1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Machine specific setup for xen 4 * 5 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 6 */ 7 8 #include <linux/init.h> 9 #include <linux/iscsi_ibft.h> 10 #include <linux/sched.h> 11 #include <linux/kstrtox.h> 12 #include <linux/mm.h> 13 #include <linux/pm.h> 14 #include <linux/memblock.h> 15 #include <linux/cpuidle.h> 16 #include <linux/cpufreq.h> 17 #include <linux/memory_hotplug.h> 18 19 #include <asm/elf.h> 20 #include <asm/vdso.h> 21 #include <asm/e820/api.h> 22 #include <asm/setup.h> 23 #include <asm/acpi.h> 24 #include <asm/numa.h> 25 #include <asm/idtentry.h> 26 #include <asm/xen/hypervisor.h> 27 #include <asm/xen/hypercall.h> 28 29 #include <xen/xen.h> 30 #include <xen/page.h> 31 #include <xen/interface/callback.h> 32 #include <xen/interface/memory.h> 33 #include <xen/interface/physdev.h> 34 #include <xen/features.h> 35 #include <xen/hvc-console.h> 36 #include "xen-ops.h" 37 #include "mmu.h" 38 39 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024) 40 41 /* Number of pages released from the initial allocation. */ 42 unsigned long xen_released_pages; 43 44 /* Memory map would allow PCI passthrough. */ 45 bool xen_pv_pci_possible; 46 47 /* E820 map used during setting up memory. */ 48 static struct e820_table xen_e820_table __initdata; 49 50 /* Number of initially usable memory pages. */ 51 static unsigned long ini_nr_pages __initdata; 52 53 /* 54 * Buffer used to remap identity mapped pages. We only need the virtual space. 55 * The physical page behind this address is remapped as needed to different 56 * buffer pages. 57 */ 58 #define REMAP_SIZE (P2M_PER_PAGE - 3) 59 static struct { 60 unsigned long next_area_mfn; 61 unsigned long target_pfn; 62 unsigned long size; 63 unsigned long mfns[REMAP_SIZE]; 64 } xen_remap_buf __initdata __aligned(PAGE_SIZE); 65 static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY; 66 67 static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB); 68 69 static void __init xen_parse_512gb(void) 70 { 71 bool val = false; 72 char *arg; 73 74 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit"); 75 if (!arg) 76 return; 77 78 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit="); 79 if (!arg) 80 val = true; 81 else if (kstrtobool(arg + strlen("xen_512gb_limit="), &val)) 82 return; 83 84 xen_512gb_limit = val; 85 } 86 87 static void __init xen_del_extra_mem(unsigned long start_pfn, 88 unsigned long n_pfns) 89 { 90 int i; 91 unsigned long start_r, size_r; 92 93 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 94 start_r = xen_extra_mem[i].start_pfn; 95 size_r = xen_extra_mem[i].n_pfns; 96 97 /* Start of region. */ 98 if (start_r == start_pfn) { 99 BUG_ON(n_pfns > size_r); 100 xen_extra_mem[i].start_pfn += n_pfns; 101 xen_extra_mem[i].n_pfns -= n_pfns; 102 break; 103 } 104 /* End of region. */ 105 if (start_r + size_r == start_pfn + n_pfns) { 106 BUG_ON(n_pfns > size_r); 107 xen_extra_mem[i].n_pfns -= n_pfns; 108 break; 109 } 110 /* Mid of region. */ 111 if (start_pfn > start_r && start_pfn < start_r + size_r) { 112 BUG_ON(start_pfn + n_pfns > start_r + size_r); 113 xen_extra_mem[i].n_pfns = start_pfn - start_r; 114 /* Calling memblock_reserve() again is okay. */ 115 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r - 116 (start_pfn + n_pfns)); 117 break; 118 } 119 } 120 memblock_phys_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); 121 } 122 123 /* 124 * Called during boot before the p2m list can take entries beyond the 125 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as 126 * invalid. 