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/sched.h> 10 #include <linux/mm.h> 11 #include <linux/pm.h> 12 #include <linux/memblock.h> 13 #include <linux/cpuidle.h> 14 #include <linux/cpufreq.h> 15 16 #include <asm/elf.h> 17 #include <asm/vdso.h> 18 #include <asm/e820/api.h> 19 #include <asm/setup.h> 20 #include <asm/acpi.h> 21 #include <asm/numa.h> 22 #include <asm/xen/hypervisor.h> 23 #include <asm/xen/hypercall.h> 24 25 #include <xen/xen.h> 26 #include <xen/page.h> 27 #include <xen/interface/callback.h> 28 #include <xen/interface/memory.h> 29 #include <xen/interface/physdev.h> 30 #include <xen/features.h> 31 #include <xen/hvc-console.h> 32 #include "xen-ops.h" 33 #include "vdso.h" 34 #include "mmu.h" 35 36 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024) 37 38 /* Amount of extra memory space we add to the e820 ranges */ 39 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; 40 41 /* Number of pages released from the initial allocation. */ 42 unsigned long xen_released_pages; 43 44 /* E820 map used during setting up memory. */ 45 static struct e820_table xen_e820_table __initdata; 46 47 /* 48 * Buffer used to remap identity mapped pages. We only need the virtual space. 49 * The physical page behind this address is remapped as needed to different 50 * buffer pages. 51 */ 52 #define REMAP_SIZE (P2M_PER_PAGE - 3) 53 static struct { 54 unsigned long next_area_mfn; 55 unsigned long target_pfn; 56 unsigned long size; 57 unsigned long mfns[REMAP_SIZE]; 58 } xen_remap_buf __initdata __aligned(PAGE_SIZE); 59 static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY; 60 61 /* 62 * The maximum amount of extra memory compared to the base size. The 63 * main scaling factor is the size of struct page. At extreme ratios 64 * of base:extra, all the base memory can be filled with page 65 * structures for the extra memory, leaving no space for anything 66 * else. 67 * 68 * 10x seems like a reasonable balance between scaling flexibility and 69 * leaving a practically usable system. 70 */ 71 #define EXTRA_MEM_RATIO (10) 72 73 static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB); 74 75 static void __init xen_parse_512gb(void) 76 { 77 bool val = false; 78 char *arg; 79 80 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit"); 81 if (!arg) 82 return; 83 84 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit="); 85 if (!arg) 86 val = true; 87 else if (strtobool(arg + strlen("xen_512gb_limit="), &val)) 88 return; 89 90 xen_512gb_limit = val; 91 } 92 93 static void __init xen_add_extra_mem(unsigned long start_pfn, 94 unsigned long n_pfns) 95 { 96 int i; 97 98 /* 99 * No need to check for zero size, should happen rarely and will only 100 * write a new entry regarded to be unused due to zero size. 101 */ 102 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 103 /* Add new region. */ 104 if (xen_extra_mem[i].n_pfns == 0) { 105 xen_extra_mem[i].start_pfn = start_pfn; 106 xen_extra_mem[i].n_pfns = n_pfns; 107 break; 108 } 109 /* Append to existing region. */ 110 if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns == 111 start_pfn) { 112 xen_extra_mem[i].n_pfns += n_pfns; 113 break; 114 } 115 } 116 if (i == XEN_EXTRA_MEM_MAX_REGIONS) 117 printk(KERN_WARNING "Warning: not enough extra memory regions\n"); 118 119 memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); 120 } 121 122 static void __init xen_del_extra_mem(unsigned long start_pfn, 123 unsigned long n_pfns) 124 { 125 int i; 126 unsigned long start_r, size_r; 127 128 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 129 start_r = xen_extra_mem[i].start_pfn; 130 size_r = xen_extra_mem[i].n_pfns; 131 132 /* Start