Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd updates from Jason Gunthorpe:
 "Several new features and uAPI for iommufd:

   - IOMMU_IOAS_MAP_FILE allows passing in a file descriptor as the
     backing memory for an iommu mapping. To date VFIO/iommufd have used
     VMA's and pin_user_pages(), this now allows using memfds and
     memfd_pin_folios(). Notably this creates a pure folio path from the
     memfd to the iommu page table where memory is never broken down to
     PAGE_SIZE.

   - IOMMU_IOAS_CHANGE_PROCESS moves the pinned page accounting between
     two processes. Combined with the above this allows iommufd to
     support a VMM re-start using exec() where something like qemu would
     exec() a new version of itself and fd pass the memfds/iommufd/etc
     to the new process. The memfd allows DMA access to the memory to
     continue while the new process is getting setup, and the
     CHANGE_PROCESS updates all the accounting.

   - Support for fault reporting to userspace on non-PRI HW, such as ARM
     stall-mode embedded devices.

   - IOMMU_VIOMMU_ALLOC introduces the concept of a HW/driver backed
     virtual iommu. This will be used by VMMs to access hardware
     features that are contained with in a VM. The first use is to
     inform the kernel of the virtual SID to physical SID mapping when
     issuing SID based invalidation on ARM. Further uses will tie HW
     features that are directly accessed by the VM, such as invalidation
     queue assignment and others.

   - IOMMU_VDEVICE_ALLOC informs the kernel about the mapping of virtual
     device to physical device within a VIOMMU. Minimially this is used
     to translate VM issued cache invalidation commands from virtual to
     physical device IDs.

   - Enhancements to IOMMU_HWPT_INVALIDATE and IOMMU_HWPT_ALLOC to work
     with the VIOMMU

   - ARM SMMuv3 support for nested translation. Using the VIOMMU and
     VDEVICE the driver can model this HW's behavior for nested
     translation. This includes a shared branch from Will"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (51 commits)
  iommu/arm-smmu-v3: Import IOMMUFD module namespace
  iommufd: IOMMU_IOAS_CHANGE_PROCESS selftest
  iommufd: Add IOMMU_IOAS_CHANGE_PROCESS
  iommufd: Lock all IOAS objects
  iommufd: Export do_update_pinned
  iommu/arm-smmu-v3: Support IOMMU_HWPT_INVALIDATE using a VIOMMU object
  iommu/arm-smmu-v3: Allow ATS for IOMMU_DOMAIN_NESTED
  iommu/arm-smmu-v3: Use S2FWB for NESTED domains
  iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTED
  iommu/arm-smmu-v3: Support IOMMU_VIOMMU_ALLOC
  Documentation: userspace-api: iommufd: Update vDEVICE
  iommufd/selftest: Add vIOMMU coverage for IOMMU_HWPT_INVALIDATE ioctl
  iommufd/selftest: Add IOMMU_TEST_OP_DEV_CHECK_CACHE test command
  iommufd/selftest: Add mock_viommu_cache_invalidate
  iommufd/viommu: Add iommufd_viommu_find_dev helper
  iommu: Add iommu_copy_struct_from_full_user_array helper
  iommufd: Allow hwpt_id to carry viommu_id for IOMMU_HWPT_INVALIDATE
  iommu/viommu: Add cache_invalidate to iommufd_viommu_ops
  iommufd/selftest: Add IOMMU_VDEVICE_ALLOC test coverage
  iommufd/viommu: Add IOMMUFD_OBJ_VDEVICE and IOMMU_VDEVICE_ALLOC ioctl
  ...

Author: torvalds

Documentation/userspace-api/iommufd.rst

@@ -1218,6 +1218,17 @@ static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)
 	return pci_rc->ats_attribute & ACPI_IORT_ATS_SUPPORTED;
 }
 
+static bool iort_pci_rc_supports_canwbs(struct acpi_iort_node *node)
+{
+	struct acpi_iort_memory_access *memory_access;
+	struct acpi_iort_root_complex *pci_rc;
+
+	pci_rc = (struct acpi_iort_root_complex *)node->node_data;
+	memory_access =
+		(struct acpi_iort_memory_access *)&pci_rc->memory_properties;
+	return memory_access->memory_flags & ACPI_IORT_MF_CANWBS;
+}
+
 static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
 			    u32 streamid)
 {
@@ -1335,6 +1346,8 @@ int iort_iommu_configure_id(struct device *dev, const u32 *id_in)
 		fwspec = dev_iommu_fwspec_get(dev);
 		if (fwspec && iort_pci_rc_supports_ats(node))
 			fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
+		if (fwspec && iort_pci_rc_supports_canwbs(node))
+			fwspec->flags |= IOMMU_FWSPEC_PCI_RC_CANWBS;
 	} else {
 		node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
 				      iort_match_node_callback, dev);

drivers/acpi/arm64/iort.c

@@ -415,6 +415,15 @@ config ARM_SMMU_V3_SVA
 	  Say Y here if your system supports SVA extensions such as PCIe PASID
 	  and PRI.
 
+config ARM_SMMU_V3_IOMMUFD
+	bool "Enable IOMMUFD features for ARM SMMUv3 (EXPERIMENTAL)"
+	depends on IOMMUFD
+	help
+	  Support for IOMMUFD features intended to support virtual machines
+	  with accelerated virtual IOMMUs.
+
+	  Say Y here if you are doing development and testing on this feature.
+
 config ARM_SMMU_V3_KUNIT_TEST
 	tristate "KUnit tests for arm-smmu-v3 driver"  if !KUNIT_ALL_TESTS
 	depends on KUNIT

drivers/iommu/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_ARM_SMMU_V3) += arm_smmu_v3.o
 arm_smmu_v3-y := arm-smmu-v3.o
+arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_IOMMUFD) += arm-smmu-v3-iommufd.o
 arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_SVA) += arm-smmu-v3-sva.o
 arm_smmu_v3-$(CONFIG_TEGRA241_CMDQV) += tegra241-cmdqv.o