1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Machine specific setup for xen
4 *
5 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
6 */
7
8 #include <linux/init.h>
9 #include <linux/iscsi_ibft.h>
10 #include <linux/sched.h>
11 #include <linux/kstrtox.h>
12 #include <linux/mm.h>
13 #include <linux/pm.h>
14 #include <linux/memblock.h>
15 #include <linux/cpuidle.h>
16 #include <linux/cpufreq.h>
17 #include <linux/memory_hotplug.h>
18 #include <linux/acpi.h>
19
20 #include <asm/elf.h>
21 #include <asm/vdso.h>
22 #include <asm/e820/api.h>
23 #include <asm/setup.h>
24 #include <asm/numa.h>
25 #include <asm/idtentry.h>
26 #include <asm/xen/hypervisor.h>
27 #include <asm/xen/hypercall.h>
28
29 #include <xen/xen.h>
30 #include <xen/page.h>
31 #include <xen/interface/callback.h>
32 #include <xen/interface/memory.h>
33 #include <xen/interface/physdev.h>
34 #include <xen/features.h>
35 #include <xen/hvc-console.h>
36 #include "xen-ops.h"
37 #include "mmu.h"
38
39 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
40
41 /* Number of pages released from the initial allocation. */
42 unsigned long xen_released_pages;
43
44 /* Memory map would allow PCI passthrough. */
45 bool xen_pv_pci_possible;
46
47 /* E820 map used during setting up memory. */
48 static struct e820_table xen_e820_table __initdata;
49
50 /* Number of initially usable memory pages. */
51 static unsigned long ini_nr_pages __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 static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
68
xen_parse_512gb(void)69 static void __init xen_parse_512gb(void)
70 {
71 bool val = false;
72 char *arg;
73
74 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
75 if (!arg)
76 return;
77
78 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
79 if (!arg)
80 val = true;
81 else if (kstrtobool(arg + strlen("xen_512gb_limit="), &val))
82 return;
83
84 xen_512gb_limit = val;
85 }
86
xen_del_extra_mem(unsigned long start_pfn,unsigned long n_pfns)87 static void __init xen_del_extra_mem(unsigned long start_pfn,
88 unsigned long n_pfns)
89 {
90 int i;
91 unsigned long start_r, size_r;
92
93 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
94 start_r = xen_extra_mem[i].start_pfn;
95 size_r = xen_extra_mem[i].n_pfns;
96
97 /* Start of region. */
98 if (start_r == start_pfn) {
99 BUG_ON(n_pfns > size_r);
100 xen_extra_mem[i].start_pfn += n_pfns;
101 xen_extra_mem[i].n_pfns -= n_pfns;
102 break;
103 }
104 /* End of region. */
105 if (start_r + size_r == start_pfn + n_pfns) {
106 BUG_ON(n_pfns > size_r);
107 xen_extra_mem[i].n_pfns -= n_pfns;
108 break;
109 }
110 /* Mid of region. */
111 if (start_pfn > start_r && start_pfn < start_r + size_r) {
112 BUG_ON(start_pfn + n_pfns > start_r + size_r);
113 xen_extra_mem[i].n_pfns = start_pfn - start_r;
114 /* Calling memblock_reserve() again is okay. */
115 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
116 (start_pfn + n_pfns));
117 break;
118 }
119 }
120 memblock_phys_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
121 }
122
123 /*
124 * Called during boot before the p2m list can take entries beyond the
125 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
126 * invalid.
127 */
xen_chk_extra_mem(unsigned long pfn)128 unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
129 {
130 int i;
131
132 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
133 if (pfn >= xen_extra_mem[i].start_pfn &&
134 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
135 return INVALID_P2M_ENTRY;
136 }
137
138 return IDENTITY_FRAME(pfn);
139 }
140
141 /*
142 * Mark all pfns of extra mem as invalid in p2m list.
143 */
xen_inv_extra_mem(void)144 void __init xen_inv_extra_mem(void)
145 {
146 unsigned long pfn, pfn_s, pfn_e;
147 int i;
148
149 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
150 if (!xen_extra_mem[i].n_pfns)
151 continue;
152 pfn_s = xen_extra_mem[i].start_pfn;
153 pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
154 for (pfn = pfn_s; pfn < pfn_e; pfn++)
155 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
156 }
157 }
158
159 /*
160 * Finds the next RAM pfn available in the E820 map after min_pfn.
