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 #include <linux/memory_hotplug.h> 16 17 #include <asm/elf.h> 18 #include <asm/vdso.h> 19 #include <asm/e820/api.h> 20 #include <asm/setup.h> 21 #include <asm/acpi.h> 22 #include <asm/numa.h> 23 #include <asm/idtentry.h> 24 #include <asm/xen/hypervisor.h> 25 #include <asm/xen/hypercall.h> 26 27 #include <xen/xen.h> 28 #include <xen/page.h> 29 #include <xen/interface/callback.h> 30 #include <xen/interface/memory.h> 31 #include <xen/interface/physdev.h> 32 #include <xen/features.h> 33 #include <xen/hvc-console.h> 34 #include "xen-ops.h" 35 #include "mmu.h" 36 37 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024) 38 39 /* Amount of extra memory space we add to the e820 ranges */ 40 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; 41 42 /* Number of pages released from the initial allocation. */ 43 unsigned long xen_released_pages; 44 45 /* E820 map used during setting up memory. */ 46 static struct e820_table xen_e820_table __initdata; 47 48 /* 49 * Buffer used to remap identity mapped pages. We only need the virtual space. 50 * The physical page behind this address is remapped as needed to different 51 * buffer pages. 52 */ 53 #define REMAP_SIZE (P2M_PER_PAGE - 3) 54 static struct { 55 unsigned long next_area_mfn; 56 unsigned long target_pfn; 57 unsigned long size; 58 unsigned long mfns[REMAP_SIZE]; 59 } xen_remap_buf __initdata __aligned(PAGE_SIZE); 60 static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY; 61 62 /* 63 * The maximum amount of extra memory compared to the base size. The 64 * main scaling factor is the size of struct page. At extreme ratios 65 * of base:extra, all the base memory can be filled with page 66 * structures for the extra memory, leaving no space for anything 67 * else. 68 * 69 * 10x seems like a reasonable balance between scaling flexibility and 70 * leaving a practically usable system. 71 */ 72 #define EXTRA_MEM_RATIO (10) 73 74 static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB); 75 76 static void __init xen_parse_512gb(void) 77 { 78 bool val = false; 79 char *arg; 80 81 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit"); 82 if (!arg) 83 return; 84 85 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit="); 86 if (!arg) 87 val = true; 88 else if (strtobool(arg + strlen("xen_512gb_limit="), &val)) 89 return; 90 91 xen_512gb_limit = val; 92 } 93 94 static void __init xen_add_extra_mem(unsigned long start_pfn, 95 unsigned long n_pfns) 96 { 97 int i; 98 99 /* 100 * No need to check for zero size, should happen rarely and will only 101 * write a new entry regarded to be unused due to zero size. 102 */ 103 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 104 /* Add new region. */ 105 if (xen_extra_mem[i].n_pfns == 0) { 106 xen_extra_mem[i].start_pfn = start_pfn; 107 xen_extra_mem[i].n_pfns = n_pfns; 108 break; 109 } 110 /* Append to existing region. */ 111 if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns == 112 start_pfn) { 113 xen_extra_mem[i].n_pfns += n_pfns; 114 break; 115 } 116 } 117 if (i == XEN_EXTRA_MEM_MAX_REGIONS) 118 printk(KERN_WARNING "Warning: not enough extra memory regions\n"); 119 120 memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); 121 } 122 123 static void __init xen_del_extra_mem(unsigned long start_pfn, 124 unsigned long n_pfns) 125 { 126 int i; 127 unsigned long start_r, size_r; 128 129 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 130 start_r = xen_extra_mem[i].start_pfn; 131 size_r = xen_extra_mem[i].n_pfns; 132 133 /* Start of region. */ 134 if (start_r == start_pfn) { 135 BUG_ON(n_pfns > size_r); 136 xen_extra_mem[i].start_pfn += n_pfns; 137 xen_extra_mem[i].n_pfns -= n_pfns; 138 break; 139 } 140 /* End of region. */ 141 if (start_r + size_r == start_pfn + n_pfns) { 142 BUG_ON(n_pfns > size_r); 143 xen_extra_mem[i].n_pfns -= n_pfns; 144 break; 145 } 146 /* Mid of region. */ 147 if (start_pfn > start_r && start_pfn < start_r + size_r) { 148 BUG_ON(start_pfn + n_pfns > start_r + size_r); 149 xen_extra_mem[i].n_pfns = start_pfn - start_r; 150 /* Calling memblock_reserve() again is okay. */ 151 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r - 152 (start_pfn + n_pfns)); 153 break; 154 } 155 } 156 memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); 157 } 158 159 /* 160 * Called during boot before the p2m list can take entries beyond the 161 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as 162 * invalid. 