linux/include/xen/interface/grant_table.h
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   1/******************************************************************************
   2 * grant_table.h
   3 *
   4 * Interface for granting foreign access to page frames, and receiving
   5 * page-ownership transfers.
   6 *
   7 * Permission is hereby granted, free of charge, to any person obtaining a copy
   8 * of this software and associated documentation files (the "Software"), to
   9 * deal in the Software without restriction, including without limitation the
  10 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  11 * sell copies of the Software, and to permit persons to whom the Software is
  12 * furnished to do so, subject to the following conditions:
  13 *
  14 * The above copyright notice and this permission notice shall be included in
  15 * all copies or substantial portions of the Software.
  16 *
  17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23 * DEALINGS IN THE SOFTWARE.
  24 *
  25 * Copyright (c) 2004, K A Fraser
  26 */
  27
  28#ifndef __XEN_PUBLIC_GRANT_TABLE_H__
  29#define __XEN_PUBLIC_GRANT_TABLE_H__
  30
  31#include <xen/interface/xen.h>
  32
  33/***********************************
  34 * GRANT TABLE REPRESENTATION
  35 */
  36
  37/* Some rough guidelines on accessing and updating grant-table entries
  38 * in a concurrency-safe manner. For more information, Linux contains a
  39 * reference implementation for guest OSes (arch/xen/kernel/grant_table.c).
  40 *
  41 * NB. WMB is a no-op on current-generation x86 processors. However, a
  42 *     compiler barrier will still be required.
  43 *
  44 * Introducing a valid entry into the grant table:
  45 *  1. Write ent->domid.
  46 *  2. Write ent->frame:
  47 *      GTF_permit_access:   Frame to which access is permitted.
  48 *      GTF_accept_transfer: Pseudo-phys frame slot being filled by new
  49 *                           frame, or zero if none.
  50 *  3. Write memory barrier (WMB).
  51 *  4. Write ent->flags, inc. valid type.
  52 *
  53 * Invalidating an unused GTF_permit_access entry:
  54 *  1. flags = ent->flags.
  55 *  2. Observe that !(flags & (GTF_reading|GTF_writing)).
  56 *  3. Check result of SMP-safe CMPXCHG(&ent->flags, flags, 0).
  57 *  NB. No need for WMB as reuse of entry is control-dependent on success of
  58 *      step 3, and all architectures guarantee ordering of ctrl-dep writes.
  59 *
  60 * Invalidating an in-use GTF_permit_access entry:
  61 *  This cannot be done directly. Request assistance from the domain controller
  62 *  which can set a timeout on the use of a grant entry and take necessary
  63 *  action. (NB. This is not yet implemented!).
  64 *
  65 * Invalidating an unused GTF_accept_transfer entry:
  66 *  1. flags = ent->flags.
  67 *  2. Observe that !(flags & GTF_transfer_committed). [*]
  68 *  3. Check result of SMP-safe CMPXCHG(&ent->flags, flags, 0).
  69 *  NB. No need for WMB as reuse of entry is control-dependent on success of
  70 *      step 3, and all architectures guarantee ordering of ctrl-dep writes.
  71 *  [*] If GTF_transfer_committed is set then the grant entry is 'committed'.
  72 *      The guest must /not/ modify the grant entry until the address of the
  73 *      transferred frame is written. It is safe for the guest to spin waiting
  74 *      for this to occur (detect by observing GTF_transfer_completed in
  75 *      ent->flags).
  76 *
  77 * Invalidating a committed GTF_accept_transfer entry:
  78 *  1. Wait for (ent->flags & GTF_transfer_completed).
  79 *
  80 * Changing a GTF_permit_access from writable to read-only:
  81 *  Use SMP-safe CMPXCHG to set GTF_readonly, while checking !GTF_writing.
  82 *
  83 * Changing a GTF_permit_access from read-only to writable:
  84 *  Use SMP-safe bit-setting instruction.
  85 */
  86
  87/*
  88 * Reference to a grant entry in a specified domain's grant table.
  89 */
  90typedef uint32_t grant_ref_t;
  91
  92/*
  93 * A grant table comprises a packed array of grant entries in one or more
  94 * page frames shared between Xen and a guest.
