aboutsummaryrefslogtreecommitdiffstats
path: root/include/kernel-version.mk
diff options
context:
space:
mode:
Diffstat (limited to 'include/kernel-version.mk')
0 files changed, 0 insertions, 0 deletions
generated by cgit v1.2.3 (git 2.25.1) at 2026-02-24 01:46:27 +0000
a> 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 
/******************************************************************************
 * arch/x86/mm/p2m.c
 *
 * physical-to-machine mappings for automatically-translated domains.
 *
 * Parts of this code are Copyright (c) 2009 by Citrix Systems, Inc. (Patrick Colp)
 * Parts of this code are Copyright (c) 2007 by Advanced Micro Devices.
 * Parts of this code are Copyright (c) 2006-2007 by XenSource Inc.
 * Parts of this code are Copyright (c) 2006 by Michael A Fetterman
 * Parts based on earlier work by Michael A Fetterman, Ian Pratt et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <asm/domain.h>
#include <asm/page.h>
#include <asm/paging.h>
#include <asm/p2m.h>
#include <asm/hvm/vmx/vmx.h> /* ept_p2m_init() */
#include <xen/iommu.h>
#include <asm/mem_event.h>
#include <public/mem_event.h>
#include <asm/mem_sharing.h>
#include <xen/event.h>
#include <asm/hvm/nestedhvm.h>
#include <asm/hvm/svm/amd-iommu-proto.h>

#include "mm-locks.h"

/* turn on/off 1GB host page table support for hap, default on */
bool_t __read_mostly opt_hap_1gb = 1;
boolean_param("hap_1gb", opt_hap_1gb);

bool_t __read_mostly opt_hap_2mb = 1;
boolean_param("hap_2mb", opt_hap_2mb);

/* Printouts */
#define P2M_PRINTK(_f, _a...)                                \
    debugtrace_printk("p2m: %s(): " _f, __func__, ##_a)
#define P2M_ERROR(_f, _a...)                                 \
    printk("pg error: %s(): " _f, __func__, ##_a)
#if P2M_DEBUGGING
#define P2M_DEBUG(_f, _a...)                                 \
    debugtrace_printk("p2mdebug: %s(): " _f, __func__, ##_a)
#else
#define P2M_DEBUG(_f, _a...) do { (void)(_f); } while(0)
#endif


/* Override macros from asm/page.h to make them work with mfn_t */
#undef mfn_to_page
#define mfn_to_page(_m) __mfn_to_page(mfn_x(_m))
#undef mfn_valid
#define mfn_valid(_mfn) __mfn_valid(mfn_x(_mfn))
#undef page_to_mfn
#define page_to_mfn(_pg) _mfn(__page_to_mfn(_pg))


/* Init the datastructures for later use by the p2m code */
static void p2m_initialise(struct domain *d, struct p2m_domain *p2m)
{
    mm_lock_init(&p2m->lock);
    mm_lock_init(&p2m->pod.lock);
    INIT_LIST_HEAD(&p2m->np2m_list);
    INIT_PAGE_LIST_HEAD(&p2m->pages);
    INIT_PAGE_LIST_HEAD(&p2m->pod.super);
    INIT_PAGE_LIST_HEAD(&p2m->pod.single);

    p2m->domain = d;
    p2m->default_access = p2m_access_rwx;

    p2m->cr3 = CR3_EADDR;

    if ( hap_enabled(d) && (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) )
        ept_p2m_init(p2m);
    else
        p2m_pt_init(p2m);

    return;
}

static int
p2m_init_nestedp2m(struct domain *d)
{
    uint8_t i;
    struct p2m_domain *p2m;

    mm_lock_init(&d->arch.nested_p2m_lock);
    for (i = 0; i < MAX_NESTEDP2M; i++) {
        d->arch.nested_p2m[i] = p2m = xzalloc(struct p2m_domain);
        if (p2m == NULL)
            return -ENOMEM;
        if ( !zalloc_cpumask_var(&p2m->dirty_cpumask) )
            return -ENOMEM;
        p2m_initialise(d, p2m);
        p2m->write_p2m_entry = nestedp2m_write_p2m_entry;
        list_add(&p2m->np2m_list, &p2m_get_hostp2m(d)->np2m_list);
    }

    return 0;
}

int p2m_init(struct domain *d)
{
    struct p2m_domain *p2m;
    int rc;

    p2m_get_hostp2m(d) = p2m = xzalloc(struct p2m_domain);
    if ( p2m == NULL )
        return -ENOMEM;
    if ( !zalloc_cpumask_var(&p2m->dirty_cpumask) )
    {
        xfree(p2m);
        return -ENOMEM;
    }
    p2m_initialise(d, p2m);

    /* Must initialise nestedp2m unconditionally
     * since nestedhvm_enabled(d) returns false here.
     * (p2m_init runs too early for HVM_PARAM_* options) */
    rc = p2m_init_nestedp2m(d);
    if ( rc ) 
        p2m_final_teardown(d);
    return rc;
}

void p2m_change_entry_type_global(struct domain *d,
                                  p2m_type_t ot, p2m_type_t nt)
{
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    p2m_lock(p2m);
    p2m->change_entry_type_global(p2m, ot, nt);
    p2m_unlock(p2m);
}

mfn_t __get_gfn_type_access(struct p2m_domain *p2m, unsigned long gfn,
                    p2m_type_t *t, p2m_access_t *a, p2m_query_t q,
                    unsigned int *page_order, bool_t locked)
{
    mfn_t mfn;

    /* Unshare makes no sense withuot populate. */
    if ( q & P2M_UNSHARE )
        q |= P2M_ALLOC;

    if ( !p2m || !paging_mode_translate(p2m->domain) )
    {
        /* Not necessarily true, but for non-translated guests, we claim
         * it's the most generic kind of memory */
        *t = p2m_ram_rw;
        return _mfn(gfn);
    }

    /* For now only perform locking on hap domains */
    if ( locked && (hap_enabled(p2m->domain)) )
        /* Grab the lock here, don't release until put_gfn */
        gfn_lock(p2m, gfn, 0);

    mfn = p2m->get_entry(p2m, gfn, t, a, q, page_order);

#ifdef __x86_64__
    if ( (q & P2M_UNSHARE) && p2m_is_shared(*t) )
    {
        ASSERT(!p2m_is_nestedp2m(p2m));
        /* Try to unshare. If we fail, communicate ENOMEM without
         * sleeping. */
        if ( mem_sharing_unshare_page(p2m->domain, gfn, 0) < 0 )
            (void)mem_sharing_notify_enomem(p2m->domain, gfn, 0);
        mfn = p2m->get_entry(p2m, gfn, t, a, q, page_order);
    }
#endif

#ifdef __x86_64__
    if (unlikely((p2m_is_broken(*t))))
    {
        /* Return invalid_mfn to avoid caller's access */
        mfn = _mfn(INVALID_MFN);
        if ( q & P2M_ALLOC )
            domain_crash(p2m->domain);
    }
#endif

    return mfn;
}

void __put_gfn(struct p2m_domain *p2m, unsigned long gfn)
{
    if ( !p2m || !paging_mode_translate(p2m->domain) 
              || !hap_enabled(p2m->domain) )
        /* Nothing to do in this case */
        return;

