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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * Machine specific setup for xen
4 *
5 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
6 */
7
8#include <linux/init.h>
9#include <linux/iscsi_ibft.h>
10#include <linux/sched.h>
11#include <linux/kstrtox.h>
12#include <linux/mm.h>
13#include <linux/pm.h>
14#include <linux/memblock.h>
15#include <linux/cpuidle.h>
16#include <linux/cpufreq.h>
17#include <linux/memory_hotplug.h>
18
19#include <asm/elf.h>
20#include <asm/vdso.h>
21#include <asm/e820/api.h>
22#include <asm/setup.h>
23#include <asm/acpi.h>
24#include <asm/numa.h>
25#include <asm/idtentry.h>
26#include <asm/xen/hypervisor.h>
27#include <asm/xen/hypercall.h>
28
29#include <xen/xen.h>
30#include <xen/page.h>
31#include <xen/interface/callback.h>
32#include <xen/interface/memory.h>
33#include <xen/interface/physdev.h>
34#include <xen/features.h>
35#include <xen/hvc-console.h>
36#include "xen-ops.h"
37#include "mmu.h"
38
39#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
40
41/* Number of pages released from the initial allocation. */
42unsigned long xen_released_pages;
43
44/* Memory map would allow PCI passthrough. */
45bool xen_pv_pci_possible;
46
47/* E820 map used during setting up memory. */
48static struct e820_table xen_e820_table __initdata;
49
50/*
51 * Buffer used to remap identity mapped pages. We only need the virtual space.
52 * The physical page behind this address is remapped as needed to different
53 * buffer pages.
54 */
55#define REMAP_SIZE (P2M_PER_PAGE - 3)
56static struct {
57 unsigned long next_area_mfn;
58 unsigned long target_pfn;
59 unsigned long size;
60 unsigned long mfns[REMAP_SIZE];
61} xen_remap_buf __initdata __aligned(PAGE_SIZE);
62static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
63
64static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
65
66static void __init xen_parse_512gb(void)
67{
68 bool val = false;
69 char *arg;
70
71 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
72 if (!arg)
73 return;
74
75 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
76 if (!arg)
77 val = true;
78 else if (kstrtobool(arg + strlen("xen_512gb_limit="), &val))
79 return;
80
81 xen_512gb_limit = val;
82}
83
84static void __init xen_del_extra_mem(unsigned long start_pfn,
85 unsigned long n_pfns)
86{
87 int i;
88 unsigned long start_r, size_r;
89
90 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
91 start_r = xen_extra_mem[i].start_pfn;
92 size_r = xen_extra_mem[i].n_pfns;
93
94 /* Start of region. */
95 if (start_r == start_pfn) {
96 BUG_ON(n_pfns > size_r);
97 xen_extra_mem[i].start_pfn += n_pfns;
98 xen_extra_mem[i].n_pfns -= n_pfns;
99 break;
100 }
101 /* End of region. */
102 if (start_r + size_r == start_pfn + n_pfns) {
103 BUG_ON(n_pfns > size_r);
104 xen_extra_mem[i].n_pfns -= n_pfns;
105 break;
106 }
107 /* Mid of region. */
108 if (start_pfn > start_r && start_pfn < start_r + size_r) {
109 BUG_ON(start_pfn + n_pfns > start_r + size_r);
110 xen_extra_mem[i].n_pfns = start_pfn - start_r;
111 /* Calling memblock_reserve() again is okay. */
112 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
113 (start_pfn + n_pfns));
114 break;
115 }
116 }
117 memblock_phys_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
118}
119
120/*
121 * Called during boot before the p2m list can take entries beyond the
122 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
123 * invalid.
124 */
125unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
126{
127 int i;
128
129 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
130 if (pfn >= xen_extra_mem[i].start_pfn &&
131 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
132 return INVALID_P2M_ENTRY;
133 }
134
135 return IDENTITY_FRAME(pfn);
136}
137
138/*
139 * Mark all pfns of extra mem as invalid in p2m list.
