On 02/12/2015 01:08 PM, Joerg Roedel wrote:
On Thu, Feb 12, 2015 at 12:53:42PM -0500, Mark Hounschell wrote:
This happens immediately after unloading one of our out of kernel GPL drivers.
The driver has done NOTHING other than load at bootup. I'm running a 3.18.7
kernel (x86_64) on an AMD platform. I can't see anything obviously wrong in our
driver. It works fine when the iommu is disabled. This particular machine has 7
of
our cards in it. Four in one expansion rack and 3 in another. The 2 PCI
expansion
racks use pci-e interface cards installed in the MB.
Feb 12 10:47:15 harley kernel: AMD-Vi: Event logged [IO_PAGE_FAULT
device=0f:00.0 domain=0x0000 address=0x00000000000ae640 flags=0x0070]
Feb 12 10:47:15 harley kernel: AMD-Vi: Event logged [IO_PAGE_FAULT
device=0f:00.0 domain=0x0000 address=0x00000000000ae660 flags=0x0070]
Feb 12 10:47:15 harley kernel: AMD-Vi: Event logged [IO_PAGE_FAULT
device=0f:00.0 domain=0x0000 address=0x00000000000ae670 flags=0x0070]
Feb 12 10:47:27 harley kernel: ------------[ cut here ]------------
Feb 12 10:47:27 harley kernel: WARNING: CPU: 3 PID: 0 at
drivers/iommu/amd_iommu.c:2637 dma_ops_domain_unmap.part.13+0x65/0x70()
This warning indicates that some driver is unmapping a dma range that
was not mapped previously (meaning that a pte in the io-page-tables is
zeroed out).
The reason for this (and the IO_PAGE_FAULTs) you see are almost
certainly because some driver does not use the DMA-API correctly.
I wonder what driver that could be. It certainly isn't the one that I
just unloaded
as it for sure has not done anything dma realated. I'm pretty sure I
uninstalled all
our other drivers but will go back and verify.
Thanks
Mark
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