127 */ 128 unsigned long __ref xen_chk_extra_mem(unsigned long pfn) 129 { 130 int i; 131 132 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 133 if (pfn >= xen_extra_mem[i].start_pfn && 134 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns) 135 return INVALID_P2M_ENTRY; 136 } 137 138 return IDENTITY_FRAME(pfn); 139 } 140 141 /* 142 * Mark all pfns of extra mem as invalid in p2m list. 143 */ 144 void __init xen_inv_extra_mem(void) 145 { 146 unsigned long pfn, pfn_s, pfn_e; 147 int i; 148 149 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 150 if (!xen_extra_mem[i].n_pfns) 151 continue; 152 pfn_s = xen_extra_mem[i].start_pfn; 153 pfn_e = pfn_s + xen_extra_mem[i].n_pfns; 154 for (pfn = pfn_s; pfn < pfn_e; pfn++) 155 set_phys_to_machine(pfn, INVALID_P2M_ENTRY); 156 } 157 } 158 159 /* 160 * Finds the next RAM pfn available in the E820 map after min_pfn. 161 * This function updates min_pfn with the pfn found and returns 162 * the size of that range or zero if not found. 163 */ 164 static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn) 165 { 166 const struct e820_entry *entry = xen_e820_table.entries; 167 unsigned int i; 168 unsigned long done = 0; 169 170 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 171 unsigned long s_pfn; 172 unsigned long e_pfn; 173 174 if (entry->type != E820_TYPE_RAM) 175 continue; 176 177 e_pfn = PFN_DOWN(entry->addr + entry->size); 178 179 /* We only care about E820 after this */ 180 if (e_pfn <= *min_pfn) 181 continue; 182 183 s_pfn = PFN_UP(entry->addr); 184 185 /* If min_pfn falls within the E820 entry, we want to start 186 * at the min_pfn PFN. 187 */ 188 if (s_pfn <= *min_pfn) { 189 done = e_pfn - *min_pfn; 190 } else { 191 done = e_pfn - s_pfn; 192 *min_pfn = s_pfn; 193 } 194 break; 195 } 196 197 return done; 198 } 199 200 static int __init xen_free_mfn(unsigned long mfn) 201 { 202 struct xen_memory_reservation reservation = { 203 .address_bits = 0, 204 .extent_order = 0, 205 .domid = DOMID_SELF 206 }; 207 208 set_xen_guest_handle(reservation.extent_start, &mfn); 209 reservation.nr_extents = 1; 210 211 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); 212 } 213 214 /* 215 * This releases a chunk of memory and then does the identity map. It's used 216 * as a fallback if the remapping fails. 217 */ 218 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, 219 unsigned long end_pfn) 220 { 221 unsigned long pfn, end; 222 int ret; 223 224 WARN_ON(start_pfn > end_pfn); 225 226 /* Release pages first. */ 227 end = min(end_pfn, ini_nr_pages); 228 for (pfn = start_pfn; pfn < end; pfn++) { 229 unsigned long mfn = pfn_to_mfn(pfn); 230 231 /* Make sure pfn exists to start with */ 232 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn) 233 continue; 234 235 ret = xen_free_mfn(mfn); 236 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret); 237 238 if (ret == 1) { 239 xen_released_pages++; 240 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY)) 241 break; 242 } else 243 break; 244 } 245 246 set_phys_range_identity(start_pfn, end_pfn); 247 } 248 249 /* 250 * Helper function to update the p2m and m2p tables and kernel mapping. 251 */ 252 static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn) 253 { 254 struct mmu_update update = { 255 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE, 256 .val = pfn 257 }; 258 259 /* Update p2m */ 260 if (!set_phys_to_machine(pfn, mfn)) { 261 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n", 262 pfn, mfn); 263 BUG(); 264 } 265 266 /* Update m2p */ 267 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) { 268 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n", 269 mfn, pfn); 270 BUG(); 271 } 272 273 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), 274 mfn_pte(mfn, PAGE_KERNEL), 0)) { 275 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n", 276 mfn, pfn); 277 BUG(); 278 } 279 } 280 281 /* 282 * This function updates the p2m and m2p tables with an identity map from 283 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the 284 * original allocation at remap_pfn. The information needed for remapping is 285 * saved in the memory itself to avoid the need for allocating buffers. The 286 * complete remap information is contained in a list of MFNs each containing 287 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap. 288 * This enables us to preserve the original mfn sequence while doing the 289 * remapping at a time when the memory management is capable of allocating 290 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and 291 * its callers. 