of region. */ 133 if (start_r == start_pfn) { 134 BUG_ON(n_pfns > size_r); 135 xen_extra_mem[i].start_pfn += n_pfns; 136 xen_extra_mem[i].n_pfns -= n_pfns; 137 break; 138 } 139 /* End of region. */ 140 if (start_r + size_r == start_pfn + n_pfns) { 141 BUG_ON(n_pfns > size_r); 142 xen_extra_mem[i].n_pfns -= n_pfns; 143 break; 144 } 145 /* Mid of region. */ 146 if (start_pfn > start_r && start_pfn < start_r + size_r) { 147 BUG_ON(start_pfn + n_pfns > start_r + size_r); 148 xen_extra_mem[i].n_pfns = start_pfn - start_r; 149 /* Calling memblock_reserve() again is okay. */ 150 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r - 151 (start_pfn + n_pfns)); 152 break; 153 } 154 } 155 memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); 156 } 157 158 /* 159 * Called during boot before the p2m list can take entries beyond the 160 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as 161 * invalid. 162 */ 163 unsigned long __ref xen_chk_extra_mem(unsigned long pfn) 164 { 165 int i; 166 167 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 168 if (pfn >= xen_extra_mem[i].start_pfn && 169 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns) 170 return INVALID_P2M_ENTRY; 171 } 172 173 return IDENTITY_FRAME(pfn); 174 } 175 176 /* 177 * Mark all pfns of extra mem as invalid in p2m list. 178 */ 179 void __init xen_inv_extra_mem(void) 180 { 181 unsigned long pfn, pfn_s, pfn_e; 182 int i; 183 184 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 185 if (!xen_extra_mem[i].n_pfns) 186 continue; 187 pfn_s = xen_extra_mem[i].start_pfn; 188 pfn_e = pfn_s + xen_extra_mem[i].n_pfns; 189 for (pfn = pfn_s; pfn < pfn_e; pfn++) 190 set_phys_to_machine(pfn, INVALID_P2M_ENTRY); 191 } 192 } 193 194 /* 195 * Finds the next RAM pfn available in the E820 map after min_pfn. 196 * This function updates min_pfn with the pfn found and returns 197 * the size of that range or zero if not found. 198 */ 199 static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn) 200 { 201 const struct e820_entry *entry = xen_e820_table.entries; 202 unsigned int i; 203 unsigned long done = 0; 204 205 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 206 unsigned long s_pfn; 207 unsigned long e_pfn; 208 209 if (entry->type != E820_TYPE_RAM) 210 continue; 211 212 e_pfn = PFN_DOWN(entry->addr + entry->size); 213 214 /* We only care about E820 after this */ 215 if (e_pfn <= *min_pfn) 216 continue; 217 218 s_pfn = PFN_UP(entry->addr); 219 220 /* If min_pfn falls within the E820 entry, we want to start 221 * at the min_pfn PFN. 222 */ 223 if (s_pfn <= *min_pfn) { 224 done = e_pfn - *min_pfn; 225 } else { 226 done = e_pfn - s_pfn; 227 *min_pfn = s_pfn; 228 } 229 break; 230 } 231 232 return done; 233 } 234 235 static int __init xen_free_mfn(unsigned long mfn) 236 { 237 struct xen_memory_reservation reservation = { 238 .address_bits = 0, 239 .extent_order = 0, 240 .domid = DOMID_SELF 241 }; 242 243 set_xen_guest_handle(reservation.extent_start, &mfn); 244 reservation.nr_extents = 1; 245 246 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); 247 } 248 249 /* 250 * This releases a chunk of memory and then does the identity map. It's used 251 * as a fallback if the remapping fails. 252 */ 253 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, 254 unsigned long end_pfn, unsigned long nr_pages) 255 { 256 unsigned long pfn, end; 257 int ret; 258 259 WARN_ON(start_pfn > end_pfn); 260 261 /* Release pages first. */ 262 end = min(end_pfn, nr_pages); 263 for (pfn = start_pfn; pfn < end; pfn++) { 264 unsigned long mfn = pfn_to_mfn(pfn); 265 266 /* Make sure pfn exists to start with */ 267 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn) 268 continue; 269 270 ret = xen_free_mfn(mfn); 271 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret); 272 273 if (ret == 1) { 274 xen_released_pages++; 275 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY)) 276 break; 277 } else 278 break; 279 } 280 281 set_phys_range_identity(start_pfn, end_pfn); 282 } 283 284 /* 285 * Helper function to update the p2m and m2p tables and kernel mapping. 