  95 * [XEN]: This field is written by Xen and read by the sharing guest.
  96 * [GST]: This field is written by the guest and read by Xen.
  97 */
  98
  99/*
 100 * Version 1 of the grant table entry structure is maintained purely
 101 * for backwards compatibility.  New guests should use version 2.
 102 */
 103struct grant_entry_v1 {
 104    /* GTF_xxx: various type and flag information.  [XEN,GST] */
 105    uint16_t flags;
 106    /* The domain being granted foreign privileges. [GST] */
 107    domid_t  domid;
 108    /*
 109     * GTF_permit_access: Frame that @domid is allowed to map and access. [GST]
 110     * GTF_accept_transfer: Frame whose ownership transferred by @domid. [XEN]
 111     */
 112    uint32_t frame;
 113};
 114
 115/*
 116 * Type of grant entry.
 117 *  GTF_invalid: This grant entry grants no privileges.
 118 *  GTF_permit_access: Allow @domid to map/access @frame.
 119 *  GTF_accept_transfer: Allow @domid to transfer ownership of one page frame
 120 *                       to this guest. Xen writes the page number to @frame.
 121 *  GTF_transitive: Allow @domid to transitively access a subrange of
 122 *                  @trans_grant in @trans_domid.  No mappings are allowed.
 123 */
 124#define GTF_invalid         (0U<<0)
 125#define GTF_permit_access   (1U<<0)
 126#define GTF_accept_transfer (2U<<0)
 127#define GTF_transitive      (3U<<0)
 128#define GTF_type_mask       (3U<<0)
 129
 130/*
 131 * Subflags for GTF_permit_access.
 132 *  GTF_readonly: Restrict @domid to read-only mappings and accesses. [GST]
 133 *  GTF_reading: Grant entry is currently mapped for reading by @domid. [XEN]
 134 *  GTF_writing: Grant entry is currently mapped for writing by @domid. [XEN]
 135 *  GTF_sub_page: Grant access to only a subrange of the page.  @domid
 136 *                will only be allowed to copy from the grant, and not
 137 *                map it. [GST]
 138 */
 139#define _GTF_readonly       (2)
 140#define GTF_readonly        (1U<<_GTF_readonly)
 141#define _GTF_reading        (3)
 142#define GTF_reading         (1U<<_GTF_reading)
 143#define _GTF_writing        (4)
 144#define GTF_writing         (1U<<_GTF_writing)
 145#define _GTF_sub_page       (8)
 146#define GTF_sub_page        (1U<<_GTF_sub_page)
 147
 148/*
 149 * Subflags for GTF_accept_transfer:
 150 *  GTF_transfer_committed: Xen sets this flag to indicate that it is committed
 151 *      to transferring ownership of a page frame. When a guest sees this flag
 152 *      it must /not/ modify the grant entry until GTF_transfer_completed is
 153 *      set by Xen.
 154 *  GTF_transfer_completed: It is safe for the guest to spin-wait on this flag
 155 *      after reading GTF_transfer_committed. Xen will always write the frame
 156 *      address, followed by ORing this flag, in a timely manner.
 157 */
 158#define _GTF_transfer_committed (2)
 159#define GTF_transfer_committed  (1U<<_GTF_transfer_committed)
 160#define _GTF_transfer_completed (3)
 161#define GTF_transfer_completed  (1U<<_GTF_transfer_completed)
 162
 163/*
 164 * Version 2 grant table entries.  These fulfil the same role as
 165 * version 1 entries, but can represent more complicated operations.
 166 * Any given domain will have either a version 1 or a version 2 table,
 167 * and every entry in the table will be the same version.
 168 *
 169 * The interface by which domains use grant references does not depend
 170 * on the grant table version in use by the other domain.
 171 */
 172
 173/*
 174 * Version 1 and version 2 grant entries share a common prefix.  The
 175 * fields of the prefix are documented as part of struct
 176 * grant_entry_v1.