292 */ 293 static void __init xen_do_set_identity_and_remap_chunk( 294 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn) 295 { 296 unsigned long buf = (unsigned long)&xen_remap_buf; 297 unsigned long mfn_save, mfn; 298 unsigned long ident_pfn_iter, remap_pfn_iter; 299 unsigned long ident_end_pfn = start_pfn + size; 300 unsigned long left = size; 301 unsigned int i, chunk; 302 303 WARN_ON(size == 0); 304 305 mfn_save = virt_to_mfn((void *)buf); 306 307 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn; 308 ident_pfn_iter < ident_end_pfn; 309 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) { 310 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE; 311 312 /* Map first pfn to xen_remap_buf */ 313 mfn = pfn_to_mfn(ident_pfn_iter); 314 set_pte_mfn(buf, mfn, PAGE_KERNEL); 315 316 /* Save mapping information in page */ 317 xen_remap_buf.next_area_mfn = xen_remap_mfn; 318 xen_remap_buf.target_pfn = remap_pfn_iter; 319 xen_remap_buf.size = chunk; 320 for (i = 0; i < chunk; i++) 321 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i); 322 323 /* Put remap buf into list. */ 324 xen_remap_mfn = mfn; 325 326 /* Set identity map */ 327 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk); 328 329 left -= chunk; 330 } 331 332 /* Restore old xen_remap_buf mapping */ 333 set_pte_mfn(buf, mfn_save, PAGE_KERNEL); 334 } 335 336 /* 337 * This function takes a contiguous pfn range that needs to be identity mapped 338 * and: 339 * 340 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn. 341 * 2) Calls the do_ function to actually do the mapping/remapping work. 342 * 343 * The goal is to not allocate additional memory but to remap the existing 344 * pages. In the case of an error the underlying memory is simply released back 345 * to Xen and not remapped. 346 */ 347 static unsigned long __init xen_set_identity_and_remap_chunk( 348 unsigned long start_pfn, unsigned long end_pfn, unsigned long remap_pfn) 349 { 350 unsigned long pfn; 351 unsigned long i = 0; 352 unsigned long n = end_pfn - start_pfn; 353 354 if (remap_pfn == 0) 355 remap_pfn = ini_nr_pages; 356 357 while (i < n) { 358 unsigned long cur_pfn = start_pfn + i; 359 unsigned long left = n - i; 360 unsigned long size = left; 361 unsigned long remap_range_size; 362 363 /* Do not remap pages beyond the current allocation */ 364 if (cur_pfn >= ini_nr_pages) { 365 /* Identity map remaining pages */ 366 set_phys_range_identity(cur_pfn, cur_pfn + size); 367 break; 368 } 369 if (cur_pfn + size > ini_nr_pages) 370 size = ini_nr_pages - cur_pfn; 371 372 remap_range_size = xen_find_pfn_range(&remap_pfn); 373 if (!remap_range_size) { 374 pr_warn("Unable to find available pfn range, not remapping identity pages\n"); 375 xen_set_identity_and_release_chunk(cur_pfn, 376 cur_pfn + left); 377 break; 378 } 379 /* Adjust size to fit in current e820 RAM region */ 380 if (size > remap_range_size) 381 size = remap_range_size; 382 383 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn); 384 385 /* Update variables to reflect new mappings. */ 386 i += size; 387 remap_pfn += size; 388 } 389 390 /* 391 * If the PFNs are currently mapped, their VA mappings need to be 392 * zapped. 