286 */ 287 static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn) 288 { 289 struct mmu_update update = { 290 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE, 291 .val = pfn 292 }; 293 294 /* Update p2m */ 295 if (!set_phys_to_machine(pfn, mfn)) { 296 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n", 297 pfn, mfn); 298 BUG(); 299 } 300 301 /* Update m2p */ 302 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) { 303 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n", 304 mfn, pfn); 305 BUG(); 306 } 307 308 /* Update kernel mapping, but not for highmem. */ 309 if (pfn >= PFN_UP(__pa(high_memory - 1))) 310 return; 311 312 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), 313 mfn_pte(mfn, PAGE_KERNEL), 0)) { 314 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n", 315 mfn, pfn); 316 BUG(); 317 } 318 } 319 320 /* 321 * This function updates the p2m and m2p tables with an identity map from 322 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the 323 * original allocation at remap_pfn. The information needed for remapping is 324 * saved in the memory itself to avoid the need for allocating buffers. The 325 * complete remap information is contained in a list of MFNs each containing 326 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap. 327 * This enables us to preserve the original mfn sequence while doing the 328 * remapping at a time when the memory management is capable of allocating 329 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and 330 * its callers. 331 */ 332 static void __init xen_do_set_identity_and_remap_chunk( 333 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn) 334 { 335 unsigned long buf = (unsigned long)&xen_remap_buf; 336 unsigned long mfn_save, mfn; 337 unsigned long ident_pfn_iter, remap_pfn_iter; 338 unsigned long ident_end_pfn = start_pfn + size; 339 unsigned long left = size; 340 unsigned int i, chunk; 341 342 WARN_ON(size == 0); 343 344 mfn_save = virt_to_mfn(buf); 345 346 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn; 347 ident_pfn_iter < ident_end_pfn; 348 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) { 349 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE; 350 351 /* Map first pfn to xen_remap_buf */ 352 mfn = pfn_to_mfn(ident_pfn_iter); 353 set_pte_mfn(buf, mfn, PAGE_KERNEL); 354 355 /* Save mapping information in page */ 356 xen_remap_buf.next_area_mfn = xen_remap_mfn; 357 xen_remap_buf.target_pfn = remap_pfn_iter; 358 xen_remap_buf.size = chunk; 359 for (i = 0; i < chunk; i++) 360 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i); 361 362 /* Put remap buf into list. */ 363 xen_remap_mfn = mfn; 364 365 /* Set identity map */ 366 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk); 367 368 left -= chunk; 369 } 370 371 /* Restore old xen_remap_buf mapping */ 372 set_pte_mfn(buf, mfn_save, PAGE_KERNEL); 373 } 374 375 /* 376 * This function takes a contiguous pfn range that needs to be identity mapped 377 * and: 378 * 379 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn. 380 * 2) Calls the do_ function to actually do the mapping/remapping work. 381 * 382 * The goal is to not allocate additional memory but to remap the existing 383 * pages. In the case of an error the underlying memory is simply released back 384 * to Xen and not remapped. 