 177 */
 178struct grant_entry_header {
 179    uint16_t flags;
 180    domid_t  domid;
 181};
 182
 183/*
 184 * Version 2 of the grant entry structure, here is a union because three
 185 * different types are suppotted: full_page, sub_page and transitive.
 186 */
 187union grant_entry_v2 {
 188    struct grant_entry_header hdr;
 189
 190    /*
 191     * This member is used for V1-style full page grants, where either:
 192     *
 193     * -- hdr.type is GTF_accept_transfer, or
 194     * -- hdr.type is GTF_permit_access and GTF_sub_page is not set.
 195     *
 196     * In that case, the frame field has the same semantics as the
 197     * field of the same name in the V1 entry structure.
 198     */
 199    struct {
 200        struct grant_entry_header hdr;
 201        uint32_t pad0;
 202        uint64_t frame;
 203    } full_page;
 204
 205    /*
 206     * If the grant type is GTF_grant_access and GTF_sub_page is set,
 207     * @domid is allowed to access bytes [@page_off,@page_off+@length)
 208     * in frame @frame.
 209     */
 210    struct {
 211        struct grant_entry_header hdr;
 212        uint16_t page_off;
 213        uint16_t length;
 214        uint64_t frame;
 215    } sub_page;
 216
 217    /*
 218     * If the grant is GTF_transitive, @domid is allowed to use the
 219     * grant @gref in domain @trans_domid, as if it was the local
 220     * domain.  Obviously, the transitive access must be compatible
 221     * with the original grant.
 222     */
 223    struct {
 224        struct grant_entry_header hdr;
 225        domid_t trans_domid;
 226        uint16_t pad0;
 227        grant_ref_t gref;
 228    } transitive;
 229
 230    uint32_t __spacer[4]; /* Pad to a power of two */
 231};
 232
 233typedef uint16_t grant_status_t;
 234
 235/***********************************
 236 * GRANT TABLE QUERIES AND USES
 237 */
 238
 239/*
 240 * Handle to track a mapping created via a grant reference.
 241 */
 242typedef uint32_t grant_handle_t;
 243
 244/*
 245 * GNTTABOP_map_grant_ref: Map the grant entry (<dom>,<ref>) for access
 246 * by devices and/or host CPUs. If successful, <handle> is a tracking number
 247 * that must be presented later to destroy the mapping(s). On error, <handle>
 248 * is a negative status code.
 249 * NOTES:
 250 *  1. If GNTMAP_device_map is specified then <dev_bus_addr> is the address
 251 *     via which I/O devices may access the granted frame.
 252 *  2. If GNTMAP_host_map is specified then a mapping will be added at
 253 *     either a host virtual address in the current address space, or at
 254 *     a PTE at the specified machine address.  The type of mapping to
 255 *     perform is selected through the GNTMAP_contains_pte flag, and the
 256 *     address is specified in <host_addr>.
 257 *  3. Mappings should only be destroyed via GNTTABOP_unmap_grant_ref. If a
 258 *     host mapping is destroyed by other means then it is *NOT* guaranteed
 259 *     to be accounted to the correct grant reference!
 260 */
 261#define GNTTABOP_map_grant_ref        0
 262struct gnttab_map_grant_ref {
 263    /* IN parameters. */
 264    uint64_t host_addr;
 265    uint32_t flags;               /* GNTMAP_* */
 266    grant_ref_t ref;
 267    domid_t  dom;
 268    /* OUT parameters. */
 269    int16_t  status;              /* GNTST_* */
 270    grant_handle_t handle;
 271    uint64_t dev_bus_addr;
 272};
 273DEFINE_GUEST_HANDLE_STRUCT(gnttab_map_grant_ref);
 274
 275/*
 276 * GNTTABOP_unmap_grant_ref: Destroy one or more grant-reference mappings
 277 * tracked by <handle>. If <host_addr> or <dev_bus_addr> is zero, that
 278 * field is ignored. If non-zero, they must refer to a device/host mapping
 279 * that is tracked by <handle>
 280 * NOTES:
 281 *  1. The call may fail in an undefined manner if either mapping is not
 282 *     tracked by <handle>.
 283 *  3. After executing a batch of unmaps, it is guaranteed that no stale
 284 *     mappings will remain in the device or host TLBs.
