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

Pull iommufd implementation from Jason Gunthorpe:
 "iommufd is the user API to control the IOMMU subsystem as it relates
  to managing IO page tables that point at user space memory.

  It takes over from drivers/vfio/vfio_iommu_type1.c (aka the VFIO
  container) which is the VFIO specific interface for a similar idea.

  We see a broad need for extended features, some being highly IOMMU
  device specific:
   - Binding iommu_domain's to PASID/SSID
   - Userspace IO page tables, for ARM, x86 and S390
   - Kernel bypassed invalidation of user page tables
   - Re-use of the KVM page table in the IOMMU
   - Dirty page tracking in the IOMMU
   - Runtime Increase/Decrease of IOPTE size
   - PRI support with faults resolved in userspace

  Many of these HW features exist to support VM use cases - for instance
  the combination of PASID, PRI and Userspace IO Page Tables allows an
  implementation of DMA Shared Virtual Addressing (vSVA) within a guest.
  Dirty tracking enables VM live migration with SRIOV devices and PASID
  support allow creating "scalable IOV" devices, among other things.

  As these features are fundamental to a VM platform they need to be
  uniformly exposed to all the driver families that do DMA into VMs,
  which is currently VFIO and VDPA"

For more background, see the extended explanations in Jason's pull request:

  https://lore.kernel.org/lkml/Y5dzTU8dlmXTbzoJ@nvidia.com/

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (62 commits)
  iommufd: Change the order of MSI setup
  iommufd: Improve a few unclear bits of code
  iommufd: Fix comment typos
  vfio: Move vfio group specific code into group.c
  vfio: Refactor dma APIs for emulated devices
  vfio: Wrap vfio group module init/clean code into helpers
  vfio: Refactor vfio_device open and close
  vfio: Make vfio_device_open() truly device specific
  vfio: Swap order of vfio_device_container_register() and open_device()
  vfio: Set device->group in helper function
  vfio: Create wrappers for group register/unregister
  vfio: Move the sanity check of the group to vfio_create_group()
  vfio: Simplify vfio_create_group()
  iommufd: Allow iommufd to supply /dev/vfio/vfio
  vfio: Make vfio_container optionally compiled
  vfio: Move container related MODULE_ALIAS statements into container.c
  vfio-iommufd: Support iommufd for emulated VFIO devices
  vfio-iommufd: Support iommufd for physical VFIO devices
  vfio-iommufd: Allow iommufd to be used in place of a container fd
  vfio: Use IOMMU_CAP_ENFORCE_CACHE_COHERENCY for vfio_file_enforced_coherent()
  ...