385 */ 386 static unsigned long __init xen_set_identity_and_remap_chunk( 387 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, 388 unsigned long remap_pfn) 389 { 390 unsigned long pfn; 391 unsigned long i = 0; 392 unsigned long n = end_pfn - start_pfn; 393 394 if (remap_pfn == 0) 395 remap_pfn = nr_pages; 396 397 while (i < n) { 398 unsigned long cur_pfn = start_pfn + i; 399 unsigned long left = n - i; 400 unsigned long size = left; 401 unsigned long remap_range_size; 402 403 /* Do not remap pages beyond the current allocation */ 404 if (cur_pfn >= nr_pages) { 405 /* Identity map remaining pages */ 406 set_phys_range_identity(cur_pfn, cur_pfn + size); 407 break; 408 } 409 if (cur_pfn + size > nr_pages) 410 size = nr_pages - cur_pfn; 411 412 remap_range_size = xen_find_pfn_range(&remap_pfn); 413 if (!remap_range_size) { 414 pr_warning("Unable to find available pfn range, not remapping identity pages\n"); 415 xen_set_identity_and_release_chunk(cur_pfn, 416 cur_pfn + left, nr_pages); 417 break; 418 } 419 /* Adjust size to fit in current e820 RAM region */ 420 if (size > remap_range_size) 421 size = remap_range_size; 422 423 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn); 424 425 /* Update variables to reflect new mappings. */ 426 i += size; 427 remap_pfn += size; 428 } 429 430 /* 431 * If the PFNs are currently mapped, the VA mapping also needs 432 * to be updated to be 1:1. 433 */ 434 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) 435 (void)HYPERVISOR_update_va_mapping( 436 (unsigned long)__va(pfn << PAGE_SHIFT), 437 mfn_pte(pfn, PAGE_KERNEL_IO), 0); 438 439 return remap_pfn; 440 } 441 442 static unsigned long __init xen_count_remap_pages( 443 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, 444 unsigned long remap_pages) 445 { 446 if (start_pfn >= nr_pages) 447 return remap_pages; 448 449 return remap_pages + min(end_pfn, nr_pages) - start_pfn; 450 } 451 452 static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, 453 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn, 454 unsigned long nr_pages, unsigned long last_val)) 455 { 456 phys_addr_t start = 0; 457 unsigned long ret_val = 0; 458 const struct e820_entry *entry = xen_e820_table.entries; 459 int i; 460 461 /* 462 * Combine non-RAM regions and gaps until a RAM region (or the 463 * end of the map) is reached, then call the provided function 464 * to perform its duty on the non-RAM region. 465 * 466 * The combined non-RAM regions are rounded to a whole number 467 * of pages so any partial pages are accessible via the 1:1 468 * mapping. This is needed for some BIOSes that put (for 469 * example) the DMI tables in a reserved region that begins on 470 * a non-page boundary. 471 */ 472 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 473 phys_addr_t end = entry->addr + entry->size; 474 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) { 475 unsigned long start_pfn = PFN_DOWN(start); 476 unsigned long end_pfn = PFN_UP(end); 477 478 if (entry->type == E820_TYPE_RAM) 479 end_pfn = PFN_UP(entry->addr); 480 481 if (start_pfn < end_pfn) 482 ret_val = func(start_pfn, end_pfn, nr_pages, 483 ret_val); 484 start = end; 485 } 486 } 487 488 return ret_val; 489 } 490 491 /* 492 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk(). 493 * The remap information (which mfn remap to which pfn) is contained in the 494 * to be remapped memory itself in a linked list anchored at xen_remap_mfn. 495 * This scheme allows to remap the different chunks in arbitrary order while 496 * the resulting mapping will be independent from the order. 