Patch RFC] ttm: nouveau accelerated on Xen pv-ops kernel

[Arvind R <arvino55@gmail.com>]

On Tue, Mar 23, 2010 at 6:57 PM, Michael D Labriola <mlabriol@gdeb.com> wrote:
> xen-devel-bounces@lists.xensource.com wrote on 03/23/2010 02:21:31 AM:
>
> *snip*
>> > with "NOUVEAU(0): Opened GPU channel 1".
>> This is strange - channel 1 is the console channel. This appears in
> dmesg on
>> nouveaufb initialisation before EDID probe to find connected outputs.
>> Start X manually to avoid confusion of logs.
>>
>> Have attached ttm_xen.patch which updates vm_page_prot after changing
> flags.
>> This is not done in the mainline drm-tree. But in the xen (old)
>> drm-tree this is done in
>> BOTH ttm_bo_mmap AND ttm_fbdev_mmap - and the attached patch does both,
>> along with the conditional VM_IO in bo_mmap. And the second vm_page_prot
>> update is for fbdev_mmap which corresponds to channel 1. Cross
>> fingers and try!
>
> Actually, both hunks of that patch are already applied in my tree.  The
> git tree from git://anongit.freedesktop.org/nouveau/linux-2.6 appears to
> already be doing the vm_page_prot update in both places.  Maybe the
> official nouveau dev tree is hosed?  Odd that it would work fine
> bare-metal...

It always did work on bare-metal and on Xen without acceleration.
The patch just enables acceleration on Xen - it seems only on PCI/E cards.

> *snip*
>> >> Xorg used to hang saying 'Opened Channel 2' and not 1.
>> >
>> > Now that's strange.  Every single one of my boxes says Opened Channel
> 1,
>> > with now reference to channel 2 at all.
>> Try with
>> Option "ShadowFB"  "true"
>> in Device section of xorg.conf (turns off acceleration) to check. The
> option
>> also sets NoAccel on and X should use the FB device
>
> Tried this.  GDM starts fine in Xen and I can log in, but wow slow.  Now
> there's no reference to any GPU channel being opened in my X log.
>
The problem may be due to the initial AGP-memory allocation setting
up the wrong flags. And the older AGP cards seem to work differently
from the newer PCI/E ones.

Until someone resolves the agp issue, I guess your best choice
is to remove the ShadowFB option in the conf file and not install the dri
package (nouveau_dri.so and swrast_dri.so) in the AGP systems. That
means you will have 2D-accel but no glx (3D-accel).