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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/kstrtox.h>
11#include <linux/mm.h>
12#include <linux/pm.h>
13#include <linux/memblock.h>
14#include <linux/cpuidle.h>
15#include <linux/cpufreq.h>
16#include <linux/memory_hotplug.h>
17
18#include <asm/elf.h>
19#include <asm/vdso.h>
20#include <asm/e820/api.h>
21#include <asm/setup.h>
22#include <asm/acpi.h>
23#include <asm/numa.h>
24#include <asm/idtentry.h>
25#include <asm/xen/hypervisor.h>
26#include <asm/xen/hypercall.h>
27
28#include <xen/xen.h>
29#include <xen/page.h>
30#include <xen/interface/callback.h>
31#include <xen/interface/memory.h>
32#include <xen/interface/physdev.h>
33#include <xen/features.h>
34#include <xen/hvc-console.h>
35#include "xen-ops.h"
36#include "mmu.h"
37
38#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
39
40/* Amount of extra memory space we add to the e820 ranges */
41struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
42
43/* Number of pages released from the initial allocation. */
44unsigned long xen_released_pages;
45
46/* E820 map used during setting up memory. */
47static struct e820_table xen_e820_table __initdata;
48
49/*
50 * Buffer used to remap identity mapped pages. We only need the virtual space.
51 * The physical page behind this address is remapped as needed to different
52 * buffer pages.
53 */
54#define REMAP_SIZE (P2M_PER_PAGE - 3)
55static struct {
56 unsigned long next_area_mfn;
57 unsigned long target_pfn;
58 unsigned long size;
59 unsigned long mfns[REMAP_SIZE];
60} xen_remap_buf __initdata __aligned(PAGE_SIZE);
61static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
62
63/*
64 * The maximum amount of extra memory compared to the base size. The
65 * main scaling factor is the size of struct page. At extreme ratios
66 * of base:extra, all the base memory can be filled with page
67 * structures for the extra memory, leaving no space for anything
68 * else.
69 *
70 * 10x seems like a reasonable balance between scaling flexibility and
71 * leaving a practically usable system.
72 */
73#define EXTRA_MEM_RATIO (10)
74
75static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
76
77static void __init xen_parse_512gb(void)
78{
79 bool val = false;
80 char *arg;
81
82 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
83 if (!arg)
84 return;
85
86 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
87 if (!arg)
88 val = true;
89 else if (kstrtobool(arg + strlen("xen_512gb_limit="), &val))
90 return;
91
92 xen_512gb_limit = val;
93}
94
95static void __init xen_add_extra_mem(unsigned long start_pfn,
96 unsigned long n_pfns)
97{
98 int i;
99
100 /*
101 * No need to check for zero size, should happen rarely and will only
102 * write a new entry regarded to be unused due to zero size.
103 */
104 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
105 /* Add new region. */
106 if (xen_extra_mem[i].n_pfns == 0) {
107 xen_extra_mem[i].start_pfn = start_pfn;
108 xen_extra_mem[i].n_pfns = n_pfns;
109 break;
110 }
111 /* Append to existing region. */
112 if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
113 start_pfn) {
114 xen_extra_mem[i].n_pfns += n_pfns;
115 break;
116 }
117 }
118 if (i == XEN_EXTRA_MEM_MAX_REGIONS)
119 printk(KERN_WARNING "Warning: not enough extra memory regions\n");
120
121 memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
122}
123
124static void __init xen_del_extra_mem(unsigned long start_pfn,
125 unsigned long n_pfns)
126{
127 int i;
128 unsigned long start_r, size_r;
129
130 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
131 start_r = xen_extra_mem[i].start_pfn;
132 size_r = xen_extra_mem[i].n_pfns;
133
134 /* Start of region. */
135 if (start_r == start_pfn) {
136 BUG_ON(n_pfns > size_r);
137 xen_extra_mem[i].start_pfn += n_pfns;
138 xen_extra_mem[i].n_pfns -= n_pfns;
139 break;
140 }
141 /* End of region. */
142 if (start_r + size_r == start_pfn + n_pfns) {
143 BUG_ON(n_pfns > size_r);
144 xen_extra_mem[i].n_pfns -= n_pfns;
145 break;
146 }
147 /* Mid of region. */
148 if (start_pfn > start_r && start_pfn < start_r + size_r) {
149 BUG_ON(start_pfn + n_pfns > start_r + size_r);
150 xen_extra_mem[i].n_pfns = start_pfn - start_r;
151 /* Calling memblock_reserve() again is okay. */
152 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
153 (start_pfn + n_pfns));
154 break;
155 }
156 }
157 memblock_phys_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
158}
159
160/*
161 * Called during boot before the p2m list can take entries beyond the
162 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
163 * invalid.
164 */
165unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
166{
167 int i;
168
169 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
170 if (pfn >= xen_extra_mem[i].start_pfn &&
171 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
172 return INVALID_P2M_ENTRY;
173 }
174
175 return IDENTITY_FRAME(pfn);
176}
177
178/*
179 * Mark all pfns of extra mem as invalid in p2m list.
180 */
181void __init xen_inv_extra_mem(void)
182{
183 unsigned long pfn, pfn_s, pfn_e;
184 int i;
185
186 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
187 if (!xen_extra_mem[i].n_pfns)
188 continue;
189 pfn_s = xen_extra_mem[i].start_pfn;
190 pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
191 for (pfn = pfn_s; pfn < pfn_e; pfn++)
192 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
193 }
194}
195
196/*
197 * Finds the next RAM pfn available in the E820 map after min_pfn.
198 * This function updates min_pfn with the pfn found and returns
199 * the size of that range or zero if not found.
200 */
201static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
202{
203 const struct e820_entry *entry = xen_e820_table.entries;
204 unsigned int i;
205 unsigned long done = 0;
206
207 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
208 unsigned long s_pfn;
209 unsigned long e_pfn;
210
211 if (entry->type != E820_TYPE_RAM)
212 continue;
213
214 e_pfn = PFN_DOWN(entry->addr + entry->size);
215
216 /* We only care about E820 after this */
217 if (e_pfn <= *min_pfn)
218 continue;
219
220 s_pfn = PFN_UP(entry->addr);
221
222 /* If min_pfn falls within the E820 entry, we want to start
223 * at the min_pfn PFN.