163 */ 164 unsigned long __ref xen_chk_extra_mem(unsigned long pfn) 165 { 166 int i; 167 168 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 169 if (pfn >= xen_extra_mem[i].start_pfn && 170 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns) 171 return INVALID_P2M_ENTRY; 172 } 173 174 return IDENTITY_FRAME(pfn); 175 } 176 177 /* 178 * Mark all pfns of extra mem as invalid in p2m list. 179 */ 180 void __init xen_inv_extra_mem(void) 181 { 182 unsigned long pfn, pfn_s, pfn_e; 183 int i; 184 185 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 186 if (!xen_extra_mem[i].n_pfns) 187 continue; 188 pfn_s = xen_extra_mem[i].start_pfn; 189 pfn_e = pfn_s + xen_extra_mem[i].n_pfns; 190 for (pfn = pfn_s; pfn < pfn_e; pfn++) 191 set_phys_to_machine(pfn, INVALID_P2M_ENTRY); 192 } 193 } 194 195 /* 196 * Finds the next RAM pfn available in the E820 map after min_pfn. 197 * This function updates min_pfn with the pfn found and returns 198 * the size of that range or zero if not found. 199 */ 200 static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn) 201 { 202 const struct e820_entry *entry = xen_e820_table.entries; 203 unsigned int i; 204 unsigned long done = 0; 205 206 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 207 unsigned long s_pfn; 208 unsigned long e_pfn; 209 210 if (entry->type != E820_TYPE_RAM) 211 continue; 212 213 e_pfn = PFN_DOWN(entry->addr + entry->size); 214 215 /* We only care about E820 after this */ 216 if (e_pfn <= *min_pfn) 217 continue; 218 219 s_pfn = PFN_UP(entry->addr); 220 221 /* If min_pfn falls within the E820 entry, we want to start 222 * at the min_pfn PFN. 223 */ 224 if (s_pfn <= *min_pfn) { 225 done = e_pfn - *min_pfn; 226 } else { 227 done = e_pfn - s_pfn; 228 *min_pfn = s_pfn; 229 } 230 break; 231 } 232 233 return done; 234 } 235 236 static int __init xen_free_mfn(unsigned long mfn) 237 { 238 struct xen_memory_reservation reservation = { 239 .address_bits = 0, 240 .extent_order = 0, 241 .domid = DOMID_SELF 242 }; 243 244 set_xen_guest_handle(reservation.extent_start, &mfn); 245 reservation.nr_extents = 1; 246 247 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); 248 } 249 250 /* 251 * This releases a chunk of memory and then does the identity map. It's used 252 * as a fallback if the remapping fails. 253 */ 254 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, 255 unsigned long end_pfn, unsigned long nr_pages) 256 { 257 unsigned long pfn, end; 258 int ret; 259 260 WARN_ON(start_pfn > end_pfn); 261 262 /* Release pages first. */ 263 end = min(end_pfn, nr_pages); 264 for (pfn = start_pfn; pfn < end; pfn++) { 265 unsigned long mfn = pfn_to_mfn(pfn); 266 267 /* Make sure pfn exists to start with */ 268 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn) 269 continue; 270 271 ret = xen_free_mfn(mfn); 272 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret); 273 274 if (ret == 1) { 275 xen_released_pages++; 276 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY)) 277 break; 278 } else 279 break; 280 } 281 282 set_phys_range_identity(start_pfn, end_pfn); 283 } 284 285 /* 286 * Helper function to update the p2m and m2p tables and kernel mapping. 287 */ 288 static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn) 289 { 290 struct mmu_update update = { 291 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE, 292 .val = pfn 293 }; 294 295 /* Update p2m */ 296 if (!set_phys_to_machine(pfn, mfn)) { 297 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n", 298 pfn, mfn); 299 BUG(); 300 } 301 302 /* Update m2p */ 303 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) { 304 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n", 305 mfn, pfn); 306 BUG(); 307 } 308 309 /* Update kernel mapping, but not for highmem. */ 310 if (pfn >= PFN_UP(__pa(high_memory - 1))) 311 return; 312 313 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), 314 mfn_pte(mfn, PAGE_KERNEL), 0)) { 315 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n", 316 mfn, pfn); 317 BUG(); 318 } 319 } 320 321 /* 322 * This