1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES.
3  */
4 #ifndef _UAPI_IOMMUFD_H
5 #define _UAPI_IOMMUFD_H
6 
7 #include <linux/types.h>
8 #include <linux/ioctl.h>
9 
10 #define IOMMUFD_TYPE (';')
11 
12 /**
13  * DOC: General ioctl format
14  *
15  * The ioctl interface follows a general format to allow for extensibility. Each
16  * ioctl is passed in a structure pointer as the argument providing the size of
17  * the structure in the first u32. The kernel checks that any structure space
18  * beyond what it understands is 0. This allows userspace to use the backward
19  * compatible portion while consistently using the newer, larger, structures.
20  *
21  * ioctls use a standard meaning for common errnos:
22  *
23  *  - ENOTTY: The IOCTL number itself is not supported at all
24  *  - E2BIG: The IOCTL number is supported, but the provided structure has
25  *    non-zero in a part the kernel does not understand.
26  *  - EOPNOTSUPP: The IOCTL number is supported, and the structure is
27  *    understood, however a known field has a value the kernel does not
28  *    understand or support.
29  *  - EINVAL: Everything about the IOCTL was understood, but a field is not
30  *    correct.
31  *  - ENOENT: An ID or IOVA provided does not exist.
32  *  - ENOMEM: Out of memory.
33  *  - EOVERFLOW: Mathematics overflowed.
34  *
35  * As well as additional errnos, within specific ioctls.
36  */
37 enum {
38 	IOMMUFD_CMD_BASE = 0x80,
39 	IOMMUFD_CMD_DESTROY = IOMMUFD_CMD_BASE,
40 	IOMMUFD_CMD_IOAS_ALLOC,
41 	IOMMUFD_CMD_IOAS_ALLOW_IOVAS,
42 	IOMMUFD_CMD_IOAS_COPY,
43 	IOMMUFD_CMD_IOAS_IOVA_RANGES,
44 	IOMMUFD_CMD_IOAS_MAP,
45 	IOMMUFD_CMD_IOAS_UNMAP,
46 	IOMMUFD_CMD_OPTION,
47 	IOMMUFD_CMD_VFIO_IOAS,
48 };
49 
50 /**
51  * struct iommu_destroy - ioctl(IOMMU_DESTROY)
52  * @size: sizeof(struct iommu_destroy)
53  * @id: iommufd object ID to destroy. Can be any destroyable object type.
54  *
55  * Destroy any object held within iommufd.
56  */
57 struct iommu_destroy {
58 	__u32 size;
59 	__u32 id;
60 };
61 #define IOMMU_DESTROY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DESTROY)
62 
63 /**
64  * struct iommu_ioas_alloc - ioctl(IOMMU_IOAS_ALLOC)
65  * @size: sizeof(struct iommu_ioas_alloc)
66  * @flags: Must be 0
67  * @out_ioas_id: Output IOAS ID for the allocated object
68  *
69  * Allocate an IO Address Space (IOAS) which holds an IO Virtual Address (IOVA)
70  * to memory mapping.
71  */
72 struct iommu_ioas_alloc {
73 	__u32 size;
74 	__u32 flags;
75 	__u32 out_ioas_id;
76 };
77 #define IOMMU_IOAS_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_ALLOC)
78 
79 /**
80  * struct iommu_iova_range - ioctl(IOMMU_IOVA_RANGE)
81  * @start: First IOVA
82  * @last: Inclusive last IOVA
83  *
84  * An interval in IOVA space.
85  */
86 struct iommu_iova_range {
87 	__aligned_u64 start;
88 	__aligned_u64 last;
89 };
90 
91 /**
92  * struct iommu_ioas_iova_ranges - ioctl(IOMMU_IOAS_IOVA_RANGES)
93  * @size: sizeof(struct iommu_ioas_iova_ranges)
94  * @ioas_id: IOAS ID to read ranges from
95  * @num_iovas: Input/Output total number of ranges in the IOAS
96  * @__reserved: Must be 0
97  * @allowed_iovas: Pointer to the output array of struct iommu_iova_range
98  * @out_iova_alignment: Minimum alignment required for mapping IOVA
99  *
100  * Query an IOAS for ranges of allowed IOVAs. Mapping IOVA outside these ranges
101  * is not allowed. num_iovas will be set to the total number of iovas and
102  * the allowed_iovas[] will be filled in as space permits.