393 */ 394 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) 395 (void)HYPERVISOR_update_va_mapping( 396 (unsigned long)__va(pfn << PAGE_SHIFT), 397 native_make_pte(0), 0); 398 399 return remap_pfn; 400 } 401 402 static unsigned long __init xen_count_remap_pages( 403 unsigned long start_pfn, unsigned long end_pfn, 404 unsigned long remap_pages) 405 { 406 if (start_pfn >= ini_nr_pages) 407 return remap_pages; 408 409 return remap_pages + min(end_pfn, ini_nr_pages) - start_pfn; 410 } 411 412 static unsigned long __init xen_foreach_remap_area( 413 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn, 414 unsigned long last_val)) 415 { 416 phys_addr_t start = 0; 417 unsigned long ret_val = 0; 418 const struct e820_entry *entry = xen_e820_table.entries; 419 int i; 420 421 /* 422 * Combine non-RAM regions and gaps until a RAM region (or the 423 * end of the map) is reached, then call the provided function 424 * to perform its duty on the non-RAM region. 425 * 426 * The combined non-RAM regions are rounded to a whole number 427 * of pages so any partial pages are accessible via the 1:1 428 * mapping. This is needed for some BIOSes that put (for 429 * example) the DMI tables in a reserved region that begins on 430 * a non-page boundary. 431 */ 432 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 433 phys_addr_t end = entry->addr + entry->size; 434 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) { 435 unsigned long start_pfn = PFN_DOWN(start); 436 unsigned long end_pfn = PFN_UP(end); 437 438 if (entry->type == E820_TYPE_RAM) 439 end_pfn = PFN_UP(entry->addr); 440 441 if (start_pfn < end_pfn) 442 ret_val = func(start_pfn, end_pfn, ret_val); 443 start = end; 444 } 445 } 446 447 return ret_val; 448 } 449 450 /* 451 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk(). 452 * The remap information (which mfn remap to which pfn) is contained in the 453 * to be remapped memory itself in a linked list anchored at xen_remap_mfn. 454 * This scheme allows to remap the different chunks in arbitrary order while 455 * the resulting mapping will be independent from the order. 456 */ 457 void __init xen_remap_memory(void) 458 { 459 unsigned long buf = (unsigned long)&xen_remap_buf; 460 unsigned long mfn_save, pfn; 461 unsigned long remapped = 0; 462 unsigned int i; 463 unsigned long pfn_s = ~0UL; 464 unsigned long len = 0; 465 466 mfn_save = virt_to_mfn((void *)buf); 467 468 while (xen_remap_mfn != INVALID_P2M_ENTRY) { 469 /* Map the remap information */ 470 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL); 471 472 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]); 473 474 pfn = xen_remap_buf.target_pfn; 475 for (i = 0; i < xen_remap_buf.size; i++) { 476 xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]); 477 remapped++; 478 pfn++; 479 } 480 if (pfn_s == ~0UL || pfn == pfn_s) { 481 pfn_s = xen_remap_buf.target_pfn; 482 len += xen_remap_buf.size; 483 } else if (pfn_s + len == xen_remap_buf.target_pfn) { 484 len += xen_remap_buf.size; 485 } else { 486 xen_del_extra_mem(pfn_s, len); 487 pfn_s = xen_remap_buf.target_pfn; 488 len = xen_remap_buf.size; 489 } 490 xen_remap_mfn = xen_remap_buf.next_area_mfn; 491 } 492 493 if (pfn_s != ~0UL && len) 494 xen_del_extra_mem(pfn_s, len); 495 496 set_pte_mfn(buf, mfn_save, PAGE_KERNEL); 497 498 pr_info("Remapped %ld page(s)\n", remapped); 499 500 xen_do_remap_nonram(); 501 } 502 503 static unsigned long __init xen_get_pages_limit(void) 504 { 505 unsigned long limit; 506 507 limit = MAXMEM / PAGE_SIZE; 508 if (!xen_initial_domain() && xen_512gb_limit) 509 limit = GB(512) / PAGE_SIZE; 510 511 return limit; 512 } 513 514 static unsigned long __init xen_get_max_pages(void) 515 { 516 unsigned long max_pages, limit; 517 domid_t domid = DOMID_SELF; 518 long ret; 519 520 limit = xen_get_pages_limit(); 521 max_pages = limit; 522 523 /* 524 * For the initial domain we use the maximum reservation as 525 * the maximum page. 526 * 527 * For guest domains the current maximum reservation reflects 528 * the current maximum rather than the static maximum. In this 529 * case the e820 map provided to us will cover the static 530 * maximum region. 