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

- IOMMUFD_OBJ_DEVICE, representing a device that is bound to iommufd by an

  external driver.

- IOMMUFD_OBJ_HW_PAGETABLE, representing an actual hardware I/O page table

  (i.e. a single struct iommu_domain) managed by the iommu driver.

- IOMMUFD_OBJ_HWPT_PAGING, representing an actual hardware I/O page table

  (i.e. a single struct iommu_domain) managed by the iommu driver. "PAGING"

  primarly indicates this type of HWPT should be linked to an IOAS. It also

  indicates that it is backed by an iommu_domain with __IOMMU_DOMAIN_PAGING

  feature flag. This can be either an UNMANAGED stage-1 domain for a device

  running in the user space, or a nesting parent stage-2 domain for mappings

  from guest-level physical addresses to host-level physical addresses.

  The IOAS has a list of HWPT_PAGINGs that share the same IOVA mapping and

  it will synchronize its mapping with each member HWPT_PAGING.

- IOMMUFD_OBJ_HWPT_NESTED, representing an actual hardware I/O page table

  (i.e. a single struct iommu_domain) managed by user space (e.g. guest OS).

  "NESTED" indicates that this type of HWPT should be linked to an HWPT_PAGING.

  It also indicates that it is backed by an iommu_domain that has a type of

  IOMMU_DOMAIN_NESTED. This must be a stage-1 domain for a device running in

  the user space (e.g. in a guest VM enabling the IOMMU nested translation

  feature.) As such, it must be created with a given nesting parent stage-2

  domain to associate to. This nested stage-1 page table managed by the user

  space usually has mappings from guest-level I/O virtual addresses to guest-

  level physical addresses.

- IOMMUFD_OBJ_VIOMMU, representing a slice of the physical IOMMU instance,

  passed to or shared with a VM. It may be some HW-accelerated virtualization

  features and some SW resources used by the VM. For examples:

  * Security namespace for guest owned ID, e.g. guest-controlled cache tags

  * Non-device-affiliated event reporting, e.g. invalidation queue errors

  * Access to a sharable nesting parent pagetable across physical IOMMUs

  * Virtualization of various platforms IDs, e.g. RIDs and others

  * Delivery of paravirtualized invalidation

  * Direct assigned invalidation queues

  * Direct assigned interrupts

  Such a vIOMMU object generally has the access to a nesting parent pagetable

  to support some HW-accelerated virtualization features. So, a vIOMMU object

  must be created given a nesting parent HWPT_PAGING object, and then it would

  encapsulate that HWPT_PAGING object. Therefore, a vIOMMU object can be used

  to allocate an HWPT_NESTED object in place of the encapsulated HWPT_PAGING.

  The IOAS has a list of HW_PAGETABLES that share the same IOVA mapping and

  it will synchronize its mapping with each member HW_PAGETABLE.

  .. note::

     The name "vIOMMU" isn't necessarily identical to a virtualized IOMMU in a

     VM. A VM can have one giant virtualized IOMMU running on a machine having

     multiple physical IOMMUs, in which case the VMM will dispatch the requests

     or configurations from this single virtualized IOMMU instance to multiple

     vIOMMU objects created for individual slices of different physical IOMMUs.

     In other words, a vIOMMU object is always a representation of one physical

     IOMMU, not necessarily of a virtualized IOMMU. For VMMs that want the full

     virtualization features from physical IOMMUs, it is suggested to build the

     same number of virtualized IOMMUs as the number of physical IOMMUs, so the

     passed-through devices would be connected to their own virtualized IOMMUs

     backed by corresponding vIOMMU objects, in which case a guest OS would do

     the "dispatch" naturally instead of VMM trappings.

- IOMMUFD_OBJ_VDEVICE, representing a virtual device for an IOMMUFD_OBJ_DEVICE

  against an IOMMUFD_OBJ_VIOMMU. This virtual device holds the device's virtual

  information or attributes (related to the vIOMMU) in a VM. An immediate vDATA

  example can be the virtual ID of the device on a vIOMMU, which is a unique ID

  that VMM assigns to the device for a translation channel/port of the vIOMMU,

  e.g. vSID of ARM SMMUv3, vDeviceID of AMD IOMMU, and vRID of Intel VT-d to a

  Context Table. Potential use cases of some advanced security information can

  be forwarded via this object too, such as security level or realm information

  in a Confidential Compute Architecture. A VMM should create a vDEVICE object

  to forward all the device information in a VM, when it connects a device to a

  vIOMMU, which is a separate ioctl call from attaching the same device to an

  HWPT_PAGING that the vIOMMU holds.

All user-visible objects are destroyed via the IOMMU_DESTROY uAPI.