140 */
141void __init xen_inv_extra_mem(void)
142{
143 unsigned long pfn, pfn_s, pfn_e;
144 int i;
145
146 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
147 if (!xen_extra_mem[i].n_pfns)
148 continue;
149 pfn_s = xen_extra_mem[i].start_pfn;
150 pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
151 for (pfn = pfn_s; pfn < pfn_e; pfn++)
152 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
153 }
154}
155
156/*
157 * Finds the next RAM pfn available in the E820 map after min_pfn.
158 * This function updates min_pfn with the pfn found and returns
159 * the size of that range or zero if not found.
160 */
161static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
162{
163 const struct e820_entry *entry = xen_e820_table.entries;
164 unsigned int i;
165 unsigned long done = 0;
166
167 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
168 unsigned long s_pfn;
169 unsigned long e_pfn;
170
171 if (entry->type != E820_TYPE_RAM)
172 continue;
173
174 e_pfn = PFN_DOWN(entry->addr + entry->size);
175
176 /* We only care about E820 after this */
177 if (e_pfn <= *min_pfn)
178 continue;
179
180 s_pfn = PFN_UP(entry->addr);
181
182 /* If min_pfn falls within the E820 entry, we want to start
183 * at the min_pfn PFN.
184 */
185 if (s_pfn <= *min_pfn) {
186 done = e_pfn - *min_pfn;
187 } else {
188 done = e_pfn - s_pfn;
189 *min_pfn = s_pfn;
190 }
191 break;
192 }
193
194 return done;
195}
196
197static int __init xen_free_mfn(unsigned long mfn)
198{
199 struct xen_memory_reservation reservation = {
200 .address_bits = 0,
201 .extent_order = 0,
202 .domid = DOMID_SELF
203 };
204
205 set_xen_guest_handle(reservation.extent_start, &mfn);
206 reservation.nr_extents = 1;
207
208 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
209}
210
211/*
212 * This releases a chunk of memory and then does the identity map. It's used
213 * as a fallback if the remapping fails.
214 */
215static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
216 unsigned long end_pfn, unsigned long nr_pages)
217{
218 unsigned long pfn, end;
219 int ret;
220
221 WARN_ON(start_pfn > end_pfn);
222
223 /* Release pages first. */
224 end = min(end_pfn, nr_pages);
225 for (pfn = start_pfn; pfn < end; pfn++) {
226 unsigned long mfn = pfn_to_mfn(pfn);
227
228 /* Make sure pfn exists to start with */
229 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
230 continue;
231
232 ret = xen_free_mfn(mfn);
233 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
234
235 if (ret == 1) {
236 xen_released_pages++;
237 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
238 break;
239 } else
240 break;
241 }
242
243 set_phys_range_identity(start_pfn, end_pfn);
244}
245
246/*
247 * Helper function to update the p2m and m2p tables and kernel mapping.
248 */
249static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
250{
251 struct mmu_update update = {
252 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
253 .val = pfn
254 };
255
256 /* Update p2m */
257 if (!set_phys_to_machine(pfn, mfn)) {
258 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
259 pfn, mfn);
260 BUG();
261 }
262
263 /* Update m2p */
264 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
265 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
266 mfn, pfn);
267 BUG();
268 }
269
270 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
271 mfn_pte(mfn, PAGE_KERNEL), 0)) {
272 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
273 mfn, pfn);
274 BUG();
275 }
276}
277
278/*
279 * This function updates the p2m and m2p tables with an identity map from
280 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
281 * original allocation at remap_pfn. The information needed for remapping is
282 * saved in the memory itself to avoid the need for allocating buffers. The
283 * complete remap information is contained in a list of MFNs each containing
284 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
285 * This enables us to preserve the original mfn sequence while doing the
286 * remapping at a time when the memory management is capable of allocating
287 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
288 * its callers.