    ASSERT(gfn_locked_by_me(p2m, gfn));

    gfn_unlock(p2m, gfn, 0);
}

int set_p2m_entry(struct p2m_domain *p2m, unsigned long gfn, mfn_t mfn, 
                  unsigned int page_order, p2m_type_t p2mt, p2m_access_t p2ma)
{
    struct domain *d = p2m->domain;
    unsigned long todo = 1ul << page_order;
    unsigned int order;
    int rc = 1;

    ASSERT(gfn_locked_by_me(p2m, gfn));

    while ( todo )
    {
        if ( hap_enabled(d) )
            order = ( (((gfn | mfn_x(mfn) | todo) & ((1ul << PAGE_ORDER_1G) - 1)) == 0) &&
                      hvm_hap_has_1gb(d) && opt_hap_1gb ) ? PAGE_ORDER_1G :
                      ((((gfn | mfn_x(mfn) | todo) & ((1ul << PAGE_ORDER_2M) - 1)) == 0) &&
                      hvm_hap_has_2mb(d) && opt_hap_2mb) ? PAGE_ORDER_2M : PAGE_ORDER_4K;
        else
            order = 0;

        if ( !p2m->set_entry(p2m, gfn, mfn, order, p2mt, p2ma) )
            rc = 0;
        gfn += 1ul << order;
        if ( mfn_x(mfn) != INVALID_MFN )
            mfn = _mfn(mfn_x(mfn) + (1ul << order));
        todo -= 1ul << order;
    }

    return rc;
}

struct page_info *p2m_alloc_ptp(struct p2m_domain *p2m, unsigned long type)
{
    struct page_info *pg;

    ASSERT(p2m);
    ASSERT(p2m->domain);
    ASSERT(p2m->domain->arch.paging.alloc_page);
    pg = p2m->domain->arch.paging.alloc_page(p2m->domain);
    if (pg == NULL)
        return NULL;

    page_list_add_tail(pg, &p2m->pages);
    pg->u.inuse.type_info = type | 1 | PGT_validated;

    return pg;
}

void p2m_free_ptp(struct p2m_domain *p2m, struct page_info *pg)
{
    ASSERT(pg);
    ASSERT(p2m);
    ASSERT(p2m->domain);
    ASSERT(p2m->domain->arch.paging.free_page);

    page_list_del(pg, &p2m->pages);
    p2m->domain->arch.paging.free_page(p2m->domain, pg);

    return;
}

// Allocate a new p2m table for a domain.
//
// The structure of the p2m table is that of a pagetable for xen (i.e. it is
// controlled by CONFIG_PAGING_LEVELS).
//
// Returns 0 for success or -errno.
//
int p2m_alloc_table(struct p2m_domain *p2m)
{
    mfn_t mfn = _mfn(INVALID_MFN);
    struct page_info *page, *p2m_top;
    unsigned int page_count = 0;
    unsigned long gfn = -1UL;
    struct domain *d = p2m->domain;

    p2m_lock(p2m);

    if ( pagetable_get_pfn(p2m_get_pagetable(p2m)) != 0 )
    {
        P2M_ERROR("p2m already allocated for this domain\n");
        p2m_unlock(p2m);
        return -EINVAL;
    }

    P2M_PRINTK("allocating p2m table\n");

    p2m_top = p2m_alloc_ptp(p2m,
#if CONFIG_PAGING_LEVELS == 4
        PGT_l4_page_table
#else
        PGT_l3_page_table
#endif
        );

    if ( p2m_top == NULL )
    {
        p2m_unlock(p2m);
        return -ENOMEM;
    }

    p2m->phys_table = pagetable_from_mfn(page_to_mfn(p2m_top));

    if ( hap_enabled(d) )
        iommu_share_p2m_table(d);

    P2M_PRINTK("populating p2m table\n");

    /* Initialise physmap tables for slot zero. Other code assumes this. */
    p2m->defer_nested_flush = 1;
    if ( !set_p2m_entry(p2m, 0, _mfn(INVALID_MFN), PAGE_ORDER_4K,
                        p2m_invalid, p2m->default_access) )
        goto error;

    if ( !p2m_is_nestedp2m(p2m) )
    {
        /* Copy all existing mappings from the page list and m2p */
        spin_lock(&p2m->domain->page_alloc_lock);
        page_list_for_each(page, &p2m->domain->page_list)
        {
            mfn = page_to_mfn(page);
            gfn = get_gpfn_from_mfn(mfn_x(mfn));
            /* Pages should not be shared that early */
            ASSERT(gfn != SHARED_M2P_ENTRY);
            page_count++;
            if ( gfn != INVALID_M2P_ENTRY
                && !set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2m_ram_rw, p2m->default_access) )
                goto error_unlock;
        }
        spin_unlock(&p2m->domain->page_alloc_lock);
    }
    p2m->defer_nested_flush = 0;

    P2M_PRINTK("p2m table initialised (%u pages)\n", page_count);
    p2m_unlock(p2m);
    return 0;

error_unlock:
    spin_unlock(&p2m->domain->page_alloc_lock);
 error:
    P2M_PRINTK("failed to initialize p2m table, gfn=%05lx, mfn=%"
               PRI_mfn "\n", gfn, mfn_x(mfn));
    p2m_unlock(p2m);
    return -ENOMEM;
}

void p2m_teardown(struct p2m_domain *p2m)
/* Return all the p2m pages to Xen.
 * We know we don't have any extra mappings to these pages */
{
    struct page_info *pg;
    struct domain *d = p2m->domain;
#ifdef __x86_64__
    unsigned long gfn;
    p2m_type_t t;
    mfn_t mfn;
#endif

    if (p2m == NULL)
        return;

    p2m_lock(p2m);

#ifdef __x86_64__
    for ( gfn=0; gfn < p2m->max_mapped_pfn; gfn++ )
    {
        p2m_access_t a;
        mfn = p2m->get_entry(p2m, gfn, &t, &a, 0, NULL);
        if ( mfn_valid(mfn) && (t == p2m_ram_shared) )
        {
            ASSERT(!p2m_is_nestedp2m(p2m));
            /* Does not fail with ENOMEM given the DESTROY flag */
            BUG_ON(mem_sharing_unshare_page(d, gfn, MEM_SHARING_DESTROY_GFN));
        }
    }
#endif

    p2m->phys_table = pagetable_null();

    while ( (pg = page_list_remove_head(&p2m->pages)) )
        d->arch.paging.free_page(d, pg);
    p2m_unlock(p2m);
}

static void p2m_teardown_nestedp2m(struct domain *d)
{
    uint8_t i;

    for (i = 0; i < MAX_NESTEDP2M; i++) {
        if ( !d->arch.nested_p2m[i] )
            continue;
        free_cpumask_var(d->arch.nested_p2m[i]->dirty_cpumask);
        xfree(d->arch.nested_p2m[i]);
        d->arch.nested_p2m[i] = NULL;
    }
}

void p2m_final_teardown(struct domain *d)
{
    /* Iterate over all p2m tables per domain */
    if ( d->arch.p2m )
    {
        free_cpumask_var(d->arch.p2m->dirty_cpumask);
        xfree(d->arch.p2m);
        d->arch.p2m = NULL;
    }

