Merge branch 'iommufd_pri' into iommufd for-next

Lu Baolu says:

====================
This series implements the functionality of delivering IO page faults to
user space through the IOMMUFD framework. One feasible use case is the
nested translation. Nested translation is a hardware feature that supports
two-stage translation tables for IOMMU. The second-stage translation table
is managed by the host VMM, while the first-stage translation table is
owned by user space. This allows user space to control the IOMMU mappings
for its devices.

When an IO page fault occurs on the first-stage translation table, the
IOMMU hardware can deliver the page fault to user space through the
IOMMUFD framework. User space can then handle the page fault and respond
to the device top-down through the IOMMUFD. This allows user space to
implement its own IO page fault handling policies.

User space application that is capable of handling IO page faults should
allocate a fault object, and bind the fault object to any domain that it
is willing to handle the fault generatd for them. On a successful return
of fault object allocation, the user can retrieve and respond to page
faults by reading or writing to the file descriptor (FD) returned.

The iommu selftest framework has been updated to test the IO page fault
delivery and response functionality.
====================

* iommufd_pri:
  iommufd/selftest: Add coverage for IOPF test
  iommufd/selftest: Add IOPF support for mock device
  iommufd: Associate fault object with iommufd_hw_pgtable
  iommufd: Fault-capable hwpt attach/detach/replace
  iommufd: Add iommufd fault object
  iommufd: Add fault and response message definitions
  iommu: Extend domain attach group with handle support
  iommu: Add attach handle to struct iopf_group
  iommu: Remove sva handle list
  iommu: Introduce domain attachment handle

Link: https://lore.kernel.org/all/20240702063444.105814-1-baolu.lu@linux.intel.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 109 insertions, 0 deletions

diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 1dfeaa2e649e..ede2b464a761 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -50,6 +50,7 @@ enum {
 	IOMMUFD_CMD_HWPT_SET_DIRTY_TRACKING,
 	IOMMUFD_CMD_HWPT_GET_DIRTY_BITMAP,
 	IOMMUFD_CMD_HWPT_INVALIDATE,
+	IOMMUFD_CMD_FAULT_QUEUE_ALLOC,
 };
 
 /**
@@ -356,10 +357,13 @@ struct iommu_vfio_ioas {
  *                                the parent HWPT in a nesting configuration.
  * @IOMMU_HWPT_ALLOC_DIRTY_TRACKING: Dirty tracking support for device IOMMU is
  *                                   enforced on device attachment
+ * @IOMMU_HWPT_FAULT_ID_VALID: The fault_id field of hwpt allocation data is
+ *                             valid.
  */
 enum iommufd_hwpt_alloc_flags {
 	IOMMU_HWPT_ALLOC_NEST_PARENT = 1 << 0,
 	IOMMU_HWPT_ALLOC_DIRTY_TRACKING = 1 << 1,
+	IOMMU_HWPT_FAULT_ID_VALID = 1 << 2,
 };
 
 /**
@@ -411,6 +415,9 @@ enum iommu_hwpt_data_type {
  * @data_type: One of enum iommu_hwpt_data_type
  * @data_len: Length of the type specific data
  * @data_uptr: User pointer to the type specific data
+ * @fault_id: The ID of IOMMUFD_FAULT object. Valid only if flags field of
+ *            IOMMU_HWPT_FAULT_ID_VALID is set.
+ * @__reserved2: Padding to 64-bit alignment. Must be 0.
  *
  * Explicitly allocate a hardware page table object. This is the same object
  * type that is returned by iommufd_device_attach() and represents the
@@ -441,6 +448,8 @@ struct iommu_hwpt_alloc {
 	__u32 data_type;
 	__u32 data_len;
 	__aligned_u64 data_uptr;
+	__u32 fault_id;
+	__u32 __reserved2;
 };
 #define IOMMU_HWPT_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_ALLOC)
 