531 */ 532 if (xen_initial_domain()) { 533 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid); 534 if (ret > 0) 535 max_pages = ret; 536 } 537 538 return min(max_pages, limit); 539 } 540 541 static void __init xen_align_and_add_e820_region(phys_addr_t start, 542 phys_addr_t size, int type) 543 { 544 phys_addr_t end = start + size; 545 546 /* Align RAM regions to page boundaries. */ 547 if (type == E820_TYPE_RAM) { 548 start = PAGE_ALIGN(start); 549 end &= ~((phys_addr_t)PAGE_SIZE - 1); 550 #ifdef CONFIG_MEMORY_HOTPLUG 551 /* 552 * Don't allow adding memory not in E820 map while booting the 553 * system. Once the balloon driver is up it will remove that 554 * restriction again. 555 */ 556 max_mem_size = end; 557 #endif 558 } 559 560 e820__range_add(start, end - start, type); 561 } 562 563 static void __init xen_ignore_unusable(void) 564 { 565 struct e820_entry *entry = xen_e820_table.entries; 566 unsigned int i; 567 568 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 569 if (entry->type == E820_TYPE_UNUSABLE) 570 entry->type = E820_TYPE_RAM; 571 } 572 } 573 574 static bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size) 575 { 576 struct e820_entry *entry; 577 unsigned mapcnt; 578 phys_addr_t end; 579 580 if (!size) 581 return false; 582 583 end = start + size; 584 entry = xen_e820_table.entries; 585 586 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { 587 if (entry->type == E820_TYPE_RAM && entry->addr <= start && 588 (entry->addr + entry->size) >= end) 589 return false; 590 591 entry++; 592 } 593 594 return true; 595 } 596 597 /* 598 * Find a free area in physical memory not yet reserved and compliant with 599 * E820 map. 600 * Used to relocate pre-allocated areas like initrd or p2m list which are in 601 * conflict with the to be used E820 map. 602 * In case no area is found, return 0. Otherwise return the physical address 603 * of the area which is already reserved for convenience. 604 */ 605 phys_addr_t __init xen_find_free_area(phys_addr_t size) 606 { 607 unsigned mapcnt; 608 phys_addr_t addr, start; 609 struct e820_entry *entry = xen_e820_table.entries; 610 611 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) { 612 if (entry->type != E820_TYPE_RAM || entry->size < size) 613 continue; 614 start = entry->addr; 615 for (addr = start; addr < start + size; addr += PAGE_SIZE) { 616 if (!memblock_is_reserved(addr)) 617 continue; 618 start = addr + PAGE_SIZE; 619 if (start + size > entry->addr + entry->size) 620 break; 621 } 622 if (addr >= start + size) { 623 memblock_reserve(start, size); 624 return start; 625 } 626 } 627 628 return 0; 629 } 630 631 /* 632 * Swap a non-RAM E820 map entry with RAM above ini_nr_pages. 633 * Note that the E820 map is modified accordingly, but the P2M map isn't yet. 634 * The adaption of the P2M must be deferred until page allocation is possible. 635 */ 636 static void __init xen_e820_swap_entry_with_ram(struct e820_entry *swap_entry) 637 { 638 struct e820_entry *entry; 639 unsigned int mapcnt; 640 phys_addr_t mem_end = PFN_PHYS(ini_nr_pages); 641 phys_addr_t swap_addr, swap_size, entry_end; 642 643 swap_addr = PAGE_ALIGN_DOWN(swap_entry->addr); 644 swap_size = PAGE_ALIGN(swap_entry->addr - swap_addr + swap_entry->size); 645 entry = xen_e820_table.entries; 646 647 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { 648 entry_end = entry->addr + entry->size; 649 if (entry->type == E820_TYPE_RAM && entry->size >= swap_size && 650 entry_end - swap_size >= mem_end) { 651 /* Reduce RAM entry by needed space (whole pages). */ 652 entry->size -= swap_size; 653 654 /* Add new entry at the end of E820 map. */ 655 entry = xen_e820_table.entries + 656 xen_e820_table.nr_entries; 657 xen_e820_table.nr_entries++; 658 659 /* Fill new entry (keep size and page offset). */ 660 entry->type = swap_entry->type; 661 entry->addr = entry_end - swap_size + 662 swap_addr - swap_entry->addr; 663 entry->size = swap_entry->size; 664 665 /* Convert old entry to RAM, align to