Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
切换分支/标签
  1. 14 8月, 2015 3 次提交
  3. 31 7月, 2015 1 次提交
  5. 30 7月, 2015 5 次提交
  7. 23 7月, 2015 1 次提交
    • A
      iommu/vt-d: Fix VM domain ID leak · 46ebb7af
      由 Alex Williamson 提交于 
      This continues the attempt to fix commit fb170fb4 ("iommu/vt-d:
Introduce helper functions to make code symmetric for readability").
The previous attempt in commit 71684406 ("iommu/vt-d: Detach
domain *only* from attached iommus") overlooked the fact that
dmar_domain.iommu_bmp gets cleared for VM domains when devices are
detached:

intel_iommu_detach_device
  domain_remove_one_dev_info
    domain_detach_iommu

The domain is detached from the iommu, but the iommu is still attached
to the domain, for whatever reason.  Thus when we get to domain_exit(),
we can't rely on iommu_bmp for VM domains to find the active iommus,
we must check them all.  Without that, the corresponding bit in
intel_iommu.domain_ids doesn't get cleared and repeated VM domain
creation and destruction will run out of domain IDs.  Meanwhile we
still can't call iommu_detach_domain() on arbitrary non-VM domains or
we risk clearing in-use domain IDs, as 71684406 attempted to
address.

It's tempting to modify iommu_detach_domain() to test the domain
iommu_bmp, but the call ordering from domain_remove_one_dev_info()
prevents it being able to work as fb170fb4 seems to have intended.
Caching of unused VM domains on the iommu object seems to be the root
of the problem, but this code is far too fragile for that kind of
rework to be proposed for stable, so we simply revert this chunk to
its state prior to fb170fb4.

Fixes: fb170fb4 ("iommu/vt-d: Introduce helper functions to make
                      code symmetric for readability")
Fixes: 71684406 ("iommu/vt-d: Detach domain *only* from attached
                      iommus")
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: stable@vger.kernel.org # v3.17+
Signed-off-by: NJoerg Roedel <jroedel@suse.de>
      46ebb7af
  9. 09 7月, 2015 5 次提交
  11. 01 7月, 2015 1 次提交
  13. 30 6月, 2015 3 次提交
  15. 19 6月, 2015 1 次提交
  17. 16 6月, 2015 19 次提交
  19. 12 6月, 2015 1 次提交
    • D
      iommu/vt-d: Only enable extended context tables if PASID is supported · c83b2f20
      由 David Woodhouse 提交于 
      Although the extended tables are theoretically a completely orthogonal
feature to PASID and anything else that *uses* the newly-available bits,
some of the early hardware has problems even when all we do is enable
them and use only the same bits that were in the old context tables.

For now, there's no motivation to support extended tables unless we're
going to use PASID support to do SVM. So just don't use them unless
PASID support is advertised too. Also add a command-line bailout just in
case later chips also have issues.

The equivalent problem for PASID support has already been fixed with the
upcoming VT-d spec update and commit bd00c606 ("iommu/vt-d: Change
PASID support to bit 40 of Extended Capability Register"), because the
problematic platforms use the old definition of the PASID-capable bit,
which is now marked as reserved and meaningless.

So with this change, we'll magically start using ECS again only when we
see the new hardware advertising "hey, we have PASID support and we
actually tested it this time" on bit 40.

The VT-d hardware architect has promised that we are not going to have
any reason to support ECS *without* PASID any time soon, and he'll make
sure he checks with us before changing that.

In the future, if hypothetical new features also use new bits in the
context tables and can be seen on implementations *without* PASID support,
we might need to add their feature bits to the ecs_enabled() macro.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      c83b2f20