1 // SPDX-License-Identifier: GPL-2.0
3 * Machine specific setup for xen
5 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
8 #include <linux/init.h>
9 #include <linux/sched.h>
12 #include <linux/memblock.h>
13 #include <linux/cpuidle.h>
14 #include <linux/cpufreq.h>
15 #include <linux/memory_hotplug.h>
19 #include <asm/e820/api.h>
20 #include <asm/setup.h>
23 #include <asm/idtentry.h>
24 #include <asm/xen/hypervisor.h>
25 #include <asm/xen/hypercall.h>
29 #include <xen/interface/callback.h>
30 #include <xen/interface/memory.h>
31 #include <xen/interface/physdev.h>
32 #include <xen/features.h>
33 #include <xen/hvc-console.h>
37 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
39 /* Amount of extra memory space we add to the e820 ranges */
40 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
42 /* Number of pages released from the initial allocation. */
43 unsigned long xen_released_pages;
45 /* E820 map used during setting up memory. */
46 static struct e820_table xen_e820_table __initdata;
49 * Buffer used to remap identity mapped pages. We only need the virtual space.
50 * The physical page behind this address is remapped as needed to different
53 #define REMAP_SIZE (P2M_PER_PAGE - 3)
55 unsigned long next_area_mfn;
56 unsigned long target_pfn;
58 unsigned long mfns[REMAP_SIZE];
59 } xen_remap_buf __initdata __aligned(PAGE_SIZE);
60 static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
63 * The maximum amount of extra memory compared to the base size. The
64 * main scaling factor is the size of struct page. At extreme ratios
65 * of base:extra, all the base memory can be filled with page
66 * structures for the extra memory, leaving no space for anything
69 * 10x seems like a reasonable balance between scaling flexibility and
70 * leaving a practically usable system.
72 #define EXTRA_MEM_RATIO (10)
74 static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
76 static void __init xen_parse_512gb(void)
81 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
85 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
88 else if (strtobool(arg + strlen("xen_512gb_limit="), &val))
91 xen_512gb_limit = val;
94 static void __init xen_add_extra_mem(unsigned long start_pfn,
100 * No need to check for zero size, should happen rarely and will only
101 * write a new entry regarded to be unused due to zero size.
103 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
104 /* Add new region. */
105 if (xen_extra_mem[i].n_pfns == 0) {
106 xen_extra_mem[i].start_pfn = start_pfn;
107 xen_extra_mem[i].n_pfns = n_pfns;
110 /* Append to existing region. */
111 if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
113 xen_extra_mem[i].n_pfns += n_pfns;
117 if (i == XEN_EXTRA_MEM_MAX_REGIONS)
118 printk(KERN_WARNING "Warning: not enough extra memory regions\n");
120 memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
123 static void __init xen_del_extra_mem(unsigned long start_pfn,
124 unsigned long n_pfns)
127 unsigned long start_r, size_r;
129 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
130 start_r = xen_extra_mem[i].start_pfn;
131 size_r = xen_extra_mem[i].n_pfns;
133 /* Start of region. */
134 if (start_r == start_pfn) {
135 BUG_ON(n_pfns > size_r);
136 xen_extra_mem[i].start_pfn += n_pfns;
137 xen_extra_mem[i].n_pfns -= n_pfns;
141 if (start_r + size_r == start_pfn + n_pfns) {
142 BUG_ON(n_pfns > size_r);
143 xen_extra_mem[i].n_pfns -= n_pfns;
147 if (start_pfn > start_r && start_pfn < start_r + size_r) {
148 BUG_ON(start_pfn + n_pfns > start_r + size_r);
149 xen_extra_mem[i].n_pfns = start_pfn - start_r;
150 /* Calling memblock_reserve() again is okay. */
151 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
152 (start_pfn + n_pfns));
156 memblock_phys_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
160 * Called during boot before the p2m list can take entries beyond the
161 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
164 unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
168 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
169 if (pfn >= xen_extra_mem[i].start_pfn &&
170 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
171 return INVALID_P2M_ENTRY;
174 return IDENTITY_FRAME(pfn);
178 * Mark all pfns of extra mem as invalid in p2m list.
180 void __init xen_inv_extra_mem(void)
182 unsigned long pfn, pfn_s, pfn_e;
185 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
186 if (!xen_extra_mem[i].n_pfns)
188 pfn_s = xen_extra_mem[i].start_pfn;
189 pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
190 for (pfn = pfn_s; pfn < pfn_e; pfn++)
191 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
196 * Finds the next RAM pfn available in the E820 map after min_pfn.