224 */
225 if (s_pfn <= *min_pfn) {
226 done = e_pfn - *min_pfn;
227 } else {
228 done = e_pfn - s_pfn;
229 *min_pfn = s_pfn;
230 }
231 break;
232 }
233
234 return done;
235}
236
237static int __init xen_free_mfn(unsigned long mfn)
238{
239 struct xen_memory_reservation reservation = {
240 .address_bits = 0,
241 .extent_order = 0,
242 .domid = DOMID_SELF
243 };
244
245 set_xen_guest_handle(reservation.extent_start, &mfn);
246 reservation.nr_extents = 1;
247
248 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
249}
250
251/*
252 * This releases a chunk of memory and then does the identity map. It's used
253 * as a fallback if the remapping fails.
254 */
255static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
256 unsigned long end_pfn, unsigned long nr_pages)
257{
258 unsigned long pfn, end;
259 int ret;
260
261 WARN_ON(start_pfn > end_pfn);
262
263 /* Release pages first. */
264 end = min(end_pfn, nr_pages);
265 for (pfn = start_pfn; pfn < end; pfn++) {
266 unsigned long mfn = pfn_to_mfn(pfn);
267
268 /* Make sure pfn exists to start with */
269 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
270 continue;
271
272 ret = xen_free_mfn(mfn);
273 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
274
275 if (ret == 1) {
276 xen_released_pages++;
277 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
278 break;
279 } else
280 break;
281 }
282
283 set_phys_range_identity(start_pfn, end_pfn);
284}
285
286/*
287 * Helper function to update the p2m and m2p tables and kernel mapping.
288 */
289static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
290{
291 struct mmu_update update = {
292 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
293 .val = pfn
294 };
295
296 /* Update p2m */
297 if (!set_phys_to_machine(pfn, mfn)) {
298 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
299 pfn, mfn);
300 BUG();
301 }
302
303 /* Update m2p */
304 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
305 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
306 mfn, pfn);
307 BUG();
308 }
309
310 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
311 mfn_pte(mfn, PAGE_KERNEL), 0)) {
312 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
313 mfn, pfn);
314 BUG();
315 }
316}
317
318/*
319 * This function updates the p2m and m2p tables with an identity map from
320 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
321 * original allocation at remap_pfn. The information needed for remapping is
322 * saved in the memory itself to avoid the need for allocating buffers. The
323 * complete remap information is contained in a list of MFNs each containing
324 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
325 * This enables us to preserve the original mfn sequence while doing the
326 * remapping at a time when the memory management is capable of allocating
327 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
328 * its callers.
329 */
330static void __init xen_do_set_identity_and_remap_chunk(
331 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
332{
333 unsigned long buf = (unsigned long)&xen_remap_buf;
334 unsigned long mfn_save, mfn;
335 unsigned long ident_pfn_iter, remap_pfn_iter;
336 unsigned long ident_end_pfn = start_pfn + size;
337 unsigned long left = size;
338 unsigned int i, chunk;
339
340 WARN_ON(size == 0);
341
342 mfn_save = virt_to_mfn(buf);
343
344 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
345 ident_pfn_iter < ident_end_pfn;
346 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
347 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
348
349 /* Map first pfn to xen_remap_buf */
350 mfn = pfn_to_mfn(ident_pfn_iter);
351 set_pte_mfn(buf, mfn, PAGE_KERNEL);
352
353 /* Save mapping information in page */
354 xen_remap_buf.next_area_mfn = xen_remap_mfn;
355 xen_remap_buf.target_pfn = remap_pfn_iter;
356 xen_remap_buf.size = chunk;
357 for (i = 0; i < chunk; i++)
358 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
359
360 /* Put remap buf into list. */
361 xen_remap_mfn = mfn;
362
363 /* Set identity map */
364 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
365
366 left -= chunk;
367 }
368
369 /* Restore old xen_remap_buf mapping */
370 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
371}
372
373/*
374 * This function takes a contiguous pfn range that needs to be identity mapped
375 * and:
376 *
377 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
378 * 2) Calls the do_ function to actually do the mapping/remapping work.
379 *
380 * The goal is to not allocate additional memory but to remap the existing
381 * pages. In the case of an error the underlying memory is simply released back
382 * to Xen and not remapped.
383 */
384static unsigned long __init xen_set_identity_and_remap_chunk(
385 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
386 unsigned long remap_pfn)
387{
388 unsigned long pfn;
389 unsigned long i = 0;
390 unsigned long n = end_pfn - start_pfn;
391
392 if (remap_pfn == 0)
393 remap_pfn = nr_pages;
394
395 while (i < n) {
396 unsigned long cur_pfn = start_pfn + i;
397 unsigned long left = n - i;
398 unsigned long size = left;
399 unsigned long remap_range_size;
400
401 /* Do not remap pages beyond the current allocation */
402 if (cur_pfn >= nr_pages) {
403 /* Identity map remaining pages */
404 set_phys_range_identity(cur_pfn, cur_pfn + size);
405 break;
406 }
407 if (cur_pfn + size > nr_pages)
408 size = nr_pages - cur_pfn;
409
410 remap_range_size = xen_find_pfn_range(&remap_pfn);
411 if (!remap_range_size) {
412 pr_warn("Unable to find available pfn range, not remapping identity pages\n");
413 xen_set_identity_and_release_chunk(cur_pfn,
414 cur_pfn + left, nr_pages);
415 break;
416 }
417 /* Adjust size to fit in current e820 RAM region */
418 if (size > remap_range_size)
419 size = remap_range_size;
420
421 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
422
423 /* Update variables to reflect new mappings. */
424 i += size;
425 remap_pfn += size;
426 }
427
428 /*
429 * If the PFNs are currently mapped, their VA mappings need to be
430 * zapped.
431 */
432 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
433 (void)HYPERVISOR_update_va_mapping(
434 (unsigned long)__va(pfn << PAGE_SHIFT),
435 native_make_pte(0), 0);
436
437 return remap_pfn;
438}
439
440static unsigned long __init xen_count_remap_pages(
441 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
442 unsigned long remap_pages)
443{
444 if (start_pfn >= nr_pages)
445 return remap_pages;
446
447 return remap_pages + min(end_pfn, nr_pages) - start_pfn;
448}
449
450static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages,
451 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
452 unsigned long nr_pages, unsigned long last_val))
453{
454 phys_addr_t start = 0;
455 unsigned long ret_val = 0;
456 const struct e820_entry *entry = xen_e820_table.entries;
457 int i;
458
459 /*
460 * Combine non-RAM regions and gaps until a RAM region (or the
461 * end of the map) is reached, then call the provided function
462 * to perform its duty on the non-RAM region.
463 *
464 * The combined non-RAM regions are rounded to a whole number
465 * of pages so any partial pages are accessible via the 1:1
466 * mapping. This is needed for some BIOSes that put (for
467 * example) the DMI tables in a reserved region that begins on
468 * a non-page boundary.
