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