 285 */
 286#define GNTTABOP_unmap_grant_ref      1
 287struct gnttab_unmap_grant_ref {
 288    /* IN parameters. */
 289    uint64_t host_addr;
 290    uint64_t dev_bus_addr;
 291    grant_handle_t handle;
 292    /* OUT parameters. */
 293    int16_t  status;              /* GNTST_* */
 294};
 295DEFINE_GUEST_HANDLE_STRUCT(gnttab_unmap_grant_ref);
 296
 297/*
 298 * GNTTABOP_setup_table: Set up a grant table for <dom> comprising at least
 299 * <nr_frames> pages. The frame addresses are written to the <frame_list>.
 300 * Only <nr_frames> addresses are written, even if the table is larger.
 301 * NOTES:
 302 *  1. <dom> may be specified as DOMID_SELF.
 303 *  2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF.
 304 *  3. Xen may not support more than a single grant-table page per domain.
 305 */
 306#define GNTTABOP_setup_table          2
 307struct gnttab_setup_table {
 308    /* IN parameters. */
 309    domid_t  dom;
 310    uint32_t nr_frames;
 311    /* OUT parameters. */
 312    int16_t  status;              /* GNTST_* */
 313    GUEST_HANDLE(xen_pfn_t) frame_list;
 314};
 315DEFINE_GUEST_HANDLE_STRUCT(gnttab_setup_table);
 316
 317/*
 318 * GNTTABOP_dump_table: Dump the contents of the grant table to the
 319 * xen console. Debugging use only.
 320 */
 321#define GNTTABOP_dump_table           3
 322struct gnttab_dump_table {
 323    /* IN parameters. */
 324    domid_t dom;
 325    /* OUT parameters. */
 326    int16_t status;               /* GNTST_* */
 327};
 328DEFINE_GUEST_HANDLE_STRUCT(gnttab_dump_table);
 329
 330/*
 331 * GNTTABOP_transfer_grant_ref: Transfer <frame> to a foreign domain. The
 332 * foreign domain has previously registered its interest in the transfer via
 333 * <domid, ref>.
 334 *
 335 * Note that, even if the transfer fails, the specified page no longer belongs
 336 * to the calling domain *unless* the error is GNTST_bad_page.
 337 */
 338#define GNTTABOP_transfer                4
 339struct gnttab_transfer {
 340    /* IN parameters. */
 341    xen_pfn_t mfn;
 342    domid_t       domid;
 343    grant_ref_t   ref;
 344    /* OUT parameters. */
 345    int16_t       status;
 346};
 347DEFINE_GUEST_HANDLE_STRUCT(gnttab_transfer);
 348
 349/*
 350 * GNTTABOP_copy: Hypervisor based copy
 351 * source and destinations can be eithers MFNs or, for foreign domains,
 352 * grant references. the foreign domain has to grant read/write access
 353 * in its grant table.
 354 *
 355 * The flags specify what type source and destinations are (either MFN
 356 * or grant reference).
 357 *
 358 * Note that this can also be used to copy data between two domains
 359 * via a third party if the source and destination domains had previously
 360 * grant appropriate access to their pages to the third party.
 361 *
 362 * source_offset specifies an offset in the source frame, dest_offset
 363 * the offset in the target frame and  len specifies the number of
 364 * bytes to be copied.
 365 */
 366
 367#define _GNTCOPY_source_gref      (0)
 368#define GNTCOPY_source_gref       (1<<_GNTCOPY_source_gref)
 369#define _GNTCOPY_dest_gref        (1)
 370#define GNTCOPY_dest_gref         (1<<_GNTCOPY_dest_gref)
 371
 372#define GNTTABOP_copy                 5
 373struct gnttab_copy {
 374        /* IN parameters. */
 375        struct {
 376                union {
 377                        grant_ref_t ref;
 378                        xen_pfn_t   gmfn;
 379                } u;
 380                domid_t  domid;
 381                uint16_t offset;
 382        } source, dest;
 383        uint16_t      len;
 384        uint16_t      flags;          /* GNTCOPY_* */
 385        /* OUT parameters. */
 386        int16_t       status;
 387};
 388DEFINE_GUEST_HANDLE_STRUCT(gnttab_copy);
 389
 390/*
 391 * GNTTABOP_query_size: Query the current and maximum sizes of the shared
 392 * grant table.