161 * This function updates min_pfn with the pfn found and returns
162 * the size of that range or zero if not found.
163 */
xen_find_pfn_range(unsigned long * min_pfn)164 static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
165 {
166 const struct e820_entry *entry = xen_e820_table.entries;
167 unsigned int i;
168 unsigned long done = 0;
169
170 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
171 unsigned long s_pfn;
172 unsigned long e_pfn;
173
174 if (entry->type != E820_TYPE_RAM)
175 continue;
176
177 e_pfn = PFN_DOWN(entry->addr + entry->size);
178
179 /* We only care about E820 after this */
180 if (e_pfn <= *min_pfn)
181 continue;
182
183 s_pfn = PFN_UP(entry->addr);
184
185 /* If min_pfn falls within the E820 entry, we want to start
186 * at the min_pfn PFN.
187 */
188 if (s_pfn <= *min_pfn) {
189 done = e_pfn - *min_pfn;
190 } else {
191 done = e_pfn - s_pfn;
192 *min_pfn = s_pfn;
193 }
194 break;
195 }
196
197 return done;
198 }
199
xen_free_mfn(unsigned long mfn)200 static int __init xen_free_mfn(unsigned long mfn)
201 {
202 struct xen_memory_reservation reservation = {
203 .address_bits = 0,
204 .extent_order = 0,
205 .domid = DOMID_SELF
206 };
207
208 set_xen_guest_handle(reservation.extent_start, &mfn);
209 reservation.nr_extents = 1;
210
211 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
212 }
213
214 /*
215 * This releases a chunk of memory and then does the identity map. It's used
216 * as a fallback if the remapping fails.
217 */
xen_set_identity_and_release_chunk(unsigned long start_pfn,unsigned long end_pfn)218 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
219 unsigned long end_pfn)
220 {
221 unsigned long pfn, end;
222 int ret;
223
224 WARN_ON(start_pfn > end_pfn);
225
226 /* Release pages first. */
227 end = min(end_pfn, ini_nr_pages);
228 for (pfn = start_pfn; pfn < end; pfn++) {
229 unsigned long mfn = pfn_to_mfn(pfn);
230
231 /* Make sure pfn exists to start with */
232 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
233 continue;
234
235 ret = xen_free_mfn(mfn);
236 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
237
238 if (ret == 1) {
239 xen_released_pages++;
240 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
241 break;
242 } else
243 break;
244 }
245
246 set_phys_range_identity(start_pfn, end_pfn);
247 }
248
249 /*
250 * Helper function to update the p2m and m2p tables and kernel mapping.
251 */
xen_update_mem_tables(unsigned long pfn,unsigned long mfn)252 static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
253 {
254 struct mmu_update update = {
255 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
256 .val = pfn
257 };
258
259 /* Update p2m */
260 if (!set_phys_to_machine(pfn, mfn)) {
261 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
262 pfn, mfn);
263 BUG();
264 }
265
266 /* Update m2p */
267 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
268 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
269 mfn, pfn);
270 BUG();
271 }
272
273 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
274 mfn_pte(mfn, PAGE_KERNEL), 0)) {
275 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
276 mfn, pfn);
277 BUG();
278 }
279 }
280
281 /*
282 * This function updates the p2m and m2p tables with an identity map from
283 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
284 * original allocation at remap_pfn. The information needed for remapping is
285 * saved in the memory itself to avoid the need for allocating buffers. The
286 * complete remap information is contained in a list of MFNs each containing
287 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
288 * This enables us to preserve the original mfn sequence while doing the
289 * remapping at a time when the memory management is capable of allocating
290 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
291 * its callers.
