Modern platforms have more than one IOMMU. Each IOMMU has its own
feature set. Some of these features must be consistent among IOMMUs.
Otherwise, these differences can lead to improper behavior in the system.
On the other hand, for some features, each IOMMU can have different
capacity values. So, different actions are required to deal with the
inconsistencies depending on the IOMMU features.
Currently, some inconsistencies are ignored by the IOMMU driver.
This patchset checks IOMMU capabilities and extended capabilities
centralizedly during boot and take different actions according to
the impacts caused by the mismatches.
For example:
1. Disable Shared Virtual Memory.
2. Use common capacity values (normally the lowest capacity value) for
all IOMMUs.
3. Report feature mismatches.
Detailed information on the IOMMU Capability / Extended Capability can
be found in Intel VT-d Specification.
Link:
https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf
Kyung Min Park (4):
iommu/vt-d: Disable SVM in the platform when IOMMUs have
inconsistencies
iommu/vt-d: Report out when IOMMU features have inconsistencies
iommu/vt-d: Audit IOMMUs for Interrupt Remapping features
iommu/vt-d: Scale capability to the lowest supported between the
IOMMUs
drivers/iommu/intel/Makefile | 4 +-
drivers/iommu/intel/audit.c | 193 ++++++++++++++++++++++++++++
drivers/iommu/intel/audit.h | 103 +++++++++++++++
drivers/iommu/intel/iommu.c | 12 +-
drivers/iommu/intel/irq_remapping.c | 8 ++
include/linux/intel-iommu.h | 3 +
6 files changed, 320 insertions(+), 3 deletions(-)
create mode 100644 drivers/iommu/intel/audit.c
create mode 100644 drivers/iommu/intel/audit.h
--
2.17.1
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