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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 "mmu.h"
31#include "xen-ops.h"
32#include "vdso.h"
33
34/* These are code, but not functions. Defined in entry.S */
35extern const char xen_hypervisor_callback[];
36extern const char xen_failsafe_callback[];
37#ifdef CONFIG_X86_64
38extern asmlinkage void nmi(void);
39#endif
40extern void xen_sysenter_target(void);
41extern void xen_syscall_target(void);
42extern void xen_syscall32_target(void);
43
44/* Amount of extra memory space we add to the e820 ranges */
45struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
46
47/* Number of pages released from the initial allocation. */
48unsigned long xen_released_pages;
49
50/*
51 * The maximum amount of extra memory compared to the base size. The
52 * main scaling factor is the size of struct page. At extreme ratios
53 * of base:extra, all the base memory can be filled with page
54 * structures for the extra memory, leaving no space for anything
55 * else.
56 *
57 * 10x seems like a reasonable balance between scaling flexibility and
58 * leaving a practically usable system.
59 */
60#define EXTRA_MEM_RATIO (10)
61
62static void __init xen_add_extra_mem(u64 start, u64 size)
63{
64 unsigned long pfn;
65 int i;
66
67 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
68 /* Add new region. */
69 if (xen_extra_mem[i].size == 0) {
70 xen_extra_mem[i].start = start;
71 xen_extra_mem[i].size = size;
72 break;
73 }
74 /* Append to existing region. */
75 if (xen_extra_mem[i].start + xen_extra_mem[i].size == start) {
76 xen_extra_mem[i].size += size;
77 break;
78 }
79 }
80 if (i == XEN_EXTRA_MEM_MAX_REGIONS)
81 printk(KERN_WARNING "Warning: not enough extra memory regions\n");
82
83 memblock_reserve(start, size);
84
85 if (xen_feature(XENFEAT_auto_translated_physmap))
86 return;
87
88 xen_max_p2m_pfn = PFN_DOWN(start + size);
89 for (pfn = PFN_DOWN(start); pfn < xen_max_p2m_pfn; pfn++) {
90 unsigned long mfn = pfn_to_mfn(pfn);
91
92 if (WARN(mfn == pfn, "Trying to over-write 1-1 mapping (pfn: %lx)\n", pfn))
93 continue;
94 WARN(mfn != INVALID_P2M_ENTRY, "Trying to remove %lx which has %lx mfn!\n",
95 pfn, mfn);
96
97 __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
98 }
99}
100
101static unsigned long __init xen_do_chunk(unsigned long start,
102 unsigned long end, bool release)
103{
104 struct xen_memory_reservation reservation = {
105 .address_bits = 0,
106 .extent_order = 0,
107 .domid = DOMID_SELF
108 };
109 unsigned long len = 0;
110 int xlated_phys = xen_feature(XENFEAT_auto_translated_physmap);
111 unsigned long pfn;
112 int ret;
113
114 for (pfn = start; pfn < end; pfn++) {
115 unsigned long frame;
116 unsigned long mfn = pfn_to_mfn(pfn);
117
118 if (release) {
119 /* Make sure pfn exists to start with */
120 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
121 continue;
122 frame = mfn;
123 } else {
124 if (!xlated_phys && mfn != INVALID_P2M_ENTRY)
125 continue;
126 frame = pfn;
127 }
128 set_xen_guest_handle(reservation.extent_start, &frame);
129 reservation.nr_extents = 1;
130
131 ret = HYPERVISOR_memory_op(release ? XENMEM_decrease_reservation : XENMEM_populate_physmap,
132 &reservation);
133 WARN(ret != 1, "Failed to %s pfn %lx err=%d\n",
134 release ? "release" : "populate", pfn, ret);
135
136 if (ret == 1) {
137 if (!early_set_phys_to_machine(pfn, release ? INVALID_P2M_ENTRY : frame)) {
138 if (release)
139 break;
140 set_xen_guest_handle(reservation.extent_start, &frame);
141 reservation.nr_extents = 1;
142 ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
143 &reservation);
144 break;
145 }
146 len++;
147 } else
148 break;
149 }
150 if (len)
151 printk(KERN_INFO "%s %lx-%lx pfn range: %lu pages %s\n",
152 release ? "Freeing" : "Populating",
153 start, end, len,
154 release ? "freed" : "added");
155
156 return len;
157}
158
159static unsigned long __init xen_release_chunk(unsigned long start,
160 unsigned long end)
161{
162 /*
163 * Xen already ballooned out the E820 non RAM regions for us
164 * and set them up properly in EPT.