pages. */ 666 swap_entry->type = E820_TYPE_RAM; 667 swap_entry->addr = swap_addr; 668 swap_entry->size = swap_size; 669 670 /* Remember PFN<->MFN relation for P2M update. */ 671 xen_add_remap_nonram(swap_addr, entry_end - swap_size, 672 swap_size); 673 674 /* Order E820 table and merge entries. */ 675 e820__update_table(&xen_e820_table); 676 677 return; 678 } 679 680 entry++; 681 } 682 683 xen_raw_console_write("No suitable area found for required E820 entry remapping action\n"); 684 BUG(); 685 } 686 687 /* 688 * Look for non-RAM memory types in a specific guest physical area and move 689 * those away if possible (ACPI NVS only for now). 690 */ 691 static void __init xen_e820_resolve_conflicts(phys_addr_t start, 692 phys_addr_t size) 693 { 694 struct e820_entry *entry; 695 unsigned int mapcnt; 696 phys_addr_t end; 697 698 if (!size) 699 return; 700 701 end = start + size; 702 entry = xen_e820_table.entries; 703 704 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { 705 if (entry->addr >= end) 706 return; 707 708 if (entry->addr + entry->size > start && 709 entry->type == E820_TYPE_NVS) 710 xen_e820_swap_entry_with_ram(entry); 711 712 entry++; 713 } 714 } 715 716 /* 717 * Check for an area in physical memory to be usable for non-movable purposes. 718 * An area is considered to usable if the used E820 map lists it to be RAM or 719 * some other type which can be moved to higher PFNs while keeping the MFNs. 720 * In case the area is not usable, crash the system with an error message. 721 */ 722 void __init xen_chk_is_e820_usable(phys_addr_t start, phys_addr_t size, 723 const char *component) 724 { 725 xen_e820_resolve_conflicts(start, size); 726 727 if (!xen_is_e820_reserved(start, size)) 728 return; 729 730 xen_raw_console_write("Xen hypervisor allocated "); 731 xen_raw_console_write(component); 732 xen_raw_console_write(" memory conflicts with E820 map\n"); 733 BUG(); 734 } 735 736 /* 737 * Like memcpy, but with physical addresses for dest and src. 738 */ 739 static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src, 740 phys_addr_t n) 741 { 742 phys_addr_t dest_off, src_off, dest_len, src_len, len; 743 void *from, *to; 744 745 while (n) { 746 dest_off = dest & ~PAGE_MASK; 747 src_off = src & ~PAGE_MASK; 748 dest_len = n; 749 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off) 750 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off; 751 src_len = n; 752 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off) 753 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off; 754 len = min(dest_len, src_len); 755 to = early_memremap(dest - dest_off, dest_len + dest_off); 756 from = early_memremap(src - src_off, src_len + src_off); 757 memcpy(to, from, len); 758 early_memunmap(to, dest_len + dest_off); 759 early_memunmap(from, src_len + src_off); 760 n -= len; 761 dest += len; 762 src += len; 763 } 764 } 765 766 /* 767 * Reserve Xen mfn_list. 768 */ 769 static void __init xen_reserve_xen_mfnlist(void) 770 { 771 phys_addr_t start, size; 772 773 if (xen_start_info->mfn_list >= __START_KERNEL_map) { 774 start = __pa(xen_start_info->mfn_list); 775 size = PFN_ALIGN(xen_start_info->nr_pages * 776 sizeof(unsigned long)); 777 } else { 778 start = PFN_PHYS(xen_start_info->first_p2m_pfn); 779 size = PFN_PHYS(xen_start_info->nr_p2m_frames); 780 } 781 782 memblock_reserve(start, size); 783 if (!xen_is_e820_reserved(start, size)) 784 return; 785 786 xen_relocate_p2m(); 787 memblock_phys_free(start, size); 788 } 789 790 /** 791 * xen_memory_setup - Hook for machine specific memory setup. 