469 */
470 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
471 phys_addr_t end = entry->addr + entry->size;
472 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
473 unsigned long start_pfn = PFN_DOWN(start);
474 unsigned long end_pfn = PFN_UP(end);
475
476 if (entry->type == E820_TYPE_RAM)
477 end_pfn = PFN_UP(entry->addr);
478
479 if (start_pfn < end_pfn)
480 ret_val = func(start_pfn, end_pfn, nr_pages,
481 ret_val);
482 start = end;
483 }
484 }
485
486 return ret_val;
487}
488
489/*
490 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
491 * The remap information (which mfn remap to which pfn) is contained in the
492 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
493 * This scheme allows to remap the different chunks in arbitrary order while
494 * the resulting mapping will be independent from the order.
495 */
496void __init xen_remap_memory(void)
497{
498 unsigned long buf = (unsigned long)&xen_remap_buf;
499 unsigned long mfn_save, pfn;
500 unsigned long remapped = 0;
501 unsigned int i;
502 unsigned long pfn_s = ~0UL;
503 unsigned long len = 0;
504
505 mfn_save = virt_to_mfn(buf);
506
507 while (xen_remap_mfn != INVALID_P2M_ENTRY) {
508 /* Map the remap information */
509 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
510
511 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
512
513 pfn = xen_remap_buf.target_pfn;
514 for (i = 0; i < xen_remap_buf.size; i++) {
515 xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
516 remapped++;
517 pfn++;
518 }
519 if (pfn_s == ~0UL || pfn == pfn_s) {
520 pfn_s = xen_remap_buf.target_pfn;
521 len += xen_remap_buf.size;
522 } else if (pfn_s + len == xen_remap_buf.target_pfn) {
523 len += xen_remap_buf.size;
524 } else {
525 xen_del_extra_mem(pfn_s, len);
526 pfn_s = xen_remap_buf.target_pfn;
527 len = xen_remap_buf.size;
528 }
529 xen_remap_mfn = xen_remap_buf.next_area_mfn;
530 }
531
532 if (pfn_s != ~0UL && len)
533 xen_del_extra_mem(pfn_s, len);
534
535 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
536
537 pr_info("Remapped %ld page(s)\n", remapped);
538}
539
540static unsigned long __init xen_get_pages_limit(void)
541{
542 unsigned long limit;
543
544 limit = MAXMEM / PAGE_SIZE;
545 if (!xen_initial_domain() && xen_512gb_limit)
546 limit = GB(512) / PAGE_SIZE;
547
548 return limit;
549}
550
551static unsigned long __init xen_get_max_pages(void)
552{
553 unsigned long max_pages, limit;
554 domid_t domid = DOMID_SELF;
555 long ret;
556
557 limit = xen_get_pages_limit();
558 max_pages = limit;
559
560 /*
561 * For the initial domain we use the maximum reservation as
562 * the maximum page.
563 *
564 * For guest domains the current maximum reservation reflects
565 * the current maximum rather than the static maximum. In this
566 * case the e820 map provided to us will cover the static
567 * maximum region.
568 */
569 if (xen_initial_domain()) {
570 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
571 if (ret > 0)
572 max_pages = ret;
573 }
574
575 return min(max_pages, limit);
576}
577
578static void __init xen_align_and_add_e820_region(phys_addr_t start,
579 phys_addr_t size, int type)
580{
581 phys_addr_t end = start + size;
582
583 /* Align RAM regions to page boundaries. */
584 if (type == E820_TYPE_RAM) {
585 start = PAGE_ALIGN(start);
586 end &= ~((phys_addr_t)PAGE_SIZE - 1);
587#ifdef CONFIG_MEMORY_HOTPLUG
588 /*
589 * Don't allow adding memory not in E820 map while booting the
590 * system. Once the balloon driver is up it will remove that
591 * restriction again.
592 */
593 max_mem_size = end;
594#endif
595 }
596
597 e820__range_add(start, end - start, type);
598}
599
600static void __init xen_ignore_unusable(void)
601{
602 struct e820_entry *entry = xen_e820_table.entries;
603 unsigned int i;
604
605 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
606 if (entry->type == E820_TYPE_UNUSABLE)
607 entry->type = E820_TYPE_RAM;
608 }
609}
610
611bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
612{
613 struct e820_entry *entry;
614 unsigned mapcnt;
615 phys_addr_t end;
616
617 if (!size)
618 return false;
619
620 end = start + size;
621 entry = xen_e820_table.entries;
622
623 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
624 if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
625 (entry->addr + entry->size) >= end)
626 return false;
627
628 entry++;
629 }
630
631 return true;
632}
633
634/*
635 * Find a free area in physical memory not yet reserved and compliant with
636 * E820 map.
637 * Used to relocate pre-allocated areas like initrd or p2m list which are in
638 * conflict with the to be used E820 map.
639 * In case no area is found, return 0. Otherwise return the physical address
640 * of the area which is already reserved for convenience.
641 */
642phys_addr_t __init xen_find_free_area(phys_addr_t size)
643{
644 unsigned mapcnt;
645 phys_addr_t addr, start;
646 struct e820_entry *entry = xen_e820_table.entries;
647
648 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
649 if (entry->type != E820_TYPE_RAM || entry->size < size)
650 continue;
651 start = entry->addr;
652 for (addr = start; addr < start + size; addr += PAGE_SIZE) {
653 if (!memblock_is_reserved(addr))
654 continue;
655 start = addr + PAGE_SIZE;
656 if (start + size > entry->addr + entry->size)
657 break;
658 }
659 if (addr >= start + size) {
660 memblock_reserve(start, size);
661 return start;
662 }
663 }
664
665 return 0;
666}
667
668/*
669 * Like memcpy, but with physical addresses for dest and src.
670 */
671static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
672 phys_addr_t n)
673{
674 phys_addr_t dest_off, src_off, dest_len, src_len, len;
675 void *from, *to;
676
677 while (n) {
678 dest_off = dest & ~PAGE_MASK;
679 src_off = src & ~PAGE_MASK;
680 dest_len = n;
681 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
682 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
683 src_len = n;
684 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
685 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
686 len = min(dest_len, src_len);
687 to = early_memremap(dest - dest_off, dest_len + dest_off);
688 from = early_memremap(src - src_off, src_len + src_off);
689 memcpy(to, from, len);
690 early_memunmap(to, dest_len + dest_off);
691 early_memunmap(from, src_len + src_off);
692 n -= len;
693 dest += len;
694 src += len;
695 }
696}
697
698/*
699 * Reserve Xen mfn_list.
