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