2 * Machine specific setup for xen
4 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
7 #include <linux/init.h>
8 #include <linux/sched.h>
11 #include <linux/memblock.h>
12 #include <linux/cpuidle.h>
13 #include <linux/cpufreq.h>
17 #include <asm/e820/api.h>
18 #include <asm/setup.h>
21 #include <asm/xen/hypervisor.h>
22 #include <asm/xen/hypercall.h>
26 #include <xen/interface/callback.h>
27 #include <xen/interface/memory.h>
28 #include <xen/interface/physdev.h>
29 #include <xen/features.h>
30 #include <xen/hvc-console.h>
35 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
37 /* Amount of extra memory space we add to the e820 ranges */
38 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
40 /* Number of pages released from the initial allocation. */
41 unsigned long xen_released_pages;
43 /* E820 map used during setting up memory. */
44 static struct e820_table xen_e820_table __initdata;
47 * Buffer used to remap identity mapped pages. We only need the virtual space.
48 * The physical page behind this address is remapped as needed to different
51 #define REMAP_SIZE (P2M_PER_PAGE - 3)
53 unsigned long next_area_mfn;
54 unsigned long target_pfn;
56 unsigned long mfns[REMAP_SIZE];
57 } xen_remap_buf __initdata __aligned(PAGE_SIZE);
58 static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
61 * The maximum amount of extra memory compared to the base size. The
62 * main scaling factor is the size of struct page. At extreme ratios
63 * of base:extra, all the base memory can be filled with page
64 * structures for the extra memory, leaving no space for anything
67 * 10x seems like a reasonable balance between scaling flexibility and
68 * leaving a practically usable system.
70 #define EXTRA_MEM_RATIO (10)
72 static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
74 static void __init xen_parse_512gb(void)
79 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
83 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
86 else if (strtobool(arg + strlen("xen_512gb_limit="), &val))
89 xen_512gb_limit = val;
92 static void __init xen_add_extra_mem(unsigned long start_pfn,
98 * No need to check for zero size, should happen rarely and will only
99 * write a new entry regarded to be unused due to zero size.
101 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
102 /* Add new region. */
103 if (xen_extra_mem[i].n_pfns == 0) {
104 xen_extra_mem[i].start_pfn = start_pfn;
105 xen_extra_mem[i].n_pfns = n_pfns;
108 /* Append to existing region. */
109 if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
111 xen_extra_mem[i].n_pfns += n_pfns;
115 if (i == XEN_EXTRA_MEM_MAX_REGIONS)
116 printk(KERN_WARNING "Warning: not enough extra memory regions\n");
118 memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
121 static void __init xen_del_extra_mem(unsigned long start_pfn,
122 unsigned long n_pfns)
125 unsigned long start_r, size_r;
127 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
128 start_r = xen_extra_mem[i].start_pfn;
129 size_r = xen_extra_mem[i].n_pfns;
131 /* Start of region. */
132 if (start_r == start_pfn) {
133 BUG_ON(n_pfns > size_r);
134 xen_extra_mem[i].start_pfn += n_pfns;
135 xen_extra_mem[i].n_pfns -= n_pfns;
139 if (start_r + size_r == start_pfn + n_pfns) {
140 BUG_ON(n_pfns > size_r);
141 xen_extra_mem[i].n_pfns -= n_pfns;
145 if (start_pfn > start_r && start_pfn < start_r + size_r) {
146 BUG_ON(start_pfn + n_pfns > start_r + size_r);
147 xen_extra_mem[i].n_pfns = start_pfn - start_r;
148 /* Calling memblock_reserve() again is okay. */
149 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
150 (start_pfn + n_pfns));
154 memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
158 * Called during boot before the p2m list can take entries beyond the
159 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
162 unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
166 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
167 if (pfn >= xen_extra_mem[i].start_pfn &&
168 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
169 return INVALID_P2M_ENTRY;
172 return IDENTITY_FRAME(pfn);
176 * Mark all pfns of extra mem as invalid in p2m list.