197 * This function updates min_pfn with the pfn found and returns
198 * the size of that range or zero if not found.
200 static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
202 const struct e820_entry *entry = xen_e820_table.entries;
204 unsigned long done = 0;
206 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
210 if (entry->type != E820_TYPE_RAM)
213 e_pfn = PFN_DOWN(entry->addr + entry->size);
215 /* We only care about E820 after this */
216 if (e_pfn <= *min_pfn)
219 s_pfn = PFN_UP(entry->addr);
221 /* If min_pfn falls within the E820 entry, we want to start
222 * at the min_pfn PFN.
224 if (s_pfn <= *min_pfn) {
225 done = e_pfn - *min_pfn;
227 done = e_pfn - s_pfn;
236 static int __init xen_free_mfn(unsigned long mfn)
238 struct xen_memory_reservation reservation = {
244 set_xen_guest_handle(reservation.extent_start, &mfn);
245 reservation.nr_extents = 1;
247 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
251 * This releases a chunk of memory and then does the identity map. It's used
252 * as a fallback if the remapping fails.
254 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
255 unsigned long end_pfn, unsigned long nr_pages)
257 unsigned long pfn, end;
260 WARN_ON(start_pfn > end_pfn);
262 /* Release pages first. */
263 end = min(end_pfn, nr_pages);
264 for (pfn = start_pfn; pfn < end; pfn++) {
265 unsigned long mfn = pfn_to_mfn(pfn);
267 /* Make sure pfn exists to start with */
268 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
271 ret = xen_free_mfn(mfn);
272 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
275 xen_released_pages++;
276 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
282 set_phys_range_identity(start_pfn, end_pfn);
286 * Helper function to update the p2m and m2p tables and kernel mapping.
288 static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
290 struct mmu_update update = {
291 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
296 if (!set_phys_to_machine(pfn, mfn)) {
297 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
303 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
304 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
309 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
310 mfn_pte(mfn, PAGE_KERNEL), 0)) {
311 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
318 * This function updates the p2m and m2p tables with an identity map from
319 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
320 * original allocation at remap_pfn. The information needed for remapping is
321 * saved in the memory itself to avoid the need for allocating buffers. The
322 * complete remap information is contained in a list of MFNs each containing
323 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
324 * This enables us to preserve the original mfn sequence while doing the
325 * remapping at a time when the memory management is capable of allocating
326 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
329 static void __init xen_do_set_identity_and_remap_chunk(
330 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
332 unsigned long buf = (unsigned long)&xen_remap_buf;
333 unsigned long mfn_save, mfn;
334 unsigned long ident_pfn_iter, remap_pfn_iter;
335 unsigned long ident_end_pfn = start_pfn + size;
336 unsigned long left = size;
337 unsigned int i, chunk;
341 mfn_save = virt_to_mfn(buf);
343 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
344 ident_pfn_iter < ident_end_pfn;
345 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
346 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
348 /* Map first pfn to xen_remap_buf */
349 mfn = pfn_to_mfn(ident_pfn_iter);
350 set_pte_mfn(buf, mfn, PAGE_KERNEL);
352 /* Save mapping information in page */
353 xen_remap_buf.next_area_mfn = xen_remap_mfn;
354 xen_remap_buf.target_pfn = remap_pfn_iter;
355 xen_remap_buf.size = chunk;
356 for (i = 0; i < chunk; i++)
357 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
359 /* Put remap buf into list. */
362 /* Set identity map */
363 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
368 /* Restore old xen_remap_buf mapping */
369 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
373 * This function takes a contiguous pfn range that needs to be identity mapped
376 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
377 * 2) Calls the do_ function to actually do the mapping/remapping work.
379 * The goal is to not allocate additional memory but to remap the existing
380 * pages. In the case of an error the underlying memory is simply released back
381 * to Xen and not remapped.