1 files changed, 347 insertions, 0 deletions

diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
new file mode 100644
index 000000000000..98ebba80cfa1
--- /dev/null
+++ b/include/uapi/linux/iommufd.h
@@ -0,0 +1,347 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES.
+ */
+#ifndef _UAPI_IOMMUFD_H
+#define _UAPI_IOMMUFD_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+#define IOMMUFD_TYPE (';')
+
+/**
+ * DOC: General ioctl format
+ *
+ * The ioctl interface follows a general format to allow for extensibility. Each
+ * ioctl is passed in a structure pointer as the argument providing the size of
+ * the structure in the first u32. The kernel checks that any structure space
+ * beyond what it understands is 0. This allows userspace to use the backward
+ * compatible portion while consistently using the newer, larger, structures.
+ *
+ * ioctls use a standard meaning for common errnos:
+ *
+ *  - ENOTTY: The IOCTL number itself is not supported at all
+ *  - E2BIG: The IOCTL number is supported, but the provided structure has
+ *    non-zero in a part the kernel does not understand.
+ *  - EOPNOTSUPP: The IOCTL number is supported, and the structure is
+ *    understood, however a known field has a value the kernel does not
+ *    understand or support.
+ *  - EINVAL: Everything about the IOCTL was understood, but a field is not
+ *    correct.
+ *  - ENOENT: An ID or IOVA provided does not exist.
+ *  - ENOMEM: Out of memory.
+ *  - EOVERFLOW: Mathematics overflowed.
+ *
+ * As well as additional errnos, within specific ioctls.
+ */
+enum {
+	IOMMUFD_CMD_BASE = 0x80,
+	IOMMUFD_CMD_DESTROY = IOMMUFD_CMD_BASE,
+	IOMMUFD_CMD_IOAS_ALLOC,
+	IOMMUFD_CMD_IOAS_ALLOW_IOVAS,
+	IOMMUFD_CMD_IOAS_COPY,
+	IOMMUFD_CMD_IOAS_IOVA_RANGES,
+	IOMMUFD_CMD_IOAS_MAP,
+	IOMMUFD_CMD_IOAS_UNMAP,
+	IOMMUFD_CMD_OPTION,
+	IOMMUFD_CMD_VFIO_IOAS,
+};
+
+/**
+ * struct iommu_destroy - ioctl(IOMMU_DESTROY)
+ * @size: sizeof(struct iommu_destroy)
+ * @id: iommufd object ID to destroy. Can be any destroyable object type.
+ *
+ * Destroy any object held within iommufd.
+ */
+struct iommu_destroy {
+	__u32 size;
+	__u32 id;
+};
+#define IOMMU_DESTROY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DESTROY)
+
+/**
+ * struct iommu_ioas_alloc - ioctl(IOMMU_IOAS_ALLOC)
+ * @size: sizeof(struct iommu_ioas_alloc)
+ * @flags: Must be 0
+ * @out_ioas_id: Output IOAS ID for the allocated object
+ *
+ * Allocate an IO Address Space (IOAS) which holds an IO Virtual Address (IOVA)
+ * to memory mapping.
+ */
+struct iommu_ioas_alloc {
+	__u32 size;
+	__u32 flags;
+	__u32 out_ioas_id;
+};
+#define IOMMU_IOAS_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_ALLOC)
+
+/**
+ * struct iommu_iova_range - ioctl(IOMMU_IOVA_RANGE)
+ * @start: First IOVA
+ * @last: Inclusive last IOVA
+ *
+ * An interval in IOVA space.
+ */
+struct iommu_iova_range {
+	__aligned_u64 start;
+	__aligned_u64 last;
+};
+
+/**
+ * struct iommu_ioas_iova_ranges - ioctl(IOMMU_IOAS_IOVA_RANGES)
+ * @size: sizeof(struct iommu_ioas_iova_ranges)
+ * @ioas_id: IOAS ID to read ranges from
+ * @num_iovas: Input/Output total number of ranges in the IOAS
+ * @__reserved: Must be 0
+ * @allowed_iovas: Pointer to the output array of struct iommu_iova_range
+ * @out_iova_alignment: Minimum alignment required for mapping IOVA
+ *
+ * Query an IOAS for ranges of allowed IOVAs. Mapping IOVA outside these ranges
+ * is not allowed. num_iovas will be set to the total number of iovas and
+ * the allowed_iovas[] will be filled in as space permits.
+ *
+ * The allowed ranges are dependent on the HW path the DMA operation takes, and
+ * can change during the lifetime of the IOAS. A fresh empty IOAS will have a
+ * full range, and each attached device will narrow the ranges based on that
+ * device's HW restrictions. Detaching a device can widen the ranges. Userspace
+ * should query ranges after every attach/detach to know what IOVAs are valid
+ * for mapping.
+ *
+ * On input num_iovas is the length of the allowed_iovas array. On output it is
+ * the total number of iovas filled in. The ioctl will return -EMSGSIZE and set
+ * num_iovas to the required value if num_iovas is too small. In this case the
+ * caller should allocate a larger output array and re-issue the ioctl.
+ *