792 **/ 793 char * __init xen_memory_setup(void) 794 { 795 unsigned long pfn_s, n_pfns; 796 phys_addr_t mem_end, addr, size, chunk_size; 797 u32 type; 798 int rc; 799 struct xen_memory_map memmap; 800 unsigned long max_pages; 801 unsigned long extra_pages = 0; 802 unsigned long maxmem_pages; 803 int i; 804 int op; 805 806 xen_parse_512gb(); 807 ini_nr_pages = min(xen_get_pages_limit(), xen_start_info->nr_pages); 808 mem_end = PFN_PHYS(ini_nr_pages); 809 810 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); 811 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); 812 813 #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON) 814 xen_saved_max_mem_size = max_mem_size; 815 #endif 816 817 op = xen_initial_domain() ? 818 XENMEM_machine_memory_map : 819 XENMEM_memory_map; 820 rc = HYPERVISOR_memory_op(op, &memmap); 821 if (rc == -ENOSYS) { 822 BUG_ON(xen_initial_domain()); 823 memmap.nr_entries = 1; 824 xen_e820_table.entries[0].addr = 0ULL; 825 xen_e820_table.entries[0].size = mem_end; 826 /* 8MB slack (to balance backend allocations). */ 827 xen_e820_table.entries[0].size += 8ULL << 20; 828 xen_e820_table.entries[0].type = E820_TYPE_RAM; 829 rc = 0; 830 } 831 BUG_ON(rc); 832 BUG_ON(memmap.nr_entries == 0); 833 xen_e820_table.nr_entries = memmap.nr_entries; 834 835 if (xen_initial_domain()) { 836 /* 837 * Xen won't allow a 1:1 mapping to be created to UNUSABLE 838 * regions, so if we're using the machine memory map leave the 839 * region as RAM as it is in the pseudo-physical map. 840 * 841 * UNUSABLE regions in domUs are not handled and will need 842 * a patch in the future. 843 */ 844 xen_ignore_unusable(); 845 846 #ifdef CONFIG_ISCSI_IBFT_FIND 847 /* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */ 848 xen_e820_table.entries[xen_e820_table.nr_entries].addr = IBFT_START; 849 xen_e820_table.entries[xen_e820_table.nr_entries].size = IBFT_END - IBFT_START; 850 xen_e820_table.entries[xen_e820_table.nr_entries].type = E820_TYPE_RESERVED; 851 xen_e820_table.nr_entries++; 852 #endif 853 } 854 855 /* Make sure the Xen-supplied memory map is well-ordered. */ 856 e820__update_table(&xen_e820_table); 857 858 max_pages = xen_get_max_pages(); 859 860 /* How many extra pages do we need due to remapping? */ 861 max_pages += xen_foreach_remap_area(xen_count_remap_pages); 862 863 if (max_pages > ini_nr_pages) 864 extra_pages += max_pages - ini_nr_pages; 865 866 /* 867 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO 868 * factor the base size. 869 * 870 * Make sure we have no memory above max_pages, as this area 871 * isn't handled by the p2m management. 872 */ 873 maxmem_pages = EXTRA_MEM_RATIO * min(ini_nr_pages, PFN_DOWN(MAXMEM)); 874 extra_pages = min3(maxmem_pages, extra_pages, max_pages - ini_nr_pages); 875 i = 0; 876 addr = xen_e820_table.entries[0].addr; 877 size = xen_e820_table.entries[0].size; 878 while (i < xen_e820_table.nr_entries) { 879 bool discard = false; 880 881 chunk_size = size; 882 type = xen_e820_table.entries[i].type; 883 884 if (type == E820_TYPE_RESERVED) 885 xen_pv_pci_possible = true; 886 887 if (type == E820_TYPE_RAM) { 888 if (addr < mem_end) { 889 chunk_size = min(size, mem_end - addr); 890 } else if (extra_pages) { 891 chunk_size = min(size, PFN_PHYS(extra_pages)); 892 pfn_s = PFN_UP(addr); 893 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s; 894 extra_pages -= n_pfns; 895 xen_add_extra_mem(pfn_s, n_pfns); 896 xen_max_p2m_pfn = pfn_s + n_pfns; 897 } else 898 discard = true; 899 } 900 901 if (!discard) 902 xen_align_and_add_e820_region(addr, chunk_size, type); 903 904 addr += chunk_size; 905 size -= chunk_size; 906 if (size == 0) { 907 i++; 908 if (i < xen_e820_table.nr_entries) { 909 addr = xen_e820_table.entries[i].addr; 910 size = xen_e820_table.entries[i].size; 911 } 912 } 913 } 914 915 /* 916 * Set the rest as identity mapped, in case PCI BARs are 917 * located here. 918 */ 919 set_phys_range_identity(addr / PAGE_SIZE, ~0ul); 920 921 /* 922 * In domU, the ISA region is normal, usable memory, but we 923 * reserve ISA memory anyway because too many things poke 924 * about in there. 