292 */
xen_do_set_identity_and_remap_chunk(unsigned long start_pfn,unsigned long size,unsigned long remap_pfn)293 static void __init xen_do_set_identity_and_remap_chunk(
294 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
295 {
296 unsigned long buf = (unsigned long)&xen_remap_buf;
297 unsigned long mfn_save, mfn;
298 unsigned long ident_pfn_iter, remap_pfn_iter;
299 unsigned long ident_end_pfn = start_pfn + size;
300 unsigned long left = size;
301 unsigned int i, chunk;
302
303 WARN_ON(size == 0);
304
305 mfn_save = virt_to_mfn((void *)buf);
306
307 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
308 ident_pfn_iter < ident_end_pfn;
309 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
310 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
311
312 /* Map first pfn to xen_remap_buf */
313 mfn = pfn_to_mfn(ident_pfn_iter);
314 set_pte_mfn(buf, mfn, PAGE_KERNEL);
315
316 /* Save mapping information in page */
317 xen_remap_buf.next_area_mfn = xen_remap_mfn;
318 xen_remap_buf.target_pfn = remap_pfn_iter;
319 xen_remap_buf.size = chunk;
320 for (i = 0; i < chunk; i++)
321 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
322
323 /* Put remap buf into list. */
324 xen_remap_mfn = mfn;
325
326 /* Set identity map */
327 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
328
329 left -= chunk;
330 }
331
332 /* Restore old xen_remap_buf mapping */
333 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
334 }
335
336 /*
337 * This function takes a contiguous pfn range that needs to be identity mapped
338 * and:
339 *
340 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
341 * 2) Calls the do_ function to actually do the mapping/remapping work.
342 *
343 * The goal is to not allocate additional memory but to remap the existing
344 * pages. In the case of an error the underlying memory is simply released back
345 * to Xen and not remapped.
346 */
xen_set_identity_and_remap_chunk(unsigned long start_pfn,unsigned long end_pfn,unsigned long remap_pfn)347 static unsigned long __init xen_set_identity_and_remap_chunk(
348 unsigned long start_pfn, unsigned long end_pfn, unsigned long remap_pfn)
349 {
350 unsigned long pfn;
351 unsigned long i = 0;
352 unsigned long n = end_pfn - start_pfn;
353
354 if (remap_pfn == 0)
355 remap_pfn = ini_nr_pages;
356
357 while (i < n) {
358 unsigned long cur_pfn = start_pfn + i;
359 unsigned long left = n - i;
360 unsigned long size = left;
361 unsigned long remap_range_size;
362
363 /* Do not remap pages beyond the current allocation */
364 if (cur_pfn >= ini_nr_pages) {
365 /* Identity map remaining pages */
366 set_phys_range_identity(cur_pfn, cur_pfn + size);
367 break;
368 }
369 if (cur_pfn + size > ini_nr_pages)
370 size = ini_nr_pages - cur_pfn;
371
372 remap_range_size = xen_find_pfn_range(&remap_pfn);
373 if (!remap_range_size) {
374 pr_warn("Unable to find available pfn range, not remapping identity pages\n");
375 xen_set_identity_and_release_chunk(cur_pfn,
376 cur_pfn + left);
377 break;
378 }
379 /* Adjust size to fit in current e820 RAM region */
380 if (size > remap_range_size)
381 size = remap_range_size;
382
383 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
384
385 /* Update variables to reflect new mappings. */
386 i += size;
387 remap_pfn += size;
388 }
389
390 /*
391 * If the PFNs are currently mapped, their VA mappings need to be
392 * zapped.
393 */
394 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
395 (void)HYPERVISOR_update_va_mapping(
396 (unsigned long)__va(pfn << PAGE_SHIFT),
397 native_make_pte(0), 0);
398
399 return remap_pfn;
400 }
401
xen_count_remap_pages(unsigned long start_pfn,unsigned long end_pfn,unsigned long remap_pages)402 static unsigned long __init xen_count_remap_pages(
403 unsigned long start_pfn, unsigned long end_pfn,
404 unsigned long remap_pages)
405 {
406 if (start_pfn >= ini_nr_pages)
407 return remap_pages;
408
409 return remap_pages + min(end_pfn, ini_nr_pages) - start_pfn;
410 }
411
xen_foreach_remap_area(unsigned long (* func)(unsigned long start_pfn,unsigned long end_pfn,unsigned long last_val))412 static unsigned long __init xen_foreach_remap_area(
413 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
414 unsigned long last_val))
415 {
416 phys_addr_t start = 0;
417 unsigned long ret_val = 0;
418 const struct e820_entry *entry = xen_e820_table.entries;
419 int i;
420
421 /*
422 * Combine non-RAM regions and gaps until a RAM region (or the
423 * end of the map) is reached, then call the provided function
424 * to perform its duty on the non-RAM region.
