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  1. 18 8月, 2021 2 次提交
  3. 26 7月, 2021 3 次提交
  5. 16 4月, 2021 2 次提交
  7. 07 4月, 2021 17 次提交
  9. 02 2月, 2021 1 次提交
  11. 28 1月, 2021 1 次提交
    • L
      iommu: use the __iommu_attach_device() directly for deferred attach · 3ab65729
      由 Lianbo Jiang 提交于 
      Currently, because domain attach allows to be deferred from iommu
driver to device driver, and when iommu initializes, the devices
on the bus will be scanned and the default groups will be allocated.

Due to the above changes, some devices could be added to the same
group as below:

[    3.859417] pci 0000:01:00.0: Adding to iommu group 16
[    3.864572] pci 0000:01:00.1: Adding to iommu group 16
[    3.869738] pci 0000:02:00.0: Adding to iommu group 17
[    3.874892] pci 0000:02:00.1: Adding to iommu group 17

But when attaching these devices, it doesn't allow that a group has
more than one device, otherwise it will return an error. This conflicts
with the deferred attaching. Unfortunately, it has two devices in the
same group for my side, for example:

[    9.627014] iommu_group_device_count(): device name[0]:0000:01:00.0
[    9.633545] iommu_group_device_count(): device name[1]:0000:01:00.1
...
[   10.255609] iommu_group_device_count(): device name[0]:0000:02:00.0
[   10.262144] iommu_group_device_count(): device name[1]:0000:02:00.1

Finally, which caused the failure of tg3 driver when tg3 driver calls
the dma_alloc_coherent() to allocate coherent memory in the tg3_test_dma().

[    9.660310] tg3 0000:01:00.0: DMA engine test failed, aborting
[    9.754085] tg3: probe of 0000:01:00.0 failed with error -12
[    9.997512] tg3 0000:01:00.1: DMA engine test failed, aborting
[   10.043053] tg3: probe of 0000:01:00.1 failed with error -12
[   10.288905] tg3 0000:02:00.0: DMA engine test failed, aborting
[   10.334070] tg3: probe of 0000:02:00.0 failed with error -12
[   10.578303] tg3 0000:02:00.1: DMA engine test failed, aborting
[   10.622629] tg3: probe of 0000:02:00.1 failed with error -12

In addition, the similar situations also occur in other drivers such
as the bnxt_en driver. That can be reproduced easily in kdump kernel
when SME is active.

Let's move the handling currently in iommu_dma_deferred_attach() into
the iommu core code so that it can call the __iommu_attach_device()
directly instead of the iommu_attach_device(). The external interface
iommu_attach_device() is not suitable for handling this situation.
Signed-off-by: NLianbo Jiang <lijiang@redhat.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210126115337.20068-3-lijiang@redhat.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>
      3ab65729
  13. 27 1月, 2021 4 次提交
  15. 25 11月, 2020 2 次提交
  17. 01 10月, 2020 2 次提交
  19. 18 9月, 2020 1 次提交
  21. 04 9月, 2020 1 次提交
  23. 09 7月, 2020 1 次提交
  25. 30 6月, 2020 1 次提交
  27. 29 5月, 2020 1 次提交
    • J
      iommu: Remove iommu_sva_ops::mm_exit() · edcc40d2
      由 Jean-Philippe Brucker 提交于 
      After binding a device to an mm, device drivers currently need to
register a mm_exit handler. This function is called when the mm exits,
to gracefully stop DMA targeting the address space and flush page faults
to the IOMMU.

This is deemed too complex for the MMU release() notifier, which may be
triggered by any mmput() invocation, from about 120 callsites [1]. The
upcoming SVA module has an example of such complexity: the I/O Page
Fault handler would need to call mmput_async() instead of mmput() after
handling an IOPF, to avoid triggering the release() notifier which would
in turn drain the IOPF queue and lock up.

Another concern is the DMA stop function taking too long, up to several
minutes [2]. For some mmput() callers this may disturb other users. For
example, if the OOM killer picks the mm bound to a device as the victim
and that mm's memory is locked, if the release() takes too long, it
might choose additional innocent victims to kill.

To simplify the MMU release notifier, don't forward the notification to
device drivers. Since they don't stop DMA on mm exit anymore, the PASID
lifetime is extended:

(1) The device driver calls bind(). A PASID is allocated.

  Here any DMA fault is handled by mm, and on error we don't print
  anything to dmesg. Userspace can easily trigger errors by issuing DMA
  on unmapped buffers.

(2) exit_mmap(), for example the process took a SIGKILL. This step
    doesn't happen during normal operations. Remove the pgd from the
    PASID table, since the page tables are about to be freed. Invalidate
    the IOTLBs.

  Here the device may still perform DMA on the address space. Incoming
  transactions are aborted but faults aren't printed out. ATS
  Translation Requests return Successful Translation Completions with
  R=W=0. PRI Page Requests return with Invalid Request.

(3) The device driver stops DMA, possibly following release of a fd, and
    calls unbind(). PASID table is cleared, IOTLB invalidated if
    necessary. The page fault queues are drained, and the PASID is
    freed.

  If DMA for that PASID is still running here, something went seriously
  wrong and errors should be reported.

For now remove iommu_sva_ops entirely. We might need to re-introduce
them at some point, for example to notify device drivers of unhandled
IOPF.

[1] https://lore.kernel.org/linux-iommu/20200306174239.GM31668@ziepe.ca/
[2] https://lore.kernel.org/linux-iommu/4d68da96-0ad5-b412-5987-2f7a6aa796c3@amd.com/Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: NLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200423125329.782066-3-jean-philippe@linaro.orgSigned-off-by: NJoerg Roedel <jroedel@suse.de>
      edcc40d2
  29. 15 5月, 2020 1 次提交