383 static unsigned long __init xen_set_identity_and_remap_chunk(
384 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
385 unsigned long remap_pfn)
389 unsigned long n = end_pfn - start_pfn;
392 remap_pfn = nr_pages;
395 unsigned long cur_pfn = start_pfn + i;
396 unsigned long left = n - i;
397 unsigned long size = left;
398 unsigned long remap_range_size;
400 /* Do not remap pages beyond the current allocation */
401 if (cur_pfn >= nr_pages) {
402 /* Identity map remaining pages */
403 set_phys_range_identity(cur_pfn, cur_pfn + size);
406 if (cur_pfn + size > nr_pages)
407 size = nr_pages - cur_pfn;
409 remap_range_size = xen_find_pfn_range(&remap_pfn);
410 if (!remap_range_size) {
411 pr_warn("Unable to find available pfn range, not remapping identity pages\n");
412 xen_set_identity_and_release_chunk(cur_pfn,
413 cur_pfn + left, nr_pages);
416 /* Adjust size to fit in current e820 RAM region */
417 if (size > remap_range_size)
418 size = remap_range_size;
420 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
422 /* Update variables to reflect new mappings. */
428 * If the PFNs are currently mapped, their VA mappings need to be
431 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
432 (void)HYPERVISOR_update_va_mapping(
433 (unsigned long)__va(pfn << PAGE_SHIFT),
434 native_make_pte(0), 0);
439 static unsigned long __init xen_count_remap_pages(
440 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
441 unsigned long remap_pages)
443 if (start_pfn >= nr_pages)
446 return remap_pages + min(end_pfn, nr_pages) - start_pfn;
449 static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages,
450 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
451 unsigned long nr_pages, unsigned long last_val))
453 phys_addr_t start = 0;
454 unsigned long ret_val = 0;
455 const struct e820_entry *entry = xen_e820_table.entries;
459 * Combine non-RAM regions and gaps until a RAM region (or the
460 * end of the map) is reached, then call the provided function
461 * to perform its duty on the non-RAM region.
463 * The combined non-RAM regions are rounded to a whole number
464 * of pages so any partial pages are accessible via the 1:1
465 * mapping. This is needed for some BIOSes that put (for
466 * example) the DMI tables in a reserved region that begins on
467 * a non-page boundary.
469 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
470 phys_addr_t end = entry->addr + entry->size;
471 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
472 unsigned long start_pfn = PFN_DOWN(start);
473 unsigned long end_pfn = PFN_UP(end);
475 if (entry->type == E820_TYPE_RAM)
476 end_pfn = PFN_UP(entry->addr);
478 if (start_pfn < end_pfn)
479 ret_val = func(start_pfn, end_pfn, nr_pages,
489 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
490 * The remap information (which mfn remap to which pfn) is contained in the
491 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
492 * This scheme allows to remap the different chunks in arbitrary order while
493 * the resulting mapping will be independent from the order.
495 void __init xen_remap_memory(void)
497 unsigned long buf = (unsigned long)&xen_remap_buf;
498 unsigned long mfn_save, pfn;
499 unsigned long remapped = 0;
501 unsigned long pfn_s = ~0UL;
502 unsigned long len = 0;
504 mfn_save = virt_to_mfn(buf);
506 while (xen_remap_mfn != INVALID_P2M_ENTRY) {
507 /* Map the remap information */
508 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
510 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
512 pfn = xen_remap_buf.target_pfn;
513 for (i = 0; i < xen_remap_buf.size; i++) {
514 xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
518 if (pfn_s == ~0UL || pfn == pfn_s) {
519 pfn_s = xen_remap_buf.target_pfn;
520 len += xen_remap_buf.size;
521 } else if (pfn_s + len == xen_remap_buf.target_pfn) {
522 len += xen_remap_buf.size;
524 xen_del_extra_mem(pfn_s, len);
525 pfn_s = xen_remap_buf.target_pfn;
526 len = xen_remap_buf.size;
528 xen_remap_mfn = xen_remap_buf.next_area_mfn;
531 if (pfn_s != ~0UL && len)
532 xen_del_extra_mem(pfn_s, len);
534 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
536 pr_info("Remapped %ld page(s)\n", remapped);
539 static unsigned long __init xen_get_pages_limit(void)
543 limit = MAXMEM / PAGE_SIZE;
544 if (!xen_initial_domain() && xen_512gb_limit)
545 limit = GB(512) / PAGE_SIZE;
550 static unsigned long __init xen_get_max_pages(void)
552 unsigned long max_pages, limit;
553 domid_t domid = DOMID_SELF;
556 limit = xen_get_pages_limit();
560 * For the initial domain we use the maximum reservation as
563 * For guest domains the current maximum reservation reflects
564 * the current maximum rather than the static maximum. In this
565 * case the e820 map provided to us will cover the static
568 if (xen_initial_domain()) {
569 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
574 return min(max_pages, limit);
577 static void __init xen_align_and_add_e820_region(phys_addr_t start,
578 phys_addr_t size, int type)
580 phys_addr_t end = start + size;
582 /* Align RAM regions to page boundaries. */
583 if (type == E820_TYPE_RAM) {
584 start = PAGE_ALIGN(start);
585 end &= ~((phys_addr_t)PAGE_SIZE - 1);
586 #ifdef CONFIG_MEMORY_HOTPLUG
588 * Don't allow adding memory not in E820 map while booting the
589 * system. Once the balloon driver is up it will remove that
596 e820__range_add(start, end - start, type);
599 static void __init xen_ignore_unusable(void)
601 struct e820_entry *entry = xen_e820_table.entries;
604 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
605 if (entry->type == E820_TYPE_UNUSABLE)
606 entry->type = E820_TYPE_RAM;
610 bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
612 struct e820_entry *entry;
620 entry = xen_e820_table.entries;
622 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
623 if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
624 (entry->addr + entry->size) >= end)
634 * Find a free area in physical memory not yet reserved and compliant with
636 * Used to relocate pre-allocated areas like initrd or p2m list which are in
637 * conflict with the to be used E820 map.
