Hi Jason, On Tue, Aug 06, 2024 at 08:41:13PM -0300, Jason Gunthorpe wrote: > This brings support for the IOMMFD ioctls: > > - IOMMU_GET_HW_INFO > - IOMMU_HWPT_ALLOC_NEST_PARENT > - IOMMU_DOMAIN_NESTED > - ops->enforce_cache_coherency() > > This is quite straightforward as the nested STE can just be built in the > special NESTED domain op and fed through the generic update machinery. > > The design allows the user provided STE fragment to control several > aspects of the translation, including putting the STE into a "virtual > bypass" or a aborting state. This duplicates functionality available by > other means, but it allows trivially preserving the VMID in the STE as we > eventually move towards the VIOMMU owning the VMID. > > Nesting support requires the system to either support S2FWB or the > stronger CANWBS ACPI flag. This is to ensure the VM cannot bypass the > cache and view incoherent data, currently VFIO lacks any cache flushing > that would make this safe. > > Yan has a series to add some of the needed infrastructure for VFIO cache > flushing here: > > https://lore.kernel.org/linux-iommu/20240507061802.20184-1-yan.y.zhao@xxxxxxxxx/ > > Which may someday allow relaxing this further. > > Remove VFIO_TYPE1_NESTING_IOMMU since it was never used and superseded by > this. > > This is the first series in what will be several to complete nesting > support. At least: > - IOMMU_RESV_SW_MSI related fixups > - VIOMMU object support to allow ATS invalidations > - vCMDQ hypervisor support for direct invalidation queue assignment > - KVM pinned VMID using VIOMMU for vBTM > - Cross instance S2 sharing > - Virtual Machine Structure using VIOMMU (for vMPAM?) > - Fault forwarding support through IOMMUFD's fault fd for vSVA > > It is enough to allow significant amounts of qemu work to progress. > Are there any qemu patches to tests this? As I am confused with some of the user space bits and that would help. Thanks, Mostafa > This is on github: https://github.com/jgunthorpe/linux/commits/smmuv3_nesting > > Jason Gunthorpe (5): > vfio: Remove VFIO_TYPE1_NESTING_IOMMU > iommu/arm-smmu-v3: Use S2FWB when available > iommu/arm-smmu-v3: Report IOMMU_CAP_ENFORCE_CACHE_COHERENCY for CANWBS > iommu/arm-smmu-v3: Implement IOMMU_HWPT_ALLOC_NEST_PARENT > iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTED > > Nicolin Chen (3): > ACPI/IORT: Support CANWBS memory access flag > iommu/arm-smmu-v3: Support IOMMU_GET_HW_INFO via struct > arm_smmu_hw_info > iommu/arm-smmu-v3: Add arm_smmu_cache_invalidate_user > > drivers/acpi/arm64/iort.c | 13 + > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 398 ++++++++++++++++++-- > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 27 ++ > drivers/iommu/arm/arm-smmu/arm-smmu.c | 16 - > drivers/iommu/io-pgtable-arm.c | 24 +- > drivers/iommu/iommu.c | 10 - > drivers/iommu/iommufd/vfio_compat.c | 7 +- > drivers/vfio/vfio_iommu_type1.c | 12 +- > include/acpi/actbl2.h | 1 + > include/linux/io-pgtable.h | 2 + > include/linux/iommu.h | 54 ++- > include/uapi/linux/iommufd.h | 79 ++++ > include/uapi/linux/vfio.h | 2 +- > 13 files changed, 572 insertions(+), 73 deletions(-) > > > base-commit: e5e288d94186b266b062b3e44c82c285dfe68712 > -- > 2.46.0 >
