[PATCH v4 0/4] iommu/vt-d: Force snooping improvement

Lu Baolu
2022-05-08T12:38:38Z

Hi folks,

Previously, the IOMMU capability of enforcing cache coherency was queried
through iommu_capable(IOMMU_CAP_CACHE_COHERENCY). This is a global
capability, hence the IOMMU driver reports support for this capability
only when all IOMMUs in the system has this support.

Commit 6043257b1de06 ("iommu: Introduce the domain op
enforce_cache_coherency()") converts this into a per-domain test-and-set
option, and the previous iommu_capable(IOMMU_CAP_CACHE_COHERENCY) is
deprecated.

This is a follow-up series which improves the Intel IOMMU driver to
support the per-domain scheme better.

Best regards,
baolu

Change log:
v4:
- Flush caches after changing PGSNP bit in the right way.

v3:
- https://lore.kernel.org/linux-iommu/20220506052727.1689687-1-baolu.lu@linux.intel.com/
- Hold the device_domain_lock when check and set force snooping.
- Refind the commit messages.

v2:
- https://lore.kernel.org/linux-iommu/20220505010710.1477739-1-baolu.lu@linux.intel.com/
- Check whether force_snooping has already been set in
intel_iommu_enforce_cache_coherency().
- Set PGSNP pasid bit field during domain attaching if forcing_snooping
is set.
- Remove redundant list_empty() checks.
- Add dmar_domain->set_pte_snp and set it if force snooping is enforced
on a domain with 2nd-level translation.

v1:
- https://lore.kernel.org/linux-iommu/20220501112434.874236-1-baolu.lu@linux.intel.com
- Initial post.

Lu Baolu (4):
iommu/vt-d: Block force-snoop domain attaching if no SC support
iommu/vt-d: Check domain force_snooping against attached devices
iommu/vt-d: Remove domain_update_iommu_snooping()
iommu/vt-d: Remove hard coding PGSNP bit in PASID entries

include/linux/intel-iommu.h | 1 +
drivers/iommu/intel/pasid.h | 2 +
drivers/iommu/intel/iommu.c | 90 ++++++++++++++++++++++---------------
drivers/iommu/intel/pasid.c | 45 +++++++++++++++++--
4 files changed, 99 insertions(+), 39 deletions(-)

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2.25.1