103  *
104  * The allowed ranges are dependent on the HW path the DMA operation takes, and
105  * can change during the lifetime of the IOAS. A fresh empty IOAS will have a
106  * full range, and each attached device will narrow the ranges based on that
107  * device's HW restrictions. Detaching a device can widen the ranges. Userspace
108  * should query ranges after every attach/detach to know what IOVAs are valid
109  * for mapping.
110  *
111  * On input num_iovas is the length of the allowed_iovas array. On output it is
112  * the total number of iovas filled in. The ioctl will return -EMSGSIZE and set
113  * num_iovas to the required value if num_iovas is too small. In this case the
114  * caller should allocate a larger output array and re-issue the ioctl.
115  *
116  * out_iova_alignment returns the minimum IOVA alignment that can be given
117  * to IOMMU_IOAS_MAP/COPY. IOVA's must satisfy::
118  *
119  *   starting_iova % out_iova_alignment == 0
120  *   (starting_iova + length) % out_iova_alignment == 0
121  *
122  * out_iova_alignment can be 1 indicating any IOVA is allowed. It cannot
123  * be higher than the system PAGE_SIZE.
124  */
125 struct iommu_ioas_iova_ranges {
126 	__u32 size;
127 	__u32 ioas_id;
128 	__u32 num_iovas;
129 	__u32 __reserved;
130 	__aligned_u64 allowed_iovas;
131 	__aligned_u64 out_iova_alignment;
132 };
133 #define IOMMU_IOAS_IOVA_RANGES _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_IOVA_RANGES)
134 
135 /**
136  * struct iommu_ioas_allow_iovas - ioctl(IOMMU_IOAS_ALLOW_IOVAS)
137  * @size: sizeof(struct iommu_ioas_allow_iovas)
138  * @ioas_id: IOAS ID to allow IOVAs from
139  * @num_iovas: Input/Output total number of ranges in the IOAS
140  * @__reserved: Must be 0
141  * @allowed_iovas: Pointer to array of struct iommu_iova_range
142  *
143  * Ensure a range of IOVAs are always available for allocation. If this call
144  * succeeds then IOMMU_IOAS_IOVA_RANGES will never return a list of IOVA ranges
145  * that are narrower than the ranges provided here. This call will fail if
146  * IOMMU_IOAS_IOVA_RANGES is currently narrower than the given ranges.
147  *
148  * When an IOAS is first created the IOVA_RANGES will be maximally sized, and as
149  * devices are attached the IOVA will narrow based on the device restrictions.
150  * When an allowed range is specified any narrowing will be refused, ie device
151  * attachment can fail if the device requires limiting within the allowed range.
152  *
153  * Automatic IOVA allocation is also impacted by this call. MAP will only
154  * allocate within the allowed IOVAs if they are present.
155  *
156  * This call replaces the entire allowed list with the given list.
157  */
158 struct iommu_ioas_allow_iovas {
159 	__u32 size;
160 	__u32 ioas_id;
161 	__u32 num_iovas;
162 	__u32 __reserved;
163 	__aligned_u64 allowed_iovas;
164 };
165 #define IOMMU_IOAS_ALLOW_IOVAS _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_ALLOW_IOVAS)
166 
167 /**
168  * enum iommufd_ioas_map_flags - Flags for map and copy
169  * @IOMMU_IOAS_MAP_FIXED_IOVA: If clear the kernel will compute an appropriate
170  *                             IOVA to place the mapping at
171  * @IOMMU_IOAS_MAP_WRITEABLE: DMA is allowed to write to this mapping
172  * @IOMMU_IOAS_MAP_READABLE: DMA is allowed to read from this mapping
173  */
174 enum iommufd_ioas_map_flags {
175 	IOMMU_IOAS_MAP_FIXED_IOVA = 1 << 0,
176 	IOMMU_IOAS_MAP_WRITEABLE = 1 << 1,
177 	IOMMU_IOAS_MAP_READABLE = 1 << 2,
178 };
179 
180 /**
181  * struct iommu_ioas_map - ioctl(IOMMU_IOAS_MAP)
182  * @size: sizeof(struct iommu_ioas_map)
183  * @flags: Combination of enum iommufd_ioas_map_flags
184  * @ioas_id: IOAS ID to change the mapping of
185  * @__reserved: Must be 0
186  * @user_va: Userspace pointer to start mapping from
187  * @length: Number of bytes to map
188  * @iova: IOVA the mapping was placed at. If IOMMU_IOAS_MAP_FIXED_IOVA is set
189  *        then this must be provided as input.
