Hi,

Qian reported more race conditions around the dma-mapping
code path in the AMD IOMMU driver. The race condtions are
between increas_address_space() and fetch_pte(), there were
two of them:

        1) the 'pt_root' and 'mode' fields of 'struct
           protection_domain' relate to each other so that
           they must be updated together atomically.

        2) The increase_address_space() function publishes
           the updated page-table before it has been written
           to the DTE. This might cause PTEs to be mapped
           and addresses handed to the device which are not
           yet reachable through the DTE entry, causing IO
           page-faults.

This patch-set fixes these issues, as tested by Qian Cai.

Thanks a lot again for reporting these issued and testing
the fixes!

Regards,

        Joerg


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()

 drivers/iommu/amd_iommu.c       | 198 +++++++++++++++++++++++++-------
 drivers/iommu/amd_iommu_types.h |   9 +-
 2 files changed, 161 insertions(+), 46 deletions(-)

-- 
2.17.1

Reply via email to