425 *
426 * The combined non-RAM regions are rounded to a whole number
427 * of pages so any partial pages are accessible via the 1:1
428 * mapping. This is needed for some BIOSes that put (for
429 * example) the DMI tables in a reserved region that begins on
430 * a non-page boundary.
431 */
432 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
433 phys_addr_t end = entry->addr + entry->size;
434 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
435 unsigned long start_pfn = PFN_DOWN(start);
436 unsigned long end_pfn = PFN_UP(end);
437
438 if (entry->type == E820_TYPE_RAM)
439 end_pfn = PFN_UP(entry->addr);
440
441 if (start_pfn < end_pfn)
442 ret_val = func(start_pfn, end_pfn, ret_val);
443 start = end;
444 }
445 }
446
447 return ret_val;
448 }
449
450 /*
451 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
452 * The remap information (which mfn remap to which pfn) is contained in the
453 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
454 * This scheme allows to remap the different chunks in arbitrary order while
455 * the resulting mapping will be independent from the order.
456 */
xen_remap_memory(void)457 void __init xen_remap_memory(void)
458 {
459 unsigned long buf = (unsigned long)&xen_remap_buf;
460 unsigned long mfn_save, pfn;
461 unsigned long remapped = 0;
462 unsigned int i;
463 unsigned long pfn_s = ~0UL;
464 unsigned long len = 0;
465
466 mfn_save = virt_to_mfn((void *)buf);
467
468 while (xen_remap_mfn != INVALID_P2M_ENTRY) {
469 /* Map the remap information */
470 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
471
472 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
473
474 pfn = xen_remap_buf.target_pfn;
475 for (i = 0; i < xen_remap_buf.size; i++) {
476 xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
477 remapped++;
478 pfn++;
479 }
480 if (pfn_s == ~0UL || pfn == pfn_s) {
481 pfn_s = xen_remap_buf.target_pfn;
482 len += xen_remap_buf.size;
483 } else if (pfn_s + len == xen_remap_buf.target_pfn) {
484 len += xen_remap_buf.size;
485 } else {
486 xen_del_extra_mem(pfn_s, len);
487 pfn_s = xen_remap_buf.target_pfn;
488 len = xen_remap_buf.size;
489 }
490 xen_remap_mfn = xen_remap_buf.next_area_mfn;
491 }
492
493 if (pfn_s != ~0UL && len)
494 xen_del_extra_mem(pfn_s, len);
495
496 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
497
498 pr_info("Remapped %ld page(s)\n", remapped);
499
500 xen_do_remap_nonram();
501 }
502
xen_get_pages_limit(void)503 static unsigned long __init xen_get_pages_limit(void)
504 {
505 unsigned long limit;
506
507 limit = MAXMEM / PAGE_SIZE;
508 if (!xen_initial_domain() && xen_512gb_limit)
509 limit = GB(512) / PAGE_SIZE;
510
511 return limit;
512 }
513
xen_get_max_pages(void)514 static unsigned long __init xen_get_max_pages(void)
515 {
516 unsigned long max_pages, limit;
517 domid_t domid = DOMID_SELF;
518 long ret;
519
520 limit = xen_get_pages_limit();
521 max_pages = limit;
522
523 /*
524 * For the initial domain we use the maximum reservation as
525 * the maximum page.
526 *
527 * For guest domains the current maximum reservation reflects
528 * the current maximum rather than the static maximum. In this
529 * case the e820 map provided to us will cover the static
530 * maximum region.
531 */
532 if (xen_initial_domain()) {
533 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
534 if (ret > 0)
535 max_pages = ret;
536 }
537
538 return min(max_pages, limit);
539 }
540
xen_align_and_add_e820_region(phys_addr_t start,phys_addr_t size,int type)541 static void __init xen_align_and_add_e820_region(phys_addr_t start,
542 phys_addr_t size, int type)
543 {
544 phys_addr_t end = start + size;
545
546 /* Align RAM regions to page boundaries. */
547 if (type == E820_TYPE_RAM) {
548 start = PAGE_ALIGN(start);
549 end &= ~((phys_addr_t)PAGE_SIZE - 1);
550 #ifdef CONFIG_MEMORY_HOTPLUG
551 /*
552 * Don't allow adding memory not in E820 map while booting the
553 * system. Once the balloon driver is up it will remove that
554 * restriction again.
