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 * 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 #include <linux/types.h> 38 39 struct ioctl_gntdev_grant_ref { 40 /* The domain ID of the grant to be mapped. */ 41 __u32 domid; 42 /* The grant reference of the grant to be mapped. */ 43 __u32 ref; 44 }; 45 46 /* 47 * Inserts the grant references into the mapping table of an instance 48 * of gntdev. N.B. This does not perform the mapping, which is deferred 49 * until mmap() is called with @index as the offset. 50 */ 51 #define IOCTL_GNTDEV_MAP_GRANT_REF \ 52 _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref)) 53 struct ioctl_gntdev_map_grant_ref { 54 /* IN parameters */ 55 /* The number of grants to be mapped. */ 56 __u32 count; 57 __u32 pad; 58 /* OUT parameters */ 59 /* The offset to be used on a subsequent call to mmap(). */ 60 __u64 index; 61 /* Variable IN parameter. */ 62 /* Array of grant references, of size @count. */ 63 struct ioctl_gntdev_grant_ref refs[1]; 64 }; 65 66 /* 67 * Removes the grant references from the mapping table of an instance of 68 * of gntdev. N.B. munmap() must be called on the relevant virtual address(es) 69 * before this ioctl is called, or an error will result. 70 */ 71 #define IOCTL_GNTDEV_UNMAP_GRANT_REF \ 72 _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref)) 73 struct ioctl_gntdev_unmap_grant_ref { 74 /* IN parameters */ 75 /* The offset was returned by the corresponding map operation. */ 76 __u64 index; 77 /* The number of pages to be unmapped. */ 78 __u32 count; 79 __u32 pad; 80 }; 81 82 /* 83 * Returns the offset in the driver's address space that corresponds 84 * to @vaddr. This can be used to perform a munmap(), followed by an 85 * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by 86 * the caller. The number of pages that were allocated at the same time as 87 * @vaddr is returned in @count. 88 * 89 * N.B. Where more than one page has been mapped into a contiguous range, the 90 * supplied @vaddr must correspond to the start of the range; otherwise 91 * an error will result. It is only possible to munmap() the entire 92 * contiguously-allocated range at once, and not any subrange thereof. 93 */ 94 #define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \ 95 _IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr)) 96 struct ioctl_gntdev_get_offset_for_vaddr { 97 /* IN parameters */ 98 /* The virtual address of the first mapped page in a range. */ 99 __u64 vaddr; 100 /* OUT parameters */ 101 /* The offset that was used in the initial mmap() operation. */ 102 __u64 offset; 103 /* The number of pages mapped in the VM area that begins at @vaddr. */ 104 __u32 count; 105 __u32 pad; 106 }; 107 108 /* 109 * Sets the maximum number of grants that may mapped at once by this gntdev 110 * instance. 111 * 112 * N.B. This must be called before any other ioctl is performed on the device. 113 */ 114 #define IOCTL_GNTDEV_SET_MAX_GRANTS \ 115 _IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants)) 116 struct ioctl_gntdev_set_max_grants { 117 /* IN parameter */ 118 /* The maximum number of grants that may be mapped at once. */ 119 __u32 count; 120 }; 121 122 /* 123 * Sets up an unmap notification within the page, so that the other side can do 124 * cleanup if this side crashes. Required to implement cross-domain robust 125 * mutexes or close notification on communication channels. 126 * 127 * Each mapped page only supports one notification; multiple calls referring to 128 * the same page overwrite the previous notification. You must clear the 129 * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it 130 * to occur. 131 */ 132 #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \ 133 _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify)) 134 struct ioctl_gntdev_unmap_notify { 135 /* IN parameters */ 136 /* Offset in the file descriptor for a byte within the page (same as 137 * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to 138 * be cleared. Otherwise, it can be any byte in the page whose 139 * notification we are adjusting. 140 */ 141 __u64 index; 142 /* Action(s) to take on unmap */ 143 __u32 action; 144 /* Event channel to notify */ 145 __u32 event_channel_port; 146 }; 147 148 struct gntdev_grant_copy_segment { 149 union { 150 void __user *virt; 151 struct { 152 grant_ref_t ref; 153 __u16 offset; 154 domid_t domid; 155 } foreign; 156 } source, dest; 157 __u16 len; 158 159 __u16 flags; /* GNTCOPY_* */ 160 __s16 status; /* GNTST_* */ 161 }; 162 163 /* 164 * Copy between grant references and local buffers. 165 * 166 * The copy is split into @count @segments, each of which can copy 167 * to/from one grant reference. 168 * 169 * Each segment is similar to struct gnttab_copy in the hypervisor ABI 170 * except the local buffer is specified using a virtual address 171 * (instead of a GFN and offset). 172 * 173 * The local buffer may cross a Xen page boundary -- the driver will 174 * split segments into multiple ops if required. 175 * 176 * Returns 0 if all segments have been processed and @status in each 177 * segment is valid. Note that one or more segments may have failed 178 * (status != GNTST_okay). 179 * 180 * If the driver had to split a segment into two or more ops, @status 181 * includes the status of the first failed op for that segment (or 182 * GNTST_okay if all ops were successful). 183 * 184 * If -1 is returned, the status of all segments is undefined. 185 * 186 * EINVAL: A segment has local buffers for both source and 187 * destination. 188 * EINVAL: A segment crosses the boundary of a foreign page. 189 * EFAULT: A segment's local buffer is not accessible. 190 */ 191 #define IOCTL_GNTDEV_GRANT_COPY \ 192 _IOC(_IOC_NONE, 'G', 8, sizeof(struct ioctl_gntdev_grant_copy)) 193 struct ioctl_gntdev_grant_copy { 194 unsigned int count; 195 struct gntdev_grant_copy_segment __user *segments; 196 }; 197 198 /* Clear (set to zero) the byte specified by index */ 199 #define UNMAP_NOTIFY_CLEAR_BYTE 0x1 200 /* Send an interrupt on the indicated event channel */ 201 #define UNMAP_NOTIFY_SEND_EVENT 0x2 202 203 #endif /* __LINUX_PUBLIC_GNTDEV_H__ */ 204