497 */ 498 void __init xen_remap_memory(void) 499 { 500 unsigned long buf = (unsigned long)&xen_remap_buf; 501 unsigned long mfn_save, pfn; 502 unsigned long remapped = 0; 503 unsigned int i; 504 unsigned long pfn_s = ~0UL; 505 unsigned long len = 0; 506 507 mfn_save = virt_to_mfn(buf); 508 509 while (xen_remap_mfn != INVALID_P2M_ENTRY) { 510 /* Map the remap information */ 511 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL); 512 513 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]); 514 515 pfn = xen_remap_buf.target_pfn; 516 for (i = 0; i < xen_remap_buf.size; i++) { 517 xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]); 518 remapped++; 519 pfn++; 520 } 521 if (pfn_s == ~0UL || pfn == pfn_s) { 522 pfn_s = xen_remap_buf.target_pfn; 523 len += xen_remap_buf.size; 524 } else if (pfn_s + len == xen_remap_buf.target_pfn) { 525 len += xen_remap_buf.size; 526 } else { 527 xen_del_extra_mem(pfn_s, len); 528 pfn_s = xen_remap_buf.target_pfn; 529 len = xen_remap_buf.size; 530 } 531 xen_remap_mfn = xen_remap_buf.next_area_mfn; 532 } 533 534 if (pfn_s != ~0UL && len) 535 xen_del_extra_mem(pfn_s, len); 536 537 set_pte_mfn(buf, mfn_save, PAGE_KERNEL); 538 539 pr_info("Remapped %ld page(s)\n", remapped); 540 } 541 542 static unsigned long __init xen_get_pages_limit(void) 543 { 544 unsigned long limit; 545 546 #ifdef CONFIG_X86_32 547 limit = GB(64) / PAGE_SIZE; 548 #else 549 limit = MAXMEM / PAGE_SIZE; 550 if (!xen_initial_domain() && xen_512gb_limit) 551 limit = GB(512) / PAGE_SIZE; 552 #endif 553 return limit; 554 } 555 556 static unsigned long __init xen_get_max_pages(void) 557 { 558 unsigned long max_pages, limit; 559 domid_t domid = DOMID_SELF; 560 long ret; 561 562 limit = xen_get_pages_limit(); 563 max_pages = limit; 564 565 /* 566 * For the initial domain we use the maximum reservation as 567 * the maximum page. 568 * 569 * For guest domains the current maximum reservation reflects 570 * the current maximum rather than the static maximum. In this 571 * case the e820 map provided to us will cover the static 572 * maximum region. 573 */ 574 if (xen_initial_domain()) { 575 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid); 576 if (ret > 0) 577 max_pages = ret; 578 } 579 580 return min(max_pages, limit); 581 } 582 583 static void __init xen_align_and_add_e820_region(phys_addr_t start, 584 phys_addr_t size, int type) 585 { 586 phys_addr_t end = start + size; 587 588 /* Align RAM regions to page boundaries. */ 589 if (type == E820_TYPE_RAM) { 590 start = PAGE_ALIGN(start); 591 end &= ~((phys_addr_t)PAGE_SIZE - 1); 592 } 593 594 e820__range_add(start, end - start, type); 595 } 596 597 static void __init xen_ignore_unusable(void) 598 { 599 struct e820_entry *entry = xen_e820_table.entries; 600 unsigned int i; 601 602 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 603 if (entry->type == E820_TYPE_UNUSABLE) 604 entry->type = E820_TYPE_RAM; 605 } 606 } 607 608 bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size) 609 { 610 struct e820_entry *entry; 611 unsigned mapcnt; 612 phys_addr_t end; 613 614 if (!size) 615 return false; 616 617 end = start + size; 618 entry = xen_e820_table.entries; 619 620 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { 621 if (entry->type == E820_TYPE_RAM && entry->addr <= start && 622 (entry->addr + entry->size) >= end) 623 return false; 624 625 entry++; 626 } 627 628 return true; 629 } 630 631 /* 632 * Find a free area in physical memory not yet reserved and compliant with 633 * E820 map. 634 * Used to relocate pre-allocated areas like initrd or p2m list which are in 635 * conflict with the to be used E820 map. 636 * In case no area is found, return 0. Otherwise return the physical address 637 * of the area which is already reserved for convenience. 