On 02/12/2015 02:37 PM, Mark Hounschell wrote:
On 02/12/2015 01:25 PM, Mark Hounschell wrote:
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.
I've cleaned the machine of all our drivers and also the nvidia driver.
If the problem is as you say, it is an in-kernel driver. I've attached a
dmesg taken after it started. I used the dgap driver from the staging
directory to unload and trigger this as I have one. That driver does NO
dma. I know because I'm one of the maintainers and have done lots of
work on it.
There was a dmesg attached to my previous email BTW
Mark
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