190  *
191  * Set an IOVA mapping from a user pointer. If FIXED_IOVA is specified then the
192  * mapping will be established at iova, otherwise a suitable location based on
193  * the reserved and allowed lists will be automatically selected and returned in
194  * iova.
195  *
196  * If IOMMU_IOAS_MAP_FIXED_IOVA is specified then the iova range must currently
197  * be unused, existing IOVA cannot be replaced.
198  */
199 struct iommu_ioas_map {
200 	__u32 size;
201 	__u32 flags;
202 	__u32 ioas_id;
203 	__u32 __reserved;
204 	__aligned_u64 user_va;
205 	__aligned_u64 length;
206 	__aligned_u64 iova;
207 };
208 #define IOMMU_IOAS_MAP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_MAP)
209 
210 /**
211  * struct iommu_ioas_copy - ioctl(IOMMU_IOAS_COPY)
212  * @size: sizeof(struct iommu_ioas_copy)
213  * @flags: Combination of enum iommufd_ioas_map_flags
214  * @dst_ioas_id: IOAS ID to change the mapping of
215  * @src_ioas_id: IOAS ID to copy from
216  * @length: Number of bytes to copy and map
217  * @dst_iova: IOVA the mapping was placed at. If IOMMU_IOAS_MAP_FIXED_IOVA is
218  *            set then this must be provided as input.
219  * @src_iova: IOVA to start the copy
220  *
221  * Copy an already existing mapping from src_ioas_id and establish it in
222  * dst_ioas_id. The src iova/length must exactly match a range used with
223  * IOMMU_IOAS_MAP.
224  *
225  * This may be used to efficiently clone a subset of an IOAS to another, or as a
226  * kind of 'cache' to speed up mapping. Copy has an efficiency advantage over
227  * establishing equivalent new mappings, as internal resources are shared, and
228  * the kernel will pin the user memory only once.
229  */
230 struct iommu_ioas_copy {
231 	__u32 size;
232 	__u32 flags;
233 	__u32 dst_ioas_id;
234 	__u32 src_ioas_id;
235 	__aligned_u64 length;
236 	__aligned_u64 dst_iova;
237 	__aligned_u64 src_iova;
238 };
239 #define IOMMU_IOAS_COPY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_COPY)
240 
241 /**
242  * struct iommu_ioas_unmap - ioctl(IOMMU_IOAS_UNMAP)
243  * @size: sizeof(struct iommu_ioas_unmap)
244  * @ioas_id: IOAS ID to change the mapping of
245  * @iova: IOVA to start the unmapping at
246  * @length: Number of bytes to unmap, and return back the bytes unmapped
247  *
248  * Unmap an IOVA range. The iova/length must be a superset of a previously
249  * mapped range used with IOMMU_IOAS_MAP or IOMMU_IOAS_COPY. Splitting or
250  * truncating ranges is not allowed. The values 0 to U64_MAX will unmap
251  * everything.