700 */
701static void __init xen_reserve_xen_mfnlist(void)
702{
703 phys_addr_t start, size;
704
705 if (xen_start_info->mfn_list >= __START_KERNEL_map) {
706 start = __pa(xen_start_info->mfn_list);
707 size = PFN_ALIGN(xen_start_info->nr_pages *
708 sizeof(unsigned long));
709 } else {
710 start = PFN_PHYS(xen_start_info->first_p2m_pfn);
711 size = PFN_PHYS(xen_start_info->nr_p2m_frames);
712 }
713
714 memblock_reserve(start, size);
715 if (!xen_is_e820_reserved(start, size))
716 return;
717
718 xen_relocate_p2m();
719 memblock_phys_free(start, size);
720}
721
722/**
723 * xen_memory_setup - Hook for machine specific memory setup.
724 **/
725char * __init xen_memory_setup(void)
726{
727 unsigned long max_pfn, pfn_s, n_pfns;
728 phys_addr_t mem_end, addr, size, chunk_size;
729 u32 type;
730 int rc;
731 struct xen_memory_map memmap;
732 unsigned long max_pages;
733 unsigned long extra_pages = 0;
734 int i;
735 int op;
736
737 xen_parse_512gb();
738 max_pfn = xen_get_pages_limit();
739 max_pfn = min(max_pfn, xen_start_info->nr_pages);
740 mem_end = PFN_PHYS(max_pfn);
741
742 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
743 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
744
745#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
746 xen_saved_max_mem_size = max_mem_size;
747#endif
748
749 op = xen_initial_domain() ?
750 XENMEM_machine_memory_map :
751 XENMEM_memory_map;
752 rc = HYPERVISOR_memory_op(op, &memmap);
753 if (rc == -ENOSYS) {
754 BUG_ON(xen_initial_domain());
755 memmap.nr_entries = 1;
756 xen_e820_table.entries[0].addr = 0ULL;
757 xen_e820_table.entries[0].size = mem_end;
758 /* 8MB slack (to balance backend allocations). */
759 xen_e820_table.entries[0].size += 8ULL << 20;
760 xen_e820_table.entries[0].type = E820_TYPE_RAM;
761 rc = 0;
762 }
763 BUG_ON(rc);
764 BUG_ON(memmap.nr_entries == 0);
765 xen_e820_table.nr_entries = memmap.nr_entries;
766
767 /*
768 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
769 * regions, so if we're using the machine memory map leave the
770 * region as RAM as it is in the pseudo-physical map.
771 *
772 * UNUSABLE regions in domUs are not handled and will need
773 * a patch in the future.
774 */
775 if (xen_initial_domain())
776 xen_ignore_unusable();
777
778 /* Make sure the Xen-supplied memory map is well-ordered. */
779 e820__update_table(&xen_e820_table);
780
781 max_pages = xen_get_max_pages();
782
783 /* How many extra pages do we need due to remapping? */
784 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages);
785
786 if (max_pages > max_pfn)
787 extra_pages += max_pages - max_pfn;
788
789 /*
790 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
791 * factor the base size.
792 *
793 * Make sure we have no memory above max_pages, as this area
794 * isn't handled by the p2m management.
795 */
796 extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
797 extra_pages, max_pages - max_pfn);
798 i = 0;
799 addr = xen_e820_table.entries[0].addr;
800 size = xen_e820_table.entries[0].size;
801 while (i < xen_e820_table.nr_entries) {
802 bool discard = false;
803
804 chunk_size = size;
805 type = xen_e820_table.entries[i].type;
806
807 if (type == E820_TYPE_RAM) {
808 if (addr < mem_end) {
809 chunk_size = min(size, mem_end - addr);
810 } else if (extra_pages) {
811 chunk_size = min(size, PFN_PHYS(extra_pages));
812 pfn_s = PFN_UP(addr);
813 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
814 extra_pages -= n_pfns;
815 xen_add_extra_mem(pfn_s, n_pfns);
816 xen_max_p2m_pfn = pfn_s + n_pfns;
817 } else
818 discard = true;
819 }
820
821 if (!discard)
822 xen_align_and_add_e820_region(addr, chunk_size, type);
823
824 addr += chunk_size;
825 size -= chunk_size;
826 if (size == 0) {
827 i++;
828 if (i < xen_e820_table.nr_entries) {
829 addr = xen_e820_table.entries[i].addr;
830 size = xen_e820_table.entries[i].size;
831 }
832 }
833 }
834
835 /*
836 * Set the rest as identity mapped, in case PCI BARs are
837 * located here.
838 */
839 set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
840
841 /*
842 * In domU, the ISA region is normal, usable memory, but we
843 * reserve ISA memory anyway because too many things poke
844 * about in there.
845 */
846 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
847
848 e820__update_table(e820_table);
849
850 /*
851 * Check whether the kernel itself conflicts with the target E820 map.
852 * Failing now is better than running into weird problems later due
853 * to relocating (and even reusing) pages with kernel text or data.
854 */
855 if (xen_is_e820_reserved(__pa_symbol(_text),
856 __pa_symbol(__bss_stop) - __pa_symbol(_text))) {
857 xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
858 BUG();
859 }
860
861 /*
862 * Check for a conflict of the hypervisor supplied page tables with
863 * the target E820 map.
864 */
865 xen_pt_check_e820();
866
867 xen_reserve_xen_mfnlist();
868
869 /* Check for a conflict of the initrd with the target E820 map. */
870 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
871 boot_params.hdr.ramdisk_size)) {
872 phys_addr_t new_area, start, size;
873
874 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
875 if (!new_area) {
876 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
877 BUG();
878 }
879
880 start = boot_params.hdr.ramdisk_image;
881 size = boot_params.hdr.ramdisk_size;
882 xen_phys_memcpy(new_area, start, size);
883 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
884 start, start + size, new_area, new_area + size);
885 memblock_phys_free(start, size);
886 boot_params.hdr.ramdisk_image = new_area;
887 boot_params.ext_ramdisk_image = new_area >> 32;
888 }
889
890 /*
891 * Set identity map on non-RAM pages and prepare remapping the
892 * underlying RAM.
