[PATCH v4 0/4] iommu/s390: add support for IOMMU passthrough

[Matthew Rosato]

This series introduces the ability for certain devices on s390 to bypass
a layer of IOMMU via the iommu.passthrough=1 option.  In order to enable
this, the concept of an identity domain is added to s390-iommu.  On s390,
IOMMU passthrough is only allowed if indicated via a special bit in s390
CLP data for the associated device group, otherwise we must fall back to
dma-iommu.

Changes for v4:
- Additional patch to handle IOAT registration within s390-iommu.  This
  fixes an issue with re-registration of identity domain during events
  like zpci_hot_reset_device
- Fixup page alignment for bus_dma_region setup
- Dropped a few review/test tags due to above changes

Changes for v3:
- Rebase onto 6.13
- fixed bus_dma_region size (Niklas) 

Changes for v2:
- Remove ARCH_HAS_PHYS_TO_DMA, use bus_dma_region
- Remove use of def_domain_type, use 1 of 2 ops chosen at init

Matthew Rosato (4):
  s390/pci: check for relaxed translation capability
  s390/pci: store DMA offset in bus_dma_region
  iommu/s390: handle IOAT registration based on domain
  iommu/s390: implement iommu passthrough via identity domain

 arch/s390/include/asm/pci.h     |   4 +-
 arch/s390/include/asm/pci_clp.h |   4 +-
 arch/s390/kvm/pci.c             |  17 +---
 arch/s390/pci/pci.c             |  35 ++++----
 arch/s390/pci/pci_bus.c         |  18 +++++
 arch/s390/pci/pci_clp.c         |   1 +
 arch/s390/pci/pci_sysfs.c       |  11 +--
 drivers/iommu/s390-iommu.c      | 138 ++++++++++++++++++++++++++------
 8 files changed, 161 insertions(+), 67 deletions(-)

-- 
2.48.1