+ * out_iova_alignment returns the minimum IOVA alignment that can be given
+ * to IOMMU_IOAS_MAP/COPY. IOVA's must satisfy::
+ *
+ *   starting_iova % out_iova_alignment == 0
+ *   (starting_iova + length) % out_iova_alignment == 0
+ *
+ * out_iova_alignment can be 1 indicating any IOVA is allowed. It cannot
+ * be higher than the system PAGE_SIZE.
+ */
+struct iommu_ioas_iova_ranges {
+	__u32 size;
+	__u32 ioas_id;
+	__u32 num_iovas;
+	__u32 __reserved;
+	__aligned_u64 allowed_iovas;
+	__aligned_u64 out_iova_alignment;
+};
+#define IOMMU_IOAS_IOVA_RANGES _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_IOVA_RANGES)
+
+/**
+ * struct iommu_ioas_allow_iovas - ioctl(IOMMU_IOAS_ALLOW_IOVAS)
+ * @size: sizeof(struct iommu_ioas_allow_iovas)
+ * @ioas_id: IOAS ID to allow IOVAs from
+ * @num_iovas: Input/Output total number of ranges in the IOAS
+ * @__reserved: Must be 0
+ * @allowed_iovas: Pointer to array of struct iommu_iova_range
+ *
+ * Ensure a range of IOVAs are always available for allocation. If this call
+ * succeeds then IOMMU_IOAS_IOVA_RANGES will never return a list of IOVA ranges
+ * that are narrower than the ranges provided here. This call will fail if
+ * IOMMU_IOAS_IOVA_RANGES is currently narrower than the given ranges.
+ *
+ * When an IOAS is first created the IOVA_RANGES will be maximally sized, and as
+ * devices are attached the IOVA will narrow based on the device restrictions.
+ * When an allowed range is specified any narrowing will be refused, ie device
+ * attachment can fail if the device requires limiting within the allowed range.
+ *
+ * Automatic IOVA allocation is also impacted by this call. MAP will only
+ * allocate within the allowed IOVAs if they are present.
+ *
+ * This call replaces the entire allowed list with the given list.
+ */
+struct iommu_ioas_allow_iovas {
+	__u32 size;
+	__u32 ioas_id;
+	__u32 num_iovas;
+	__u32 __reserved;
+	__aligned_u64 allowed_iovas;
+};
+#define IOMMU_IOAS_ALLOW_IOVAS _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_ALLOW_IOVAS)
+
+/**
+ * enum iommufd_ioas_map_flags - Flags for map and copy
+ * @IOMMU_IOAS_MAP_FIXED_IOVA: If clear the kernel will compute an appropriate
+ *                             IOVA to place the mapping at
+ * @IOMMU_IOAS_MAP_WRITEABLE: DMA is allowed to write to this mapping
+ * @IOMMU_IOAS_MAP_READABLE: DMA is allowed to read from this mapping
+ */
+enum iommufd_ioas_map_flags {
+	IOMMU_IOAS_MAP_FIXED_IOVA = 1 << 0,
+	IOMMU_IOAS_MAP_WRITEABLE = 1 << 1,
+	IOMMU_IOAS_MAP_READABLE = 1 << 2,
+};
+
+/**
+ * struct iommu_ioas_map - ioctl(IOMMU_IOAS_MAP)
+ * @size: sizeof(struct iommu_ioas_map)
+ * @flags: Combination of enum iommufd_ioas_map_flags
+ * @ioas_id: IOAS ID to change the mapping of
+ * @__reserved: Must be 0
+ * @user_va: Userspace pointer to start mapping from
+ * @length: Number of bytes to map
+ * @iova: IOVA the mapping was placed at. If IOMMU_IOAS_MAP_FIXED_IOVA is set
+ *        then this must be provided as input.
+ *
+ * Set an IOVA mapping from a user pointer. If FIXED_IOVA is specified then the
+ * mapping will be established at iova, otherwise a suitable location based on
+ * the reserved and allowed lists will be automatically selected and returned in
+ * iova.
+ *
+ * If IOMMU_IOAS_MAP_FIXED_IOVA is specified then the iova range must currently
+ * be unused, existing IOVA cannot be replaced.
+ */
+struct iommu_ioas_map {
+	__u32 size;
+	__u32 flags;
+	__u32 ioas_id;
+	__u32 __reserved;
+	__aligned_u64 user_va;
+	__aligned_u64 length;
+	__aligned_u64 iova;
+};
+#define IOMMU_IOAS_MAP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_MAP)
+
+/**
+ * struct iommu_ioas_copy - ioctl(IOMMU_IOAS_COPY)
+ * @size: sizeof(struct iommu_ioas_copy)
+ * @flags: Combination of enum iommufd_ioas_map_flags
+ * @dst_ioas_id: IOAS ID to change the mapping of
+ * @src_ioas_id: IOAS ID to copy from
+ * @length: Number of bytes to copy and map
+ * @dst_iova: IOVA the mapping was placed at. If IOMMU_IOAS_MAP_FIXED_IOVA is
+ *            set then this must be provided as input.
+ * @src_iova: IOVA to start the copy
+ *
+ * Copy an already existing mapping from src_ioas_id and establish it in
+ * dst_ioas_id. The src iova/length must exactly match a range used with
+ * IOMMU_IOAS_MAP.
+ *
+ * This may be used to efficiently clone a subset of an IOAS to another, or as a