555 */
556 max_mem_size = end;
557 #endif
558 }
559
560 e820__range_add(start, end - start, type);
561 }
562
xen_ignore_unusable(void)563 static void __init xen_ignore_unusable(void)
564 {
565 struct e820_entry *entry = xen_e820_table.entries;
566 unsigned int i;
567
568 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
569 if (entry->type == E820_TYPE_UNUSABLE)
570 entry->type = E820_TYPE_RAM;
571 }
572 }
573
xen_is_e820_reserved(phys_addr_t start,phys_addr_t size)574 static bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
575 {
576 struct e820_entry *entry;
577 unsigned mapcnt;
578 phys_addr_t end;
579
580 if (!size)
581 return false;
582
583 end = start + size;
584 entry = xen_e820_table.entries;
585
586 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
587 if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
588 (entry->addr + entry->size) >= end)
589 return false;
590
591 entry++;
592 }
593
594 return true;
595 }
596
597 /*
598 * Find a free area in physical memory not yet reserved and compliant with
599 * E820 map.
600 * Used to relocate pre-allocated areas like initrd or p2m list which are in
601 * conflict with the to be used E820 map.
602 * In case no area is found, return 0. Otherwise return the physical address
603 * of the area which is already reserved for convenience.
604 */
xen_find_free_area(phys_addr_t size)605 phys_addr_t __init xen_find_free_area(phys_addr_t size)
606 {
607 unsigned mapcnt;
608 phys_addr_t addr, start;
609 struct e820_entry *entry = xen_e820_table.entries;
610
611 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
612 if (entry->type != E820_TYPE_RAM || entry->size < size)
613 continue;
614 start = entry->addr;
615 for (addr = start; addr < start + size; addr += PAGE_SIZE) {
616 if (!memblock_is_reserved(addr))
617 continue;
618 start = addr + PAGE_SIZE;
619 if (start + size > entry->addr + entry->size)
620 break;
621 }
622 if (addr >= start + size) {
623 memblock_reserve(start, size);
624 return start;
625 }
626 }
627
628 return 0;
629 }
630
631 /*
632 * Swap a non-RAM E820 map entry with RAM above ini_nr_pages.
633 * Note that the E820 map is modified accordingly, but the P2M map isn't yet.
634 * The adaption of the P2M must be deferred until page allocation is possible.
635 */
xen_e820_swap_entry_with_ram(struct e820_entry * swap_entry)636 static void __init xen_e820_swap_entry_with_ram(struct e820_entry *swap_entry)
637 {
638 struct e820_entry *entry;
639 unsigned int mapcnt;
640 phys_addr_t mem_end = PFN_PHYS(ini_nr_pages);
641 phys_addr_t swap_addr, swap_size, entry_end;
642
643 swap_addr = PAGE_ALIGN_DOWN(swap_entry->addr);
644 swap_size = PAGE_ALIGN(swap_entry->addr - swap_addr + swap_entry->size);
645 entry = xen_e820_table.entries;
646
647 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
648 entry_end = entry->addr + entry->size;
649 if (entry->type == E820_TYPE_RAM && entry->size >= swap_size &&
650 entry_end - swap_size >= mem_end) {
651 /* Reduce RAM entry by needed space (whole pages). */
652 entry->size -= swap_size;
653
654 /* Add new entry at the end of E820 map. */
655 entry = xen_e820_table.entries +
656 xen_e820_table.nr_entries;
657 xen_e820_table.nr_entries++;
658
659 /* Fill new entry (keep size and page offset). */
660 entry->type = swap_entry->type;
661 entry->addr = entry_end - swap_size +
662 swap_addr - swap_entry->addr;
663 entry->size = swap_entry->size;
664
665 /* Convert old entry to RAM, align to pages. */
666 swap_entry->type = E820_TYPE_RAM;
667 swap_entry->addr = swap_addr;
668 swap_entry->size = swap_size;
669
670 /* Remember PFN<->MFN relation for P2M update. */
671 xen_add_remap_nonram(swap_addr, entry_end - swap_size,
672 swap_size);
673
674 /* Order E820 table and merge entries. */
675 e820__update_table(&xen_e820_table);
676
677 return;
678 }
679
680 entry++;
681 }
682
683 xen_raw_console_write("No suitable area found for required E820 entry remapping action\n");
684 BUG();
685 }
686
687 /*
688 * Look for non-RAM memory types in a specific guest physical area and move
689 * those away if possible (ACPI NVS only for now).