function updates the p2m and m2p tables with an identity map from 323 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the 324 * original allocation at remap_pfn. The information needed for remapping is 325 * saved in the memory itself to avoid the need for allocating buffers. The 326 * complete remap information is contained in a list of MFNs each containing 327 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap. 328 * This enables us to preserve the original mfn sequence while doing the 329 * remapping at a time when the memory management is capable of allocating 330 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and 331 * its callers. 332 */ 333 static void __init xen_do_set_identity_and_remap_chunk( 334 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn) 335 { 336 unsigned long buf = (unsigned long)&xen_remap_buf; 337 unsigned long mfn_save, mfn; 338 unsigned long ident_pfn_iter, remap_pfn_iter; 339 unsigned long ident_end_pfn = start_pfn + size; 340 unsigned long left = size; 341 unsigned int i, chunk; 342 343 WARN_ON(size == 0); 344 345 mfn_save = virt_to_mfn(buf); 346 347 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn; 348 ident_pfn_iter < ident_end_pfn; 349 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) { 350 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE; 351 352 /* Map first pfn to xen_remap_buf */ 353 mfn = pfn_to_mfn(ident_pfn_iter); 354 set_pte_mfn(buf, mfn, PAGE_KERNEL); 355 356 /* Save mapping information in page */ 357 xen_remap_buf.next_area_mfn = xen_remap_mfn; 358 xen_remap_buf.target_pfn = remap_pfn_iter; 359 xen_remap_buf.size = chunk; 360 for (i = 0; i < chunk; i++) 361 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i); 362 363 /* Put remap buf into list. */ 364 xen_remap_mfn = mfn; 365 366 /* Set identity map */ 367 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk); 368 369 left -= chunk; 370 } 371 372 /* Restore old xen_remap_buf mapping */ 373 set_pte_mfn(buf, mfn_save, PAGE_KERNEL); 374 } 375 376 /* 377 * This function takes a contiguous pfn range that needs to be identity mapped 378 * and: 379 * 380 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn. 381 * 2) Calls the do_ function to actually do the mapping/remapping work. 382 * 383 * The goal is to not allocate additional memory but to remap the existing 384 * pages. In the case of an error the underlying memory is simply released back 385 * to Xen and not remapped. 386 */ 387 static unsigned long __init xen_set_identity_and_remap_chunk( 388 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, 389 unsigned long remap_pfn) 390 { 391 unsigned long pfn; 392 unsigned long i = 0; 393 unsigned long n = end_pfn - start_pfn; 394 395 if (remap_pfn == 0) 396 remap_pfn = nr_pages; 397 398 while (i < n) { 399 unsigned long cur_pfn = start_pfn + i; 400 unsigned long left = n - i; 401 unsigned long size = left; 402 unsigned long remap_range_size; 403 404 /* Do not remap pages beyond the current allocation */ 405 if (cur_pfn >= nr_pages) { 406 /* Identity map remaining pages */ 407 set_phys_range_identity(cur_pfn, cur_pfn + size); 408 break; 409 } 410 if (cur_pfn + size > nr_pages) 411 size = nr_pages - cur_pfn; 412 413 remap_range_size = xen_find_pfn_range(&remap_pfn); 414 if (!remap_range_size) { 415 pr_warn("Unable to find available pfn range, not remapping identity pages\n"); 416 xen_set_identity_and_release_chunk(cur_pfn, 417 cur_pfn + left, nr_pages); 418 break; 419 } 420 /* Adjust size to fit in current e820 RAM region */ 421 if (size > remap_range_size) 422 size = remap_range_size; 423 424 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn); 425 426 /* Update variables to reflect new mappings. */ 427 i += size; 428 remap_pfn += size; 429 } 430 431 /* 432 * If the PFNs are currently mapped, the VA mapping also needs 433 * to be updated to be 1:1. 