638 */ 639 phys_addr_t __init xen_find_free_area(phys_addr_t size) 640 { 641 unsigned mapcnt; 642 phys_addr_t addr, start; 643 struct e820_entry *entry = xen_e820_table.entries; 644 645 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) { 646 if (entry->type != E820_TYPE_RAM || entry->size < size) 647 continue; 648 start = entry->addr; 649 for (addr = start; addr < start + size; addr += PAGE_SIZE) { 650 if (!memblock_is_reserved(addr)) 651 continue; 652 start = addr + PAGE_SIZE; 653 if (start + size > entry->addr + entry->size) 654 break; 655 } 656 if (addr >= start + size) { 657 memblock_reserve(start, size); 658 return start; 659 } 660 } 661 662 return 0; 663 } 664 665 /* 666 * Like memcpy, but with physical addresses for dest and src. 667 */ 668 static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src, 669 phys_addr_t n) 670 { 671 phys_addr_t dest_off, src_off, dest_len, src_len, len; 672 void *from, *to; 673 674 while (n) { 675 dest_off = dest & ~PAGE_MASK; 676 src_off = src & ~PAGE_MASK; 677 dest_len = n; 678 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off) 679 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off; 680 src_len = n; 681 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off) 682 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off; 683 len = min(dest_len, src_len); 684 to = early_memremap(dest - dest_off, dest_len + dest_off); 685 from = early_memremap(src - src_off, src_len + src_off); 686 memcpy(to, from, len); 687 early_memunmap(to, dest_len + dest_off); 688 early_memunmap(from, src_len + src_off); 689 n -= len; 690 dest += len; 691 src += len; 692 } 693 } 694 695 /* 696 * Reserve Xen mfn_list. 697 */ 698 static void __init xen_reserve_xen_mfnlist(void) 699 { 700 phys_addr_t start, size; 701 702 if (xen_start_info->mfn_list >= __START_KERNEL_map) { 703 start = __pa(xen_start_info->mfn_list); 704 size = PFN_ALIGN(xen_start_info->nr_pages * 705 sizeof(unsigned long)); 706 } else { 707 start = PFN_PHYS(xen_start_info->first_p2m_pfn); 708 size = PFN_PHYS(xen_start_info->nr_p2m_frames); 709 } 710 711 memblock_reserve(start, size); 712 if (!xen_is_e820_reserved(start, size)) 713 return; 714 715 #ifdef CONFIG_X86_32 716 /* 717 * Relocating the p2m on 32 bit system to an arbitrary virtual address 718 * is not supported, so just give up. 719 */ 720 xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with E820 map\n"); 721 BUG(); 722 #else 723 xen_relocate_p2m(); 724 memblock_free(start, size); 725 #endif 726 } 727 728 /** 729 * machine_specific_memory_setup - Hook for machine specific memory setup. 730 **/ 731 char * __init xen_memory_setup(void) 732 { 733 unsigned long max_pfn, pfn_s, n_pfns; 734 phys_addr_t mem_end, addr, size, chunk_size; 735 u32 type; 736 int rc; 737 struct xen_memory_map memmap; 738 unsigned long max_pages; 739 unsigned long extra_pages = 0; 740 int i; 741 int op; 742 743 xen_parse_512gb(); 744 max_pfn = xen_get_pages_limit(); 745 max_pfn = min(max_pfn, xen_start_info->nr_pages); 746 mem_end = PFN_PHYS(max_pfn); 747 748 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); 749 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); 750 751 op = xen_initial_domain() ? 