1 /* SPDX-License-Identifier: ((GPL-2.0 WITH Lin 1 /* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR MIT) */
2 /********************************************* 2 /******************************************************************************
3 * gntdev.h 3 * gntdev.h
4 * 4 *
5 * Interface to /dev/xen/gntdev. 5 * Interface to /dev/xen/gntdev.
6 * 6 *
7 * Copyright (c) 2007, D G Murray 7 * Copyright (c) 2007, D G Murray
8 * Copyright (c) 2018, Oleksandr Andrushchenko <<
9 * 8 *
10 * This program is free software; you can redi 9 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Genera 10 * modify it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundatio 11 * as published by the Free Software Foundation; or, when distributed
13 * separately from the Linux kernel or incorpo 12 * separately from the Linux kernel or incorporated into other
14 * software packages, subject to the following 13 * software packages, subject to the following license:
15 * 14 *
16 * Permission is hereby granted, free of charg 15 * Permission is hereby granted, free of charge, to any person obtaining a copy
17 * of this source file (the "Software"), to de 16 * of this source file (the "Software"), to deal in the Software without
18 * restriction, including without limitation t 17 * restriction, including without limitation the rights to use, copy, modify,
19 * merge, publish, distribute, sublicense, and 18 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
20 * and to permit persons to whom the Software 19 * and to permit persons to whom the Software is furnished to do so, subject to
21 * the following conditions: 20 * the following conditions:
22 * 21 *
23 * The above copyright notice and this permiss 22 * The above copyright notice and this permission notice shall be included in
24 * all copies or substantial portions of the S 23 * all copies or substantial portions of the Software.
25 * 24 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT W 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE W 26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINF 27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
29 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
30 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT 29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
31 * FROM, OUT OF OR IN CONNECTION WITH THE SOFT 30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 * IN THE SOFTWARE. 31 * IN THE SOFTWARE.
33 */ 32 */
34 33
35 #ifndef __LINUX_PUBLIC_GNTDEV_H__ 34 #ifndef __LINUX_PUBLIC_GNTDEV_H__
36 #define __LINUX_PUBLIC_GNTDEV_H__ 35 #define __LINUX_PUBLIC_GNTDEV_H__
37 36
38 #include <linux/types.h> 37 #include <linux/types.h>
39 38
40 struct ioctl_gntdev_grant_ref { 39 struct ioctl_gntdev_grant_ref {
41 /* The domain ID of the grant to be ma 40 /* The domain ID of the grant to be mapped. */
42 __u32 domid; 41 __u32 domid;
43 /* The grant reference of the grant to 42 /* The grant reference of the grant to be mapped. */
44 __u32 ref; 43 __u32 ref;
45 }; 44 };
46 45
47 /* 46 /*
48 * Inserts the grant references into the mappi 47 * Inserts the grant references into the mapping table of an instance
49 * of gntdev. N.B. This does not perform the m 48 * of gntdev. N.B. This does not perform the mapping, which is deferred
50 * until mmap() is called with @index as the o !! 49 * until mmap() is called with @index as the offset.
51 * considered opaque to userspace, with one ex <<
52 * references have ever been inserted into the <<
53 * instance, @index will be set to 0. This is <<
54 * with userspace APIs that expect a file desc <<
55 * mmap()'d at offset 0, such as Wayland. If @ <<
56 * ioctl will fail. <<
57 */ 50 */
58 #define IOCTL_GNTDEV_MAP_GRANT_REF \ 51 #define IOCTL_GNTDEV_MAP_GRANT_REF \
59 _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gn 52 _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
60 struct ioctl_gntdev_map_grant_ref { 53 struct ioctl_gntdev_map_grant_ref {
61 /* IN parameters */ 54 /* IN parameters */
62 /* The number of grants to be mapped. 55 /* The number of grants to be mapped. */
63 __u32 count; 56 __u32 count;
64 __u32 pad; 57 __u32 pad;
65 /* OUT parameters */ 58 /* OUT parameters */
66 /* The offset to be used on a subseque 59 /* The offset to be used on a subsequent call to mmap(). */
67 __u64 index; 60 __u64 index;
68 /* Variable IN parameter. */ 61 /* Variable IN parameter. */
69 /* Array of grant references, of size 62 /* Array of grant references, of size @count. */
70 struct ioctl_gntdev_grant_ref refs[1]; 63 struct ioctl_gntdev_grant_ref refs[1];
71 }; 64 };
72 65
73 /* 66 /*
74 * Removes the grant references from the mappi 67 * Removes the grant references from the mapping table of an instance of
75 * gntdev. N.B. munmap() must be called on the !! 68 * of gntdev. N.B. munmap() must be called on the relevant virtual address(es)
76 * before this ioctl is called, or an error wi 69 * before this ioctl is called, or an error will result.