The diagram below shows relationship between user-visible objects and kernel

The diagrams below show relationships between user-visible objects and kernel

datastructures (external to iommufd), with numbers referred to operations

creating the objects and links::

  _________________________________________________________

 |                         iommufd                         |

 |       [1]                                               |

 |  _________________                                      |

 | |                 |                                     |

 | |                 |                                     |

 | |                 |                                     |

 | |                 |                                     |

 | |                 |                                     |

 | |                 |                                     |

 | |                 |        [3]                 [2]      |

 | |                 |    ____________         __________  |

 | |      IOAS       |<--|            |<------|          | |

 | |                 |   |HW_PAGETABLE|       |  DEVICE  | |

 | |                 |   |____________|       |__________| |

 | |                 |         |                   |       |

 | |                 |         |                   |       |

  _______________________________________________________________________

 |                      iommufd (HWPT_PAGING only)                       |

 |                                                                       |

 |        [1]                  [3]                                [2]    |

 |  ________________      _____________                        ________  |

 | |                |    |             |                      |        | |

 | |      IOAS      |<---| HWPT_PAGING |<---------------------| DEVICE | |

 | |________________|    |_____________|                      |________| |

 |         |                    |                                  |     |

 |_________|____________________|__________________________________|_____|

           |                    |                                  |

           |              ______v_____                          ___v__

           | PFN storage |  (paging)  |                        |struct|

           |------------>|iommu_domain|<-----------------------|device|

                         |____________|                        |______|

  _______________________________________________________________________

 |                      iommufd (with HWPT_NESTED)                       |

 |                                                                       |

 |        [1]                  [3]                [4]             [2]    |

 |  ________________      _____________      _____________     ________  |

 | |                |    |             |    |             |   |        | |

 | |      IOAS      |<---| HWPT_PAGING |<---| HWPT_NESTED |<--| DEVICE | |

 | |________________|    |_____________|    |_____________|   |________| |

 |         |                    |                  |               |     |

 |_________|____________________|__________________|_______________|_____|

           |                    |                  |               |

           |              ______v_____       ______v_____       ___v__

           | PFN storage |  (paging)  |     |  (nested)  |     |struct|

           |------------>|iommu_domain|<----|iommu_domain|<----|device|

                         |____________|     |____________|     |______|

  _______________________________________________________________________

 |                      iommufd (with vIOMMU/vDEVICE)                    |

 |                                                                       |

 |                             [5]                [6]                    |

 |                        _____________      _____________               |

 |                       |             |    |             |              |

 |      |----------------|    vIOMMU   |<---|   vDEVICE   |<----|        |

 |      |                |             |    |_____________|     |        |

 |      |                |             |                        |        |

 | |_________________|         |                   |       |

 |      |      [1]       |             |          [4]           | [2]    |

 |      |     ______     |             |     _____________     _|______  |

 |      |    |      |    |     [3]     |    |             |   |        | |

 |      |    | IOAS |<---|(HWPT_PAGING)|<---| HWPT_NESTED |<--| DEVICE | |

 |      |    |______|    |_____________|    |_____________|   |________| |

 |      |        |              |                  |               |     |

 |______|________|______________|__________________|_______________|_____|

        |        |              |                  |               |

 |_________|___________________|___________________|_______|

           |                   |                   |

           |              _____v______      _______v_____

           | PFN storage |            |    |             |

           |------------>|iommu_domain|    |struct device|

                         |____________|    |_____________|

  ______v_____   |        ______v_____       ______v_____       ___v__

 |   struct   |  |  PFN  |  (paging)  |     |  (nested)  |     |struct|

 |iommu_device|  |------>|iommu_domain|<----|iommu_domain|<----|device|

 |____________|   storage|____________|     |____________|     |______|

1. IOMMUFD_OBJ_IOAS is created via the IOMMU_IOAS_ALLOC uAPI. An iommufd can

   hold multiple IOAS objects. IOAS is the most generic object and does not

   device. The driver must also set the driver_managed_dma flag and must not

   touch the device until this operation succeeds.

3. IOMMUFD_OBJ_HW_PAGETABLE is created when an external driver calls the IOMMUFD

   kAPI to attach a bound device to an IOAS. Similarly the external driver uAPI

   allows userspace to initiate the attaching operation. If a compatible

   pagetable already exists then it is reused for the attachment. Otherwise a

   new pagetable object and iommu_domain is created. Successful completion of

   this operation sets up the linkages among IOAS, device and iommu_domain. Once

   this completes the device could do DMA.

   Every iommu_domain inside the IOAS is also represented to userspace as a

   HW_PAGETABLE object.