289 */
290static void __init xen_do_set_identity_and_remap_chunk(
291 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
292{
293 unsigned long buf = (unsigned long)&xen_remap_buf;
294 unsigned long mfn_save, mfn;
295 unsigned long ident_pfn_iter, remap_pfn_iter;
296 unsigned long ident_end_pfn = start_pfn + size;
297 unsigned long left = size;
298 unsigned int i, chunk;
299
300 WARN_ON(size == 0);
301
302 mfn_save = virt_to_mfn((void *)buf);
303
304 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
305 ident_pfn_iter < ident_end_pfn;
306 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
307 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
308
309 /* Map first pfn to xen_remap_buf */
310 mfn = pfn_to_mfn(ident_pfn_iter);
311 set_pte_mfn(buf, mfn, PAGE_KERNEL);
312
313 /* Save mapping information in page */
314 xen_remap_buf.next_area_mfn = xen_remap_mfn;
315 xen_remap_buf.target_pfn = remap_pfn_iter;
316 xen_remap_buf.size = chunk;
317 for (i = 0; i < chunk; i++)
318 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
319
320 /* Put remap buf into list. */
321 xen_remap_mfn = mfn;
322
323 /* Set identity map */
324 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
325
326 left -= chunk;
327 }
328
329 /* Restore old xen_remap_buf mapping */
330 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
331}
332
333/*
334 * This function takes a contiguous pfn range that needs to be identity mapped
335 * and:
336 *
337 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
338 * 2) Calls the do_ function to actually do the mapping/remapping work.
339 *
340 * The goal is to not allocate additional memory but to remap the existing
341 * pages. In the case of an error the underlying memory is simply released back
342 * to Xen and not remapped.
343 */
344static unsigned long __init xen_set_identity_and_remap_chunk(
345 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
346 unsigned long remap_pfn)
347{
348 unsigned long pfn;
349 unsigned long i = 0;
350 unsigned long n = end_pfn - start_pfn;
351
352 if (remap_pfn == 0)
353 remap_pfn = nr_pages;
354
355 while (i < n) {
356 unsigned long cur_pfn = start_pfn + i;
357 unsigned long left = n - i;
358 unsigned long size = left;
359 unsigned long remap_range_size;
360
361 /* Do not remap pages beyond the current allocation */
362 if (cur_pfn >= nr_pages) {
363 /* Identity map remaining pages */
364 set_phys_range_identity(cur_pfn, cur_pfn + size);
365 break;
366 }
367 if (cur_pfn + size > nr_pages)
368 size = nr_pages - cur_pfn;
369
370 remap_range_size = xen_find_pfn_range(&remap_pfn);
371 if (!remap_range_size) {
372 pr_warn("Unable to find available pfn range, not remapping identity pages\n");
373 xen_set_identity_and_release_chunk(cur_pfn,
374 cur_pfn + left, nr_pages);
375 break;
376 }
377 /* Adjust size to fit in current e820 RAM region */
378 if (size > remap_range_size)
379 size = remap_range_size;
380
381 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
382
383 /* Update variables to reflect new mappings. */
384 i += size;
385 remap_pfn += size;
386 }
387
388 /*
389 * If the PFNs are currently mapped, their VA mappings need to be
390 * zapped.
391 */
392 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
393 (void)HYPERVISOR_update_va_mapping(
394 (unsigned long)__va(pfn << PAGE_SHIFT),
395 native_make_pte(0), 0);
396
397 return remap_pfn;
398}
399
400static unsigned long __init xen_count_remap_pages(
401 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
402 unsigned long remap_pages)
403{
404 if (start_pfn >= nr_pages)
405 return remap_pages;
406
407 return remap_pages + min(end_pfn, nr_pages) - start_pfn;
408}
409
410static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages,
411 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
412 unsigned long nr_pages, unsigned long last_val))
413{
414 phys_addr_t start = 0;
415 unsigned long ret_val = 0;
416 const struct e820_entry *entry = xen_e820_table.entries;
417 int i;
418
419 /*
420 * Combine non-RAM regions and gaps until a RAM region (or the
421 * end of the map) is reached, then call the provided function
422 * to perform its duty on the non-RAM region.
