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

[Wei Wang <wei.wang2@amd.com>]

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@amd.com>
>
>
> 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)

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

(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?)

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?

Thanks,
Wei


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