752 XENMEM_machine_memory_map : 753 XENMEM_memory_map; 754 rc = HYPERVISOR_memory_op(op, &memmap); 755 if (rc == -ENOSYS) { 756 BUG_ON(xen_initial_domain()); 757 memmap.nr_entries = 1; 758 xen_e820_table.entries[0].addr = 0ULL; 759 xen_e820_table.entries[0].size = mem_end; 760 /* 8MB slack (to balance backend allocations). */ 761 xen_e820_table.entries[0].size += 8ULL << 20; 762 xen_e820_table.entries[0].type = E820_TYPE_RAM; 763 rc = 0; 764 } 765 BUG_ON(rc); 766 BUG_ON(memmap.nr_entries == 0); 767 xen_e820_table.nr_entries = memmap.nr_entries; 768 769 /* 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 if (xen_initial_domain()) 778 xen_ignore_unusable(); 779 780 /* Make sure the Xen-supplied memory map is well-ordered. */ 781 e820__update_table(&xen_e820_table); 782 783 max_pages = xen_get_max_pages(); 784 785 /* How many extra pages do we need due to remapping? */ 786 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages); 787 788 if (max_pages > max_pfn) 789 extra_pages += max_pages - max_pfn; 790 791 /* 792 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO 793 * factor the base size. On non-highmem systems, the base 794 * size is the full initial memory allocation; on highmem it 795 * is limited to the max size of lowmem, so that it doesn't 796 * get completely filled. 797 * 798 * Make sure we have no memory above max_pages, as this area 799 * isn't handled by the p2m management. 800 * 801 * In principle there could be a problem in lowmem systems if 802 * the initial memory is also very large with respect to 803 * lowmem, but we won't try to deal with that here. 804 */ 805 extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), 806 extra_pages, max_pages - max_pfn); 807 i = 0; 808 addr = xen_e820_table.entries[0].addr; 809 size = xen_e820_table.entries[0].size; 810 while (i < xen_e820_table.nr_entries) { 811 bool discard = false; 812 813 chunk_size = size; 814 type = xen_e820_table.entries[i].type; 815 816 if (type == E820_TYPE_RAM) { 817 if (addr < mem_end) { 818 chunk_size = min(size, mem_end - addr); 819 } else if (extra_pages) { 820 chunk_size = min(size, PFN_PHYS(extra_pages)); 821 pfn_s = PFN_UP(addr); 822 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s; 823 extra_pages -= n_pfns; 824 xen_add_extra_mem(pfn_s, n_pfns); 825 xen_max_p2m_pfn = pfn_s + n_pfns; 826 } else 827 discard = true; 828 } 829 830 if (!discard) 831 xen_align_and_add_e820_region(addr, chunk_size, type); 832 833 addr += chunk_size; 834 size -= chunk_size; 835 if (size == 0) { 836 i++; 837 if (i < xen_e820_table.nr_entries) { 838 addr = xen_e820_table.entries[i].addr; 839 size = xen_e820_table.entries[i].size; 840 } 841 } 842 } 843 844 /* 845 * Set the rest as identity mapped, in case PCI BARs are 846 * located here. 847 */ 848 set_phys_range_identity(addr / PAGE_SIZE, ~0ul); 849 850 /* 851 * In domU, the ISA region is normal, usable memory, but we 852 * reserve ISA memory anyway because too many things poke 853 * about in there. 854 */ 855 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED); 856 857 e820__update_table(e820_table); 858 859 /* 860 * Check whether the kernel itself conflicts with the target E820 map. 861 * Failing now is better than running into weird problems later due 862 * to relocating (and even reusing) pages with kernel text or data. 863 */ 864 if (xen_is_e820_reserved(__pa_symbol(_text), 865 __pa_symbol(__bss_stop) - __pa_symbol(_text))) { 866 xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n"); 867 BUG(); 868 } 869 870 /* 871 * Check for a conflict of the hypervisor supplied page tables with 872 * the target E820 map. 873 */ 874 xen_pt_check_e820(); 875 876 xen_reserve_xen_mfnlist(); 877 878 /* Check for a conflict of the initrd with the target E820 map. */ 879 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image, 880 boot_params.hdr.ramdisk_size)) { 881 phys_addr_t new_area, start, size; 882 883 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size); 884 if (!new_area) { 885 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n"); 