423 *
424 * The combined non-RAM regions are rounded to a whole number
425 * of pages so any partial pages are accessible via the 1:1
426 * mapping. This is needed for some BIOSes that put (for
427 * example) the DMI tables in a reserved region that begins on
428 * a non-page boundary.
429 */
430 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
431 phys_addr_t end = entry->addr + entry->size;
432 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
433 unsigned long start_pfn = PFN_DOWN(start);
434 unsigned long end_pfn = PFN_UP(end);
435
436 if (entry->type == E820_TYPE_RAM)
437 end_pfn = PFN_UP(entry->addr);
438
439 if (start_pfn < end_pfn)
440 ret_val = func(start_pfn, end_pfn, nr_pages,
441 ret_val);
442 start = end;
443 }
444 }
445
446 return ret_val;
447}
448
449/*
450 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
451 * The remap information (which mfn remap to which pfn) is contained in the
452 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
453 * This scheme allows to remap the different chunks in arbitrary order while
454 * the resulting mapping will be independent from the order.
455 */
456void __init xen_remap_memory(void)
457{
458 unsigned long buf = (unsigned long)&xen_remap_buf;
459 unsigned long mfn_save, pfn;
460 unsigned long remapped = 0;
461 unsigned int i;
462 unsigned long pfn_s = ~0UL;
463 unsigned long len = 0;
464
465 mfn_save = virt_to_mfn((void *)buf);
466
467 while (xen_remap_mfn != INVALID_P2M_ENTRY) {
468 /* Map the remap information */
469 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
470
471 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
472
473 pfn = xen_remap_buf.target_pfn;
474 for (i = 0; i < xen_remap_buf.size; i++) {
475 xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
476 remapped++;
477 pfn++;
478 }
479 if (pfn_s == ~0UL || pfn == pfn_s) {
480 pfn_s = xen_remap_buf.target_pfn;
481 len += xen_remap_buf.size;
482 } else if (pfn_s + len == xen_remap_buf.target_pfn) {
483 len += xen_remap_buf.size;
484 } else {
485 xen_del_extra_mem(pfn_s, len);
486 pfn_s = xen_remap_buf.target_pfn;
487 len = xen_remap_buf.size;
488 }
489 xen_remap_mfn = xen_remap_buf.next_area_mfn;
490 }
491
492 if (pfn_s != ~0UL && len)
493 xen_del_extra_mem(pfn_s, len);
494
495 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
496
497 pr_info("Remapped %ld page(s)\n", remapped);
498}
499
500static unsigned long __init xen_get_pages_limit(void)
501{
502 unsigned long limit;
503
504 limit = MAXMEM / PAGE_SIZE;
505 if (!xen_initial_domain() && xen_512gb_limit)
506 limit = GB(512) / PAGE_SIZE;
507
508 return limit;
509}
510
511static unsigned long __init xen_get_max_pages(void)
512{
513 unsigned long max_pages, limit;
514 domid_t domid = DOMID_SELF;
515 long ret;
516
517 limit = xen_get_pages_limit();
518 max_pages = limit;
519
520 /*
521 * For the initial domain we use the maximum reservation as
522 * the maximum page.
523 *
524 * For guest domains the current maximum reservation reflects
525 * the current maximum rather than the static maximum. In this
526 * case the e820 map provided to us will cover the static
527 * maximum region.
528 */
529 if (xen_initial_domain()) {
530 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
531 if (ret > 0)
532 max_pages = ret;
533 }
534
535 return min(max_pages, limit);
536}
537
538static void __init xen_align_and_add_e820_region(phys_addr_t start,
539 phys_addr_t size, int type)
540{
541 phys_addr_t end = start + size;
542
543 /* Align RAM regions to page boundaries. */
544 if (type == E820_TYPE_RAM) {
545 start = PAGE_ALIGN(start);
546 end &= ~((phys_addr_t)PAGE_SIZE - 1);
547#ifdef CONFIG_MEMORY_HOTPLUG
548 /*
549 * Don't allow adding memory not in E820 map while booting the
550 * system. Once the balloon driver is up it will remove that
551 * restriction again.