638 * In case no area is found, return 0. Otherwise return the physical address
639 * of the area which is already reserved for convenience.
641 phys_addr_t __init xen_find_free_area(phys_addr_t size)
644 phys_addr_t addr, start;
645 struct e820_entry *entry = xen_e820_table.entries;
647 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
648 if (entry->type != E820_TYPE_RAM || entry->size < size)
651 for (addr = start; addr < start + size; addr += PAGE_SIZE) {
652 if (!memblock_is_reserved(addr))
654 start = addr + PAGE_SIZE;
655 if (start + size > entry->addr + entry->size)
658 if (addr >= start + size) {
659 memblock_reserve(start, size);
668 * Like memcpy, but with physical addresses for dest and src.
670 static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
673 phys_addr_t dest_off, src_off, dest_len, src_len, len;
677 dest_off = dest & ~PAGE_MASK;
678 src_off = src & ~PAGE_MASK;
680 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
681 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
683 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
684 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
685 len = min(dest_len, src_len);
686 to = early_memremap(dest - dest_off, dest_len + dest_off);
687 from = early_memremap(src - src_off, src_len + src_off);
688 memcpy(to, from, len);
689 early_memunmap(to, dest_len + dest_off);
690 early_memunmap(from, src_len + src_off);
698 * Reserve Xen mfn_list.
700 static void __init xen_reserve_xen_mfnlist(void)
702 phys_addr_t start, size;
704 if (xen_start_info->mfn_list >= __START_KERNEL_map) {
705 start = __pa(xen_start_info->mfn_list);
706 size = PFN_ALIGN(xen_start_info->nr_pages *
707 sizeof(unsigned long));
709 start = PFN_PHYS(xen_start_info->first_p2m_pfn);
710 size = PFN_PHYS(xen_start_info->nr_p2m_frames);
713 memblock_reserve(start, size);
714 if (!xen_is_e820_reserved(start, size))
718 memblock_phys_free(start, size);
722 * xen_memory_setup - Hook for machine specific memory setup.
724 char * __init xen_memory_setup(void)
726 unsigned long max_pfn, pfn_s, n_pfns;
727 phys_addr_t mem_end, addr, size, chunk_size;
730 struct xen_memory_map memmap;
731 unsigned long max_pages;
732 unsigned long extra_pages = 0;
737 max_pfn = xen_get_pages_limit();
738 max_pfn = min(max_pfn, xen_start_info->nr_pages);
739 mem_end = PFN_PHYS(max_pfn);
741 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
742 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
744 #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
745 xen_saved_max_mem_size = max_mem_size;
748 op = xen_initial_domain() ?
749 XENMEM_machine_memory_map :
751 rc = HYPERVISOR_memory_op(op, &memmap);
753 BUG_ON(xen_initial_domain());
754 memmap.nr_entries = 1;
755 xen_e820_table.entries[0].addr = 0ULL;
756 xen_e820_table.entries[0].size = mem_end;
757 /* 8MB slack (to balance backend allocations). */
758 xen_e820_table.entries[0].size += 8ULL << 20;
759 xen_e820_table.entries[0].type = E820_TYPE_RAM;
763 BUG_ON(memmap.nr_entries == 0);
764 xen_e820_table.nr_entries = memmap.nr_entries;
767 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
768 * regions, so if we're using the machine memory map leave the
769 * region as RAM as it is in the pseudo-physical map.
771 * UNUSABLE regions in domUs are not handled and will need
772 * a patch in the future.