165 */
166 if (xen_feature(XENFEAT_auto_translated_physmap))
167 return end - start;
168
169 return xen_do_chunk(start, end, true);
170}
171
172static unsigned long __init xen_populate_chunk(
173 const struct e820entry *list, size_t map_size,
174 unsigned long max_pfn, unsigned long *last_pfn,
175 unsigned long credits_left)
176{
177 const struct e820entry *entry;
178 unsigned int i;
179 unsigned long done = 0;
180 unsigned long dest_pfn;
181
182 for (i = 0, entry = list; i < map_size; i++, entry++) {
183 unsigned long s_pfn;
184 unsigned long e_pfn;
185 unsigned long pfns;
186 long capacity;
187
188 if (credits_left <= 0)
189 break;
190
191 if (entry->type != E820_RAM)
192 continue;
193
194 e_pfn = PFN_DOWN(entry->addr + entry->size);
195
196 /* We only care about E820 after the xen_start_info->nr_pages */
197 if (e_pfn <= max_pfn)
198 continue;
199
200 s_pfn = PFN_UP(entry->addr);
201 /* If the E820 falls within the nr_pages, we want to start
202 * at the nr_pages PFN.
203 * If that would mean going past the E820 entry, skip it
204 */
205 if (s_pfn <= max_pfn) {
206 capacity = e_pfn - max_pfn;
207 dest_pfn = max_pfn;
208 } else {
209 capacity = e_pfn - s_pfn;
210 dest_pfn = s_pfn;
211 }
212
213 if (credits_left < capacity)
214 capacity = credits_left;
215
216 pfns = xen_do_chunk(dest_pfn, dest_pfn + capacity, false);
217 done += pfns;
218 *last_pfn = (dest_pfn + pfns);
219 if (pfns < capacity)
220 break;
221 credits_left -= pfns;
222 }
223 return done;
224}
225
226static void __init xen_set_identity_and_release_chunk(
227 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
228 unsigned long *released, unsigned long *identity)
229{
230 unsigned long pfn;
231
232 /*
233 * If the PFNs are currently mapped, clear the mappings
234 * (except for the ISA region which must be 1:1 mapped) to
235 * release the refcounts (in Xen) on the original frames.
236 */
237
238 /*
239 * PVH E820 matches the hypervisor's P2M which means we need to
240 * account for the proper values of *release and *identity.
241 */
242 for (pfn = start_pfn; !xen_feature(XENFEAT_auto_translated_physmap) &&
243 pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) {
244 pte_t pte = __pte_ma(0);
245
246 if (pfn < PFN_UP(ISA_END_ADDRESS))
247 pte = mfn_pte(pfn, PAGE_KERNEL_IO);
248
249 (void)HYPERVISOR_update_va_mapping(
250 (unsigned long)__va(pfn << PAGE_SHIFT), pte, 0);
251 }
252
253 if (start_pfn < nr_pages)
254 *released += xen_release_chunk(
255 start_pfn, min(end_pfn, nr_pages));
256
257 *identity += set_phys_range_identity(start_pfn, end_pfn);
258}
259
260static unsigned long __init xen_set_identity_and_release(
261 const struct e820entry *list, size_t map_size, unsigned long nr_pages)
262{
263 phys_addr_t start = 0;
264 unsigned long released = 0;
265 unsigned long identity = 0;
266 const struct e820entry *entry;
267 int i;
268
269 /*
270 * Combine non-RAM regions and gaps until a RAM region (or the
271 * end of the map) is reached, then set the 1:1 map and
272 * release the pages (if available) in those non-RAM regions.