77 */ 70 */
78 #define IOCTL_GNTDEV_UNMAP_GRANT_REF \ 71 #define IOCTL_GNTDEV_UNMAP_GRANT_REF \
79 _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gn 72 _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
80 struct ioctl_gntdev_unmap_grant_ref { 73 struct ioctl_gntdev_unmap_grant_ref {
81 /* IN parameters */ 74 /* IN parameters */
82 /* The offset was returned by the corr 75 /* The offset was returned by the corresponding map operation. */
83 __u64 index; 76 __u64 index;
84 /* The number of pages to be unmapped. 77 /* The number of pages to be unmapped. */
85 __u32 count; 78 __u32 count;
86 __u32 pad; 79 __u32 pad;
87 }; 80 };
88 81
89 /* 82 /*
90 * Returns the offset in the driver's address 83 * Returns the offset in the driver's address space that corresponds
91 * to @vaddr. This can be used to perform a mu 84 * to @vaddr. This can be used to perform a munmap(), followed by an
92 * UNMAP_GRANT_REF ioctl, where no state about 85 * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by
93 * the caller. The number of pages that were a 86 * the caller. The number of pages that were allocated at the same time as
94 * @vaddr is returned in @count. 87 * @vaddr is returned in @count.
95 * 88 *
96 * N.B. Where more than one page has been mapp 89 * N.B. Where more than one page has been mapped into a contiguous range, the
97 * supplied @vaddr must correspond to the 90 * supplied @vaddr must correspond to the start of the range; otherwise
98 * an error will result. It is only possi 91 * an error will result. It is only possible to munmap() the entire
99 * contiguously-allocated range at once, 92 * contiguously-allocated range at once, and not any subrange thereof.
100 */ 93 */
101 #define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \ 94 #define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \
102 _IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gn 95 _IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr))
103 struct ioctl_gntdev_get_offset_for_vaddr { 96 struct ioctl_gntdev_get_offset_for_vaddr {
104 /* IN parameters */ 97 /* IN parameters */
105 /* The virtual address of the first ma 98 /* The virtual address of the first mapped page in a range. */
106 __u64 vaddr; 99 __u64 vaddr;
107 /* OUT parameters */ 100 /* OUT parameters */
108 /* The offset that was used in the ini 101 /* The offset that was used in the initial mmap() operation. */
109 __u64 offset; 102 __u64 offset;
110 /* The number of pages mapped in the V 103 /* The number of pages mapped in the VM area that begins at @vaddr. */
111 __u32 count; 104 __u32 count;
112 __u32 pad; 105 __u32 pad;
113 }; 106 };
114 107
115 /* 108 /*
116 * Sets the maximum number of grants that may 109 * Sets the maximum number of grants that may mapped at once by this gntdev
117 * instance. 110 * instance.
118 * 111 *
119 * N.B. This must be called before any other i 112 * N.B. This must be called before any other ioctl is performed on the device.
120 */ 113 */
121 #define IOCTL_GNTDEV_SET_MAX_GRANTS \ 114 #define IOCTL_GNTDEV_SET_MAX_GRANTS \
122 _IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gn 115 _IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants))
123 struct ioctl_gntdev_set_max_grants { 116 struct ioctl_gntdev_set_max_grants {
124 /* IN parameter */ 117 /* IN parameter */
125 /* The maximum number of grants that m 118 /* The maximum number of grants that may be mapped at once. */
126 __u32 count; 119 __u32 count;
127 }; 120 };
128 121
129 /* 122 /*
130 * Sets up an unmap notification within the pa 123 * Sets up an unmap notification within the page, so that the other side can do
131 * cleanup if this side crashes. Required to i 124 * cleanup if this side crashes. Required to implement cross-domain robust
132 * mutexes or close notification on communicat 125 * mutexes or close notification on communication channels.
133 * 126 *
134 * Each mapped page only supports one notifica 127 * Each mapped page only supports one notification; multiple calls referring to
135 * the same page overwrite the previous notifi 128 * the same page overwrite the previous notification. You must clear the
136 * notification prior to the IOCTL_GNTALLOC_DE 129 * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it
137 * to occur. 130 * to occur.