690 */
xen_e820_resolve_conflicts(phys_addr_t start,phys_addr_t size)691 static void __init xen_e820_resolve_conflicts(phys_addr_t start,
692 phys_addr_t size)
693 {
694 struct e820_entry *entry;
695 unsigned int mapcnt;
696 phys_addr_t end;
697
698 if (!size)
699 return;
700
701 end = start + size;
702 entry = xen_e820_table.entries;
703
704 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
705 if (entry->addr >= end)
706 return;
707
708 if (entry->addr + entry->size > start &&
709 entry->type == E820_TYPE_NVS)
710 xen_e820_swap_entry_with_ram(entry);
711
712 entry++;
713 }
714 }
715
716 /*
717 * Check for an area in physical memory to be usable for non-movable purposes.
718 * An area is considered to usable if the used E820 map lists it to be RAM or
719 * some other type which can be moved to higher PFNs while keeping the MFNs.
720 * In case the area is not usable, crash the system with an error message.
721 */
xen_chk_is_e820_usable(phys_addr_t start,phys_addr_t size,const char * component)722 void __init xen_chk_is_e820_usable(phys_addr_t start, phys_addr_t size,
723 const char *component)
724 {
725 xen_e820_resolve_conflicts(start, size);
726
727 if (!xen_is_e820_reserved(start, size))
728 return;
729
730 xen_raw_console_write("Xen hypervisor allocated ");
731 xen_raw_console_write(component);
732 xen_raw_console_write(" memory conflicts with E820 map\n");
733 BUG();
734 }
735
736 /*
737 * Like memcpy, but with physical addresses for dest and src.
738 */
xen_phys_memcpy(phys_addr_t dest,phys_addr_t src,phys_addr_t n)739 static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
740 phys_addr_t n)
741 {
742 phys_addr_t dest_off, src_off, dest_len, src_len, len;
743 void *from, *to;
744
745 while (n) {
746 dest_off = dest & ~PAGE_MASK;
747 src_off = src & ~PAGE_MASK;
748 dest_len = n;
749 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
750 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
751 src_len = n;
752 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
753 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
754 len = min(dest_len, src_len);
755 to = early_memremap(dest - dest_off, dest_len + dest_off);
756 from = early_memremap(src - src_off, src_len + src_off);
757 memcpy(to, from, len);
758 early_memunmap(to, dest_len + dest_off);
759 early_memunmap(from, src_len + src_off);
760 n -= len;
761 dest += len;
762 src += len;
763 }
764 }
765
766 /*
767 * Reserve Xen mfn_list.
768 */
xen_reserve_xen_mfnlist(void)769 static void __init xen_reserve_xen_mfnlist(void)
770 {
771 phys_addr_t start, size;
772
773 if (xen_start_info->mfn_list >= __START_KERNEL_map) {
774 start = __pa(xen_start_info->mfn_list);
775 size = PFN_ALIGN(xen_start_info->nr_pages *
776 sizeof(unsigned long));
777 } else {
778 start = PFN_PHYS(xen_start_info->first_p2m_pfn);
779 size = PFN_PHYS(xen_start_info->nr_p2m_frames);
780 }
781
782 memblock_reserve(start, size);
783 if (!xen_is_e820_reserved(start, size))
784 return;
785
786 xen_relocate_p2m();
787 memblock_phys_free(start, size);
788 }
789
790 /**
791 * xen_memory_setup - Hook for machine specific memory setup.
792 **/
xen_memory_setup(void)793 char * __init xen_memory_setup(void)
794 {
795 unsigned long pfn_s, n_pfns;
796 phys_addr_t mem_end, addr, size, chunk_size;
797 u32 type;
798 int rc;
799 struct xen_memory_map memmap;
800 unsigned long max_pages;
801 unsigned long extra_pages = 0;
802 unsigned long maxmem_pages;
803 int i;
804 int op;
805
806 xen_parse_512gb();
807 ini_nr_pages = min(xen_get_pages_limit(), xen_start_info->nr_pages);
808 mem_end = PFN_PHYS(ini_nr_pages);
809
810 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
811 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
812
813 #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
814 xen_saved_max_mem_size = max_mem_size;
815 #endif
816
817 op = xen_initial_domain() ?