 393 * NOTES:
 394 *  1. <dom> may be specified as DOMID_SELF.
 395 *  2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF.
 396 */
 397#define GNTTABOP_query_size           6
 398struct gnttab_query_size {
 399    /* IN parameters. */
 400    domid_t  dom;
 401    /* OUT parameters. */
 402    uint32_t nr_frames;
 403    uint32_t max_nr_frames;
 404    int16_t  status;              /* GNTST_* */
 405};
 406DEFINE_GUEST_HANDLE_STRUCT(gnttab_query_size);
 407
 408/*
 409 * GNTTABOP_unmap_and_replace: Destroy one or more grant-reference mappings
 410 * tracked by <handle> but atomically replace the page table entry with one
 411 * pointing to the machine address under <new_addr>.  <new_addr> will be
 412 * redirected to the null entry.
 413 * NOTES:
 414 *  1. The call may fail in an undefined manner if either mapping is not
 415 *     tracked by <handle>.
 416 *  2. After executing a batch of unmaps, it is guaranteed that no stale
 417 *     mappings will remain in the device or host TLBs.
 418 */
 419#define GNTTABOP_unmap_and_replace    7
 420struct gnttab_unmap_and_replace {
 421    /* IN parameters. */
 422    uint64_t host_addr;
 423    uint64_t new_addr;
 424    grant_handle_t handle;
 425    /* OUT parameters. */
 426    int16_t  status;              /* GNTST_* */
 427};
 428DEFINE_GUEST_HANDLE_STRUCT(gnttab_unmap_and_replace);
 429
 430/*
 431 * GNTTABOP_set_version: Request a particular version of the grant
 432 * table shared table structure.  This operation can only be performed
 433 * once in any given domain.  It must be performed before any grants
 434 * are activated; otherwise, the domain will be stuck with version 1.
 435 * The only defined versions are 1 and 2.
 436 */
 437#define GNTTABOP_set_version          8
 438struct gnttab_set_version {
 439    /* IN parameters */
 440    uint32_t version;
 441};
 442DEFINE_GUEST_HANDLE_STRUCT(gnttab_set_version);
 443
 444/*
 445 * GNTTABOP_get_status_frames: Get the list of frames used to store grant
 446 * status for <dom>. In grant format version 2, the status is separated
 447 * from the other shared grant fields to allow more efficient synchronization
 448 * using barriers instead of atomic cmpexch operations.
 449 * <nr_frames> specify the size of vector <frame_list>.
 450 * The frame addresses are returned in the <frame_list>.
 451 * Only <nr_frames> addresses are returned, even if the table is larger.
 452 * NOTES:
 453 *  1. <dom> may be specified as DOMID_SELF.
 454 *  2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF.
 455 */
 456#define GNTTABOP_get_status_frames     9
 457struct gnttab_get_status_frames {
 458    /* IN parameters. */
 459    uint32_t nr_frames;
 460    domid_t  dom;
 461    /* OUT parameters. */
 462    int16_t  status;              /* GNTST_* */
 463    GUEST_HANDLE(uint64_t) frame_list;
 464};
 465DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_status_frames);
 466
 467/*
 468 * GNTTABOP_get_version: Get the grant table version which is in
 469 * effect for domain <dom>.
 470 */
 471#define GNTTABOP_get_version          10
 472struct gnttab_get_version {
 473    /* IN parameters */
 474    domid_t dom;
 475    uint16_t pad;
 476    /* OUT parameters */
 477    uint32_t version;
 478};
 479DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_version);
 480
 481/*
 482 * Issue one or more cache maintenance operations on a portion of a
 483 * page granted to the calling domain by a foreign domain.