138 */ 131 */
139 #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \ 132 #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \
140 _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gn 133 _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify))
141 struct ioctl_gntdev_unmap_notify { 134 struct ioctl_gntdev_unmap_notify {
142 /* IN parameters */ 135 /* IN parameters */
143 /* Offset in the file descriptor for a 136 /* Offset in the file descriptor for a byte within the page (same as
144 * used in mmap). If using UNMAP_NOTIF 137 * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to
145 * be cleared. Otherwise, it can be an 138 * be cleared. Otherwise, it can be any byte in the page whose
146 * notification we are adjusting. 139 * notification we are adjusting.
147 */ 140 */
148 __u64 index; 141 __u64 index;
149 /* Action(s) to take on unmap */ 142 /* Action(s) to take on unmap */
150 __u32 action; 143 __u32 action;
151 /* Event channel to notify */ 144 /* Event channel to notify */
152 __u32 event_channel_port; 145 __u32 event_channel_port;
153 }; 146 };
154 147
155 struct gntdev_grant_copy_segment { 148 struct gntdev_grant_copy_segment {
156 union { 149 union {
157 void __user *virt; 150 void __user *virt;
158 struct { 151 struct {
159 grant_ref_t ref; 152 grant_ref_t ref;
160 __u16 offset; 153 __u16 offset;
161 domid_t domid; 154 domid_t domid;
162 } foreign; 155 } foreign;
163 } source, dest; 156 } source, dest;
164 __u16 len; 157 __u16 len;
165 158
166 __u16 flags; /* GNTCOPY_* */ 159 __u16 flags; /* GNTCOPY_* */
167 __s16 status; /* GNTST_* */ 160 __s16 status; /* GNTST_* */
168 }; 161 };
169 162
170 /* 163 /*
171 * Copy between grant references and local buf 164 * Copy between grant references and local buffers.
172 * 165 *
173 * The copy is split into @count @segments, ea 166 * The copy is split into @count @segments, each of which can copy
174 * to/from one grant reference. 167 * to/from one grant reference.
175 * 168 *
176 * Each segment is similar to struct gnttab_co 169 * Each segment is similar to struct gnttab_copy in the hypervisor ABI
177 * except the local buffer is specified using 170 * except the local buffer is specified using a virtual address
178 * (instead of a GFN and offset). 171 * (instead of a GFN and offset).
179 * 172 *
180 * The local buffer may cross a Xen page bound 173 * The local buffer may cross a Xen page boundary -- the driver will
181 * split segments into multiple ops if require 174 * split segments into multiple ops if required.
182 * 175 *
183 * Returns 0 if all segments have been process 176 * Returns 0 if all segments have been processed and @status in each
184 * segment is valid. Note that one or more se 177 * segment is valid. Note that one or more segments may have failed
185 * (status != GNTST_okay). 178 * (status != GNTST_okay).
186 * 179 *
187 * If the driver had to split a segment into t 180 * If the driver had to split a segment into two or more ops, @status
188 * includes the status of the first failed op 181 * includes the status of the first failed op for that segment (or
189 * GNTST_okay if all ops were successful). 182 * GNTST_okay if all ops were successful).
190 * 183 *
191 * If -1 is returned, the status of all segmen 184 * If -1 is returned, the status of all segments is undefined.
192 * 185 *
193 * EINVAL: A segment has local buffers for bot 186 * EINVAL: A segment has local buffers for both source and
194 * destination. 187 * destination.
195 * EINVAL: A segment crosses the boundary of a 188 * EINVAL: A segment crosses the boundary of a foreign page.
196 * EFAULT: A segment's local buffer is not acc 189 * EFAULT: A segment's local buffer is not accessible.