893 */
894 xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk);
895
896 pr_info("Released %ld page(s)\n", xen_released_pages);
897
898 return "Xen";
899}
900
901static int register_callback(unsigned type, const void *func)
902{
903 struct callback_register callback = {
904 .type = type,
905 .address = XEN_CALLBACK(__KERNEL_CS, func),
906 .flags = CALLBACKF_mask_events,
907 };
908
909 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
910}
911
912void xen_enable_sysenter(void)
913{
914 if (cpu_feature_enabled(X86_FEATURE_SYSENTER32) &&
915 register_callback(CALLBACKTYPE_sysenter, xen_entry_SYSENTER_compat))
916 setup_clear_cpu_cap(X86_FEATURE_SYSENTER32);
917}
918
919void xen_enable_syscall(void)
920{
921 int ret;
922
923 ret = register_callback(CALLBACKTYPE_syscall, xen_entry_SYSCALL_64);
924 if (ret != 0) {
925 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
926 /* Pretty fatal; 64-bit userspace has no other
927 mechanism for syscalls. */
928 }
929
930 if (cpu_feature_enabled(X86_FEATURE_SYSCALL32) &&
931 register_callback(CALLBACKTYPE_syscall32, xen_entry_SYSCALL_compat))
932 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
933}
934
935static void __init xen_pvmmu_arch_setup(void)
936{
937 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
938 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
939
940 HYPERVISOR_vm_assist(VMASST_CMD_enable,
941 VMASST_TYPE_pae_extended_cr3);
942
943 if (register_callback(CALLBACKTYPE_event,
944 xen_asm_exc_xen_hypervisor_callback) ||
945 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
946 BUG();
947
948 xen_enable_sysenter();
949 xen_enable_syscall();
950}
951
952/* This function is not called for HVM domains */
953void __init xen_arch_setup(void)
954{
955 xen_panic_handler_init();
956 xen_pvmmu_arch_setup();
957
958#ifdef CONFIG_ACPI
959 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
960 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
961 disable_acpi();
962 }
963#endif
964
965 memcpy(boot_command_line, xen_start_info->cmd_line,
966 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
967 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
968
969 /* Set up idle, making sure it calls safe_halt() pvop */
970 disable_cpuidle();
971 disable_cpufreq();
972 WARN_ON(xen_set_default_idle());
973#ifdef CONFIG_NUMA
974 numa_off = 1;
975#endif
976}
1/*
2 * Machine specific setup for xen
3 *
4 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
5 */
6
7#include <linux/module.h>
8#include <linux/sched.h>
9#include <linux/mm.h>
10#include <linux/pm.h>
11#include <linux/memblock.h>
12#include <linux/cpuidle.h>
13#include <linux/cpufreq.h>
14
15#include <asm/elf.h>
16#include <asm/vdso.h>
17#include <asm/e820.h>
18#include <asm/setup.h>
19#include <asm/acpi.h>
20#include <asm/numa.h>
21#include <asm/xen/hypervisor.h>
22#include <asm/xen/hypercall.h>
23
24#include <xen/xen.h>
25#include <xen/page.h>
26#include <xen/interface/callback.h>
27#include <xen/interface/memory.h>
28#include <xen/interface/physdev.h>
29#include <xen/features.h>
30#include <xen/hvc-console.h>
31#include "xen-ops.h"
32#include "vdso.h"
33#include "mmu.h"
34
35#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
36
37/* Amount of extra memory space we add to the e820 ranges */
38struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
39
40/* Number of pages released from the initial allocation. */
41unsigned long xen_released_pages;
42
43/* E820 map used during setting up memory. */
44static struct e820entry xen_e820_map[E820MAX] __initdata;
45static u32 xen_e820_map_entries __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)
53static 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);
59static 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
73static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
74
75static 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
93static 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
122static 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 */
163unsigned 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 */
179void __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 */
199static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
200{
201 const struct e820entry *entry = xen_e820_map;
202 unsigned int i;
203 unsigned long done = 0;
204
205 for (i = 0; i < xen_e820_map_entries; i++, entry++) {
206 unsigned long s_pfn;
207 unsigned long e_pfn;
208
209 if (entry->type != E820_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
235static 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 */
253static 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 */
287static 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 */
332static 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 BUG_ON(xen_feature(XENFEAT_auto_translated_physmap));
345
346 mfn_save = virt_to_mfn(buf);
347
348 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
349 ident_pfn_iter < ident_end_pfn;
350 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
351 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
352
353 /* Map first pfn to xen_remap_buf */
354 mfn = pfn_to_mfn(ident_pfn_iter);
355 set_pte_mfn(buf, mfn, PAGE_KERNEL);
356
357 /* Save mapping information in page */
358 xen_remap_buf.next_area_mfn = xen_remap_mfn;
359 xen_remap_buf.target_pfn = remap_pfn_iter;
360 xen_remap_buf.size = chunk;
361 for (i = 0; i < chunk; i++)
362 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
363
364 /* Put remap buf into list. */
365 xen_remap_mfn = mfn;
366
367 /* Set identity map */
368 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
369
370 left -= chunk;
371 }
372
373 /* Restore old xen_remap_buf mapping */
374 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
375}
376
377/*
378 * This function takes a contiguous pfn range that needs to be identity mapped
379 * and:
380 *
381 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
382 * 2) Calls the do_ function to actually do the mapping/remapping work.
383 *
384 * The goal is to not allocate additional memory but to remap the existing
385 * pages. In the case of an error the underlying memory is simply released back
386 * to Xen and not remapped.
387 */
388static unsigned long __init xen_set_identity_and_remap_chunk(
389 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
390 unsigned long remap_pfn)
391{
392 unsigned long pfn;
393 unsigned long i = 0;
394 unsigned long n = end_pfn - start_pfn;
395
396 while (i < n) {
397 unsigned long cur_pfn = start_pfn + i;
398 unsigned long left = n - i;
399 unsigned long size = left;
400 unsigned long remap_range_size;
401
402 /* Do not remap pages beyond the current allocation */
403 if (cur_pfn >= nr_pages) {
404 /* Identity map remaining pages */
405 set_phys_range_identity(cur_pfn, cur_pfn + size);
406 break;
407 }
408 if (cur_pfn + size > nr_pages)
409 size = nr_pages - cur_pfn;
410
411 remap_range_size = xen_find_pfn_range(&remap_pfn);
412 if (!remap_range_size) {
413 pr_warning("Unable to find available pfn range, not remapping identity pages\n");
414 xen_set_identity_and_release_chunk(cur_pfn,
415 cur_pfn + left, nr_pages);
416 break;
417 }
418 /* Adjust size to fit in current e820 RAM region */
419 if (size > remap_range_size)
420 size = remap_range_size;
421
422 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
423
424 /* Update variables to reflect new mappings. */
425 i += size;
426 remap_pfn += size;
427 }
428
429 /*
430 * If the PFNs are currently mapped, the VA mapping also needs
431 * to be updated to be 1:1.