434 */ 435 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) 436 (void)HYPERVISOR_update_va_mapping( 437 (unsigned long)__va(pfn << PAGE_SHIFT), 438 mfn_pte(pfn, PAGE_KERNEL_IO), 0); 439 440 return remap_pfn; 441 } 442 443 static unsigned long __init xen_count_remap_pages( 444 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, 445 unsigned long remap_pages) 446 { 447 if (start_pfn >= nr_pages) 448 return remap_pages; 449 450 return remap_pages + min(end_pfn, nr_pages) - start_pfn; 451 } 452 453 static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, 454 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn, 455 unsigned long nr_pages, unsigned long last_val)) 456 { 457 phys_addr_t start = 0; 458 unsigned long ret_val = 0; 459 const struct e820_entry *entry = xen_e820_table.entries; 460 int i; 461 462 /* 463 * Combine non-RAM regions and gaps until a RAM region (or the 464 * end of the map) is reached, then call the provided function 465 * to perform its duty on the non-RAM region. 466 * 467 * The combined non-RAM regions are rounded to a whole number 468 * of pages so any partial pages are accessible via the 1:1 469 * mapping. This is needed for some BIOSes that put (for 470 * example) the DMI tables in a reserved region that begins on 471 * a non-page boundary. 472 */ 473 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 474 phys_addr_t end = entry->addr + entry->size; 475 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) { 476 unsigned long start_pfn = PFN_DOWN(start); 477 unsigned long end_pfn = PFN_UP(end); 478 479 if (entry->type == E820_TYPE_RAM) 480 end_pfn = PFN_UP(entry->addr); 481 482 if (start_pfn < end_pfn) 483 ret_val = func(start_pfn, end_pfn, nr_pages, 484 ret_val); 485 start = end; 486 } 487 } 488 489 return ret_val; 490 } 491 492 /* 493 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk(). 494 * The remap information (which mfn remap to which pfn) is contained in the 495 * to be remapped memory itself in a linked list anchored at xen_remap_mfn. 496 * This scheme allows to remap the different chunks in arbitrary order while 497 * the resulting mapping will be independent from the order. 498 */ 499 void __init xen_remap_memory(void) 500 { 501 unsigned long buf = (unsigned long)&xen_remap_buf; 502 unsigned long mfn_save, pfn; 503 unsigned long remapped = 0; 504 unsigned int i; 505 unsigned long pfn_s = ~0UL; 506 unsigned long len = 0; 507 508 mfn_save = virt_to_mfn(buf); 509 510 while (xen_remap_mfn != INVALID_P2M_ENTRY) { 511 /* Map the remap information */ 512 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL); 513 514 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]); 515 516 pfn = xen_remap_buf.target_pfn; 517 for (i = 0; i < xen_remap_buf.size; i++) { 518 xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]); 519 remapped++; 520 pfn++; 521 } 522 if (pfn_s == ~0UL || pfn == pfn_s) { 523 pfn_s = xen_remap_buf.target_pfn; 524 len += xen_remap_buf.size; 525 } else if (pfn_s + len == xen_remap_buf.target_pfn) { 526 len += xen_remap_buf.size; 527 } else { 528 xen_del_extra_mem(pfn_s, len); 529 pfn_s = xen_remap_buf.target_pfn; 530 len = xen_remap_buf.size; 531 } 532 xen_remap_mfn = xen_remap_buf.next_area_mfn; 533 } 534 535 if (pfn_s != ~0UL && len) 536 xen_del_extra_mem(pfn_s, len); 537 538 set_pte_mfn(buf, mfn_save, PAGE_KERNEL); 539 540 pr_info("Remapped %ld page(s)\n", remapped); 541 } 542 543 static unsigned long __init xen_get_pages_limit(void) 544 { 545 unsigned long limit; 546 547 limit = MAXMEM / PAGE_SIZE; 548 if (!xen_initial_domain() && xen_512gb_limit) 549 limit = GB(512) / PAGE_SIZE; 550 551 return limit; 552 } 553 554 static unsigned long __init xen_get_max_pages(void) 555 { 556 unsigned long max_pages, limit; 557 domid_t domid = DOMID_SELF; 558 long ret; 559 560 limit = xen_get_pages_limit(); 561 max_pages = limit; 562 563 /* 564 * For the initial domain we use the maximum reservation as 565 * the maximum page. 566 * 567 * For guest domains the current maximum reservation reflects 568 * the current maximum rather than the static maximum. In this 569 * case the e820 map provided to us will cover the static 570 * maximum region. 571 */ 572 if (xen_initial_domain()) { 573 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid); 574 if (ret > 0) 575 max_pages = ret; 576 } 577 578 return min(max_pages, limit); 579 } 580 581 static void __init xen_align_and_add_e820_region(phys_addr_t start, 582 phys_addr_t size, int type) 583 { 584 phys_addr_t end = start + size; 585 586 /* Align RAM regions to page boundaries. */ 587 if (type == E820_TYPE_RAM) { 588 start = PAGE_ALIGN(start); 589 end &= ~((phys_addr_t)PAGE_SIZE - 1); 590 #ifdef CONFIG_MEMORY_HOTPLUG 591 /* 592 * Don't allow adding memory not in E820 map while booting the 593 * system. Once the balloon driver is up it will remove that 594 * restriction again. 