    /* We must teardown unconditionally because
     * we initialise them unconditionally.
     */
    p2m_teardown_nestedp2m(d);
}


static void
p2m_remove_page(struct p2m_domain *p2m, unsigned long gfn, unsigned long mfn,
                unsigned int page_order)
{
    unsigned long i;
    mfn_t mfn_return;
    p2m_type_t t;
    p2m_access_t a;

    if ( !paging_mode_translate(p2m->domain) )
    {
        if ( need_iommu(p2m->domain) )
            for ( i = 0; i < (1 << page_order); i++ )
                iommu_unmap_page(p2m->domain, mfn + i);
        return;
    }

    ASSERT(gfn_locked_by_me(p2m, gfn));
    P2M_DEBUG("removing gfn=%#lx mfn=%#lx\n", gfn, mfn);

    if ( mfn_valid(_mfn(mfn)) )
    {
        for ( i = 0; i < (1UL << page_order); i++ )
        {
            mfn_return = p2m->get_entry(p2m, gfn + i, &t, &a, 0, NULL);
            if ( !p2m_is_grant(t) && !p2m_is_shared(t) )
                set_gpfn_from_mfn(mfn+i, INVALID_M2P_ENTRY);
            ASSERT( !p2m_is_valid(t) || mfn + i == mfn_x(mfn_return) );
        }
    }
    set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), page_order, p2m_invalid, p2m->default_access);
}

void
guest_physmap_remove_page(struct domain *d, unsigned long gfn,
                          unsigned long mfn, unsigned int page_order)
{
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    gfn_lock(p2m, gfn, page_order);
    p2m_remove_page(p2m, gfn, mfn, page_order);
    gfn_unlock(p2m, gfn, page_order);
}

int
guest_physmap_add_entry(struct domain *d, unsigned long gfn,
                        unsigned long mfn, unsigned int page_order, 
                        p2m_type_t t)
{
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    unsigned long i, ogfn;
    p2m_type_t ot;
    p2m_access_t a;
    mfn_t omfn;
    int pod_count = 0;
    int rc = 0;

    if ( !paging_mode_translate(d) )
    {
        if ( need_iommu(d) && t == p2m_ram_rw )
        {
            for ( i = 0; i < (1 << page_order); i++ )
            {
                rc = iommu_map_page(
                    d, mfn + i, mfn + i, IOMMUF_readable|IOMMUF_writable);
                if ( rc != 0 )
                {
                    while ( i-- > 0 )
                        iommu_unmap_page(d, mfn + i);
                    return rc;
                }
            }
        }
        return 0;
    }

    rc = p2m_gfn_check_limit(d, gfn, page_order);
    if ( rc != 0 )
        return rc;

    p2m_lock(p2m);

    P2M_DEBUG("adding gfn=%#lx mfn=%#lx\n", gfn, mfn);

    /* First, remove m->p mappings for existing p->m mappings */
    for ( i = 0; i < (1UL << page_order); i++ )
    {
        omfn = p2m->get_entry(p2m, gfn + i, &ot, &a, 0, NULL);
#ifdef __x86_64__
        if ( p2m_is_shared(ot) )
        {
            /* Do an unshare to cleanly take care of all corner 
             * cases. */
            int rc;
            rc = mem_sharing_unshare_page(p2m->domain, gfn + i, 0);
            if ( rc )
            {
                p2m_unlock(p2m);
                /* NOTE: Should a guest domain bring this upon itself,
                 * there is not a whole lot we can do. We are buried
                 * deep in locks from most code paths by now. So, fail
                 * the call and don't try to sleep on a wait queue
                 * while placing the mem event.
                 *
                 * However, all current (changeset 3432abcf9380) code
                 * paths avoid this unsavoury situation. For now.
                 *
                 * Foreign domains are okay to place an event as they 
                 * won't go to sleep. */
                (void)mem_sharing_notify_enomem(p2m->domain, gfn + i, 0);
                return rc;
            }
            omfn = p2m->get_entry(p2m, gfn + i, &ot, &a, 0, NULL);
            ASSERT(!p2m_is_shared(ot));
        }
#endif /* __x86_64__ */
        if ( p2m_is_grant(ot) )
        {
            /* Really shouldn't be unmapping grant maps this way */
            domain_crash(d);
            p2m_unlock(p2m);
            
            return -EINVAL;
        }
        else if ( p2m_is_ram(ot) && !p2m_is_paged(ot) )
        {
            ASSERT(mfn_valid(omfn));
            set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);
        }
        else if ( ot == p2m_populate_on_demand )
        {
            /* Count how man PoD entries we'll be replacing if successful */
            pod_count++;
        }
        else if ( p2m_is_paging(ot) && (ot != p2m_ram_paging_out) )
        {
            /* We're plugging a hole in the physmap where a paged out page was */
            atomic_dec(&d->paged_pages);
        }
    }

    /* Then, look for m->p mappings for this range and deal with them */
    for ( i = 0; i < (1UL << page_order); i++ )
    {
        if ( page_get_owner(mfn_to_page(_mfn(mfn + i))) == dom_cow )
        {
            /* This is no way to add a shared page to your physmap! */
            gdprintk(XENLOG_ERR, "Adding shared mfn %lx directly to dom %hu "
                        "physmap not allowed.\n", mfn+i, d->domain_id);
            p2m_unlock(p2m);
            return -EINVAL;
        }
        if ( page_get_owner(mfn_to_page(_mfn(mfn + i))) != d )
            continue;
        ogfn = mfn_to_gfn(d, _mfn(mfn+i));
        if ( (ogfn != INVALID_M2P_ENTRY) && (ogfn != gfn + i) )
        {
            /* This machine frame is already mapped at another physical
             * address */
            P2M_DEBUG("aliased! mfn=%#lx, old gfn=%#lx, new gfn=%#lx\n",
                      mfn + i, ogfn, gfn + i);
            omfn = p2m->get_entry(p2m, ogfn, &ot, &a, 0, NULL);
            if ( p2m_is_ram(ot) && !p2m_is_paged(ot) )
            {
                ASSERT(mfn_valid(omfn));
                P2M_DEBUG("old gfn=%#lx -> mfn %#lx\n",
                          ogfn , mfn_x(omfn));
                if ( mfn_x(omfn) == (mfn + i) )
                    p2m_remove_page(p2m, ogfn, mfn + i, 0);
            }
        }
    }