273 *
274 * The combined non-RAM regions are rounded to a whole number
275 * of pages so any partial pages are accessible via the 1:1
276 * mapping. This is needed for some BIOSes that put (for
277 * example) the DMI tables in a reserved region that begins on
278 * a non-page boundary.
279 */
280 for (i = 0, entry = list; i < map_size; i++, entry++) {
281 phys_addr_t end = entry->addr + entry->size;
282 if (entry->type == E820_RAM || i == map_size - 1) {
283 unsigned long start_pfn = PFN_DOWN(start);
284 unsigned long end_pfn = PFN_UP(end);
285
286 if (entry->type == E820_RAM)
287 end_pfn = PFN_UP(entry->addr);
288
289 if (start_pfn < end_pfn)
290 xen_set_identity_and_release_chunk(
291 start_pfn, end_pfn, nr_pages,
292 &released, &identity);
293
294 start = end;
295 }
296 }
297
298 if (released)
299 printk(KERN_INFO "Released %lu pages of unused memory\n", released);
300 if (identity)
301 printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
302
303 return released;
304}
305
306static unsigned long __init xen_get_max_pages(void)
307{
308 unsigned long max_pages = MAX_DOMAIN_PAGES;
309 domid_t domid = DOMID_SELF;
310 int ret;
311
312 /*
313 * For the initial domain we use the maximum reservation as
314 * the maximum page.
315 *
316 * For guest domains the current maximum reservation reflects
317 * the current maximum rather than the static maximum. In this
318 * case the e820 map provided to us will cover the static
319 * maximum region.
320 */
321 if (xen_initial_domain()) {
322 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
323 if (ret > 0)
324 max_pages = ret;
325 }
326
327 return min(max_pages, MAX_DOMAIN_PAGES);
328}
329
330static void xen_align_and_add_e820_region(u64 start, u64 size, int type)
331{
332 u64 end = start + size;
333
334 /* Align RAM regions to page boundaries. */
335 if (type == E820_RAM) {
336 start = PAGE_ALIGN(start);
337 end &= ~((u64)PAGE_SIZE - 1);
338 }
339
340 e820_add_region(start, end - start, type);
341}
342
343void xen_ignore_unusable(struct e820entry *list, size_t map_size)
344{
345 struct e820entry *entry;
346 unsigned int i;
347
348 for (i = 0, entry = list; i < map_size; i++, entry++) {
349 if (entry->type == E820_UNUSABLE)
350 entry->type = E820_RAM;
351 }
352}
353
354/**
355 * machine_specific_memory_setup - Hook for machine specific memory setup.
356 **/
357char * __init xen_memory_setup(void)
358{
359 static struct e820entry map[E820MAX] __initdata;
360
361 unsigned long max_pfn = xen_start_info->nr_pages;
362 unsigned long long mem_end;
363 int rc;
364 struct xen_memory_map memmap;
365 unsigned long max_pages;
366 unsigned long last_pfn = 0;
367 unsigned long extra_pages = 0;
368 unsigned long populated;
369 int i;
370 int op;
371
372 max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
373 mem_end = PFN_PHYS(max_pfn);
374
375 memmap.nr_entries = E820MAX;
376 set_xen_guest_handle(memmap.buffer, map);
377
378 op = xen_initial_domain() ?
