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