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

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 03/15/2010 07:44 AM, Michael D Labriola wrote:
> xen-devel-bounces@lists.xensource.com wrote on 03/13/2010 05:03:22 PM:
>
>    
>> On 03/12/2010 01:45 PM, Arvind R wrote:
>>      
>>> On Thu, Mar 11, 2010 at 4:32 PM, Pekka Paalanen<pq@iki.fi>  wrote:
>>>        
>>>> I'm adding dri-devel@ to CC, since this suggested patch touches
>>>> TTM code, and none of the Nouveau code. TTM patches go via
>>>> dri-devel@.
>>>>
>>>> Thanks.
>>>>
>>>>
>>>> On Wed, 10 Mar 2010 18:51:21 +0530
>>>> Arvind R<arvino55@gmail.com>  wrote:
>>>>
>>>>          
>>>>> Hi,
>>>>> Following is a simple patch that is needed in nouveau to get
>>>>> accelerated X on a Xen dom0 pv_ops kernel. The kernel is jeremy's
>>>>> 2.6.31.6 as of 20100222. The whole gpu tree of nouveau (which is
>>>>> almost the mainline merge), was substituted into the kernel-tree.
>>>>> All components of X (mesa, Xorg-server-7.5, xf86-nouveau, libdrm)
>>>>> used of the same day.
>>>>>
>>>>> Patch:
>>>>> diff -Naur nouveau-kernel.orig/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>>>> nouveau-kernel.new/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>>>> --- nouveau-kernel.orig/drivers/gpu/drm/ttm/ttm_bo_vm.c 2010-01-27
>>>>> 10:19:28.000000000 +0530
>>>>> +++ nouveau-kernel.new/drivers/gpu/drm/ttm/ttm_bo_vm.c  2010-03-10
>>>>> 17:28:59.000000000 +0530
>>>>> @@ -271,7 +271,10 @@
>>>>>           */
>>>>>
>>>>>          vma->vm_private_data = bo;
>>>>> -       vma->vm_flags |= VM_RESERVED | VM_IO | VM_MIXEDMAP |
>>>>> VM_DONTEXPAND;
>>>>> +       vma->vm_flags |= VM_RESERVED | VM_MIXEDMAP |
>>>>> VM_DONTEXPAND;
>>>>> +       if (!((bo->mem.placement&  TTM_PL_MASK_MEM)&
>>>>> TTM_PL_FLAG_TT))
>>>>> +               vma->vm_flags |= VM_IO;
>>>>> +       vma->vm_page_prot = vma_get_vm_prot(vma->vm_flags);
>>>>>          return 0;
>>>>>   out_unref:
>>>>>          ttm_bo_unref(&bo);
>>>>>
>>>>>            
>>> sorry for the typo and other procedural errors.
>>> the last added line should be
>>> +    vma->vm_page_prot = vm_get_page_prot(vma->vm_flags)
>>>
>>>        
>>>>> This patch is necessary because, in Xen, PFN of a page is
>>>>> virtualised. So physical addresses
>>>>> for DMA programming needs to use the MFN. Xen transparently does
>>>>> the correct translation
>>>>> using the _PAGE_IOMEM prot-bit in the PTE. If the bit is set,
>>>>> then Xen assumes that the backing
>>>>> memory is in the IOMEM space, and PFN equals MFN. If not set,
>>>>> page_to_pfn() returns MFN.
>>>>>
>>>>> The patch enables the ttm_bo_vm_fault() handler to behave
>>>>> correctly under Xen, and has no
>>>>> side-effects on normal (not under Xen) operations. The use of
>>>>> TTM_PL_FLAG_TT in the
>>>>> check assumes that all other placements are backed by device
>>>>> memory or IO. If there are
>>>>> any other placements that use system memory, that flag has to be
>>>>> OR'ed into the check.
>>>>>
>>>>> The above patch has no implications on a normal kernel or a Xen
>>>>> pv_ops kernel booted without
>>>>> the Xen hypervisor. My testing is on a debian-lenny environment
>>>>> on a Core2 processor with
>>>>> nVidia GeForce 9400 GT.
>>>>>            
>>>>          
>>> Efficacy of patch:
>>> successful flightgear run on dom0 AND bareboot!
>>>
>>>        
>> Jeremy, will you be merging this patch into any of the xen/stable-*
>> branches any time soon?
>>
>> Thanks,
>> joanna.
>>      
> Hmm... I just verified that this patch fixes KMS/Nouveau issues in Xen on
> my two primary test boxes (GeForce 6200, GeForce 7300).  However, on my
> really old machines (AGP GeForce2 MX200), this causes a new crash.  These
> old boxes were actually working fine in Xen prior to this patch, just
> w/out 3d acceleration.  Now I get the following messages in dmesg:
>
> [  129.637319] [drm] nouveau 0000:01:00.0: Allocating FIFO number 1
> [  129.638853] [drm] nouveau 0000:01:00.0: nouveau_channel_alloc:
> initialised FIFO 1
> [  129.643791] X: Corrupted page table at address 40412000
> [  129.643815] *pdpt = 0000000015216001 *pde = 0000000000000000
> [  129.643856] Bad pagetable: 000f [#1] SMP
> [  129.643897] last sysfs file:
> /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/boot_vga
> [  129.643916] Modules linked in: bridge stp ipv6 autofs4 sunrpc raid1
> video output sbs sbshc pci_slot lp sg nouveau snd_intel8x0 snd_ac97_codec
> ac97_bus snd_seq_dummy he atm ttm drm_kms_helper snd_seq_oss
> snd_seq_midi_event sr_mod snd_seq cdrom drm serio_raw snd_seq_device
> snd_pcm_oss snd_mixer_oss snd_pcm e100 mii i2c_algo_bit snd_timer
> ata_generic snd pcspkr i2c_i801 i2c_core intel_rng soundcore i82860_edac
> snd_page_alloc pata_acpi edac_core parport_pc floppy parport dm_snapshot
> dm_zero dm_mirror dm_region_hash dm_log dm_mod raid0 ext3 mbcache jbd
> aic7xxx scsi_transport_spi ata_piix libata sd_mod scsi_mod
> [  129.644024]
> [  129.644024] Pid: 3690, comm: X Not tainted (2.6.31.6-mdl5 #1) P4DC6
> [  129.644024] EIP: 0073:[<40394596>] EFLAGS: 00210206 CPU: 0
> [  129.644024] EIP is at 0x40394596
> [  129.644024] EAX: 40412000 EBX: 40396cd8 ECX: 0909ee98 EDX: 00044000
> [  129.644024] ESI: 00000034 EDI: 0909edd8 EBP: bfe7f798 ESP: bfe7f780
> [  129.644024]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
> [  129.644024] Process X (pid: 3690, ti=ea1ce000 task=ea77f110
> task.ti=ea1ce000)
> [  129.644024]
> [  129.644024] EIP: [<40394596>] 0x40394596 SS:ESP 007b:bfe7f780
> [  129.644024] ---[ end trace 569eb18d737a8611 ]---
> [  129.652216] [drm] nouveau 0000:01:00.0: nouveau_channel_free: freeing
> fifo 1
>
>
> And my X log ends abruptly after this line:
> (II) NOUVEAU(0): Opened GPU Channel 1
>
> Any ideas?
>    

BTW, what chipset does this machine have?  Is it Intel?  AMD?  Other?

     J