886 BUG(); 887 } 888 889 start = boot_params.hdr.ramdisk_image; 890 size = boot_params.hdr.ramdisk_size; 891 xen_phys_memcpy(new_area, start, size); 892 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n", 893 start, start + size, new_area, new_area + size); 894 memblock_free(start, size); 895 boot_params.hdr.ramdisk_image = new_area; 896 boot_params.ext_ramdisk_image = new_area >> 32; 897 } 898 899 /* 900 * Set identity map on non-RAM pages and prepare remapping the 901 * underlying RAM. 902 */ 903 xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk); 904 905 pr_info("Released %ld page(s)\n", xen_released_pages); 906 907 return "Xen"; 908 } 909 910 /* 911 * Set the bit indicating "nosegneg" library variants should be used. 912 * We only need to bother in pure 32-bit mode; compat 32-bit processes 913 * can have un-truncated segments, so wrapping around is allowed. 914 */ 915 static void __init fiddle_vdso(void) 916 { 917 #ifdef CONFIG_X86_32 918 u32 *mask = vdso_image_32.data + 919 vdso_image_32.sym_VDSO32_NOTE_MASK; 920 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; 921 #endif 922 } 923 924 static int register_callback(unsigned type, const void *func) 925 { 926 struct callback_register callback = { 927 .type = type, 928 .address = XEN_CALLBACK(__KERNEL_CS, func), 929 .flags = CALLBACKF_mask_events, 930 }; 931 932 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback); 933 } 934 935 void xen_enable_sysenter(void) 936 { 937 int ret; 938 unsigned sysenter_feature; 939 940 #ifdef CONFIG_X86_32 941 sysenter_feature = X86_FEATURE_SEP; 942 #else 943 sysenter_feature = X86_FEATURE_SYSENTER32; 944 #endif 945 946 if (!boot_cpu_has(sysenter_feature)) 947 return; 948 949 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target); 950 if(ret != 0) 951 setup_clear_cpu_cap(sysenter_feature); 952 } 953 954 void xen_enable_syscall(void) 955 { 956 #ifdef CONFIG_X86_64 957 int ret; 958 959 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target); 960 if (ret != 0) { 961 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret); 962 /* Pretty fatal; 64-bit userspace has no other 963 mechanism for syscalls. */ 964 } 965 966 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) { 967 ret = register_callback(CALLBACKTYPE_syscall32, 968 xen_syscall32_target); 969 if (ret != 0) 970 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); 971 } 972 #endif /* CONFIG_X86_64 */ 973 } 974 975 void __init xen_pvmmu_arch_setup(void) 976 { 977 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments); 978 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); 979 980 HYPERVISOR_vm_assist(VMASST_CMD_enable, 981 VMASST_TYPE_pae_extended_cr3); 982 983 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) || 984 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback)) 985 BUG(); 986 987 xen_enable_sysenter(); 988 xen_enable_syscall(); 989 } 990 991 /* This function is not called for HVM domains */ 992 void __init xen_arch_setup(void) 993 { 994 xen_panic_handler_init(); 995 xen_pvmmu_arch_setup(); 996 997 #ifdef CONFIG_ACPI 998 if (!(xen_start_info->flags & SIF_INITDOMAIN)) { 999 printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); 1000 disable_acpi(); 1001 } 1002 #endif 1003 1004 memcpy(boot_command_line, xen_start_info->cmd_line, 1005 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? 1006 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); 1007 1008 /* Set up idle, making sure it calls safe_halt() pvop */ 1009 disable_cpuidle(); 1010 disable_cpufreq(); 1011 WARN_ON(xen_set_default_idle()); 1012 fiddle_vdso(); 1013 #ifdef CONFIG_NUMA 1014 numa_off = 1; 1015 #endif 1016 } 1017