1 /****************************************************************************** 2 * grant_table.h 3 * 4 * Two sets of functionality: 5 * 1. Granting foreign access to our memory reservation. 6 * 2. Accessing others' memory reservations via grant references. 7 * (i.e., mechanisms for both sender and recipient of grant references) 8 * 9 * Copyright (c) 2004-2005, K A Fraser 10 * Copyright (c) 2005, Christopher Clark 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License version 2 14 * as published by the Free Software Foundation; or, when distributed 15 * separately from the Linux kernel or incorporated into other 16 * software packages, subject to the following license: 17 * 18 * Permission is hereby granted, free of charge, to any person obtaining a copy 19 * of this source file (the "Software"), to deal in the Software without 20 * restriction, including without limitation the rights to use, copy, modify, 21 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 22 * and to permit persons to whom the Software is furnished to do so, subject to 23 * the following conditions: 24 * 25 * The above copyright notice and this permission notice shall be included in 26 * all copies or substantial portions of the Software. 27 * 28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 29 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 30 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 31 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 32 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 33 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 34 * IN THE SOFTWARE. 35 */ 36 37 #ifndef __ASM_GNTTAB_H__ 38 #define __ASM_GNTTAB_H__ 39 40 #include <asm/page.h> 41 42 #include <xen/interface/xen.h> 43 #include <xen/interface/grant_table.h> 44 45 #include <asm/xen/hypervisor.h> 46 47 #include <xen/features.h> 48 49 #define GNTTAB_RESERVED_XENSTORE 1 50 51 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ 52 #define NR_GRANT_FRAMES 4 53 54 struct gnttab_free_callback { 55 struct gnttab_free_callback *next; 56 void (*fn)(void *); 57 void *arg; 58 u16 count; 59 }; 60 61 int gnttab_init(void); 62 int gnttab_suspend(void); 63 int gnttab_resume(void); 64 65 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, 66 int readonly); 67 int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, 68 int flags, unsigned page_off, 69 unsigned length); 70 int gnttab_grant_foreign_access_trans(domid_t domid, int flags, 71 domid_t trans_domid, 72 grant_ref_t trans_gref); 73 74 /* 75 * Are sub-page grants available on this version of Xen? Returns true if they 76 * are, and false if they're not. 77 */ 78 bool gnttab_subpage_grants_available(void); 79 80 /* 81 * Are transitive grants available on this version of Xen? Returns true if they 82 * are, and false if they're not. 83 */ 84 bool gnttab_trans_grants_available(void); 85 86 /* 87 * End access through the given grant reference, iff the grant entry is no 88 * longer in use. Return 1 if the grant entry was freed, 0 if it is still in 89 * use. 90 */ 91 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly); 92 93 /* 94 * Eventually end access through the given grant reference, and once that 95 * access has been ended, free the given page too. Access will be ended 96 * immediately iff the grant entry is not in use, otherwise it will happen 97 * some time later. page may be 0, in which case no freeing will occur. 98 */ 99 void gnttab_end_foreign_access(grant_ref_t ref, int readonly, 100 unsigned long page); 101 102 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn); 103 104 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); 105 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); 106 107 int gnttab_query_foreign_access(grant_ref_t ref); 108 109 /* 110 * operations on reserved batches of grant references 111 */ 112 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head); 113 114 void gnttab_free_grant_reference(grant_ref_t ref); 115 116 void gnttab_free_grant_references(grant_ref_t head); 117 118 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); 119 120 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); 121 122 void gnttab_release_grant_reference(grant_ref_t *private_head, 123 grant_ref_t release); 124 125 void gnttab_request_free_callback(struct gnttab_free_callback *callback, 126 void (*fn)(void *), void *arg, u16 count); 127 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); 128 129 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, 130 unsigned long frame, int readonly); 131 int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, 132 unsigned long frame, int flags, 133 unsigned page_off, 134 unsigned length); 135 int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid, 136 int flags, domid_t trans_domid, 137 grant_ref_t trans_gref); 138 139 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, 140 unsigned long pfn); 141 142 static inline void 143 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, 144 uint32_t flags, grant_ref_t ref, domid_t domid) 145 { 146 if (flags & GNTMAP_contains_pte) 147 map->host_addr = addr; 148 else if (xen_feature(XENFEAT_auto_translated_physmap)) 149 map->host_addr = __pa(addr); 150 else 151 map->host_addr = addr; 152 153 map->flags = flags; 154 map->ref = ref; 155 map->dom = domid; 156 } 157 158 static inline void 159 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, 160 uint32_t flags, grant_handle_t handle) 161 { 162 if (flags & GNTMAP_contains_pte) 163 unmap->host_addr = addr; 164 else if (xen_feature(XENFEAT_auto_translated_physmap)) 165 unmap->host_addr = __pa(addr); 166 else 167 unmap->host_addr = addr; 168 169 unmap->handle = handle; 170 unmap->dev_bus_addr = 0; 171 } 172 173 int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes, 174 unsigned long max_nr_gframes, 175 void **__shared); 176 int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes, 177 unsigned long max_nr_gframes, 178 grant_status_t **__shared); 179 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes); 180 181 extern unsigned long xen_hvm_resume_frames; 182 unsigned int gnttab_max_grant_frames(void); 183 184 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) 185 186 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, 187 struct gnttab_map_grant_ref *kmap_ops, 188 struct page **pages, unsigned int count); 189 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, 190 struct gnttab_map_grant_ref *kunmap_ops, 191 struct page **pages, unsigned int count); 192 193 /* Perform a batch of grant map/copy operations. Retry every batch slot 194 * for which the hypervisor returns GNTST_eagain. This is typically due 195 * to paged out target frames. 196 * 197 * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds. 198 * 199 * Return value in each iand every status field of the batch guaranteed 200 * to not be GNTST_eagain. 201 */ 202 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count); 203 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count); 204 205 #endif /* __ASM_GNTTAB_H__ */ 206