178 void __init xen_inv_extra_mem(void)
180 unsigned long pfn, pfn_s, pfn_e;
183 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
184 if (!xen_extra_mem[i].n_pfns)
186 pfn_s = xen_extra_mem[i].start_pfn;
187 pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
188 for (pfn = pfn_s; pfn < pfn_e; pfn++)
189 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
194 * Finds the next RAM pfn available in the E820 map after min_pfn.
195 * This function updates min_pfn with the pfn found and returns
196 * the size of that range or zero if not found.
198 static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
200 const struct e820_entry *entry = xen_e820_table.entries;
202 unsigned long done = 0;
204 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
208 if (entry->type != E820_TYPE_RAM)
211 e_pfn = PFN_DOWN(entry->addr + entry->size);
213 /* We only care about E820 after this */
214 if (e_pfn <= *min_pfn)
217 s_pfn = PFN_UP(entry->addr);
219 /* If min_pfn falls within the E820 entry, we want to start
220 * at the min_pfn PFN.
222 if (s_pfn <= *min_pfn) {
223 done = e_pfn - *min_pfn;
225 done = e_pfn - s_pfn;
234 static int __init xen_free_mfn(unsigned long mfn)
236 struct xen_memory_reservation reservation = {
242 set_xen_guest_handle(reservation.extent_start, &mfn);
243 reservation.nr_extents = 1;
245 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
249 * This releases a chunk of memory and then does the identity map. It's used
250 * as a fallback if the remapping fails.
252 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
253 unsigned long end_pfn, unsigned long nr_pages)
255 unsigned long pfn, end;
258 WARN_ON(start_pfn > end_pfn);
260 /* Release pages first. */
261 end = min(end_pfn, nr_pages);
262 for (pfn = start_pfn; pfn < end; pfn++) {
263 unsigned long mfn = pfn_to_mfn(pfn);
265 /* Make sure pfn exists to start with */
266 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
269 ret = xen_free_mfn(mfn);
270 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
273 xen_released_pages++;
274 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
280 set_phys_range_identity(start_pfn, end_pfn);
284 * Helper function to update the p2m and m2p tables and kernel mapping.
286 static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
288 struct mmu_update update = {
289 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
294 if (!set_phys_to_machine(pfn, mfn)) {
295 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
301 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
302 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
307 /* Update kernel mapping, but not for highmem. */
308 if (pfn >= PFN_UP(__pa(high_memory - 1)))
311 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
312 mfn_pte(mfn, PAGE_KERNEL), 0)) {
313 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
320 * This function updates the p2m and m2p tables with an identity map from
321 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
322 * original allocation at remap_pfn. The information needed for remapping is
323 * saved in the memory itself to avoid the need for allocating buffers. The
324 * complete remap information is contained in a list of MFNs each containing
325 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
326 * This enables us to preserve the original mfn sequence while doing the
327 * remapping at a time when the memory management is capable of allocating
328 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
331 static void __init xen_do_set_identity_and_remap_chunk(
332 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
334 unsigned long buf = (unsigned long)&xen_remap_buf;
335 unsigned long mfn_save, mfn;
336 unsigned long ident_pfn_iter, remap_pfn_iter;
337 unsigned long ident_end_pfn = start_pfn + size;
338 unsigned long left = size;
339 unsigned int i, chunk;
343 BUG_ON(xen_feature(XENFEAT_auto_translated_physmap));
345 mfn_save = virt_to_mfn(buf);
347 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
348 ident_pfn_iter < ident_end_pfn;
349 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
350 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
352 /* Map first pfn to xen_remap_buf */
353 mfn = pfn_to_mfn(ident_pfn_iter);
354 set_pte_mfn(buf, mfn, PAGE_KERNEL);
356 /* Save mapping information in page */
357 xen_remap_buf.next_area_mfn = xen_remap_mfn;
358 xen_remap_buf.target_pfn = remap_pfn_iter;
359 xen_remap_buf.size = chunk;
360 for (i = 0; i < chunk; i++)
361 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
363 /* Put remap buf into list. */
366 /* Set identity map */
367 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
372 /* Restore old xen_remap_buf mapping */
373 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
377 * This function takes a contiguous pfn range that needs to be identity mapped
380 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
381 * 2) Calls the do_ function to actually do the mapping/remapping work.