432 */
433 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
434 (void)HYPERVISOR_update_va_mapping(
435 (unsigned long)__va(pfn << PAGE_SHIFT),
436 mfn_pte(pfn, PAGE_KERNEL_IO), 0);
437
438 return remap_pfn;
439}
440
441static void __init xen_set_identity_and_remap(unsigned long nr_pages)
442{
443 phys_addr_t start = 0;
444 unsigned long last_pfn = nr_pages;
445 const struct e820entry *entry = xen_e820_map;
446 int i;
447
448 /*
449 * Combine non-RAM regions and gaps until a RAM region (or the
450 * end of the map) is reached, then set the 1:1 map and
451 * remap the memory in those non-RAM regions.
452 *
453 * The combined non-RAM regions are rounded to a whole number
454 * of pages so any partial pages are accessible via the 1:1
455 * mapping. This is needed for some BIOSes that put (for
456 * example) the DMI tables in a reserved region that begins on
457 * a non-page boundary.
458 */
459 for (i = 0; i < xen_e820_map_entries; i++, entry++) {
460 phys_addr_t end = entry->addr + entry->size;
461 if (entry->type == E820_RAM || i == xen_e820_map_entries - 1) {
462 unsigned long start_pfn = PFN_DOWN(start);
463 unsigned long end_pfn = PFN_UP(end);
464
465 if (entry->type == E820_RAM)
466 end_pfn = PFN_UP(entry->addr);
467
468 if (start_pfn < end_pfn)
469 last_pfn = xen_set_identity_and_remap_chunk(
470 start_pfn, end_pfn, nr_pages,
471 last_pfn);
472 start = end;
473 }
474 }
475
476 pr_info("Released %ld page(s)\n", xen_released_pages);
477}
478
479/*
480 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
481 * The remap information (which mfn remap to which pfn) is contained in the
482 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
483 * This scheme allows to remap the different chunks in arbitrary order while
484 * the resulting mapping will be independant from the order.
485 */
486void __init xen_remap_memory(void)
487{
488 unsigned long buf = (unsigned long)&xen_remap_buf;
489 unsigned long mfn_save, mfn, pfn;
490 unsigned long remapped = 0;
491 unsigned int i;
492 unsigned long pfn_s = ~0UL;
493 unsigned long len = 0;
494
495 mfn_save = virt_to_mfn(buf);
496
497 while (xen_remap_mfn != INVALID_P2M_ENTRY) {
498 /* Map the remap information */
499 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
500
501 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
502
503 pfn = xen_remap_buf.target_pfn;
504 for (i = 0; i < xen_remap_buf.size; i++) {
505 mfn = xen_remap_buf.mfns[i];
506 xen_update_mem_tables(pfn, mfn);
507 remapped++;
508 pfn++;
509 }
510 if (pfn_s == ~0UL || pfn == pfn_s) {
511 pfn_s = xen_remap_buf.target_pfn;
512 len += xen_remap_buf.size;
513 } else if (pfn_s + len == xen_remap_buf.target_pfn) {
514 len += xen_remap_buf.size;
515 } else {
516 xen_del_extra_mem(pfn_s, len);
517 pfn_s = xen_remap_buf.target_pfn;
518 len = xen_remap_buf.size;
519 }
520
521 mfn = xen_remap_mfn;
522 xen_remap_mfn = xen_remap_buf.next_area_mfn;
523 }
524
525 if (pfn_s != ~0UL && len)
526 xen_del_extra_mem(pfn_s, len);
527
528 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
529
530 pr_info("Remapped %ld page(s)\n", remapped);
531}
532
533static unsigned long __init xen_get_pages_limit(void)
534{
535 unsigned long limit;
536
537#ifdef CONFIG_X86_32
538 limit = GB(64) / PAGE_SIZE;
539#else
540 limit = MAXMEM / PAGE_SIZE;
541 if (!xen_initial_domain() && xen_512gb_limit)
542 limit = GB(512) / PAGE_SIZE;
543#endif
544 return limit;
545}
546
547static unsigned long __init xen_get_max_pages(void)
548{
549 unsigned long max_pages, limit;
550 domid_t domid = DOMID_SELF;
551 long ret;
552
553 limit = xen_get_pages_limit();
554 max_pages = limit;
555
556 /*
557 * For the initial domain we use the maximum reservation as
558 * the maximum page.
559 *
560 * For guest domains the current maximum reservation reflects
561 * the current maximum rather than the static maximum. In this
562 * case the e820 map provided to us will cover the static
563 * maximum region.
564 */
565 if (xen_initial_domain()) {
566 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
567 if (ret > 0)
568 max_pages = ret;
569 }
570
571 return min(max_pages, limit);
572}
573
574static void __init xen_align_and_add_e820_region(phys_addr_t start,
575 phys_addr_t size, int type)
576{
577 phys_addr_t end = start + size;
578
579 /* Align RAM regions to page boundaries. */
580 if (type == E820_RAM) {
581 start = PAGE_ALIGN(start);
582 end &= ~((phys_addr_t)PAGE_SIZE - 1);
583 }
584
585 e820_add_region(start, end - start, type);
586}
587
588static void __init xen_ignore_unusable(void)
589{
590 struct e820entry *entry = xen_e820_map;
591 unsigned int i;
592
593 for (i = 0; i < xen_e820_map_entries; i++, entry++) {
594 if (entry->type == E820_UNUSABLE)
595 entry->type = E820_RAM;
596 }
597}
598
599static unsigned long __init xen_count_remap_pages(unsigned long max_pfn)
600{
601 unsigned long extra = 0;
602 unsigned long start_pfn, end_pfn;
603 const struct e820entry *entry = xen_e820_map;
604 int i;
605
606 end_pfn = 0;
607 for (i = 0; i < xen_e820_map_entries; i++, entry++) {
608 start_pfn = PFN_DOWN(entry->addr);
609 /* Adjacent regions on non-page boundaries handling! */
610 end_pfn = min(end_pfn, start_pfn);
611
612 if (start_pfn >= max_pfn)
613 return extra + max_pfn - end_pfn;
614
615 /* Add any holes in map to result. */
616 extra += start_pfn - end_pfn;
617
618 end_pfn = PFN_UP(entry->addr + entry->size);
619 end_pfn = min(end_pfn, max_pfn);
620
621 if (entry->type != E820_RAM)
622 extra += end_pfn - start_pfn;
623 }
624
625 return extra;
626}
627
628bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
629{
630 struct e820entry *entry;
631 unsigned mapcnt;
632 phys_addr_t end;
633
634 if (!size)
635 return false;
636
637 end = start + size;
638 entry = xen_e820_map;
639
640 for (mapcnt = 0; mapcnt < xen_e820_map_entries; mapcnt++) {
641 if (entry->type == E820_RAM && entry->addr <= start &&
642 (entry->addr + entry->size) >= end)
643 return false;
644
645 entry++;
646 }
647
648 return true;
649}
650
651/*
652 * Find a free area in physical memory not yet reserved and compliant with
653 * E820 map.