774 if (xen_initial_domain())
775 xen_ignore_unusable();
777 /* Make sure the Xen-supplied memory map is well-ordered. */
778 e820__update_table(&xen_e820_table);
780 max_pages = xen_get_max_pages();
782 /* How many extra pages do we need due to remapping? */
783 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages);
785 if (max_pages > max_pfn)
786 extra_pages += max_pages - max_pfn;
789 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
790 * factor the base size.
792 * Make sure we have no memory above max_pages, as this area
793 * isn't handled by the p2m management.
795 extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
796 extra_pages, max_pages - max_pfn);
798 addr = xen_e820_table.entries[0].addr;
799 size = xen_e820_table.entries[0].size;
800 while (i < xen_e820_table.nr_entries) {
801 bool discard = false;
804 type = xen_e820_table.entries[i].type;
806 if (type == E820_TYPE_RAM) {
807 if (addr < mem_end) {
808 chunk_size = min(size, mem_end - addr);
809 } else if (extra_pages) {
810 chunk_size = min(size, PFN_PHYS(extra_pages));
811 pfn_s = PFN_UP(addr);
812 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
813 extra_pages -= n_pfns;
814 xen_add_extra_mem(pfn_s, n_pfns);
815 xen_max_p2m_pfn = pfn_s + n_pfns;
821 xen_align_and_add_e820_region(addr, chunk_size, type);
827 if (i < xen_e820_table.nr_entries) {
828 addr = xen_e820_table.entries[i].addr;
829 size = xen_e820_table.entries[i].size;
835 * Set the rest as identity mapped, in case PCI BARs are
838 set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
841 * In domU, the ISA region is normal, usable memory, but we
842 * reserve ISA memory anyway because too many things poke
845 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
847 e820__update_table(e820_table);
850 * Check whether the kernel itself conflicts with the target E820 map.
851 * Failing now is better than running into weird problems later due
852 * to relocating (and even reusing) pages with kernel text or data.
854 if (xen_is_e820_reserved(__pa_symbol(_text),
855 __pa_symbol(__bss_stop) - __pa_symbol(_text))) {
856 xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
861 * Check for a conflict of the hypervisor supplied page tables with
862 * the target E820 map.
866 xen_reserve_xen_mfnlist();
868 /* Check for a conflict of the initrd with the target E820 map. */
869 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
870 boot_params.hdr.ramdisk_size)) {
871 phys_addr_t new_area, start, size;
873 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
875 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
879 start = boot_params.hdr.ramdisk_image;
880 size = boot_params.hdr.ramdisk_size;
881 xen_phys_memcpy(new_area, start, size);
882 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
883 start, start + size, new_area, new_area + size);
884 memblock_phys_free(start, size);
885 boot_params.hdr.ramdisk_image = new_area;
886 boot_params.ext_ramdisk_image = new_area >> 32;
890 * Set identity map on non-RAM pages and prepare remapping the
893 xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk);
895 pr_info("Released %ld page(s)\n", xen_released_pages);
900 static int register_callback(unsigned type, const void *func)
902 struct callback_register callback = {
904 .address = XEN_CALLBACK(__KERNEL_CS, func),
905 .flags = CALLBACKF_mask_events,
908 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
911 void xen_enable_sysenter(void)
914 unsigned sysenter_feature;
916 sysenter_feature = X86_FEATURE_SYSENTER32;
918 if (!boot_cpu_has(sysenter_feature))
921 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
923 setup_clear_cpu_cap(sysenter_feature);
926 void xen_enable_syscall(void)
930 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
932 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
933 /* Pretty fatal; 64-bit userspace has no other
934 mechanism for syscalls. */
937 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
938 ret = register_callback(CALLBACKTYPE_syscall32,
939 xen_syscall32_target);
941 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
945 static void __init xen_pvmmu_arch_setup(void)
947 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
948 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
950 HYPERVISOR_vm_assist(VMASST_CMD_enable,
951 VMASST_TYPE_pae_extended_cr3);
953 if (register_callback(CALLBACKTYPE_event,
954 xen_asm_exc_xen_hypervisor_callback) ||
955 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
958 xen_enable_sysenter();
959 xen_enable_syscall();
962 /* This function is not called for HVM domains */
963 void __init xen_arch_setup(void)
965 xen_panic_handler_init();
966 xen_pvmmu_arch_setup();
969 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
970 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
975 memcpy(boot_command_line, xen_start_info->cmd_line,
976 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
977 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
979 /* Set up idle, making sure it calls safe_halt() pvop */
982 WARN_ON(xen_set_default_idle());