595 */ 596 max_mem_size = end; 597 #endif 598 } 599 600 e820__range_add(start, end - start, type); 601 } 602 603 static void __init xen_ignore_unusable(void) 604 { 605 struct e820_entry *entry = xen_e820_table.entries; 606 unsigned int i; 607 608 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 609 if (entry->type == E820_TYPE_UNUSABLE) 610 entry->type = E820_TYPE_RAM; 611 } 612 } 613 614 bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size) 615 { 616 struct e820_entry *entry; 617 unsigned mapcnt; 618 phys_addr_t end; 619 620 if (!size) 621 return false; 622 623 end = start + size; 624 entry = xen_e820_table.entries; 625 626 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { 627 if (entry->type == E820_TYPE_RAM && entry->addr <= start && 628 (entry->addr + entry->size) >= end) 629 return false; 630 631 entry++; 632 } 633 634 return true; 635 } 636 637 /* 638 * Find a free area in physical memory not yet reserved and compliant with 639 * E820 map. 640 * Used to relocate pre-allocated areas like initrd or p2m list which are in 641 * conflict with the to be used E820 map. 642 * In case no area is found, return 0. Otherwise return the physical address 643 * of the area which is already reserved for convenience. 644 */ 645 phys_addr_t __init xen_find_free_area(phys_addr_t size) 646 { 647 unsigned mapcnt; 648 phys_addr_t addr, start; 649 struct e820_entry *entry = xen_e820_table.entries; 650 651 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) { 652 if (entry->type != E820_TYPE_RAM || entry->size < size) 653 continue; 654 start = entry->addr; 655 for (addr = start; addr < start + size; addr += PAGE_SIZE) { 656 if (!memblock_is_reserved(addr)) 657 continue; 658 start = addr + PAGE_SIZE; 659 if (start + size > entry->addr + entry->size) 660 break; 661 } 662 if (addr >= start + size) { 663 memblock_reserve(start, size); 664 return start; 665 } 666 } 667 668 return 0; 669 } 670 671 /* 672 * Like memcpy, but with physical addresses for dest and src. 673 */ 674 static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src, 675 phys_addr_t n) 676 { 677 phys_addr_t dest_off, src_off, dest_len, src_len, len; 678 void *from, *to; 679 680 while (n) { 681 dest_off = dest & ~PAGE_MASK; 682 src_off = src & ~PAGE_MASK; 683 dest_len = n; 684 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off) 685 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off; 686 src_len = n; 687 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off) 688 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off; 689 len = min(dest_len, src_len); 690 to = early_memremap(dest - dest_off, dest_len + dest_off); 691 from = early_memremap(src - src_off, src_len + src_off); 692 memcpy(to, from, len); 693 early_memunmap(to, dest_len + dest_off); 694 early_memunmap(from, src_len + src_off); 695 n -= len; 696 dest += len; 697 src += len; 698 } 699 } 700 701 /* 702 * Reserve Xen mfn_list. 703 */ 704 static void __init xen_reserve_xen_mfnlist(void) 705 { 706 phys_addr_t start, size; 707 708 if (xen_start_info->mfn_list >= __START_KERNEL_map) { 709 start = __pa(xen_start_info->mfn_list); 710 size = PFN_ALIGN(xen_start_info->nr_pages * 711 sizeof(unsigned long)); 712 } else { 713 start = PFN_PHYS(xen_start_info->first_p2m_pfn); 714 size = PFN_PHYS(xen_start_info->nr_p2m_frames); 715 } 716 717 memblock_reserve(start, size); 718 if (!xen_is_e820_reserved(start, size)) 719 return; 720 721 xen_relocate_p2m(); 722 memblock_free(start, size); 723 } 724 725 /** 726 * machine_specific_memory_setup - Hook for machine specific memory setup. 727 **/ 728 char * __init xen_memory_setup(void) 729 { 730 unsigned long max_pfn, pfn_s, n_pfns; 731 phys_addr_t mem_end, addr, size, chunk_size; 732 u32 type; 733 int rc; 734 struct xen_memory_map memmap; 735 unsigned long max_pages; 736 unsigned long extra_pages = 0; 737 int i; 738 int op; 739 740 xen_parse_512gb(); 741 max_pfn = xen_get_pages_limit(); 742 max_pfn = min(max_pfn, xen_start_info->nr_pages); 743 mem_end = PFN_PHYS(max_pfn); 744 745 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); 746 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); 747 748 #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON) 749 xen_saved_max_mem_size = max_mem_size; 750 #endif 751 752 op = xen_initial_domain() ? 