552 */
553 max_mem_size = end;
554#endif
555 }
556
557 e820__range_add(start, end - start, type);
558}
559
560static void __init xen_ignore_unusable(void)
561{
562 struct e820_entry *entry = xen_e820_table.entries;
563 unsigned int i;
564
565 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
566 if (entry->type == E820_TYPE_UNUSABLE)
567 entry->type = E820_TYPE_RAM;
568 }
569}
570
571bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
572{
573 struct e820_entry *entry;
574 unsigned mapcnt;
575 phys_addr_t end;
576
577 if (!size)
578 return false;
579
580 end = start + size;
581 entry = xen_e820_table.entries;
582
583 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
584 if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
585 (entry->addr + entry->size) >= end)
586 return false;
587
588 entry++;
589 }
590
591 return true;
592}
593
594/*
595 * Find a free area in physical memory not yet reserved and compliant with
596 * E820 map.
597 * Used to relocate pre-allocated areas like initrd or p2m list which are in
598 * conflict with the to be used E820 map.
599 * In case no area is found, return 0. Otherwise return the physical address
600 * of the area which is already reserved for convenience.
601 */
602phys_addr_t __init xen_find_free_area(phys_addr_t size)
603{
604 unsigned mapcnt;
605 phys_addr_t addr, start;
606 struct e820_entry *entry = xen_e820_table.entries;
607
608 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
609 if (entry->type != E820_TYPE_RAM || entry->size < size)
610 continue;
611 start = entry->addr;
612 for (addr = start; addr < start + size; addr += PAGE_SIZE) {
613 if (!memblock_is_reserved(addr))
614 continue;
615 start = addr + PAGE_SIZE;
616 if (start + size > entry->addr + entry->size)
617 break;
618 }
619 if (addr >= start + size) {
620 memblock_reserve(start, size);
621 return start;
622 }
623 }
624
625 return 0;
626}
627
628/*
629 * Like memcpy, but with physical addresses for dest and src.
630 */
631static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
632 phys_addr_t n)
633{
634 phys_addr_t dest_off, src_off, dest_len, src_len, len;
635 void *from, *to;
636
637 while (n) {
638 dest_off = dest & ~PAGE_MASK;
639 src_off = src & ~PAGE_MASK;
640 dest_len = n;
641 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
642 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
643 src_len = n;
644 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
645 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
646 len = min(dest_len, src_len);
647 to = early_memremap(dest - dest_off, dest_len + dest_off);
648 from = early_memremap(src - src_off, src_len + src_off);
649 memcpy(to, from, len);
650 early_memunmap(to, dest_len + dest_off);
651 early_memunmap(from, src_len + src_off);
652 n -= len;
653 dest += len;
654 src += len;
655 }
656}
657
658/*
659 * Reserve Xen mfn_list.
660 */
661static void __init xen_reserve_xen_mfnlist(void)
662{
663 phys_addr_t start, size;
664
665 if (xen_start_info->mfn_list >= __START_KERNEL_map) {
666 start = __pa(xen_start_info->mfn_list);
667 size = PFN_ALIGN(xen_start_info->nr_pages *
668 sizeof(unsigned long));
669 } else {
670 start = PFN_PHYS(xen_start_info->first_p2m_pfn);
671 size = PFN_PHYS(xen_start_info->nr_p2m_frames);
672 }
673
674 memblock_reserve(start, size);
675 if (!xen_is_e820_reserved(start, size))
676 return;
677
678 xen_relocate_p2m();
679 memblock_phys_free(start, size);
680}
681
682/**
683 * xen_memory_setup - Hook for machine specific memory setup.
