1 /****************************************************************************** 2 * gntdev.h 3 * 4 * Interface to /dev/xen/gntdev. 5 * 6 * Copyright (c) 2007, D G Murray 7 * Copyright (c) 2018, Oleksandr Andrushchenko, EPAM Systems Inc. 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License version 2 11 * as published by the Free Software Foundation; or, when distributed 12 * separately from the Linux kernel or incorporated into other 13 * software packages, subject to the following license: 14 * 15 * Permission is hereby granted, free of charge, to any person obtaining a copy 16 * of this source file (the "Software"), to deal in the Software without 17 * restriction, including without limitation the rights to use, copy, modify, 18 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 19 * and to permit persons to whom the Software is furnished to do so, subject to 20 * the following conditions: 21 * 22 * The above copyright notice and this permission notice shall be included in 23 * all copies or substantial portions of the Software. 24 * 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 31 * IN THE SOFTWARE. 32 */ 33 34 #ifndef __LINUX_PUBLIC_GNTDEV_H__ 35 #define __LINUX_PUBLIC_GNTDEV_H__ 36 37 struct ioctl_gntdev_grant_ref { 38 /* The domain ID of the grant to be mapped. */ 39 uint32_t domid; 40 /* The grant reference of the grant to be mapped. */ 41 uint32_t ref; 42 }; 43 44 /* 45 * Inserts the grant references into the mapping table of an instance 46 * of gntdev. N.B. This does not perform the mapping, which is deferred 47 * until mmap() is called with @index as the offset. 48 */ 49 #define IOCTL_GNTDEV_MAP_GRANT_REF \ 50 _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref)) 51 struct ioctl_gntdev_map_grant_ref { 52 /* IN parameters */ 53 /* The number of grants to be mapped. */ 54 uint32_t count; 55 uint32_t pad; 56 /* OUT parameters */ 57 /* The offset to be used on a subsequent call to mmap(). */ 58 uint64_t index; 59 /* Variable IN parameter. */ 60 /* Array of grant references, of size @count. */ 61 struct ioctl_gntdev_grant_ref refs[1]; 62 }; 63 64 /* 65 * Removes the grant references from the mapping table of an instance of 66 * of gntdev. N.B. munmap() must be called on the relevant virtual address(es) 67 * before this ioctl is called, or an error will result. 68 */ 69 #define IOCTL_GNTDEV_UNMAP_GRANT_REF \ 70 _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref)) 71 struct ioctl_gntdev_unmap_grant_ref { 72 /* IN parameters */ 73 /* The offset was returned by the corresponding map operation. */ 74 uint64_t index; 75 /* The number of pages to be unmapped. */ 76 uint32_t count; 77 uint32_t pad; 78 }; 79 80 /* 81 * Returns the offset in the driver's address space that corresponds 82 * to @vaddr. This can be used to perform a munmap(), followed by an 83 * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by 84 * the caller. The number of pages that were allocated at the same time as 85 * @vaddr is returned in @count. 86 * 87 * N.B. Where more than one page has been mapped into a contiguous range, the 88 * supplied @vaddr must correspond to the start of the range; otherwise 89 * an error will result. It is only possible to munmap() the entire 90 * contiguously-allocated range at once, and not any subrange thereof. 91 */ 92 #define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \ 93 _IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr)) 94 struct ioctl_gntdev_get_offset_for_vaddr { 95 /* IN parameters */ 96 /* The virtual address of the first mapped page in a range. */ 97 uint64_t vaddr; 98 /* OUT parameters */ 99 /* The offset that was used in the initial mmap() operation. */ 100 uint64_t offset; 101 /* The number of pages mapped in the VM area that begins at @vaddr. */ 102 uint32_t count; 103 uint32_t pad; 104 }; 105 106 /* 107 * Sets the maximum number of grants that may mapped at once by this gntdev 108 * instance. 109 * 110 * N.B. This must be called before any other ioctl is performed on the device. 111 */ 112 #define IOCTL_GNTDEV_SET_MAX_GRANTS \ 113 _IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants)) 114 struct ioctl_gntdev_set_max_grants { 115 /* IN parameter */ 116 /* The maximum number of grants that may be mapped at once. */ 117 uint32_t count; 118 }; 119 120 /* 121 * Sets up an unmap notification within the page, so that the other side can do 122 * cleanup if this side crashes. Required to implement cross-domain robust 123 * mutexes or close notification on communication channels. 124 * 125 * Each mapped page only supports one notification; multiple calls referring to 126 * the same page overwrite the previous notification. You must clear the 127 * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it 128 * to occur. 