379 XENMEM_machine_memory_map :
380 XENMEM_memory_map;
381 rc = HYPERVISOR_memory_op(op, &memmap);
382 if (rc == -ENOSYS) {
383 BUG_ON(xen_initial_domain());
384 memmap.nr_entries = 1;
385 map[0].addr = 0ULL;
386 map[0].size = mem_end;
387 /* 8MB slack (to balance backend allocations). */
388 map[0].size += 8ULL << 20;
389 map[0].type = E820_RAM;
390 rc = 0;
391 }
392 BUG_ON(rc);
393
394 /*
395 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
396 * regions, so if we're using the machine memory map leave the
397 * region as RAM as it is in the pseudo-physical map.
398 *
399 * UNUSABLE regions in domUs are not handled and will need
400 * a patch in the future.
401 */
402 if (xen_initial_domain())
403 xen_ignore_unusable(map, memmap.nr_entries);
404
405 /* Make sure the Xen-supplied memory map is well-ordered. */
406 sanitize_e820_map(map, memmap.nr_entries, &memmap.nr_entries);
407
408 max_pages = xen_get_max_pages();
409 if (max_pages > max_pfn)
410 extra_pages += max_pages - max_pfn;
411
412 /*
413 * Set P2M for all non-RAM pages and E820 gaps to be identity
414 * type PFNs. Any RAM pages that would be made inaccesible by
415 * this are first released.
416 */
417 xen_released_pages = xen_set_identity_and_release(
418 map, memmap.nr_entries, max_pfn);
419
420 /*
421 * Populate back the non-RAM pages and E820 gaps that had been
422 * released. */
423 populated = xen_populate_chunk(map, memmap.nr_entries,
424 max_pfn, &last_pfn, xen_released_pages);
425
426 xen_released_pages -= populated;
427 extra_pages += xen_released_pages;
428
429 if (last_pfn > max_pfn) {
430 max_pfn = min(MAX_DOMAIN_PAGES, last_pfn);
431 mem_end = PFN_PHYS(max_pfn);
432 }
433 /*
434 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
435 * factor the base size. On non-highmem systems, the base
436 * size is the full initial memory allocation; on highmem it
437 * is limited to the max size of lowmem, so that it doesn't
438 * get completely filled.
439 *
440 * In principle there could be a problem in lowmem systems if
441 * the initial memory is also very large with respect to
442 * lowmem, but we won't try to deal with that here.
443 */
444 extra_pages = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
445 extra_pages);
446 i = 0;
447 while (i < memmap.nr_entries) {
448 u64 addr = map[i].addr;
449 u64 size = map[i].size;
450 u32 type = map[i].type;
451
452 if (type == E820_RAM) {
453 if (addr < mem_end) {
454 size = min(size, mem_end - addr);
455 } else if (extra_pages) {
456 size = min(size, (u64)extra_pages * PAGE_SIZE);
457 extra_pages -= size / PAGE_SIZE;
458 xen_add_extra_mem(addr, size);
459 } else
460 type = E820_UNUSABLE;
461 }
462
463 xen_align_and_add_e820_region(addr, size, type);
464
465 map[i].addr += size;
466 map[i].size -= size;
467 if (map[i].size == 0)
468 i++;
469 }
470
471 /*
472 * In domU, the ISA region is normal, usable memory, but we
473 * reserve ISA memory anyway because too many things poke
474 * about in there.
475 */
476 e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
477 E820_RESERVED);
478
479 /*
480 * Reserve Xen bits:
481 * - mfn_list
482 * - xen_start_info
483 * See comment above "struct start_info" in <xen/interface/xen.h>
484 * We tried to make the the memblock_reserve more selective so
485 * that it would be clear what region is reserved. Sadly we ran
486 * in the problem wherein on a 64-bit hypervisor with a 32-bit
487 * initial domain, the pt_base has the cr3 value which is not
488 * neccessarily where the pagetable starts! As Jan put it: "
489 * Actually, the adjustment turns out to be correct: The page
490 * tables for a 32-on-64 dom0 get allocated in the order "first L1",
491 * "first L2", "first L3", so the offset to the page table base is
492 * indeed 2. When reading xen/include/public/xen.h's comment
493 * very strictly, this is not a violation (since there nothing is said
494 * that the first thing in the page table space is pointed to by
495 * pt_base; I admit that this seems to be implied though, namely
496 * do I think that it is implied that the page table space is the
497 * range [pt_base, pt_base + nt_pt_frames), whereas that
498 * range here indeed is [pt_base - 2, pt_base - 2 + nt_pt_frames),
499 * which - without a priori knowledge - the kernel would have
500 * difficulty to figure out)." - so lets just fall back to the
501 * easy way and reserve the whole region.