    /* Now, actually do the two-way mapping */
    if ( mfn_valid(_mfn(mfn)) ) 
    {
        if ( !set_p2m_entry(p2m, gfn, _mfn(mfn), page_order, t, p2m->default_access) )
            rc = -EINVAL;
        if ( !p2m_is_grant(t) )
        {
            for ( i = 0; i < (1UL << page_order); i++ )
                set_gpfn_from_mfn(mfn+i, gfn+i);
        }
    }
    else
    {
        gdprintk(XENLOG_WARNING, "Adding bad mfn to p2m map (%#lx -> %#lx)\n",
                 gfn, mfn);
        if ( !set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), page_order, 
                            p2m_invalid, p2m->default_access) )
            rc = -EINVAL;
        else
        {
            pod_lock(p2m);
            p2m->pod.entry_count -= pod_count;
            BUG_ON(p2m->pod.entry_count < 0);
            pod_unlock(p2m);
        }
    }

    p2m_unlock(p2m);

    return rc;
}


/* Modify the p2m type of a single gfn from ot to nt, returning the 
 * entry's previous type.  Resets the access permissions. */
p2m_type_t p2m_change_type(struct domain *d, unsigned long gfn, 
                           p2m_type_t ot, p2m_type_t nt)
{
    p2m_access_t a;
    p2m_type_t pt;
    mfn_t mfn;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);

    BUG_ON(p2m_is_grant(ot) || p2m_is_grant(nt));

    gfn_lock(p2m, gfn, 0);

    mfn = p2m->get_entry(p2m, gfn, &pt, &a, 0, NULL);
    if ( pt == ot )
        set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, nt, p2m->default_access);

    gfn_unlock(p2m, gfn, 0);

    return pt;
}

/* Modify the p2m type of a range of gfns from ot to nt.
 * Resets the access permissions. */
void p2m_change_type_range(struct domain *d, 
                           unsigned long start, unsigned long end,
                           p2m_type_t ot, p2m_type_t nt)
{
    p2m_access_t a;
    p2m_type_t pt;
    unsigned long gfn;
    mfn_t mfn;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);

    BUG_ON(p2m_is_grant(ot) || p2m_is_grant(nt));

    p2m_lock(p2m);
    p2m->defer_nested_flush = 1;

    for ( gfn = start; gfn < end; gfn++ )
    {
        mfn = p2m->get_entry(p2m, gfn, &pt, &a, 0, NULL);
        if ( pt == ot )
            set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, nt, p2m->default_access);
    }

    p2m->defer_nested_flush = 0;
    if ( nestedhvm_enabled(d) )
        p2m_flush_nestedp2m(d);
    p2m_unlock(p2m);
}



int
set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
{
    int rc = 0;
    p2m_access_t a;
    p2m_type_t ot;
    mfn_t omfn;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);

    if ( !paging_mode_translate(d) )
        return 0;

    gfn_lock(p2m, gfn, 0);
    omfn = p2m->get_entry(p2m, gfn, &ot, &a, 0, NULL);
    if ( p2m_is_grant(ot) )
    {
        p2m_unlock(p2m);
        domain_crash(d);
        return 0;
    }
    else if ( p2m_is_ram(ot) )
    {
        ASSERT(mfn_valid(omfn));
        set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);
    }

    P2M_DEBUG("set mmio %lx %lx\n", gfn, mfn_x(mfn));
    rc = set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2m_mmio_direct, p2m->default_access);
    gfn_unlock(p2m, gfn, 0);
    if ( 0 == rc )
        gdprintk(XENLOG_ERR,
            "set_mmio_p2m_entry: set_p2m_entry failed! mfn=%08lx\n",
            mfn_x(get_gfn_query_unlocked(p2m->domain, gfn, &ot)));
    return rc;
}

int
clear_mmio_p2m_entry(struct domain *d, unsigned long gfn)
{
    int rc = 0;
    mfn_t mfn;
    p2m_access_t a;
    p2m_type_t t;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);

    if ( !paging_mode_translate(d) )
        return 0;

    gfn_lock(p2m, gfn, 0);
    mfn = p2m->get_entry(p2m, gfn, &t, &a, 0, NULL);

    /* Do not use mfn_valid() here as it will usually fail for MMIO pages. */
    if ( (INVALID_MFN == mfn_x(mfn)) || (t != p2m_mmio_direct) )
    {
        gdprintk(XENLOG_ERR,
            "clear_mmio_p2m_entry: gfn_to_mfn failed! gfn=%08lx\n", gfn);
        goto out;
    }
    rc = set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), PAGE_ORDER_4K, p2m_invalid, p2m->default_access);

out:
    gfn_unlock(p2m, gfn, 0);

    return rc;
}

int
set_shared_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn)
{
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    int rc = 0;
    p2m_access_t a;
    p2m_type_t ot;
    mfn_t omfn;
    unsigned long pg_type;

    if ( !paging_mode_translate(p2m->domain) )
        return 0;

    gfn_lock(p2m, gfn, 0);
    omfn = p2m->get_entry(p2m, gfn, &ot, &a, 0, NULL);
    /* At the moment we only allow p2m change if gfn has already been made
     * sharable first */
    ASSERT(p2m_is_shared(ot));
    ASSERT(mfn_valid(omfn));
    /* Set the m2p entry to invalid only if there are no further type
     * refs to this page as shared */
    pg_type = read_atomic(&(mfn_to_page(omfn)->u.inuse.type_info));
    if ( (pg_type & PGT_count_mask) == 0
         || (pg_type & PGT_type_mask) != PGT_shared_page )
        set_gpfn_from_mfn(mfn_x(omfn), INVALID_M2P_ENTRY);

    P2M_DEBUG("set shared %lx %lx\n", gfn, mfn_x(mfn));
    rc = set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2m_ram_shared, p2m->default_access);
    gfn_unlock(p2m, gfn, 0);
    if ( 0 == rc )
        gdprintk(XENLOG_ERR,
            "set_shared_p2m_entry: set_p2m_entry failed! mfn=%08lx\n",
            mfn_x(get_gfn_query_unlocked(p2m->domain, gfn, &ot)));
    return rc;
}

#ifdef __x86_64__
/**
 * p2m_mem_paging_nominate - Mark a guest page as to-be-paged-out
 * @d: guest domain
 * @gfn: guest page to nominate
 *
 * Returns 0 for success or negative errno values if gfn is not pageable.
 *
 * p2m_mem_paging_nominate() is called by the pager and checks if a guest page
 * can be paged out. If the following conditions are met the p2mt will be
 * changed:
 * - the gfn is backed by a mfn
 * - the p2mt of the gfn is pageable
 * - the mfn is not used for IO
 * - the mfn has exactly one user and has no special meaning
 *
 * Once the p2mt is changed the page is readonly for the guest.  On success the
 * pager can write the page contents to disk and later evict the page.
 */
int p2m_mem_paging_nominate(struct domain *d, unsigned long gfn)
{
    struct page_info *page;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    p2m_type_t p2mt;
    p2m_access_t a;
    mfn_t mfn;
    int ret = -EBUSY;

    gfn_lock(p2m, gfn, 0);

    mfn = p2m->get_entry(p2m, gfn, &p2mt, &a, 0, NULL);

    /* Check if mfn is valid */
    if ( !mfn_valid(mfn) )
        goto out;

    /* Check p2m type */
    if ( !p2m_is_pageable(p2mt) )
        goto out;