925 */ 926 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED); 927 928 e820__update_table(e820_table); 929 930 /* 931 * Check whether the kernel itself conflicts with the target E820 map. 932 * Failing now is better than running into weird problems later due 933 * to relocating (and even reusing) pages with kernel text or data. 934 */ 935 xen_chk_is_e820_usable(__pa_symbol(_text), 936 __pa_symbol(_end) - __pa_symbol(_text), 937 "kernel"); 938 939 /* 940 * Check for a conflict of the xen_start_info memory with the target 941 * E820 map. 942 */ 943 xen_chk_is_e820_usable(__pa(xen_start_info), sizeof(*xen_start_info), 944 "xen_start_info"); 945 946 /* 947 * Check for a conflict of the hypervisor supplied page tables with 948 * the target E820 map. 949 */ 950 xen_pt_check_e820(); 951 952 xen_reserve_xen_mfnlist(); 953 954 /* Check for a conflict of the initrd with the target E820 map. */ 955 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image, 956 boot_params.hdr.ramdisk_size)) { 957 phys_addr_t new_area, start, size; 958 959 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size); 960 if (!new_area) { 961 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n"); 962 BUG(); 963 } 964 965 start = boot_params.hdr.ramdisk_image; 966 size = boot_params.hdr.ramdisk_size; 967 xen_phys_memcpy(new_area, start, size); 968 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n", 969 start, start + size, new_area, new_area + size); 970 memblock_phys_free(start, size); 971 boot_params.hdr.ramdisk_image = new_area; 972 boot_params.ext_ramdisk_image = new_area >> 32; 973 } 974 975 /* 976 * Set identity map on non-RAM pages and prepare remapping the 977 * underlying RAM. 978 */ 979 xen_foreach_remap_area(xen_set_identity_and_remap_chunk); 980 981 pr_info("Released %ld page(s)\n", xen_released_pages); 982 983 return "Xen"; 984 } 985 986 static int register_callback(unsigned type, const void *func) 987 { 988 struct callback_register callback = { 989 .type = type, 990 .address = XEN_CALLBACK(__KERNEL_CS, func), 991 .flags = CALLBACKF_mask_events, 992 }; 993 994 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback); 995 } 996 997 void xen_enable_sysenter(void) 998 { 999 if (cpu_feature_enabled(X86_FEATURE_SYSENTER32) && 1000 register_callback(CALLBACKTYPE_sysenter, xen_entry_SYSENTER_compat)) 1001 setup_clear_cpu_cap(X86_FEATURE_SYSENTER32); 1002 } 1003 1004 void xen_enable_syscall(void) 1005 { 1006 int ret; 1007 1008 ret = register_callback(CALLBACKTYPE_syscall, xen_entry_SYSCALL_64); 1009 if (ret != 0) { 1010 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret); 1011 /* Pretty fatal; 64-bit userspace has no other 1012 mechanism for syscalls. */ 1013 } 1014 1015 if (cpu_feature_enabled(X86_FEATURE_SYSCALL32) && 1016 register_callback(CALLBACKTYPE_syscall32, xen_entry_SYSCALL_compat)) 1017 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); 1018 } 1019 1020 static void __init xen_pvmmu_arch_setup(void) 1021 { 1022 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); 1023 1024 if (register_callback(CALLBACKTYPE_event, 1025 xen_asm_exc_xen_hypervisor_callback) || 1026 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback)) 1027 BUG(); 1028 1029 xen_enable_sysenter(); 1030 xen_enable_syscall(); 1031 } 1032 1033 /* This function is not called for HVM domains */ 1034 void __init xen_arch_setup(void) 1035 { 1036 xen_panic_handler_init(); 1037 xen_pvmmu_arch_setup(); 1038 1039 #ifdef CONFIG_ACPI 1040 if (!(xen_start_info->flags & SIF_INITDOMAIN)) { 1041 printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); 1042 disable_acpi(); 1043 } 1044 #endif 1045 1046 memcpy(boot_command_line, xen_start_info->cmd_line, 1047 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? 1048 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); 1049 1050 /* Set up idle, making sure it calls safe_halt() pvop */ 1051 disable_cpuidle(); 1052 disable_cpufreq(); 1053 WARN_ON(xen_set_default_idle()); 1054 #ifdef CONFIG_NUMA 1055 numa_off = 1; 1056 #endif 1057 } 1058