Re: [dm-devel] AMD-Vi IO_PAGE_FAULTs and ata3.00: failed command: READ FPDMA QUEUED errors since Linux 4.0

[Joerg Roedel <joro@8bytes.org>]

On Wed, Oct 07, 2015 at 07:02:32PM +0200, Andreas Hartmann wrote:
> Binding the device to vfio isn't a problem (it's done before the vm is
> started). The problem occurs during start of qemu-system-x86_64 (2.3.0).
> 
> The attached dmesg.out doesn't show the trace, but the desired iommu dump.
> 
> > Also, which device are you trying to attach to the guest (pci
> > bus/device/function)?
> 
> See attached ath9k.device.

Hmm, can you also test this again with the v4.3-rc4 please? The device
you are attaching has its own group and no aliases, so I really can't
see how the trace could happen, and I can't reproduce it here either.

So I just want to make sure it is not a follow-on bug from the previous
problem.


Thanks,

	Joerg

P.S.: When you build the kernel with debug symbols and the problem
      occurs again, you can find out the source file and line where the
      bug happened with

      	$ objdump -Dlz --start-address=<rip> vmlinux | head

      Replace <rip> with the RIP from the kernel oops and the output
      should show you where in the source the bug comes from. The
      vmlinux file is in the kernels build directory.