252  */
253 struct iommu_ioas_unmap {
254 	__u32 size;
255 	__u32 ioas_id;
256 	__aligned_u64 iova;
257 	__aligned_u64 length;
258 };
259 #define IOMMU_IOAS_UNMAP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_UNMAP)
260 
261 /**
262  * enum iommufd_option - ioctl(IOMMU_OPTION_RLIMIT_MODE) and
263  *                       ioctl(IOMMU_OPTION_HUGE_PAGES)
264  * @IOMMU_OPTION_RLIMIT_MODE:
265  *    Change how RLIMIT_MEMLOCK accounting works. The caller must have privilege
266  *    to invoke this. Value 0 (default) is user based accouting, 1 uses process
267  *    based accounting. Global option, object_id must be 0
268  * @IOMMU_OPTION_HUGE_PAGES:
269  *    Value 1 (default) allows contiguous pages to be combined when generating
270  *    iommu mappings. Value 0 disables combining, everything is mapped to
271  *    PAGE_SIZE. This can be useful for benchmarking.  This is a per-IOAS
272  *    option, the object_id must be the IOAS ID.
273  */
274 enum iommufd_option {
275 	IOMMU_OPTION_RLIMIT_MODE = 0,
276 	IOMMU_OPTION_HUGE_PAGES = 1,
277 };
278 
279 /**
280  * enum iommufd_option_ops - ioctl(IOMMU_OPTION_OP_SET) and
281  *                           ioctl(IOMMU_OPTION_OP_GET)
282  * @IOMMU_OPTION_OP_SET: Set the option's value
283  * @IOMMU_OPTION_OP_GET: Get the option's value
284  */
285 enum iommufd_option_ops {
286 	IOMMU_OPTION_OP_SET = 0,
287 	IOMMU_OPTION_OP_GET = 1,
288 };
289 
290 /**
291  * struct iommu_option - iommu option multiplexer
292  * @size: sizeof(struct iommu_option)
293  * @option_id: One of enum iommufd_option
294  * @op: One of enum iommufd_option_ops
295  * @__reserved: Must be 0
296  * @object_id: ID of the object if required
297  * @val64: Option value to set or value returned on get
298  *
299  * Change a simple option value. This multiplexor allows controlling options
300  * on objects. IOMMU_OPTION_OP_SET will load an option and IOMMU_OPTION_OP_GET
301  * will return the current value.
302  */
303 struct iommu_option {
304 	__u32 size;
305 	__u32 option_id;
306 	__u16 op;
307 	__u16 __reserved;
308 	__u32 object_id;
309 	__aligned_u64 val64;
310 };
311 #define IOMMU_OPTION _IO(IOMMUFD_TYPE, IOMMUFD_CMD_OPTION)
312 
313 /**
314  * enum iommufd_vfio_ioas_op - IOMMU_VFIO_IOAS_* ioctls
315  * @IOMMU_VFIO_IOAS_GET: Get the current compatibility IOAS
316  * @IOMMU_VFIO_IOAS_SET: Change the current compatibility IOAS
317  * @IOMMU_VFIO_IOAS_CLEAR: Disable VFIO compatibility
318  */
319 enum iommufd_vfio_ioas_op {
320 	IOMMU_VFIO_IOAS_GET = 0,
321 	IOMMU_VFIO_IOAS_SET = 1,
322 	IOMMU_VFIO_IOAS_CLEAR = 2,
323 };
324 
325 /**
326  * struct iommu_vfio_ioas - ioctl(IOMMU_VFIO_IOAS)
327  * @size: sizeof(struct iommu_vfio_ioas)
328  * @ioas_id: For IOMMU_VFIO_IOAS_SET the input IOAS ID to set
329  *           For IOMMU_VFIO_IOAS_GET will output the IOAS ID
330  * @op: One of enum iommufd_vfio_ioas_op
331  * @__reserved: Must be 0
332  *
333  * The VFIO compatibility support uses a single ioas because VFIO APIs do not
334  * support the ID field. Set or Get the IOAS that VFIO compatibility will use.
335  * When VFIO_GROUP_SET_CONTAINER is used on an iommufd it will get the
336  * compatibility ioas, either by taking what is already set, or auto creating
337  * one. From then on VFIO will continue to use that ioas and is not effected by
338  * this ioctl. SET or CLEAR does not destroy any auto-created IOAS.
339  */
340 struct iommu_vfio_ioas {
341 	__u32 size;
342 	__u32 ioas_id;
343 	__u16 op;
344 	__u16 __reserved;
345 };
346 #define IOMMU_VFIO_IOAS _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VFIO_IOAS)
347 #endif
348