Re: [Xen-devel] [PATCH] amd iommu: Dump flags of IO page faults

[Sander Eikelenboom <linux@xxxxxxxxxxxxxx>]

Thursday, September 6, 2012, 3:32:51 PM, you wrote:

> On 09/06/2012 12:59 AM, Sander Eikelenboom wrote:
>>
>> Wednesday, September 5, 2012, 4:42:42 PM, you wrote:
>>
>>> Hi Jan,
>>> Attached patch dumps io page fault flags. The flags show the reason of
>>> the fault and tell us if this is an unmapped interrupt fault or a DMA fault.
>>
>>> Thanks,
>>> Wei
>>
>>> signed-off-by: Wei Wang<wei.wang2@xxxxxxx>
>>
>>
>> I have applied the patch and the flags seem to differ between the faults:
>>
>> AMD-Vi: IO_PAGE_FAULT: domain = 0, device id = 0x0a06, fault address = 
>> 0xc2c2c2c0, flags = 0x000
>> (XEN) [2012-09-05 20:54:16] AMD-Vi: IO_PAGE_FAULT: domain = 0, device id = 
>> 0x0a06, fault address = 0xc2c2c2c0, flags = 0x000
>> (XEN) [2012-09-05 20:54:16] AMD-Vi: IO_PAGE_FAULT: domain = 14, device id = 
>> 0x0700, fault address = 0xa8d339e0, flags = 0x020
>> (XEN) [2012-09-05 20:54:16] AMD-Vi: IO_PAGE_FAULT: domain = 14, device id = 
>> 0x0700, fault address = 0xa8d33a40, flags = 0x020

> OK, so they are not interrupt requests. I guess further information from 
> your system would be helpful to debug this issue:
> 1) xl info
> 2) xl list
> 3) lscpi -vvv (NOTE: not in dom0 but in your guest)
> 4) cat /proc/iomem (in both dom0 and your hvm guest)

dom14 is not a HVM guest,it's a PV guest.

I will try to make a complete package, and try with one pv domain only where 
the devices are being passed through just to simplify the setup.


> * I would also like to know the symptoms of device 0x0700 when IO_PF 
> happened. Did it stop working?

Yes it stops working, the video capture just freezes, but the driver doesn't 
bail out.
For the USB controller (0x0a06) it starts to give errors for usbdev_open in the 
guest.

> (BTW: I copied a few options from your boot cmd line and it worked with 
> my RD890 system

> dom0_mem=1024M,max:1024M loglvl=all loglvl_guest=all console_timestamps 
> cpuidle cpufreq=xen noreboot debug lapic=debug apic_verbosity=debug 
> apic=debug iommu=on,verbose,debug,no-sharept

> * so, what OEM board you have?)

MSI 890FXA-GD70

> Also from your log, these lines looks very strange:

> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xd5, mfn=0xa4a11
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xd7, mfn=0xa4a0f
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xd9, mfn=0xa4a0d
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xdb, mfn=0xa4a0b
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xdd, mfn=0xa4a09
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xdf, mfn=0xa4a07
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xe1, mfn=0xa4a05
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xe3, mfn=0xa4a03
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xe5, mfn=0xa4a01
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xe7, mfn=0xa463f
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xe9, mfn=0xa463d
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xeb, mfn=0xa463b
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xed, mfn=0xa4639
> (XEN) [2012-09-04 15:54:35] hvm.c:2435:d15 guest attempted write to 
> read-only memory page. gfn=0xef, mfn=0xa4637
> (XEN) [2012-09-04 16:13:56] AMD-Vi: IO_PAGE_FAULT: domain = 0, device id 
> = 0x0a06, fault address = 0xc2c2c2c0
> (XEN) [2012-09-04 16:13:56] AMD-Vi: IO_PAGE_FAULT: domain = 14, device 
> id = 0x0700, fault address = 0xa90f8300
> (XEN) [2012-09-04 16:13:56] AMD-Vi: IO_PAGE_FAULT: domain = 14, device 
> id = 0x0700, fault address = 0xa90f8340
> (XEN) [2012-09-04 16:13:56] AMD-Vi: IO_PAGE_FAULT: domain = 14, device 
> id = 0x0700, fault address = 0xa90f8380
> (XEN) [2012-09-04 16:13:56] AMD-Vi: IO_PAGE_FAULT: domain = 14, device 
> id = 0x0700, fault address = 0xa90f83c0

> * they are just followed by the IO PAGE fault. Do you know where are 
> they from? Your video card driver maybe?

>From a HVM domain with a old (3.0.3) kernel, but the faults also occur without 
>this domain being started.


> Thanks,
> Wei


>> Complete xl dmesg and lspci -vvvknn attached.
>>
>> Thx
>>
>> --
>> Sander





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