    /* Check for io memory page */
    if ( is_iomem_page(mfn_x(mfn)) )
        goto out;

    /* Check page count and type */
    page = mfn_to_page(mfn);
    if ( (page->count_info & (PGC_count_mask | PGC_allocated)) !=
         (1 | PGC_allocated) )
        goto out;

    if ( (page->u.inuse.type_info & PGT_count_mask) != 0 )
        goto out;

    /* Fix p2m entry */
    set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2m_ram_paging_out, a);
    ret = 0;

 out:
    gfn_unlock(p2m, gfn, 0);
    return ret;
}

/**
 * p2m_mem_paging_evict - Mark a guest page as paged-out
 * @d: guest domain
 * @gfn: guest page to evict
 *
 * Returns 0 for success or negative errno values if eviction is not possible.
 *
 * p2m_mem_paging_evict() is called by the pager and will free a guest page and
 * release it back to Xen. If the following conditions are met the page can be
 * freed:
 * - the gfn is backed by a mfn
 * - the gfn was nominated
 * - the mfn has still exactly one user and has no special meaning
 *
 * After successful nomination some other process could have mapped the page. In
 * this case eviction can not be done. If the gfn was populated before the pager
 * could evict it, eviction can not be done either. In this case the gfn is
 * still backed by a mfn.
 */
int p2m_mem_paging_evict(struct domain *d, unsigned long gfn)
{
    struct page_info *page;
    p2m_type_t p2mt;
    p2m_access_t a;
    mfn_t mfn;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    int ret = -EBUSY;

    gfn_lock(p2m, gfn, 0);

    /* Get mfn */
    mfn = p2m->get_entry(p2m, gfn, &p2mt, &a, 0, NULL);
    if ( unlikely(!mfn_valid(mfn)) )
        goto out;

    /* Allow only nominated pages */
    if ( p2mt != p2m_ram_paging_out )
        goto out;

    /* Get the page so it doesn't get modified under Xen's feet */
    page = mfn_to_page(mfn);
    if ( unlikely(!get_page(page, d)) )
        goto out;

    /* Check page count and type once more */
    if ( (page->count_info & (PGC_count_mask | PGC_allocated)) !=
         (2 | PGC_allocated) )
        goto out_put;

    if ( (page->u.inuse.type_info & PGT_count_mask) != 0 )
        goto out_put;

    /* Decrement guest domain's ref count of the page */
    if ( test_and_clear_bit(_PGC_allocated, &page->count_info) )
        put_page(page);

    /* Remove mapping from p2m table */
    set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), PAGE_ORDER_4K, p2m_ram_paged, a);

    /* Clear content before returning the page to Xen */
    scrub_one_page(page);

    /* Track number of paged gfns */
    atomic_inc(&d->paged_pages);

    ret = 0;

 out_put:
    /* Put the page back so it gets freed */
    put_page(page);

 out:
    gfn_unlock(p2m, gfn, 0);
    return ret;
}

/**
 * p2m_mem_paging_drop_page - Tell pager to drop its reference to a paged page
 * @d: guest domain
 * @gfn: guest page to drop
 *
 * p2m_mem_paging_drop_page() will notify the pager that a paged-out gfn was
 * released by the guest. The pager is supposed to drop its reference of the
 * gfn.
 */
void p2m_mem_paging_drop_page(struct domain *d, unsigned long gfn,
                                p2m_type_t p2mt)
{
    mem_event_request_t req = { .gfn = gfn };

    /* We allow no ring in this unique case, because it won't affect
     * correctness of the guest execution at this point.  If this is the only
     * page that happens to be paged-out, we'll be okay..  but it's likely the
     * guest will crash shortly anyways. */
    int rc = mem_event_claim_slot(d, &d->mem_event->paging);
    if ( rc < 0 )
        return;

    /* Send release notification to pager */
    req.flags = MEM_EVENT_FLAG_DROP_PAGE;

    /* Update stats unless the page hasn't yet been evicted */
    if ( p2mt != p2m_ram_paging_out )
        atomic_dec(&d->paged_pages);
    else
        /* Evict will fail now, tag this request for pager */
        req.flags |= MEM_EVENT_FLAG_EVICT_FAIL;

    mem_event_put_request(d, &d->mem_event->paging, &req);
}

/**
 * p2m_mem_paging_populate - Tell pager to populete a paged page
 * @d: guest domain
 * @gfn: guest page in paging state
 *
 * p2m_mem_paging_populate() will notify the pager that a page in any of the
 * paging states needs to be written back into the guest.
 * This function needs to be called whenever gfn_to_mfn() returns any of the p2m
 * paging types because the gfn may not be backed by a mfn.
 *
 * The gfn can be in any of the paging states, but the pager needs only be
 * notified when the gfn is in the paging-out path (paging_out or paged).  This
 * function may be called more than once from several vcpus. If the vcpu belongs
 * to the guest, the vcpu must be stopped and the pager notified that the vcpu
 * was stopped. The pager needs to handle several requests for the same gfn.
 *
 * If the gfn is not in the paging-out path and the vcpu does not belong to the
 * guest, nothing needs to be done and the function assumes that a request was
 * already sent to the pager. In this case the caller has to try again until the
 * gfn is fully paged in again.
 */
void p2m_mem_paging_populate(struct domain *d, unsigned long gfn)
{
    struct vcpu *v = current;
    mem_event_request_t req = { .gfn = gfn };
    p2m_type_t p2mt;
    p2m_access_t a;
    mfn_t mfn;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);

    /* We're paging. There should be a ring */
    int rc = mem_event_claim_slot(d, &d->mem_event->paging);
    if ( rc == -ENOSYS )
    {
        gdprintk(XENLOG_ERR, "Domain %hu paging gfn %lx yet no ring "
                             "in place\n", d->domain_id, gfn);
        /* Prevent the vcpu from faulting repeatedly on the same gfn */
        if ( v->domain == d )
            vcpu_pause_nosync(v);
        domain_crash(d);
        return;
    }
    else if ( rc < 0 )
        return;

    /* Fix p2m mapping */
    gfn_lock(p2m, gfn, 0);
    mfn = p2m->get_entry(p2m, gfn, &p2mt, &a, 0, NULL);
    /* Allow only nominated or evicted pages to enter page-in path */
    if ( p2mt == p2m_ram_paging_out || p2mt == p2m_ram_paged )
    {
        /* Evict will fail now, tag this request for pager */
        if ( p2mt == p2m_ram_paging_out )
            req.flags |= MEM_EVENT_FLAG_EVICT_FAIL;

        set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2m_ram_paging_in, a);
    }
    gfn_unlock(p2m, gfn, 0);

    /* Pause domain if request came from guest and gfn has paging type */
    if ( p2m_is_paging(p2mt) && v->domain == d )
    {
        vcpu_pause_nosync(v);
        req.flags |= MEM_EVENT_FLAG_VCPU_PAUSED;
    }
    /* No need to inform pager if the gfn is not in the page-out path */
    else if ( p2mt != p2m_ram_paging_out && p2mt != p2m_ram_paged )
    {
        /* gfn is already on its way back and vcpu is not paused */
        mem_event_cancel_slot(d, &d->mem_event->paging);
        return;
    }