+ * kind of 'cache' to speed up mapping. Copy has an efficiency advantage over
+ * establishing equivalent new mappings, as internal resources are shared, and
+ * the kernel will pin the user memory only once.
+ */
+struct iommu_ioas_copy {
+	__u32 size;
+	__u32 flags;
+	__u32 dst_ioas_id;
+	__u32 src_ioas_id;
+	__aligned_u64 length;
+	__aligned_u64 dst_iova;
+	__aligned_u64 src_iova;
+};
+#define IOMMU_IOAS_COPY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_COPY)
+
+/**
+ * struct iommu_ioas_unmap - ioctl(IOMMU_IOAS_UNMAP)
+ * @size: sizeof(struct iommu_ioas_unmap)
+ * @ioas_id: IOAS ID to change the mapping of
+ * @iova: IOVA to start the unmapping at
+ * @length: Number of bytes to unmap, and return back the bytes unmapped
+ *
+ * Unmap an IOVA range. The iova/length must be a superset of a previously
+ * mapped range used with IOMMU_IOAS_MAP or IOMMU_IOAS_COPY. Splitting or
+ * truncating ranges is not allowed. The values 0 to U64_MAX will unmap
+ * everything.
+ */
+struct iommu_ioas_unmap {
+	__u32 size;
+	__u32 ioas_id;
+	__aligned_u64 iova;
+	__aligned_u64 length;
+};
+#define IOMMU_IOAS_UNMAP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_UNMAP)
+
+/**
+ * enum iommufd_option - ioctl(IOMMU_OPTION_RLIMIT_MODE) and
+ *                       ioctl(IOMMU_OPTION_HUGE_PAGES)
+ * @IOMMU_OPTION_RLIMIT_MODE:
+ *    Change how RLIMIT_MEMLOCK accounting works. The caller must have privilege
+ *    to invoke this. Value 0 (default) is user based accouting, 1 uses process
+ *    based accounting. Global option, object_id must be 0
+ * @IOMMU_OPTION_HUGE_PAGES:
+ *    Value 1 (default) allows contiguous pages to be combined when generating
+ *    iommu mappings. Value 0 disables combining, everything is mapped to
+ *    PAGE_SIZE. This can be useful for benchmarking.  This is a per-IOAS
+ *    option, the object_id must be the IOAS ID.
+ */
+enum iommufd_option {
+	IOMMU_OPTION_RLIMIT_MODE = 0,
+	IOMMU_OPTION_HUGE_PAGES = 1,
+};
+
+/**
+ * enum iommufd_option_ops - ioctl(IOMMU_OPTION_OP_SET) and
+ *                           ioctl(IOMMU_OPTION_OP_GET)
+ * @IOMMU_OPTION_OP_SET: Set the option's value
+ * @IOMMU_OPTION_OP_GET: Get the option's value
+ */
+enum iommufd_option_ops {
+	IOMMU_OPTION_OP_SET = 0,
+	IOMMU_OPTION_OP_GET = 1,
+};
+
+/**
+ * struct iommu_option - iommu option multiplexer
+ * @size: sizeof(struct iommu_option)
+ * @option_id: One of enum iommufd_option
+ * @op: One of enum iommufd_option_ops
+ * @__reserved: Must be 0
+ * @object_id: ID of the object if required
+ * @val64: Option value to set or value returned on get
+ *
+ * Change a simple option value. This multiplexor allows controlling options
+ * on objects. IOMMU_OPTION_OP_SET will load an option and IOMMU_OPTION_OP_GET
+ * will return the current value.
+ */
+struct iommu_option {
+	__u32 size;
+	__u32 option_id;
+	__u16 op;
+	__u16 __reserved;
+	__u32 object_id;
+	__aligned_u64 val64;
+};
+#define IOMMU_OPTION _IO(IOMMUFD_TYPE, IOMMUFD_CMD_OPTION)
+
+/**
+ * enum iommufd_vfio_ioas_op - IOMMU_VFIO_IOAS_* ioctls
+ * @IOMMU_VFIO_IOAS_GET: Get the current compatibility IOAS
+ * @IOMMU_VFIO_IOAS_SET: Change the current compatibility IOAS
+ * @IOMMU_VFIO_IOAS_CLEAR: Disable VFIO compatibility
+ */
+enum iommufd_vfio_ioas_op {
+	IOMMU_VFIO_IOAS_GET = 0,
+	IOMMU_VFIO_IOAS_SET = 1,
+	IOMMU_VFIO_IOAS_CLEAR = 2,
+};
+
+/**
+ * struct iommu_vfio_ioas - ioctl(IOMMU_VFIO_IOAS)
+ * @size: sizeof(struct iommu_vfio_ioas)
+ * @ioas_id: For IOMMU_VFIO_IOAS_SET the input IOAS ID to set
+ *           For IOMMU_VFIO_IOAS_GET will output the IOAS ID
+ * @op: One of enum iommufd_vfio_ioas_op
+ * @__reserved: Must be 0
+ *
+ * The VFIO compatibility support uses a single ioas because VFIO APIs do not
+ * support the ID field. Set or Get the IOAS that VFIO compatibility will use.
+ * When VFIO_GROUP_SET_CONTAINER is used on an iommufd it will get the
+ * compatibility ioas, either by taking what is already set, or auto creating
+ * one. From then on VFIO will continue to use that ioas and is not effected by
+ * this ioctl. SET or CLEAR does not destroy any auto-created IOAS.
+ */
+struct iommu_vfio_ioas {
+	__u32 size;
+	__u32 ioas_id;
+	__u16 op;
+	__u16 __reserved;
+};
+#define IOMMU_VFIO_IOAS _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VFIO_IOAS)
+#endif