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

[Wei Wang <wei.wang2@xxxxxxx>]

On 09/06/2012 03:50 PM, Sander Eikelenboom wrote:
> 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.
Ah, I see. PV guest is quite different than hvm, it does use p2m tables 
as io page tables. So no-sharept option does not work in this case. PV 
guests always use separated io page tables. There might be some 
incorrect mappings on the page tables. I will check this on my side.
Thanks,
Wei

> 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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