684 **/
685char * __init xen_memory_setup(void)
686{
687 unsigned long max_pfn, pfn_s, n_pfns;
688 phys_addr_t mem_end, addr, size, chunk_size;
689 u32 type;
690 int rc;
691 struct xen_memory_map memmap;
692 unsigned long max_pages;
693 unsigned long extra_pages = 0;
694 int i;
695 int op;
696
697 xen_parse_512gb();
698 max_pfn = xen_get_pages_limit();
699 max_pfn = min(max_pfn, xen_start_info->nr_pages);
700 mem_end = PFN_PHYS(max_pfn);
701
702 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
703 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
704
705#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
706 xen_saved_max_mem_size = max_mem_size;
707#endif
708
709 op = xen_initial_domain() ?
710 XENMEM_machine_memory_map :
711 XENMEM_memory_map;
712 rc = HYPERVISOR_memory_op(op, &memmap);
713 if (rc == -ENOSYS) {
714 BUG_ON(xen_initial_domain());
715 memmap.nr_entries = 1;
716 xen_e820_table.entries[0].addr = 0ULL;
717 xen_e820_table.entries[0].size = mem_end;
718 /* 8MB slack (to balance backend allocations). */
719 xen_e820_table.entries[0].size += 8ULL << 20;
720 xen_e820_table.entries[0].type = E820_TYPE_RAM;
721 rc = 0;
722 }
723 BUG_ON(rc);
724 BUG_ON(memmap.nr_entries == 0);
725 xen_e820_table.nr_entries = memmap.nr_entries;
726
727 if (xen_initial_domain()) {
728 /*
729 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
730 * regions, so if we're using the machine memory map leave the
731 * region as RAM as it is in the pseudo-physical map.
732 *
733 * UNUSABLE regions in domUs are not handled and will need
734 * a patch in the future.
735 */
736 xen_ignore_unusable();
737
738#ifdef CONFIG_ISCSI_IBFT_FIND
739 /* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */
740 xen_e820_table.entries[xen_e820_table.nr_entries].addr = IBFT_START;
741 xen_e820_table.entries[xen_e820_table.nr_entries].size = IBFT_END - IBFT_START;
742 xen_e820_table.entries[xen_e820_table.nr_entries].type = E820_TYPE_RESERVED;
743 xen_e820_table.nr_entries++;
744#endif
745 }
746
747 /* Make sure the Xen-supplied memory map is well-ordered. */
748 e820__update_table(&xen_e820_table);
749
750 max_pages = xen_get_max_pages();
751
752 /* How many extra pages do we need due to remapping? */
753 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages);
754
755 if (max_pages > max_pfn)
756 extra_pages += max_pages - max_pfn;
757
758 /*
759 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
760 * factor the base size.
761 *
762 * Make sure we have no memory above max_pages, as this area
763 * isn't handled by the p2m management.
764 */
765 extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
766 extra_pages, max_pages - max_pfn);
767 i = 0;
768 addr = xen_e820_table.entries[0].addr;
769 size = xen_e820_table.entries[0].size;
770 while (i < xen_e820_table.nr_entries) {
771 bool discard = false;
772
773 chunk_size = size;
774 type = xen_e820_table.entries[i].type;
775
776 if (type == E820_TYPE_RESERVED)
777 xen_pv_pci_possible = true;
778
779 if (type == E820_TYPE_RAM) {
780 if (addr < mem_end) {
781 chunk_size = min(size, mem_end - addr);
782 } else if (extra_pages) {
783 chunk_size = min(size, PFN_PHYS(extra_pages));
784 pfn_s = PFN_UP(addr);
785 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
786 extra_pages -= n_pfns;
787 xen_add_extra_mem(pfn_s, n_pfns);
788 xen_max_p2m_pfn = pfn_s + n_pfns;
789 } else
790 discard = true;
791 }
792
793 if (!discard)
794 xen_align_and_add_e820_region(addr, chunk_size, type);
795
796 addr += chunk_size;
797 size -= chunk_size;
798 if (size == 0) {
799 i++;
800 if (i < xen_e820_table.nr_entries) {
801 addr = xen_e820_table.entries[i].addr;
802 size = xen_e820_table.entries[i].size;
803 }
804 }
805 }
806
807 /*
808 * Set the rest as identity mapped, in case PCI BARs are
809 * located here.