129 */ 130 #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \ 131 _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify)) 132 struct ioctl_gntdev_unmap_notify { 133 /* IN parameters */ 134 /* Offset in the file descriptor for a byte within the page. This offset 135 * is the result of the IOCTL_GNTDEV_MAP_GRANT_REF and is the same as 136 * is used with mmap(). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte 137 * within the page to be cleared. 138 */ 139 uint64_t index; 140 /* Action(s) to take on unmap */ 141 uint32_t action; 142 /* Event channel to notify */ 143 uint32_t event_channel_port; 144 }; 145 146 /* Clear (set to zero) the byte specified by index */ 147 #define UNMAP_NOTIFY_CLEAR_BYTE 0x1 148 /* Send an interrupt on the indicated event channel */ 149 #define UNMAP_NOTIFY_SEND_EVENT 0x2 150 151 struct ioctl_gntdev_grant_copy_segment { 152 union { 153 void *virt; 154 struct { 155 uint32_t ref; 156 uint16_t offset; 157 uint16_t domid; 158 } foreign; 159 } source, dest; 160 uint16_t len; 161 uint16_t flags; 162 int16_t status; 163 }; 164 165 #define IOCTL_GNTDEV_GRANT_COPY \ 166 _IOC(_IOC_NONE, 'G', 8, sizeof(struct ioctl_gntdev_grant_copy)) 167 struct ioctl_gntdev_grant_copy { 168 unsigned int count; 169 struct ioctl_gntdev_grant_copy_segment *segments; 170 }; 171 172 /* 173 * Flags to be used while requesting memory mapping's backing storage 174 * to be allocated with DMA API. 175 */ 176 177 /* 178 * The buffer is backed with memory allocated with dma_alloc_wc. 179 */ 180 #define GNTDEV_DMA_FLAG_WC (1 << 0) 181 182 /* 183 * The buffer is backed with memory allocated with dma_alloc_coherent. 184 */ 185 #define GNTDEV_DMA_FLAG_COHERENT (1 << 1) 186 187 /* 188 * Create a dma-buf [1] from grant references @refs of count @count provided 189 * by the foreign domain @domid with flags @flags. 190 * 191 * By default dma-buf is backed by system memory pages, but by providing 192 * one of the GNTDEV_DMA_FLAG_XXX flags it can also be created as 193 * a DMA write-combine or coherent buffer, e.g. allocated with dma_alloc_wc/ 194 * dma_alloc_coherent. 195 * 196 * Returns 0 if dma-buf was successfully created and the corresponding 197 * dma-buf's file descriptor is returned in @fd. 198 * 199 * [1] https://elixir.bootlin.com/linux/latest/source/Documentation/driver-api/dma-buf.rst 200 */ 201 202 #define IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS \ 203 _IOC(_IOC_NONE, 'G', 9, \ 204 sizeof(struct ioctl_gntdev_dmabuf_exp_from_refs)) 205 struct ioctl_gntdev_dmabuf_exp_from_refs { 206 /* IN parameters. */ 207 /* Specific options for this dma-buf: see GNTDEV_DMABUF_FLAG_XXX. */ 208 uint32_t flags; 209 /* Number of grant references in @refs array. */ 210 uint32_t count; 211 /* OUT parameters. */ 212 /* File descriptor of the dma-buf. */ 213 uint32_t fd; 214 /* The domain ID of the grant references to be mapped. */ 215 uint32_t domid; 216 /* Variable IN parameter. */ 217 /* Array of grant references of size @count. */ 218 uint32_t refs[1]; 219 }; 220 221 /* 222 * This will block until the dma-buf with the file descriptor @fd is 223 * released. This is only valid for buffers created with 224 * IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS. 225 * 226 * If withing @wait_to_ms milliseconds the buffer is not released 227 * then -ETIMEDOUT error is returned. 228 * If the buffer with file descriptor @fd does not exist or has already 229 * been released, then -ENOENT is returned. For valid file descriptors 230 * this must not be treated as error. 231 */ 232 #define IOCTL_GNTDEV_DMABUF_EXP_WAIT_RELEASED \ 233 _IOC(_IOC_NONE, 'G', 10, \ 234 sizeof(struct ioctl_gntdev_dmabuf_exp_wait_released)) 235 struct ioctl_gntdev_dmabuf_exp_wait_released { 236 /* IN parameters */ 237 uint32_t fd; 238 uint32_t wait_to_ms; 239 }; 240 241 /* 242 * Import a dma-buf with file descriptor @fd and export granted references 243 * to the pages of that dma-buf into array @refs of size @count. 244 */ 245 #define IOCTL_GNTDEV_DMABUF_IMP_TO_REFS \ 246 _IOC(_IOC_NONE, 'G', 11, \ 247 sizeof(struct ioctl_gntdev_dmabuf_imp_to_refs)) 248 struct ioctl_gntdev_dmabuf_imp_to_refs { 249 /* IN parameters. */ 250 /* File descriptor of the dma-buf. */ 251 uint32_t fd; 252 /* Number of grant references in @refs array. */ 253 uint32_t count; 254 /* The domain ID for which references to be granted. */ 255 uint32_t domid; 256 /* Reserved - must be zero. */ 257 uint32_t reserved; 258 /* OUT parameters. */ 259 /* Array of grant references of size @count. */ 260 uint32_t refs[1]; 261 }; 262 263 /* 264 * This will close all references to an imported buffer, so it can be 265 * released by the owner. This is only valid for buffers created with 266 * IOCTL_GNTDEV_DMABUF_IMP_TO_REFS. 267 */ 268 #define IOCTL_GNTDEV_DMABUF_IMP_RELEASE \ 269 _IOC(_IOC_NONE, 'G', 12, \ 270 sizeof(struct ioctl_gntdev_dmabuf_imp_release)) 271 struct ioctl_gntdev_dmabuf_imp_release { 272 /* IN parameters */ 273 uint32_t fd; 274 uint32_t reserved; 275 }; 276 277 #endif /* __LINUX_PUBLIC_GNTDEV_H__ */ 278