1. 15 11月, 2011 1 次提交
    • A
      iommu: Add iommu_device_group callback and iommu_group sysfs entry · 1460432c
      Alex Williamson 提交于
      An IOMMU group is a set of devices for which the IOMMU cannot
      distinguish transactions.  For PCI devices, a group often occurs
      when a PCI bridge is involved.  Transactions from any device
      behind the bridge appear to be sourced from the bridge itself.
      We leave it to the IOMMU driver to define the grouping restraints
      for their platform.
      
      Using this new interface, the group for a device can be retrieved
      using the iommu_device_group() callback.  Users will compare the
      value returned against the value returned for other devices to
      determine whether they are part of the same group.  Devices with
      no group are not translated by the IOMMU.  There should be no
      expectations about the group numbers as they may be arbitrarily
      assigned by the IOMMU driver and may not be persistent across boots.
      
      We also provide a sysfs interface to the group numbers here so
      that userspace can understand IOMMU dependencies between devices
      for managing safe, userspace drivers.
      
      [Some code changes by Joerg Roedel <joerg.roedel@amd.com>]
      Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
      Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
      1460432c
  2. 08 11月, 2011 28 次提交
  3. 07 11月, 2011 11 次提交