include/xen/grant_table.h

   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 #include <linux/mm_types.h>
  49 #include <linux/page-flags.h>
  50
  51 #define GNTTAB_RESERVED_XENSTORE 1
  52
  53 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
  54 #define NR_GRANT_FRAMES 4
  55
  56 struct gnttab_free_callback {
  57         struct gnttab_free_callback *next;
  58         void (*fn)(void *);
  59         void *arg;
  60         u16 count;
  61 };
  62
  63 struct gntab_unmap_queue_data;
  64
  65 typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data);
  66
  67 struct gntab_unmap_queue_data
  68 {
  69         struct delayed_work     gnttab_work;
  70         void *data;
  71         gnttab_unmap_refs_done  done;
  72         struct gnttab_unmap_grant_ref *unmap_ops;
  73         struct gnttab_unmap_grant_ref *kunmap_ops;
  74         struct page **pages;
  75         unsigned int count;
  76         unsigned int age;
  77 };
  78
  79 int gnttab_init(void);
  80 int gnttab_suspend(void);
  81 int gnttab_resume(void);
  82
  83 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
  84                                 int readonly);
  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
 132 void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
 133                                        unsigned long pfn);
 134
 135 static inline void
 136 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
 137                   uint32_t flags, grant_ref_t ref, domid_t domid)
 138 {
 139         if (flags & GNTMAP_contains_pte)
 140                 map->host_addr = addr;
 141         else if (xen_feature(XENFEAT_auto_translated_physmap))
 142                 map->host_addr = __pa(addr);
 143         else
 144                 map->host_addr = addr;
 145
 146         map->flags = flags;
 147         map->ref = ref;
 148         map->dom = domid;
 149 }
 150
 151 static inline void
 152 gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
 153                     uint32_t flags, grant_handle_t handle)
 154 {
 155         if (flags & GNTMAP_contains_pte)
 156                 unmap->host_addr = addr;
 157         else if (xen_feature(XENFEAT_auto_translated_physmap))
 158                 unmap->host_addr = __pa(addr);
 159         else
 160                 unmap->host_addr = addr;
 161
 162         unmap->handle = handle;
 163         unmap->dev_bus_addr = 0;
 164 }
 165
 166 int arch_gnttab_init(unsigned long nr_shared);
 167 int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes,
 168                            unsigned long max_nr_gframes,
 169                            void **__shared);
 170 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes);
 171
 172 struct grant_frames {
 173         xen_pfn_t *pfn;
 174         unsigned int count;
 175         void *vaddr;
 176 };
 177 extern struct grant_frames xen_auto_xlat_grant_frames;
 178 unsigned int gnttab_max_grant_frames(void);
 179 int gnttab_setup_auto_xlat_frames(phys_addr_t addr);
 180 void gnttab_free_auto_xlat_frames(void);
 181
 182 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
 183
 184 int gnttab_alloc_pages(int nr_pages, struct page **pages);
 185 void gnttab_free_pages(int nr_pages, struct page **pages);
 186
 187 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 188                     struct gnttab_map_grant_ref *kmap_ops,
 189                     struct page **pages, unsigned int count);
 190 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 191                       struct gnttab_unmap_grant_ref *kunmap_ops,
 192                       struct page **pages, unsigned int count);
 193 void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item);
 194
 195
 196 /* Perform a batch of grant map/copy operations. Retry every batch slot
 197  * for which the hypervisor returns GNTST_eagain. This is typically due
 198  * to paged out target frames.
 199  *
 200  * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds.
 201  *
 202  * Return value in each iand every status field of the batch guaranteed
 203  * to not be GNTST_eagain.
 204  */
 205 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
 206 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
 207
 208
 209 struct xen_page_foreign {
 210         domid_t domid;
 211         grant_ref_t gref;
 212 };
 213
 214 static inline struct xen_page_foreign *xen_page_foreign(struct page *page)
 215 {
 216         if (!PageForeign(page))
 217                 return NULL;
 218 #if BITS_PER_LONG < 64
 219         return (struct xen_page_foreign *)page->private;
 220 #else
 221         BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG);
 222         return (struct xen_page_foreign *)&page->private;
 223 #endif
 224 }
 225
 226 #endif /* __ASM_GNTTAB_H__ */