197 */ 190 */
198 #define IOCTL_GNTDEV_GRANT_COPY \ 191 #define IOCTL_GNTDEV_GRANT_COPY \
199 _IOC(_IOC_NONE, 'G', 8, sizeof(struct 192 _IOC(_IOC_NONE, 'G', 8, sizeof(struct ioctl_gntdev_grant_copy))
200 struct ioctl_gntdev_grant_copy { 193 struct ioctl_gntdev_grant_copy {
201 unsigned int count; 194 unsigned int count;
202 struct gntdev_grant_copy_segment __use 195 struct gntdev_grant_copy_segment __user *segments;
203 }; 196 };
204 197
205 /* Clear (set to zero) the byte specified by i 198 /* Clear (set to zero) the byte specified by index */
206 #define UNMAP_NOTIFY_CLEAR_BYTE 0x1 199 #define UNMAP_NOTIFY_CLEAR_BYTE 0x1
207 /* Send an interrupt on the indicated event ch 200 /* Send an interrupt on the indicated event channel */
208 #define UNMAP_NOTIFY_SEND_EVENT 0x2 201 #define UNMAP_NOTIFY_SEND_EVENT 0x2
209 <<
210 /* <<
211 * Flags to be used while requesting memory ma <<
212 * to be allocated with DMA API. <<
213 */ <<
214 <<
215 /* <<
216 * The buffer is backed with memory allocated <<
217 */ <<
218 #define GNTDEV_DMA_FLAG_WC (1 << <<
219 <<
220 /* <<
221 * The buffer is backed with memory allocated <<
222 */ <<
223 #define GNTDEV_DMA_FLAG_COHERENT (1 << <<
224 <<
225 /* <<
226 * Create a dma-buf [1] from grant references <<
227 * by the foreign domain @domid with flags @fl <<
228 * <<
229 * By default dma-buf is backed by system memo <<
230 * one of the GNTDEV_DMA_FLAG_XXX flags it can <<
231 * a DMA write-combine or coherent buffer, e.g <<
232 * dma_alloc_coherent. <<
233 * <<
234 * Returns 0 if dma-buf was successfully creat <<
235 * dma-buf's file descriptor is returned in @f <<
236 * <<
237 * [1] Documentation/driver-api/dma-buf.rst <<
238 */ <<
239 <<
240 #define IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS \ <<
241 _IOC(_IOC_NONE, 'G', 9, \ <<
242 sizeof(struct ioctl_gntdev_dmabuf <<
243 struct ioctl_gntdev_dmabuf_exp_from_refs { <<
244 /* IN parameters. */ <<
245 /* Specific options for this dma-buf: <<
246 __u32 flags; <<
247 /* Number of grant references in @refs <<
248 __u32 count; <<
249 /* OUT parameters. */ <<
250 /* File descriptor of the dma-buf. */ <<
251 __u32 fd; <<
252 /* The domain ID of the grant referenc <<
253 __u32 domid; <<
254 /* Variable IN parameter. */ <<
255 /* Array of grant references of size @ <<
256 __u32 refs[1]; <<
257 }; <<
258 <<
259 /* <<
260 * This will block until the dma-buf with the <<
261 * released. This is only valid for buffers cr <<
262 * IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS. <<
263 * <<
264 * If within @wait_to_ms milliseconds the buff <<
265 * then -ETIMEDOUT error is returned. <<
266 * If the buffer with the file descriptor @fd <<
267 * been released, then -ENOENT is returned. Fo <<
268 * this must not be treated as error. <<
269 */ <<
270 #define IOCTL_GNTDEV_DMABUF_EXP_WAIT_RELEASED <<
271 _IOC(_IOC_NONE, 'G', 10, \ <<
272 sizeof(struct ioctl_gntdev_dmabuf <<
273 struct ioctl_gntdev_dmabuf_exp_wait_released { <<
274 /* IN parameters */ <<
275 __u32 fd; <<
276 __u32 wait_to_ms; <<
277 }; <<
278 <<
279 /* <<
280 * Import a dma-buf with file descriptor @fd a <<
281 * to the pages of that dma-buf into array @re <<
282 */ <<
283 #define IOCTL_GNTDEV_DMABUF_IMP_TO_REFS \ <<
284 _IOC(_IOC_NONE, 'G', 11, \ <<
285 sizeof(struct ioctl_gntdev_dmabuf <<
286 struct ioctl_gntdev_dmabuf_imp_to_refs { <<
287 /* IN parameters. */ <<
288 /* File descriptor of the dma-buf. */ <<
289 __u32 fd; <<
290 /* Number of grant references in @refs <<
291 __u32 count; <<
292 /* The domain ID for which references <<
293 __u32 domid; <<
294 /* Reserved - must be zero. */ <<
295 __u32 reserved; <<
296 /* OUT parameters. */ <<
297 /* Array of grant references of size @ <<
298 __u32 refs[1]; <<
299 }; <<
300 <<
301 /* <<
302 * This will close all references to the impor <<
303 * @fd, so it can be released by the owner. Th <<
304 * created with IOCTL_GNTDEV_DMABUF_IMP_TO_REF <<
305 */ <<
306 #define IOCTL_GNTDEV_DMABUF_IMP_RELEASE \ <<
307 _IOC(_IOC_NONE, 'G', 12, \ <<
308 sizeof(struct ioctl_gntdev_dmabuf <<
309 struct ioctl_gntdev_dmabuf_imp_release { <<
310 /* IN parameters */ <<
311 __u32 fd; <<
312 __u32 reserved; <<
313 }; <<
314 202
315 #endif /* __LINUX_PUBLIC_GNTDEV_H__ */ 203 #endif /* __LINUX_PUBLIC_GNTDEV_H__ */
316 204
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