[git pull] IOMMU Fixes for Linux v5.7-rc4

Joerg Roedel joro at 8bytes.org
Sun May 10 12:26:40 UTC 2020

Hi Linus,

The following changes since commit 0e698dfa282211e414076f9dc7e83c1c288314fd:

  Linux 5.7-rc4 (2020-05-03 14:56:04 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git tags/iommu-fixes-v5.7-rc4

for you to fetch changes up to fb3637a113349f53830f7d6ca45891b7192cd28f:

  iommu/virtio: Reverse arguments to list_add (2020-05-08 17:31:18 +0200)

IOMMU Fixes for Linux v5.7-rc4


	- The race condition fixes for the AMD IOMMU driver. This are 5
	  patches fixing two race conditions around
	  increase_address_space(). The first race condition was around
	  the non-atomic update of the domain page-table root pointer
	  and the variable containing the page-table depth (called
	  mode). This is fixed now be merging page-table root and mode
	  into one 64-bit field which is read/written atomically.

	  The second race condition was around updating the page-table
	  root pointer and making it public before the hardware caches
	  were flushed. This could cause addresses to be mapped and
	  returned to drivers which are not reachable by IOMMU hardware
	  yet, causing IO page-faults. This is fixed too by adding the
	  necessary flushes before a new page-table root is published.

	  Related to the race condition fixes these patches also add a
	  missing domain_flush_complete() barrier to update_domain() and
	  a fix to bail out of the loop which tries to increase the
	  address space when the call to increase_address_space() fails.

	  Qian was able to trigger the race conditions under high load
	  and memory pressure within a few days of testing. He confirmed
	  that he has seen no issues anymore with the fixes included

	- Fix for a list-handling bug in the VirtIO IOMMU driver.

Joerg Roedel (5):
      iommu/amd: Fix race in increase_address_space()/fetch_pte()
      iommu/amd: Do not loop forever when trying to increase address space
      iommu/amd: Call domain_flush_complete() in update_domain()
      iommu/amd: Update Device Table in increase_address_space()
      iommu/amd: Do not flush Device Table in iommu_map_page()

Julia Lawall (1):
      iommu/virtio: Reverse arguments to list_add

 drivers/iommu/amd_iommu.c       | 198 +++++++++++++++++++++++++++++++---------
 drivers/iommu/amd_iommu_types.h |   9 +-
 drivers/iommu/virtio-iommu.c    |   2 +-
 3 files changed, 162 insertions(+), 47 deletions(-)

Please pull.


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