@@ -692,4 +701,104 @@ struct iommu_hwpt_invalidate {
 	__u32 __reserved;
 };
 #define IOMMU_HWPT_INVALIDATE _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_INVALIDATE)
+
+/**
+ * enum iommu_hwpt_pgfault_flags - flags for struct iommu_hwpt_pgfault
+ * @IOMMU_PGFAULT_FLAGS_PASID_VALID: The pasid field of the fault data is
+ *                                   valid.
+ * @IOMMU_PGFAULT_FLAGS_LAST_PAGE: It's the last fault of a fault group.
+ */
+enum iommu_hwpt_pgfault_flags {
+	IOMMU_PGFAULT_FLAGS_PASID_VALID		= (1 << 0),
+	IOMMU_PGFAULT_FLAGS_LAST_PAGE		= (1 << 1),
+};
+
+/**
+ * enum iommu_hwpt_pgfault_perm - perm bits for struct iommu_hwpt_pgfault
+ * @IOMMU_PGFAULT_PERM_READ: request for read permission
+ * @IOMMU_PGFAULT_PERM_WRITE: request for write permission
+ * @IOMMU_PGFAULT_PERM_EXEC: (PCIE 10.4.1) request with a PASID that has the
+ *                           Execute Requested bit set in PASID TLP Prefix.
+ * @IOMMU_PGFAULT_PERM_PRIV: (PCIE 10.4.1) request with a PASID that has the
+ *                           Privileged Mode Requested bit set in PASID TLP
+ *                           Prefix.
+ */
+enum iommu_hwpt_pgfault_perm {
+	IOMMU_PGFAULT_PERM_READ			= (1 << 0),
+	IOMMU_PGFAULT_PERM_WRITE		= (1 << 1),
+	IOMMU_PGFAULT_PERM_EXEC			= (1 << 2),
+	IOMMU_PGFAULT_PERM_PRIV			= (1 << 3),
+};
+
+/**
+ * struct iommu_hwpt_pgfault - iommu page fault data
+ * @flags: Combination of enum iommu_hwpt_pgfault_flags
+ * @dev_id: id of the originated device
+ * @pasid: Process Address Space ID
+ * @grpid: Page Request Group Index
+ * @perm: Combination of enum iommu_hwpt_pgfault_perm
+ * @addr: Fault address
+ * @length: a hint of how much data the requestor is expecting to fetch. For
+ *          example, if the PRI initiator knows it is going to do a 10MB
+ *          transfer, it could fill in 10MB and the OS could pre-fault in
+ *          10MB of IOVA. It's default to 0 if there's no such hint.
+ * @cookie: kernel-managed cookie identifying a group of fault messages. The
+ *          cookie number encoded in the last page fault of the group should
+ *          be echoed back in the response message.
+ */
+struct iommu_hwpt_pgfault {
+	__u32 flags;
+	__u32 dev_id;
+	__u32 pasid;
+	__u32 grpid;
+	__u32 perm;
+	__u64 addr;
+	__u32 length;
+	__u32 cookie;
+};
+
+/**
+ * enum iommufd_page_response_code - Return status of fault handlers
+ * @IOMMUFD_PAGE_RESP_SUCCESS: Fault has been handled and the page tables
+ *                             populated, retry the access. This is the
+ *                             "Success" defined in PCI 10.4.2.1.
+ * @IOMMUFD_PAGE_RESP_INVALID: Could not handle this fault, don't retry the
+ *                             access. This is the "Invalid Request" in PCI
+ *                             10.4.2.1.
+ * @IOMMUFD_PAGE_RESP_FAILURE: General error. Drop all subsequent faults from
+ *                             this device if possible. This is the "Response
+ *                             Failure" in PCI 10.4.2.1.
+ */
+enum iommufd_page_response_code {
+	IOMMUFD_PAGE_RESP_SUCCESS = 0,
+	IOMMUFD_PAGE_RESP_INVALID,
+	IOMMUFD_PAGE_RESP_FAILURE,
+};
+
+/**
+ * struct iommu_hwpt_page_response - IOMMU page fault response
+ * @cookie: The kernel-managed cookie reported in the fault message.
+ * @code: One of response code in enum iommufd_page_response_code.
+ */
+struct iommu_hwpt_page_response {
+	__u32 cookie;
+	__u32 code;
+};
+
+/**
+ * struct iommu_fault_alloc - ioctl(IOMMU_FAULT_QUEUE_ALLOC)
+ * @size: sizeof(struct iommu_fault_alloc)
+ * @flags: Must be 0
+ * @out_fault_id: The ID of the new FAULT
+ * @out_fault_fd: The fd of the new FAULT
+ *
+ * Explicitly allocate a fault handling object.
+ */
+struct iommu_fault_alloc {
+	__u32 size;
+	__u32 flags;
+	__u32 out_fault_id;
+	__u32 out_fault_fd;
+};
+#define IOMMU_FAULT_QUEUE_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_FAULT_QUEUE_ALLOC)
 #endif