654 * Used to relocate pre-allocated areas like initrd or p2m list which are in
655 * conflict with the to be used E820 map.
656 * In case no area is found, return 0. Otherwise return the physical address
657 * of the area which is already reserved for convenience.
658 */
659phys_addr_t __init xen_find_free_area(phys_addr_t size)
660{
661 unsigned mapcnt;
662 phys_addr_t addr, start;
663 struct e820entry *entry = xen_e820_map;
664
665 for (mapcnt = 0; mapcnt < xen_e820_map_entries; mapcnt++, entry++) {
666 if (entry->type != E820_RAM || entry->size < size)
667 continue;
668 start = entry->addr;
669 for (addr = start; addr < start + size; addr += PAGE_SIZE) {
670 if (!memblock_is_reserved(addr))
671 continue;
672 start = addr + PAGE_SIZE;
673 if (start + size > entry->addr + entry->size)
674 break;
675 }
676 if (addr >= start + size) {
677 memblock_reserve(start, size);
678 return start;
679 }
680 }
681
682 return 0;
683}
684
685/*
686 * Like memcpy, but with physical addresses for dest and src.
687 */
688static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
689 phys_addr_t n)
690{
691 phys_addr_t dest_off, src_off, dest_len, src_len, len;
692 void *from, *to;
693
694 while (n) {
695 dest_off = dest & ~PAGE_MASK;
696 src_off = src & ~PAGE_MASK;
697 dest_len = n;
698 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
699 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
700 src_len = n;
701 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
702 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
703 len = min(dest_len, src_len);
704 to = early_memremap(dest - dest_off, dest_len + dest_off);
705 from = early_memremap(src - src_off, src_len + src_off);
706 memcpy(to, from, len);
707 early_memunmap(to, dest_len + dest_off);
708 early_memunmap(from, src_len + src_off);
709 n -= len;
710 dest += len;
711 src += len;
712 }
713}
714
715/*
716 * Reserve Xen mfn_list.
717 */
718static void __init xen_reserve_xen_mfnlist(void)
719{
720 phys_addr_t start, size;
721
722 if (xen_start_info->mfn_list >= __START_KERNEL_map) {
723 start = __pa(xen_start_info->mfn_list);
724 size = PFN_ALIGN(xen_start_info->nr_pages *
725 sizeof(unsigned long));
726 } else {
727 start = PFN_PHYS(xen_start_info->first_p2m_pfn);
728 size = PFN_PHYS(xen_start_info->nr_p2m_frames);
729 }
730
731 if (!xen_is_e820_reserved(start, size)) {
732 memblock_reserve(start, size);
733 return;
734 }
735
736#ifdef CONFIG_X86_32
737 /*
738 * Relocating the p2m on 32 bit system to an arbitrary virtual address
739 * is not supported, so just give up.
740 */
741 xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with E820 map\n");
742 BUG();
743#else
744 xen_relocate_p2m();
745#endif
746}
747
748/**
749 * machine_specific_memory_setup - Hook for machine specific memory setup.
750 **/
751char * __init xen_memory_setup(void)
752{
753 unsigned long max_pfn, pfn_s, n_pfns;
754 phys_addr_t mem_end, addr, size, chunk_size;
755 u32 type;
756 int rc;
757 struct xen_memory_map memmap;
758 unsigned long max_pages;
759 unsigned long extra_pages = 0;
760 int i;
761 int op;
762
763 xen_parse_512gb();
764 max_pfn = xen_get_pages_limit();
765 max_pfn = min(max_pfn, xen_start_info->nr_pages);
766 mem_end = PFN_PHYS(max_pfn);
767
768 memmap.nr_entries = E820MAX;
769 set_xen_guest_handle(memmap.buffer, xen_e820_map);
770
771 op = xen_initial_domain() ?
772 XENMEM_machine_memory_map :
773 XENMEM_memory_map;
774 rc = HYPERVISOR_memory_op(op, &memmap);
775 if (rc == -ENOSYS) {
776 BUG_ON(xen_initial_domain());
777 memmap.nr_entries = 1;
778 xen_e820_map[0].addr = 0ULL;
779 xen_e820_map[0].size = mem_end;
780 /* 8MB slack (to balance backend allocations). */
781 xen_e820_map[0].size += 8ULL << 20;
782 xen_e820_map[0].type = E820_RAM;
783 rc = 0;
784 }
785 BUG_ON(rc);
786 BUG_ON(memmap.nr_entries == 0);
787 xen_e820_map_entries = memmap.nr_entries;
788
789 /*
790 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
791 * regions, so if we're using the machine memory map leave the
792 * region as RAM as it is in the pseudo-physical map.
793 *
794 * UNUSABLE regions in domUs are not handled and will need
795 * a patch in the future.
796 */
797 if (xen_initial_domain())
798 xen_ignore_unusable();
799
800 /* Make sure the Xen-supplied memory map is well-ordered. */
801 sanitize_e820_map(xen_e820_map, ARRAY_SIZE(xen_e820_map),
802 &xen_e820_map_entries);
803
804 max_pages = xen_get_max_pages();
805
806 /* How many extra pages do we need due to remapping? */
807 max_pages += xen_count_remap_pages(max_pfn);
808
809 if (max_pages > max_pfn)
810 extra_pages += max_pages - max_pfn;
811
812 /*
813 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
814 * factor the base size. On non-highmem systems, the base
815 * size is the full initial memory allocation; on highmem it
816 * is limited to the max size of lowmem, so that it doesn't
817 * get completely filled.
818 *
819 * Make sure we have no memory above max_pages, as this area
820 * isn't handled by the p2m management.
821 *
822 * In principle there could be a problem in lowmem systems if
823 * the initial memory is also very large with respect to
824 * lowmem, but we won't try to deal with that here.