    /* Send request to pager */
    req.p2mt = p2mt;
    req.vcpu_id = v->vcpu_id;

    mem_event_put_request(d, &d->mem_event->paging, &req);
}

/**
 * p2m_mem_paging_prep - Allocate a new page for the guest
 * @d: guest domain
 * @gfn: guest page in paging state
 *
 * p2m_mem_paging_prep() will allocate a new page for the guest if the gfn is
 * not backed by a mfn. It is called by the pager.
 * It is required that the gfn was already populated. The gfn may already have a
 * mfn if populate was called for  gfn which was nominated but not evicted. In
 * this case only the p2mt needs to be forwarded.
 */
int p2m_mem_paging_prep(struct domain *d, unsigned long gfn, uint64_t buffer)
{
    struct page_info *page;
    p2m_type_t p2mt;
    p2m_access_t a;
    mfn_t mfn;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    int ret, page_extant = 1;
    const void *user_ptr = (const void *) buffer;

    if ( user_ptr )
        /* Sanity check the buffer and bail out early if trouble */
        if ( (buffer & (PAGE_SIZE - 1)) || 
             (!access_ok(user_ptr, PAGE_SIZE)) )
            return -EINVAL;

    gfn_lock(p2m, gfn, 0);

    mfn = p2m->get_entry(p2m, gfn, &p2mt, &a, 0, NULL);

    ret = -ENOENT;
    /* Allow missing pages */
    if ( (p2mt != p2m_ram_paging_in) && (p2mt != p2m_ram_paged) )
        goto out;

    /* Allocate a page if the gfn does not have one yet */
    if ( !mfn_valid(mfn) )
    {
        /* If the user did not provide a buffer, we disallow */
        ret = -EINVAL;
        if ( unlikely(user_ptr == NULL) )
            goto out;
        /* Get a free page */
        ret = -ENOMEM;
        page = alloc_domheap_page(p2m->domain, 0);
        if ( unlikely(page == NULL) )
            goto out;
        mfn = page_to_mfn(page);
        page_extant = 0;
    }

    /* If we were given a buffer, now is the time to use it */
    if ( !page_extant && user_ptr )
    {
        void *guest_map;
        int rc;

        ASSERT( mfn_valid(mfn) );
        guest_map = map_domain_page(mfn_x(mfn));
        rc = copy_from_user(guest_map, user_ptr, PAGE_SIZE);
        unmap_domain_page(guest_map);
        if ( rc )
        {
            gdprintk(XENLOG_ERR, "Failed to load paging-in gfn %lx domain %u "
                                 "bytes left %d\n", gfn, d->domain_id, rc);
            ret = -EFAULT;
            put_page(page); /* Don't leak pages */
            goto out;            
        }
    }

    /* Make the page already guest-accessible. If the pager still has a
     * pending resume operation, it will be idempotent p2m entry-wise,
     * but will unpause the vcpu */
    set_p2m_entry(p2m, gfn, mfn, PAGE_ORDER_4K, 
                    paging_mode_log_dirty(d) ? p2m_ram_logdirty : 
                    p2m_ram_rw, a);
    set_gpfn_from_mfn(mfn_x(mfn), gfn);

    if ( !page_extant )
        atomic_dec(&d->paged_pages);

    ret = 0;

 out:
    gfn_unlock(p2m, gfn, 0);
    return ret;
}

/**
 * p2m_mem_paging_resume - Resume guest gfn and vcpus
 * @d: guest domain
 * @gfn: guest page in paging state
 *
 * p2m_mem_paging_resume() will forward the p2mt of a gfn to ram_rw and all
 * waiting vcpus will be unpaused again. It is called by the pager.
 * 
 * The gfn was previously either evicted and populated, or nominated and
 * populated. If the page was evicted the p2mt will be p2m_ram_paging_in. If
 * the page was just nominated the p2mt will be p2m_ram_paging_in_start because
 * the pager did not call p2m_mem_paging_prep().
 *
 * If the gfn was dropped the vcpu needs to be unpaused.
 */
void p2m_mem_paging_resume(struct domain *d)
{
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    mem_event_response_t rsp;
    p2m_type_t p2mt;
    p2m_access_t a;
    mfn_t mfn;

    /* Pull all responses off the ring */
    while( mem_event_get_response(d, &d->mem_event->paging, &rsp) )
    {
        if ( rsp.flags & MEM_EVENT_FLAG_DUMMY )
            continue;
        /* Fix p2m entry if the page was not dropped */
        if ( !(rsp.flags & MEM_EVENT_FLAG_DROP_PAGE) )
        {
            gfn_lock(p2m, rsp.gfn, 0);
            mfn = p2m->get_entry(p2m, rsp.gfn, &p2mt, &a, 0, NULL);
            /* Allow only pages which were prepared properly, or pages which
             * were nominated but not evicted */
            if ( mfn_valid(mfn) && (p2mt == p2m_ram_paging_in) )
            {
                set_p2m_entry(p2m, rsp.gfn, mfn, PAGE_ORDER_4K, 
                                paging_mode_log_dirty(d) ? p2m_ram_logdirty : 
                                p2m_ram_rw, a);
                set_gpfn_from_mfn(mfn_x(mfn), rsp.gfn);
            }
            gfn_unlock(p2m, rsp.gfn, 0);
        }
        /* Unpause domain */
        if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
            vcpu_unpause(d->vcpu[rsp.vcpu_id]);
    }
}

bool_t p2m_mem_access_check(unsigned long gpa, bool_t gla_valid, unsigned long gla, 
                          bool_t access_r, bool_t access_w, bool_t access_x,
                          mem_event_request_t **req_ptr)
{
    struct vcpu *v = current;
    unsigned long gfn = gpa >> PAGE_SHIFT;
    struct domain *d = v->domain;    
    struct p2m_domain* p2m = p2m_get_hostp2m(d);
    mfn_t mfn;
    p2m_type_t p2mt;
    p2m_access_t p2ma;
    mem_event_request_t *req;

    /* First, handle rx2rw conversion automatically */
    gfn_lock(p2m, gfn, 0);
    mfn = p2m->get_entry(p2m, gfn, &p2mt, &p2ma, 0, NULL);

    if ( access_w && p2ma == p2m_access_rx2rw ) 
    {
        p2m->set_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2mt, p2m_access_rw);
        gfn_unlock(p2m, gfn, 0);
        return 1;
    }
    else if ( p2ma == p2m_access_n2rwx )
    {
        ASSERT(access_w || access_r || access_x);
        p2m->set_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2mt, p2m_access_rwx);
    }
    gfn_unlock(p2m, gfn, 0);