810 */
811 set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
812
813 /*
814 * In domU, the ISA region is normal, usable memory, but we
815 * reserve ISA memory anyway because too many things poke
816 * about in there.
817 */
818 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
819
820 e820__update_table(e820_table);
821
822 /*
823 * Check whether the kernel itself conflicts with the target E820 map.
824 * Failing now is better than running into weird problems later due
825 * to relocating (and even reusing) pages with kernel text or data.
826 */
827 if (xen_is_e820_reserved(__pa_symbol(_text),
828 __pa_symbol(__bss_stop) - __pa_symbol(_text))) {
829 xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
830 BUG();
831 }
832
833 /*
834 * Check for a conflict of the hypervisor supplied page tables with
835 * the target E820 map.
836 */
837 xen_pt_check_e820();
838
839 xen_reserve_xen_mfnlist();
840
841 /* Check for a conflict of the initrd with the target E820 map. */
842 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
843 boot_params.hdr.ramdisk_size)) {
844 phys_addr_t new_area, start, size;
845
846 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
847 if (!new_area) {
848 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
849 BUG();
850 }
851
852 start = boot_params.hdr.ramdisk_image;
853 size = boot_params.hdr.ramdisk_size;
854 xen_phys_memcpy(new_area, start, size);
855 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
856 start, start + size, new_area, new_area + size);
857 memblock_phys_free(start, size);
858 boot_params.hdr.ramdisk_image = new_area;
859 boot_params.ext_ramdisk_image = new_area >> 32;
860 }
861
862 /*
863 * Set identity map on non-RAM pages and prepare remapping the
864 * underlying RAM.
865 */
866 xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk);
867
868 pr_info("Released %ld page(s)\n", xen_released_pages);
869
870 return "Xen";
871}
872
873static int register_callback(unsigned type, const void *func)
874{
875 struct callback_register callback = {
876 .type = type,
877 .address = XEN_CALLBACK(__KERNEL_CS, func),
878 .flags = CALLBACKF_mask_events,
879 };
880
881 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
882}
883
884void xen_enable_sysenter(void)
885{
886 if (cpu_feature_enabled(X86_FEATURE_SYSENTER32) &&
887 register_callback(CALLBACKTYPE_sysenter, xen_entry_SYSENTER_compat))
888 setup_clear_cpu_cap(X86_FEATURE_SYSENTER32);
889}
890
891void xen_enable_syscall(void)
892{
893 int ret;
894
895 ret = register_callback(CALLBACKTYPE_syscall, xen_entry_SYSCALL_64);
896 if (ret != 0) {
897 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
898 /* Pretty fatal; 64-bit userspace has no other
899 mechanism for syscalls. */
900 }
901
902 if (cpu_feature_enabled(X86_FEATURE_SYSCALL32) &&
903 register_callback(CALLBACKTYPE_syscall32, xen_entry_SYSCALL_compat))
904 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
905}
906
907static void __init xen_pvmmu_arch_setup(void)
908{
909 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
910
911 if (register_callback(CALLBACKTYPE_event,
912 xen_asm_exc_xen_hypervisor_callback) ||
913 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
914 BUG();
915
916 xen_enable_sysenter();
917 xen_enable_syscall();
918}
919
920/* This function is not called for HVM domains */
921void __init xen_arch_setup(void)
922{
923 xen_panic_handler_init();
924 xen_pvmmu_arch_setup();
925
926#ifdef CONFIG_ACPI
927 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
928 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
929 disable_acpi();
930 }
931#endif
932
933 memcpy(boot_command_line, xen_start_info->cmd_line,
934 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
935 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
936
937 /* Set up idle, making sure it calls safe_halt() pvop */
938 disable_cpuidle();
939 disable_cpufreq();
940 WARN_ON(xen_set_default_idle());
941#ifdef CONFIG_NUMA
942 numa_off = 1;
943#endif
944}