818 XENMEM_machine_memory_map :
819 XENMEM_memory_map;
820 rc = HYPERVISOR_memory_op(op, &memmap);
821 if (rc == -ENOSYS) {
822 BUG_ON(xen_initial_domain());
823 memmap.nr_entries = 1;
824 xen_e820_table.entries[0].addr = 0ULL;
825 xen_e820_table.entries[0].size = mem_end;
826 /* 8MB slack (to balance backend allocations). */
827 xen_e820_table.entries[0].size += 8ULL << 20;
828 xen_e820_table.entries[0].type = E820_TYPE_RAM;
829 rc = 0;
830 }
831 BUG_ON(rc);
832 BUG_ON(memmap.nr_entries == 0);
833 xen_e820_table.nr_entries = memmap.nr_entries;
834
835 if (xen_initial_domain()) {
836 /*
837 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
838 * regions, so if we're using the machine memory map leave the
839 * region as RAM as it is in the pseudo-physical map.
840 *
841 * UNUSABLE regions in domUs are not handled and will need
842 * a patch in the future.
843 */
844 xen_ignore_unusable();
845
846 #ifdef CONFIG_ISCSI_IBFT_FIND
847 /* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */
848 xen_e820_table.entries[xen_e820_table.nr_entries].addr = IBFT_START;
849 xen_e820_table.entries[xen_e820_table.nr_entries].size = IBFT_END - IBFT_START;
850 xen_e820_table.entries[xen_e820_table.nr_entries].type = E820_TYPE_RESERVED;
851 xen_e820_table.nr_entries++;
852 #endif
853 }
854
855 /* Make sure the Xen-supplied memory map is well-ordered. */
856 e820__update_table(&xen_e820_table);
857
858 /*
859 * Check whether the kernel itself conflicts with the target E820 map.
860 * Failing now is better than running into weird problems later due
861 * to relocating (and even reusing) pages with kernel text or data.
862 */
863 xen_chk_is_e820_usable(__pa_symbol(_text),
864 __pa_symbol(_end) - __pa_symbol(_text),
865 "kernel");
866
867 /*
868 * Check for a conflict of the xen_start_info memory with the target
869 * E820 map.
870 */
871 xen_chk_is_e820_usable(__pa(xen_start_info), sizeof(*xen_start_info),
872 "xen_start_info");
873
874 /*
875 * Check for a conflict of the hypervisor supplied page tables with
876 * the target E820 map.
877 */
878 xen_pt_check_e820();
879
880 max_pages = xen_get_max_pages();
881
882 /* How many extra pages do we need due to remapping? */
883 max_pages += xen_foreach_remap_area(xen_count_remap_pages);
884
885 if (max_pages > ini_nr_pages)
886 extra_pages += max_pages - ini_nr_pages;
887
888 /*
889 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
890 * factor the base size.
891 *
892 * Make sure we have no memory above max_pages, as this area
893 * isn't handled by the p2m management.
894 */
895 maxmem_pages = EXTRA_MEM_RATIO * min(ini_nr_pages, PFN_DOWN(MAXMEM));
896 extra_pages = min3(maxmem_pages, extra_pages, max_pages - ini_nr_pages);
897 i = 0;
898 addr = xen_e820_table.entries[0].addr;
899 size = xen_e820_table.entries[0].size;
900 while (i < xen_e820_table.nr_entries) {
901 bool discard = false;
902
903 chunk_size = size;
904 type = xen_e820_table.entries[i].type;
905
906 if (type == E820_TYPE_RESERVED)
907 xen_pv_pci_possible = true;
908
909 if (type == E820_TYPE_RAM) {
910 if (addr < mem_end) {
911 chunk_size = min(size, mem_end - addr);
912 } else if (extra_pages) {
913 chunk_size = min(size, PFN_PHYS(extra_pages));
914 pfn_s = PFN_UP(addr);
915 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
916 extra_pages -= n_pfns;
917 xen_add_extra_mem(pfn_s, n_pfns);
918 xen_max_p2m_pfn = pfn_s + n_pfns;
919 } else
920 discard = true;
921 }
922
923 if (!discard)
924 xen_align_and_add_e820_region(addr, chunk_size, type);
925
926 addr += chunk_size;
927 size -= chunk_size;
928 if (size == 0) {
929 i++;
930 if (i < xen_e820_table.nr_entries) {
931 addr = xen_e820_table.entries[i].addr;
932 size = xen_e820_table.entries[i].size;
933 }
934 }
935 }
936
937 /*
938 * Set the rest as identity mapped, in case PCI BARs are
939 * located here.