    /* Otherwise, check if there is a memory event listener, and send the message along */
    if ( !mem_event_check_ring(&d->mem_event->access) || !req_ptr ) 
    {
        /* No listener */
        if ( p2m->access_required ) 
        {
            gdprintk(XENLOG_INFO, "Memory access permissions failure, "
                                  "no mem_event listener VCPU %d, dom %d\n",
                                  v->vcpu_id, d->domain_id);
            domain_crash(v->domain);
            return 0;
        }
        else
        {
            if ( p2ma != p2m_access_n2rwx )
            {
                /* A listener is not required, so clear the access restrictions */
                gfn_lock(p2m, gfn, 0);
                p2m->set_entry(p2m, gfn, mfn, PAGE_ORDER_4K, p2mt, p2m_access_rwx);
                gfn_unlock(p2m, gfn, 0);
            }
            return 1;
        }
    }

    *req_ptr = NULL;
    req = xmalloc(mem_event_request_t);
    if ( req )
    {
        *req_ptr = req;
        memset(req, 0, sizeof(req));
        req->reason = MEM_EVENT_REASON_VIOLATION;

        /* Pause the current VCPU */
        if ( p2ma != p2m_access_n2rwx )
            req->flags |= MEM_EVENT_FLAG_VCPU_PAUSED;

        /* Send request to mem event */
        req->gfn = gfn;
        req->offset = gpa & ((1 << PAGE_SHIFT) - 1);
        req->gla_valid = gla_valid;
        req->gla = gla;
        req->access_r = access_r;
        req->access_w = access_w;
        req->access_x = access_x;
    
        req->vcpu_id = v->vcpu_id;
    }

    /* Pause the current VCPU */
    if ( p2ma != p2m_access_n2rwx )
        vcpu_pause_nosync(v);

    /* VCPU may be paused, return whether we promoted automatically */
    return (p2ma == p2m_access_n2rwx);
}

void p2m_mem_access_resume(struct domain *d)
{
    mem_event_response_t rsp;

    /* Pull all responses off the ring */
    while( mem_event_get_response(d, &d->mem_event->access, &rsp) )
    {
        if ( rsp.flags & MEM_EVENT_FLAG_DUMMY )
            continue;
        /* Unpause domain */
        if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
            vcpu_unpause(d->vcpu[rsp.vcpu_id]);
    }
}

/* Set access type for a region of pfns.
 * If start_pfn == -1ul, sets the default access type */
int p2m_set_mem_access(struct domain *d, unsigned long start_pfn, 
                       uint32_t nr, hvmmem_access_t access) 
{
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    unsigned long pfn;
    p2m_access_t a, _a;
    p2m_type_t t;
    mfn_t mfn;
    int rc = 0;

    /* N.B. _not_ static: initializer depends on p2m->default_access */
    p2m_access_t memaccess[] = {
        p2m_access_n,
        p2m_access_r,
        p2m_access_w,
        p2m_access_rw,
        p2m_access_x,
        p2m_access_rx,
        p2m_access_wx,
        p2m_access_rwx,
        p2m_access_rx2rw,
        p2m_access_n2rwx,
        p2m->default_access,
    };

    if ( access >= HVMMEM_access_default || access < 0 )
        return -EINVAL;

    a = memaccess[access];

    /* If request to set default access */
    if ( start_pfn == ~0ull ) 
    {
        p2m->default_access = a;
        return 0;
    }

    p2m_lock(p2m);
    for ( pfn = start_pfn; pfn < start_pfn + nr; pfn++ )
    {
        mfn = p2m->get_entry(p2m, pfn, &t, &_a, 0, NULL);
        if ( p2m->set_entry(p2m, pfn, mfn, PAGE_ORDER_4K, t, a) == 0 )
        {
            rc = -ENOMEM;
            break;
        }
    }
    p2m_unlock(p2m);
    return rc;
}

/* Get access type for a pfn
 * If pfn == -1ul, gets the default access type */
int p2m_get_mem_access(struct domain *d, unsigned long pfn, 
                       hvmmem_access_t *access)
{
    struct p2m_domain *p2m = p2m_get_hostp2m(d);
    p2m_type_t t;
    p2m_access_t a;
    mfn_t mfn;

    static const hvmmem_access_t memaccess[] = {
        HVMMEM_access_n,
        HVMMEM_access_r,
        HVMMEM_access_w,
        HVMMEM_access_rw,
        HVMMEM_access_x,
        HVMMEM_access_rx,
        HVMMEM_access_wx,
        HVMMEM_access_rwx,
        HVMMEM_access_rx2rw
    };

    /* If request to get default access */
    if ( pfn == ~0ull ) 
    {
        *access = memaccess[p2m->default_access];
        return 0;
    }

    gfn_lock(p2m, gfn, 0);
    mfn = p2m->get_entry(p2m, pfn, &t, &a, 0, NULL);
    gfn_unlock(p2m, gfn, 0);

    if ( mfn_x(mfn) == INVALID_MFN )
        return -ESRCH;
    
    if ( a >= ARRAY_SIZE(memaccess) || a < 0 )
        return -ERANGE;

    *access =  memaccess[a];
    return 0;
}


#endif /* __x86_64__ */

static struct p2m_domain *
p2m_getlru_nestedp2m(struct domain *d, struct p2m_domain *p2m)
{
    struct list_head *lru_list = &p2m_get_hostp2m(d)->np2m_list;
    
    ASSERT(!list_empty(lru_list));

    if ( p2m == NULL )
        p2m = list_entry(lru_list->prev, struct p2m_domain, np2m_list);

    list_move(&p2m->np2m_list, lru_list);

    return p2m;
}

/* Reset this p2m table to be empty */
static void
p2m_flush_table(struct p2m_domain *p2m)
{
    struct page_info *top, *pg;
    struct domain *d = p2m->domain;
    void *p;

    p2m_lock(p2m);

    /* "Host" p2m tables can have shared entries &c that need a bit more 
     * care when discarding them */
    ASSERT(p2m_is_nestedp2m(p2m));
    /* Nested p2m's do not do pod, hence the asserts (and no pod lock)*/
    ASSERT(page_list_empty(&p2m->pod.super));
    ASSERT(page_list_empty(&p2m->pod.single));

    /* This is no longer a valid nested p2m for any address space */
    p2m->cr3 = CR3_EADDR;
    
    /* Zap the top level of the trie */
    top = mfn_to_page(pagetable_get_mfn(p2m_get_pagetable(p2m)));
    p = __map_domain_page(top);
    clear_page(p);
    unmap_domain_page(p);

    /* Make sure nobody else is using this p2m table */
    nestedhvm_vmcx_flushtlb(p2m);

    /* Free the rest of the trie pages back to the paging pool */
    while ( (pg = page_list_remove_head(&p2m->pages)) )
        if ( pg != top ) 
            d->arch.paging.free_page(d, pg);
    page_list_add(top, &p2m->pages);

    p2m_unlock(p2m);
}

void
p2m_flush(struct vcpu *v, struct p2m_domain *p2m)
{
    ASSERT(v->domain == p2m->domain);
    vcpu_nestedhvm(v).nv_p2m = NULL;
    p2m_flush_table(p2m);
    hvm_asid_flush_vcpu(v);
}

void
p2m_flush_nestedp2m(struct domain *d)
{
    int i;
    for ( i = 0; i < MAX_NESTEDP2M; i++ )
        p2m_flush_table(d->arch.nested_p2m[i]);
}

struct p2m_domain *
p2m_get_nestedp2m(struct vcpu *v, uint64_t cr3)
{
    /* Use volatile to prevent gcc to cache nv->nv_p2m in a cpu register as
     * this may change within the loop by an other (v)cpu.
     */
    volatile struct nestedvcpu *nv = &vcpu_nestedhvm(v);
    struct domain *d;
    struct p2m_domain *p2m;

