1 /****************************************************************************** 2 * gntdev.h 3 * 4 * Interface to /dev/xen/gntdev. 5 * 6 * Copyright (c) 2007, D G Murray 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License version 2 10 * as published by the Free Software Foundation; or, when distributed 11 * separately from the Linux kernel or incorporated into other 12 * software packages, subject to the following license: 13 * 14 * Permission is hereby granted, free of charge, to any person obtaining a copy 15 * of this source file (the "Software"), to deal in the Software without 16 * restriction, including without limitation the rights to use, copy, modify, 17 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 18 * and to permit persons to whom the Software is furnished to do so, subject to 19 * the following conditions: 20 * 21 * The above copyright notice and this permission notice shall be included in 22 * all copies or substantial portions of the Software. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 25 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 26 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 27 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 28 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 29 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 30 * IN THE SOFTWARE. 31 */ 32 33 #ifndef __LINUX_PUBLIC_GNTDEV_H__ 34 #define __LINUX_PUBLIC_GNTDEV_H__ 35 36 #include <linux/types.h> 37 38 struct ioctl_gntdev_grant_ref { 39 /* The domain ID of the grant to be mapped. */ 40 __u32 domid; 41 /* The grant reference of the grant to be mapped. */ 42 __u32 ref; 43 }; 44 45 /* 46 * Inserts the grant references into the mapping table of an instance 47 * of gntdev. N.B. This does not perform the mapping, which is deferred 48 * until mmap() is called with @index as the offset. 49 */ 50 #define IOCTL_GNTDEV_MAP_GRANT_REF \ 51 _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref)) 52 struct ioctl_gntdev_map_grant_ref { 53 /* IN parameters */ 54 /* The number of grants to be mapped. */ 55 __u32 count; 56 __u32 pad; 57 /* OUT parameters */ 58 /* The offset to be used on a subsequent call to mmap(). */ 59 __u64 index; 60 /* Variable IN parameter. */ 61 /* Array of grant references, of size @count. */ 62 struct ioctl_gntdev_grant_ref refs[1]; 63 }; 64 65 /* 66 * Removes the grant references from the mapping table of an instance of 67 * of gntdev. N.B. munmap() must be called on the relevant virtual address(es) 68 * before this ioctl is called, or an error will result. 69 */ 70 #define IOCTL_GNTDEV_UNMAP_GRANT_REF \ 71 _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref)) 72 struct ioctl_gntdev_unmap_grant_ref { 73 /* IN parameters */ 74 /* The offset was returned by the corresponding map operation. */ 75 __u64 index; 76 /* The number of pages to be unmapped. */ 77 __u32 count; 78 __u32 pad; 79 }; 80 81 /* 82 * Returns the offset in the driver's address space that corresponds 83 * to @vaddr. This can be used to perform a munmap(), followed by an 84 * UNMAP_GRANT_REF ioctl, where no state about the offset is retained by 85 * the caller. The number of pages that were allocated at the same time as 86 * @vaddr is returned in @count. 87 * 88 * N.B. Where more than one page has been mapped into a contiguous range, the 89 * supplied @vaddr must correspond to the start of the range; otherwise 90 * an error will result. It is only possible to munmap() the entire 91 * contiguously-allocated range at once, and not any subrange thereof. 92 */ 93 #define IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR \ 94 _IOC(_IOC_NONE, 'G', 2, sizeof(struct ioctl_gntdev_get_offset_for_vaddr)) 95 struct ioctl_gntdev_get_offset_for_vaddr { 96 /* IN parameters */ 97 /* The virtual address of the first mapped page in a range. */ 98 __u64 vaddr; 99 /* OUT parameters */ 100 /* The offset that was used in the initial mmap() operation. */ 101 __u64 offset; 102 /* The number of pages mapped in the VM area that begins at @vaddr. */ 103 __u32 count; 104 __u32 pad; 105 }; 106 107 /* 108 * Sets the maximum number of grants that may mapped at once by this gntdev 109 * instance. 110 * 111 * N.B. This must be called before any other ioctl is performed on the device. 112 */ 113 #define IOCTL_GNTDEV_SET_MAX_GRANTS \ 114 _IOC(_IOC_NONE, 'G', 3, sizeof(struct ioctl_gntdev_set_max_grants)) 115 struct ioctl_gntdev_set_max_grants { 116 /* IN parameter */ 117 /* The maximum number of grants that may be mapped at once. */ 118 __u32 count; 119 }; 120 121 /* 122 * Sets up an unmap notification within the page, so that the other side can do 123 * cleanup if this side crashes. Required to implement cross-domain robust 124 * mutexes or close notification on communication channels. 125 * 126 * Each mapped page only supports one notification; multiple calls referring to 127 * the same page overwrite the previous notification. You must clear the 128 * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want it 129 * to occur. 130 */ 131 #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \ 132 _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify)) 133 struct ioctl_gntdev_unmap_notify { 134 /* IN parameters */ 135 /* Offset in the file descriptor for a byte within the page (same as 136 * used in mmap). If using UNMAP_NOTIFY_CLEAR_BYTE, this is the byte to 137 * be cleared. Otherwise, it can be any byte in the page whose 138 * notification we are adjusting. 139 */ 140 __u64 index; 141 /* Action(s) to take on unmap */ 142 __u32 action; 143 /* Event channel to notify */ 144 __u32 event_channel_port; 145 }; 146 147 struct gntdev_grant_copy_segment { 148 union { 149 void __user *virt; 150 struct { 151 grant_ref_t ref; 152 __u16 offset; 153 domid_t domid; 154 } foreign; 155 } source, dest; 156 __u16 len; 157 158 __u16 flags; /* GNTCOPY_* */ 159 __s16 status; /* GNTST_* */ 160 }; 161 162 /* 163 * Copy between grant references and local buffers. 164 * 165 * The copy is split into @count @segments, each of which can copy 166 * to/from one grant reference. 167 * 168 * Each segment is similar to struct gnttab_copy in the hypervisor ABI 169 * except the local buffer is specified using a virtual address 170 * (instead of a GFN and offset). 171 * 172 * The local buffer may cross a Xen page boundary -- the driver will 173 * split segments into multiple ops if required. 174 * 175 * Returns 0 if all segments have been processed and @status in each 176 * segment is valid. Note that one or more segments may have failed 177 * (status != GNTST_okay). 178 * 179 * If the driver had to split a segment into two or more ops, @status 180 * includes the status of the first failed op for that segment (or 181 * GNTST_okay if all ops were successful). 182 * 183 * If -1 is returned, the status of all segments is undefined. 184 * 185 * EINVAL: A segment has local buffers for both source and 186 * destination. 187 * EINVAL: A segment crosses the boundary of a foreign page. 188 * EFAULT: A segment's local buffer is not accessible. 189 */ 190 #define IOCTL_GNTDEV_GRANT_COPY \ 191 _IOC(_IOC_NONE, 'G', 8, sizeof(struct ioctl_gntdev_grant_copy)) 192 struct ioctl_gntdev_grant_copy { 193 unsigned int count; 194 struct gntdev_grant_copy_segment __user *segments; 195 }; 196 197 /* Clear (set to zero) the byte specified by index */ 198 #define UNMAP_NOTIFY_CLEAR_BYTE 0x1 199 /* Send an interrupt on the indicated event channel */ 200 #define UNMAP_NOTIFY_SEND_EVENT 0x2 201 202 #endif /* __LINUX_PUBLIC_GNTDEV_H__ */ 203