502 */
503 memblock_reserve(__pa(xen_start_info->mfn_list),
504 xen_start_info->pt_base - xen_start_info->mfn_list);
505
506 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
507
508 return "Xen";
509}
510
511/*
512 * Set the bit indicating "nosegneg" library variants should be used.
513 * We only need to bother in pure 32-bit mode; compat 32-bit processes
514 * can have un-truncated segments, so wrapping around is allowed.
515 */
516static void __init fiddle_vdso(void)
517{
518#ifdef CONFIG_X86_32
519 u32 *mask;
520 mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
521 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
522 mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
523 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
524#endif
525}
526
527static int register_callback(unsigned type, const void *func)
528{
529 struct callback_register callback = {
530 .type = type,
531 .address = XEN_CALLBACK(__KERNEL_CS, func),
532 .flags = CALLBACKF_mask_events,
533 };
534
535 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
536}
537
538void xen_enable_sysenter(void)
539{
540 int ret;
541 unsigned sysenter_feature;
542
543#ifdef CONFIG_X86_32
544 sysenter_feature = X86_FEATURE_SEP;
545#else
546 sysenter_feature = X86_FEATURE_SYSENTER32;
547#endif
548
549 if (!boot_cpu_has(sysenter_feature))
550 return;
551
552 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
553 if(ret != 0)
554 setup_clear_cpu_cap(sysenter_feature);
555}
556
557void xen_enable_syscall(void)
558{
559#ifdef CONFIG_X86_64
560 int ret;
561
562 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
563 if (ret != 0) {
564 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
565 /* Pretty fatal; 64-bit userspace has no other
566 mechanism for syscalls. */
567 }
568
569 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
570 ret = register_callback(CALLBACKTYPE_syscall32,
571 xen_syscall32_target);
572 if (ret != 0)
573 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
574 }
575#endif /* CONFIG_X86_64 */
576}
577void xen_enable_nmi(void)
578{
579#ifdef CONFIG_X86_64
580 if (register_callback(CALLBACKTYPE_nmi, (char *)nmi))
581 BUG();
582#endif
583}
584void __init xen_pvmmu_arch_setup(void)
585{
586 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
587 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
588
589 HYPERVISOR_vm_assist(VMASST_CMD_enable,
590 VMASST_TYPE_pae_extended_cr3);
591
592 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
593 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
594 BUG();
595
596 xen_enable_sysenter();
597 xen_enable_syscall();
598 xen_enable_nmi();
599}
600
601/* This function is not called for HVM domains */
602void __init xen_arch_setup(void)
603{
604 xen_panic_handler_init();
605 if (!xen_feature(XENFEAT_auto_translated_physmap))
606 xen_pvmmu_arch_setup();
607
608#ifdef CONFIG_ACPI
609 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
610 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
611 disable_acpi();
612 }
613#endif
614
615 memcpy(boot_command_line, xen_start_info->cmd_line,
616 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
617 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
618
619 /* Set up idle, making sure it calls safe_halt() pvop */
620 disable_cpuidle();
621 disable_cpufreq();
622 WARN_ON(xen_set_default_idle());
623 fiddle_vdso();
624#ifdef CONFIG_NUMA
625 numa_off = 1;
626#endif
627}