    /* Mask out low bits; this avoids collisions with CR3_EADDR */
    cr3 &= ~(0xfffull);

    if (nv->nv_flushp2m && nv->nv_p2m) {
        nv->nv_p2m = NULL;
    }

    d = v->domain;
    nestedp2m_lock(d);
    p2m = nv->nv_p2m;
    if ( p2m ) 
    {
        p2m_lock(p2m);
        if ( p2m->cr3 == cr3 || p2m->cr3 == CR3_EADDR )
        {
            nv->nv_flushp2m = 0;
            p2m_getlru_nestedp2m(d, p2m);
            nv->nv_p2m = p2m;
            if (p2m->cr3 == CR3_EADDR)
                hvm_asid_flush_vcpu(v);
            p2m->cr3 = cr3;
            cpumask_set_cpu(v->processor, p2m->dirty_cpumask);
            p2m_unlock(p2m);
            nestedp2m_unlock(d);
            return p2m;
        }
        p2m_unlock(p2m);
    }

    /* All p2m's are or were in use. Take the least recent used one,
     * flush it and reuse. */
    p2m = p2m_getlru_nestedp2m(d, NULL);
    p2m_flush_table(p2m);
    p2m_lock(p2m);
    nv->nv_p2m = p2m;
    p2m->cr3 = cr3;
    nv->nv_flushp2m = 0;
    hvm_asid_flush_vcpu(v);
    cpumask_set_cpu(v->processor, p2m->dirty_cpumask);
    p2m_unlock(p2m);
    nestedp2m_unlock(d);

    return p2m;
}

struct p2m_domain *
p2m_get_p2m(struct vcpu *v)
{
    if (!nestedhvm_is_n2(v))
        return p2m_get_hostp2m(v->domain);

    return p2m_get_nestedp2m(v, nhvm_vcpu_hostcr3(v));
}

unsigned long paging_gva_to_gfn(struct vcpu *v,
                                unsigned long va,
                                uint32_t *pfec)
{
    struct p2m_domain *hostp2m = p2m_get_hostp2m(v->domain);
    const struct paging_mode *hostmode = paging_get_hostmode(v);

    if ( is_hvm_domain(v->domain)
        && paging_mode_hap(v->domain) 
        && nestedhvm_is_n2(v) )
    {
        unsigned long gfn;
        struct p2m_domain *p2m;
        const struct paging_mode *mode;
        uint64_t ncr3 = nhvm_vcpu_hostcr3(v);

        /* translate l2 guest va into l2 guest gfn */
        p2m = p2m_get_nestedp2m(v, ncr3);
        mode = paging_get_nestedmode(v);
        gfn = mode->gva_to_gfn(v, p2m, va, pfec);

        /* translate l2 guest gfn into l1 guest gfn */
        return hostmode->p2m_ga_to_gfn(v, hostp2m, ncr3,
                                       gfn << PAGE_SHIFT, pfec, NULL);
    }

    return hostmode->gva_to_gfn(v, hostp2m, va, pfec);
}

/*** Audit ***/

#if P2M_AUDIT
void audit_p2m(struct domain *d,
               uint64_t *orphans,
                uint64_t *m2p_bad,
                uint64_t *p2m_bad)
{
    struct page_info *page;
    struct domain *od;
    unsigned long mfn, gfn;
    mfn_t p2mfn;
    unsigned long orphans_count = 0, mpbad = 0, pmbad = 0;
    p2m_access_t p2ma;
    p2m_type_t type;
    struct p2m_domain *p2m = p2m_get_hostp2m(d);

    if ( !paging_mode_translate(d) )
        goto out_p2m_audit;

    P2M_PRINTK("p2m audit starts\n");

    p2m_lock(p2m);
    pod_lock(p2m);

    if (p2m->audit_p2m)
        pmbad = p2m->audit_p2m(p2m);

    /* Audit part two: walk the domain's page allocation list, checking
     * the m2p entries. */
    spin_lock(&d->page_alloc_lock);
    page_list_for_each ( page, &d->page_list )
    {
        mfn = mfn_x(page_to_mfn(page));

        P2M_PRINTK("auditing guest page, mfn=%#lx\n", mfn);

        od = page_get_owner(page);

        if ( od != d )
        {
            P2M_PRINTK("wrong owner %#lx -> %p(%u) != %p(%u)\n",
                       mfn, od, (od?od->domain_id:-1), d, d->domain_id);
            continue;
        }

        gfn = get_gpfn_from_mfn(mfn);
        if ( gfn == INVALID_M2P_ENTRY )
        {
            orphans_count++;
            P2M_PRINTK("orphaned guest page: mfn=%#lx has invalid gfn\n",
                           mfn);
            continue;
        }

        if ( gfn == SHARED_M2P_ENTRY )
        {
            P2M_PRINTK("shared mfn (%lx) on domain page list!\n",
                    mfn);
            continue;
        }

        p2mfn = get_gfn_type_access(p2m, gfn, &type, &p2ma, 0, NULL);
        if ( mfn_x(p2mfn) != mfn )
        {
            mpbad++;
            P2M_PRINTK("map mismatch mfn %#lx -> gfn %#lx -> mfn %#lx"
                       " (-> gfn %#lx)\n",
                       mfn, gfn, mfn_x(p2mfn),
                       (mfn_valid(p2mfn)
                        ? get_gpfn_from_mfn(mfn_x(p2mfn))
                        : -1u));
            /* This m2p entry is stale: the domain has another frame in
             * this physical slot.  No great disaster, but for neatness,
             * blow away the m2p entry. */
            set_gpfn_from_mfn(mfn, INVALID_M2P_ENTRY);
        }
        __put_gfn(p2m, gfn);

        P2M_PRINTK("OK: mfn=%#lx, gfn=%#lx, p2mfn=%#lx\n",
                       mfn, gfn, mfn_x(p2mfn));
    }
    spin_unlock(&d->page_alloc_lock);

    pod_unlock(p2m);
    p2m_unlock(p2m);
 
    P2M_PRINTK("p2m audit complete\n");
    if ( orphans_count | mpbad | pmbad )
        P2M_PRINTK("p2m audit found %lu orphans\n", orphans);
    if ( mpbad | pmbad )
    {
        P2M_PRINTK("p2m audit found %lu odd p2m, %lu bad m2p entries\n",
                   pmbad, mpbad);
        WARN();
    }

out_p2m_audit:
    *orphans = (uint64_t) orphans_count;
    *m2p_bad = (uint64_t) mpbad;
    *p2m_bad = (uint64_t) pmbad;
}
#endif /* P2M_AUDIT */

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 4
 * indent-tabs-mode: nil
 * End:
 */