3. IOMMUFD_OBJ_HWPT_PAGING can be created in two ways:

   * IOMMUFD_OBJ_HWPT_PAGING is automatically created when an external driver

     calls the IOMMUFD kAPI to attach a bound device to an IOAS. Similarly the

     external driver uAPI allows userspace to initiate the attaching operation.

     If a compatible member HWPT_PAGING object exists in the IOAS's HWPT_PAGING

     list, then it will be reused. Otherwise a new HWPT_PAGING that represents

     an iommu_domain to userspace will be created, and then added to the list.

     Successful completion of this operation sets up the linkages among IOAS,

     device and iommu_domain. Once this completes the device could do DMA.

   * IOMMUFD_OBJ_HWPT_PAGING can be manually created via the IOMMU_HWPT_ALLOC

     uAPI, provided an ioas_id via @pt_id to associate the new HWPT_PAGING to

     the corresponding IOAS object. The benefit of this manual allocation is to

     allow allocation flags (defined in enum iommufd_hwpt_alloc_flags), e.g. it

     allocates a nesting parent HWPT_PAGING if the IOMMU_HWPT_ALLOC_NEST_PARENT

     flag is set.

4. IOMMUFD_OBJ_HWPT_NESTED can be only manually created via the IOMMU_HWPT_ALLOC

   uAPI, provided an hwpt_id or a viommu_id of a vIOMMU object encapsulating a

   nesting parent HWPT_PAGING via @pt_id to associate the new HWPT_NESTED object

   to the corresponding HWPT_PAGING object. The associating HWPT_PAGING object

   must be a nesting parent manually allocated via the same uAPI previously with

   an IOMMU_HWPT_ALLOC_NEST_PARENT flag, otherwise the allocation will fail. The

   allocation will be further validated by the IOMMU driver to ensure that the

   nesting parent domain and the nested domain being allocated are compatible.

   Successful completion of this operation sets up linkages among IOAS, device,

   and iommu_domains. Once this completes the device could do DMA via a 2-stage

   translation, a.k.a nested translation. Note that multiple HWPT_NESTED objects

   can be allocated by (and then associated to) the same nesting parent.

   .. note::

      Future IOMMUFD updates will provide an API to create and manipulate the

      HW_PAGETABLE directly.

      Either a manual IOMMUFD_OBJ_HWPT_PAGING or an IOMMUFD_OBJ_HWPT_NESTED is

      created via the same IOMMU_HWPT_ALLOC uAPI. The difference is at the type

      of the object passed in via the @pt_id field of struct iommufd_hwpt_alloc.

5. IOMMUFD_OBJ_VIOMMU can be only manually created via the IOMMU_VIOMMU_ALLOC

   uAPI, provided a dev_id (for the device's physical IOMMU to back the vIOMMU)

   and an hwpt_id (to associate the vIOMMU to a nesting parent HWPT_PAGING). The

   iommufd core will link the vIOMMU object to the struct iommu_device that the

   struct device is behind. And an IOMMU driver can implement a viommu_alloc op

   to allocate its own vIOMMU data structure embedding the core-level structure

   iommufd_viommu and some driver-specific data. If necessary, the driver can

   also configure its HW virtualization feature for that vIOMMU (and thus for

   the VM). Successful completion of this operation sets up the linkages between

   the vIOMMU object and the HWPT_PAGING, then this vIOMMU object can be used

   as a nesting parent object to allocate an HWPT_NESTED object described above.

6. IOMMUFD_OBJ_VDEVICE can be only manually created via the IOMMU_VDEVICE_ALLOC

   uAPI, provided a viommu_id for an iommufd_viommu object and a dev_id for an

   iommufd_device object. The vDEVICE object will be the binding between these

   two parent objects. Another @virt_id will be also set via the uAPI providing

   the iommufd core an index to store the vDEVICE object to a vDEVICE array per

   vIOMMU. If necessary, the IOMMU driver may choose to implement a vdevce_alloc

   op to init its HW for virtualization feature related to a vDEVICE. Successful

   completion of this operation sets up the linkages between vIOMMU and device.

A device can only bind to an iommufd due to DMA ownership claim and attach to at

most one IOAS object (no support of PASID yet).

- iommufd_ioas for IOMMUFD_OBJ_IOAS.

- iommufd_device for IOMMUFD_OBJ_DEVICE.

- iommufd_hw_pagetable for IOMMUFD_OBJ_HW_PAGETABLE.

- iommufd_hwpt_paging for IOMMUFD_OBJ_HWPT_PAGING.

- iommufd_hwpt_nested for IOMMUFD_OBJ_HWPT_NESTED.

- iommufd_viommu for IOMMUFD_OBJ_VIOMMU.

- iommufd_vdevice for IOMMUFD_OBJ_VDEVICE.

Several terminologies when looking at these datastructures:

	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)

{

		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);

	  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

# 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