 484 */
 485#define GNTTABOP_cache_flush          12
 486struct gnttab_cache_flush {
 487    union {
 488        uint64_t dev_bus_addr;
 489        grant_ref_t ref;
 490    } a;
 491    uint16_t offset;   /* offset from start of grant */
 492    uint16_t length;   /* size within the grant */
 493#define GNTTAB_CACHE_CLEAN          (1<<0)
 494#define GNTTAB_CACHE_INVAL          (1<<1)
 495#define GNTTAB_CACHE_SOURCE_GREF    (1<<31)
 496    uint32_t op;
 497};
 498DEFINE_GUEST_HANDLE_STRUCT(gnttab_cache_flush);
 499
 500/*
 501 * Bitfield values for update_pin_status.flags.
 502 */
 503 /* Map the grant entry for access by I/O devices. */
 504#define _GNTMAP_device_map      (0)
 505#define GNTMAP_device_map       (1<<_GNTMAP_device_map)
 506 /* Map the grant entry for access by host CPUs. */
 507#define _GNTMAP_host_map        (1)
 508#define GNTMAP_host_map         (1<<_GNTMAP_host_map)
 509 /* Accesses to the granted frame will be restricted to read-only access. */
 510#define _GNTMAP_readonly        (2)
 511#define GNTMAP_readonly         (1<<_GNTMAP_readonly)
 512 /*
 513  * GNTMAP_host_map subflag:
 514  *  0 => The host mapping is usable only by the guest OS.
 515  *  1 => The host mapping is usable by guest OS + current application.
 516  */
 517#define _GNTMAP_application_map (3)
 518#define GNTMAP_application_map  (1<<_GNTMAP_application_map)
 519
 520 /*
 521  * GNTMAP_contains_pte subflag:
 522  *  0 => This map request contains a host virtual address.
 523  *  1 => This map request contains the machine addess of the PTE to update.
 524  */
 525#define _GNTMAP_contains_pte    (4)
 526#define GNTMAP_contains_pte     (1<<_GNTMAP_contains_pte)
 527
 528/*
 529 * Bits to be placed in guest kernel available PTE bits (architecture
 530 * dependent; only supported when XENFEAT_gnttab_map_avail_bits is set).
 531 */
 532#define _GNTMAP_guest_avail0    (16)
 533#define GNTMAP_guest_avail_mask ((uint32_t)~0 << _GNTMAP_guest_avail0)
 534
 535/*
 536 * Values for error status returns. All errors are -ve.
 537 */
 538#define GNTST_okay             (0)  /* Normal return.                        */
 539#define GNTST_general_error    (-1) /* General undefined error.              */
 540#define GNTST_bad_domain       (-2) /* Unrecognsed domain id.                */
 541#define GNTST_bad_gntref       (-3) /* Unrecognised or inappropriate gntref. */
 542#define GNTST_bad_handle       (-4) /* Unrecognised or inappropriate handle. */
 543#define GNTST_bad_virt_addr    (-5) /* Inappropriate virtual address to map. */
 544#define GNTST_bad_dev_addr     (-6) /* Inappropriate device address to unmap.*/
 545#define GNTST_no_device_space  (-7) /* Out of space in I/O MMU.              */
 546#define GNTST_permission_denied (-8) /* Not enough privilege for operation.  */
 547#define GNTST_bad_page         (-9) /* Specified page was invalid for op.    */
 548#define GNTST_bad_copy_arg    (-10) /* copy arguments cross page boundary.   */
 549#define GNTST_address_too_big (-11) /* transfer page address too large.      */
 550#define GNTST_eagain          (-12) /* Operation not done; try again.        */
 551
 552#define GNTTABOP_error_msgs {                   \
 553    "okay",                                     \
 554    "undefined error",                          \
 555    "unrecognised domain id",                   \
 556    "invalid grant reference",                  \
 557    "invalid mapping handle",                   \
 558    "invalid virtual address",                  \
 559    "invalid device address",                   \
 560    "no spare translation slot in the I/O MMU", \
 561    "permission denied",                        \
 562    "bad page",                                 \
 563    "copy arguments cross page boundary",       \
 564    "page address size too large",              \
 565    "operation not done; try again"             \
 566}
 567
 568#endif /* __XEN_PUBLIC_GRANT_TABLE_H__ */
 569