753 XENMEM_machine_memory_map : 754 XENMEM_memory_map; 755 rc = HYPERVISOR_memory_op(op, &memmap); 756 if (rc == -ENOSYS) { 757 BUG_ON(xen_initial_domain()); 758 memmap.nr_entries = 1; 759 xen_e820_table.entries[0].addr = 0ULL; 760 xen_e820_table.entries[0].size = mem_end; 761 /* 8MB slack (to balance backend allocations). */ 762 xen_e820_table.entries[0].size += 8ULL << 20; 763 xen_e820_table.entries[0].type = E820_TYPE_RAM; 764 rc = 0; 765 } 766 BUG_ON(rc); 767 BUG_ON(memmap.nr_entries == 0); 768 xen_e820_table.nr_entries = memmap.nr_entries; 769 770 /* 771 * Xen won't allow a 1:1 mapping to be created to UNUSABLE 772 * regions, so if we're using the machine memory map leave the 773 * region as RAM as it is in the pseudo-physical map. 774 * 775 * UNUSABLE regions in domUs are not handled and will need 776 * a patch in the future. 777 */ 778 if (xen_initial_domain()) 779 xen_ignore_unusable(); 780 781 /* Make sure the Xen-supplied memory map is well-ordered. */ 782 e820__update_table(&xen_e820_table); 783 784 max_pages = xen_get_max_pages(); 785 786 /* How many extra pages do we need due to remapping? */ 787 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages); 788 789 if (max_pages > max_pfn) 790 extra_pages += max_pages - max_pfn; 791 792 /* 793 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO 794 * factor the base size. On non-highmem systems, the base 795 * size is the full initial memory allocation; on highmem it 796 * is limited to the max size of lowmem, so that it doesn't 797 * get completely filled. 798 * 799 * Make sure we have no memory above max_pages, as this area 800 * isn't handled by the p2m management. 801 * 802 * In principle there could be a problem in lowmem systems if 803 * the initial memory is also very large with respect to 804 * lowmem, but we won't try to deal with that here. 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_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 int ret; 925 unsigned sysenter_feature; 926 927 sysenter_feature = X86_FEATURE_SYSENTER32; 928 929 if (!boot_cpu_has(sysenter_feature)) 930 return; 931 932 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target); 933 if(ret != 0) 934 setup_clear_cpu_cap(sysenter_feature); 935 } 936 937 void xen_enable_syscall(void) 938 { 939 int ret; 940 941 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target); 942 if (ret != 0) { 943 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret); 944 /* Pretty fatal; 64-bit userspace has no other 945 mechanism for syscalls. */ 946 } 947 948 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) { 949 ret = register_callback(CALLBACKTYPE_syscall32, 950 xen_syscall32_target); 951 if (ret != 0) 952 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); 953 } 954 } 955 956 static void __init xen_pvmmu_arch_setup(void) 957 { 958 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments); 959 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); 960 961 HYPERVISOR_vm_assist(VMASST_CMD_enable, 962 VMASST_TYPE_pae_extended_cr3); 963 964 if (register_callback(CALLBACKTYPE_event, 965 xen_asm_exc_xen_hypervisor_callback) || 966 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback)) 967 BUG(); 968 969 xen_enable_sysenter(); 970 xen_enable_syscall(); 971 } 972 973 /* This function is not called for HVM domains */ 974 void __init xen_arch_setup(void) 975 { 976 xen_panic_handler_init(); 977 xen_pvmmu_arch_setup(); 978 979 #ifdef CONFIG_ACPI 980 if (!(xen_start_info->flags & SIF_INITDOMAIN)) { 981 printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); 982 disable_acpi(); 983 } 984 #endif 985 986 memcpy(boot_command_line, xen_start_info->cmd_line, 987 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? 988 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); 989 990 /* Set up idle, making sure it calls safe_halt() pvop */ 991 disable_cpuidle(); 992 disable_cpufreq(); 993 WARN_ON(xen_set_default_idle()); 994 #ifdef CONFIG_NUMA 995 numa_off = 1; 996 #endif 997 } 998