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