825 */
826 extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
827 extra_pages, max_pages - max_pfn);
828 i = 0;
829 addr = xen_e820_map[0].addr;
830 size = xen_e820_map[0].size;
831 while (i < xen_e820_map_entries) {
832 bool discard = false;
833
834 chunk_size = size;
835 type = xen_e820_map[i].type;
836
837 if (type == E820_RAM) {
838 if (addr < mem_end) {
839 chunk_size = min(size, mem_end - addr);
840 } else if (extra_pages) {
841 chunk_size = min(size, PFN_PHYS(extra_pages));
842 pfn_s = PFN_UP(addr);
843 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
844 extra_pages -= n_pfns;
845 xen_add_extra_mem(pfn_s, n_pfns);
846 xen_max_p2m_pfn = pfn_s + n_pfns;
847 } else
848 discard = true;
849 }
850
851 if (!discard)
852 xen_align_and_add_e820_region(addr, chunk_size, type);
853
854 addr += chunk_size;
855 size -= chunk_size;
856 if (size == 0) {
857 i++;
858 if (i < xen_e820_map_entries) {
859 addr = xen_e820_map[i].addr;
860 size = xen_e820_map[i].size;
861 }
862 }
863 }
864
865 /*
866 * Set the rest as identity mapped, in case PCI BARs are
867 * located here.
868 */
869 set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
870
871 /*
872 * In domU, the ISA region is normal, usable memory, but we
873 * reserve ISA memory anyway because too many things poke
874 * about in there.
875 */
876 e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
877 E820_RESERVED);
878
879 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
880
881 /*
882 * Check whether the kernel itself conflicts with the target E820 map.
883 * Failing now is better than running into weird problems later due
884 * to relocating (and even reusing) pages with kernel text or data.
885 */
886 if (xen_is_e820_reserved(__pa_symbol(_text),
887 __pa_symbol(__bss_stop) - __pa_symbol(_text))) {
888 xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
889 BUG();
890 }
891
892 /*
893 * Check for a conflict of the hypervisor supplied page tables with
894 * the target E820 map.
895 */
896 xen_pt_check_e820();
897
898 xen_reserve_xen_mfnlist();
899
900 /* Check for a conflict of the initrd with the target E820 map. */
901 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
902 boot_params.hdr.ramdisk_size)) {
903 phys_addr_t new_area, start, size;
904
905 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
906 if (!new_area) {
907 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
908 BUG();
909 }
910
911 start = boot_params.hdr.ramdisk_image;
912 size = boot_params.hdr.ramdisk_size;
913 xen_phys_memcpy(new_area, start, size);
914 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
915 start, start + size, new_area, new_area + size);
916 memblock_free(start, size);
917 boot_params.hdr.ramdisk_image = new_area;
918 boot_params.ext_ramdisk_image = new_area >> 32;
919 }
920
921 /*
922 * Set identity map on non-RAM pages and prepare remapping the
923 * underlying RAM.
924 */
925 xen_set_identity_and_remap(max_pfn);
926
927 return "Xen";
928}
929
930/*
931 * Machine specific memory setup for auto-translated guests.
932 */
933char * __init xen_auto_xlated_memory_setup(void)
934{
935 struct xen_memory_map memmap;
936 int i;
937 int rc;
938
939 memmap.nr_entries = E820MAX;
940 set_xen_guest_handle(memmap.buffer, xen_e820_map);
941
942 rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
943 if (rc < 0)
944 panic("No memory map (%d)\n", rc);
945
946 xen_e820_map_entries = memmap.nr_entries;
947
948 sanitize_e820_map(xen_e820_map, ARRAY_SIZE(xen_e820_map),
949 &xen_e820_map_entries);
950
951 for (i = 0; i < xen_e820_map_entries; i++)
952 e820_add_region(xen_e820_map[i].addr, xen_e820_map[i].size,
953 xen_e820_map[i].type);
954
955 /* Remove p2m info, it is not needed. */
956 xen_start_info->mfn_list = 0;
957 xen_start_info->first_p2m_pfn = 0;
958 xen_start_info->nr_p2m_frames = 0;
959
960 return "Xen";
961}
962
963/*
964 * Set the bit indicating "nosegneg" library variants should be used.
965 * We only need to bother in pure 32-bit mode; compat 32-bit processes
966 * can have un-truncated segments, so wrapping around is allowed.
967 */
968static void __init fiddle_vdso(void)
969{
970#ifdef CONFIG_X86_32
971 u32 *mask = vdso_image_32.data +
972 vdso_image_32.sym_VDSO32_NOTE_MASK;
973 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
974#endif
975}
976
977static int register_callback(unsigned type, const void *func)
978{
979 struct callback_register callback = {
980 .type = type,
981 .address = XEN_CALLBACK(__KERNEL_CS, func),
982 .flags = CALLBACKF_mask_events,
983 };
984
985 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
986}
987
988void xen_enable_sysenter(void)
989{
990 int ret;
991 unsigned sysenter_feature;
992
993#ifdef CONFIG_X86_32
994 sysenter_feature = X86_FEATURE_SEP;
995#else
996 sysenter_feature = X86_FEATURE_SYSENTER32;
997#endif
998
999 if (!boot_cpu_has(sysenter_feature))
1000 return;
1001
1002 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
1003 if(ret != 0)
1004 setup_clear_cpu_cap(sysenter_feature);
1005}
1006
1007void xen_enable_syscall(void)
1008{
1009#ifdef CONFIG_X86_64
1010 int ret;
1011
1012 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
1013 if (ret != 0) {
1014 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
1015 /* Pretty fatal; 64-bit userspace has no other
1016 mechanism for syscalls. */
1017 }
1018
1019 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
1020 ret = register_callback(CALLBACKTYPE_syscall32,
1021 xen_syscall32_target);
1022 if (ret != 0)
1023 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
1024 }
1025#endif /* CONFIG_X86_64 */
1026}
1027
1028void __init xen_pvmmu_arch_setup(void)
1029{
1030 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
1031 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
1032
1033 HYPERVISOR_vm_assist(VMASST_CMD_enable,
1034 VMASST_TYPE_pae_extended_cr3);
1035
1036 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
1037 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
1038 BUG();
1039
1040 xen_enable_sysenter();
1041 xen_enable_syscall();
1042}
1043
1044/* This function is not called for HVM domains */
1045void __init xen_arch_setup(void)
1046{
1047 xen_panic_handler_init();
1048 if (!xen_feature(XENFEAT_auto_translated_physmap))
1049 xen_pvmmu_arch_setup();
1050
1051#ifdef CONFIG_ACPI
1052 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
1053 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
1054 disable_acpi();
1055 }
1056#endif
1057
1058 memcpy(boot_command_line, xen_start_info->cmd_line,
1059 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
1060 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
1061
1062 /* Set up idle, making sure it calls safe_halt() pvop */
1063 disable_cpuidle();
1064 disable_cpufreq();
1065 WARN_ON(xen_set_default_idle());
1066 fiddle_vdso();
1067#ifdef CONFIG_NUMA
1068 numa_off = 1;
1069#endif
1070}