940 */
941 set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
942
943 /*
944 * In domU, the ISA region is normal, usable memory, but we
945 * reserve ISA memory anyway because too many things poke
946 * about in there.
947 */
948 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
949
950 e820__update_table(e820_table);
951
952 xen_reserve_xen_mfnlist();
953
954 /* Check for a conflict of the initrd with the target E820 map. */
955 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
956 boot_params.hdr.ramdisk_size)) {
957 phys_addr_t new_area, start, size;
958
959 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
960 if (!new_area) {
961 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
962 BUG();
963 }
964
965 start = boot_params.hdr.ramdisk_image;
966 size = boot_params.hdr.ramdisk_size;
967 xen_phys_memcpy(new_area, start, size);
968 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
969 start, start + size, new_area, new_area + size);
970 memblock_phys_free(start, size);
971 boot_params.hdr.ramdisk_image = new_area;
972 boot_params.ext_ramdisk_image = new_area >> 32;
973 }
974
975 /*
976 * Set identity map on non-RAM pages and prepare remapping the
977 * underlying RAM.
978 */
979 xen_foreach_remap_area(xen_set_identity_and_remap_chunk);
980
981 pr_info("Released %ld page(s)\n", xen_released_pages);
982
983 return "Xen";
984 }
985
register_callback(unsigned type,const void * func)986 static int register_callback(unsigned type, const void *func)
987 {
988 struct callback_register callback = {
989 .type = type,
990 .address = XEN_CALLBACK(__KERNEL_CS, func),
991 .flags = CALLBACKF_mask_events,
992 };
993
994 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
995 }
996
xen_enable_sysenter(void)997 void xen_enable_sysenter(void)
998 {
999 if (cpu_feature_enabled(X86_FEATURE_SYSENTER32) &&
1000 register_callback(CALLBACKTYPE_sysenter, xen_entry_SYSENTER_compat))
1001 setup_clear_cpu_cap(X86_FEATURE_SYSENTER32);
1002 }
1003
xen_enable_syscall(void)1004 void xen_enable_syscall(void)
1005 {
1006 int ret;
1007
1008 ret = register_callback(CALLBACKTYPE_syscall, xen_entry_SYSCALL_64);
1009 if (ret != 0) {
1010 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
1011 /* Pretty fatal; 64-bit userspace has no other
1012 mechanism for syscalls. */
1013 }
1014
1015 if (cpu_feature_enabled(X86_FEATURE_SYSCALL32) &&
1016 register_callback(CALLBACKTYPE_syscall32, xen_entry_SYSCALL_compat))
1017 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
1018 }
1019
xen_pvmmu_arch_setup(void)1020 static void __init xen_pvmmu_arch_setup(void)
1021 {
1022 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
1023
1024 if (register_callback(CALLBACKTYPE_event,
1025 xen_asm_exc_xen_hypervisor_callback) ||
1026 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
1027 BUG();
1028
1029 xen_enable_sysenter();
1030 xen_enable_syscall();
1031 }
1032
1033 /* This function is not called for HVM domains */
xen_arch_setup(void)1034 void __init xen_arch_setup(void)
1035 {
1036 xen_panic_handler_init();
1037 xen_pvmmu_arch_setup();
1038
1039 #ifdef CONFIG_ACPI
1040 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
1041 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
1042 disable_acpi();
1043 }
1044 #endif
1045
1046 memcpy(boot_command_line, xen_start_info->cmd_line,
1047 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
1048 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
1049
1050 /* Set up idle, making sure it calls safe_halt() pvop */
1051 disable_cpuidle();
1052 disable_cpufreq();
1053 WARN_ON(xen_set_default_idle());
1054 #ifdef CONFIG_NUMA
1055 numa_off = 1;
1056 #endif
1057 }
1058