383 * The goal is to not allocate additional memory but to remap the existing
384 * pages. In the case of an error the underlying memory is simply released back
385 * to Xen and not remapped.
387 static unsigned long __init xen_set_identity_and_remap_chunk(
388 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
389 unsigned long remap_pfn)
393 unsigned long n = end_pfn - start_pfn;
396 remap_pfn = nr_pages;
399 unsigned long cur_pfn = start_pfn + i;
400 unsigned long left = n - i;
401 unsigned long size = left;
402 unsigned long remap_range_size;
404 /* Do not remap pages beyond the current allocation */
405 if (cur_pfn >= nr_pages) {
406 /* Identity map remaining pages */
407 set_phys_range_identity(cur_pfn, cur_pfn + size);
410 if (cur_pfn + size > nr_pages)
411 size = nr_pages - cur_pfn;
413 remap_range_size = xen_find_pfn_range(&remap_pfn);
414 if (!remap_range_size) {
415 pr_warning("Unable to find available pfn range, not remapping identity pages\n");
416 xen_set_identity_and_release_chunk(cur_pfn,
417 cur_pfn + left, nr_pages);
420 /* Adjust size to fit in current e820 RAM region */
421 if (size > remap_range_size)
422 size = remap_range_size;
424 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
426 /* Update variables to reflect new mappings. */
432 * If the PFNs are currently mapped, the VA mapping also needs
433 * to be updated to be 1:1.
435 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
436 (void)HYPERVISOR_update_va_mapping(
437 (unsigned long)__va(pfn << PAGE_SHIFT),
438 mfn_pte(pfn, PAGE_KERNEL_IO), 0);
443 static unsigned long __init xen_count_remap_pages(
444 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
445 unsigned long remap_pages)
447 if (start_pfn >= nr_pages)
450 return remap_pages + min(end_pfn, nr_pages) - start_pfn;
453 static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages,
454 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
455 unsigned long nr_pages, unsigned long last_val))
457 phys_addr_t start = 0;
458 unsigned long ret_val = 0;
459 const struct e820_entry *entry = xen_e820_table.entries;
463 * Combine non-RAM regions and gaps until a RAM region (or the
464 * end of the map) is reached, then call the provided function
465 * to perform its duty on the non-RAM region.
467 * The combined non-RAM regions are rounded to a whole number
468 * of pages so any partial pages are accessible via the 1:1
469 * mapping. This is needed for some BIOSes that put (for
470 * example) the DMI tables in a reserved region that begins on
471 * a non-page boundary.
473 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
474 phys_addr_t end = entry->addr + entry->size;
475 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
476 unsigned long start_pfn = PFN_DOWN(start);
477 unsigned long end_pfn = PFN_UP(end);
479 if (entry->type == E820_TYPE_RAM)
480 end_pfn = PFN_UP(entry->addr);
482 if (start_pfn < end_pfn)
483 ret_val = func(start_pfn, end_pfn, nr_pages,
493 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
494 * The remap information (which mfn remap to which pfn) is contained in the
495 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
496 * This scheme allows to remap the different chunks in arbitrary order while
497 * the resulting mapping will be independant from the order.
499 void __init xen_remap_memory(void)
501 unsigned long buf = (unsigned long)&xen_remap_buf;
502 unsigned long mfn_save, mfn, pfn;
503 unsigned long remapped = 0;
505 unsigned long pfn_s = ~0UL;
506 unsigned long len = 0;
508 mfn_save = virt_to_mfn(buf);
510 while (xen_remap_mfn != INVALID_P2M_ENTRY) {
511 /* Map the remap information */
512 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
514 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
516 pfn = xen_remap_buf.target_pfn;
517 for (i = 0; i < xen_remap_buf.size; i++) {
518 mfn = xen_remap_buf.mfns[i];
519 xen_update_mem_tables(pfn, mfn);
523 if (pfn_s == ~0UL || pfn == pfn_s) {
524 pfn_s = xen_remap_buf.target_pfn;
525 len += xen_remap_buf.size;
526 } else if (pfn_s + len == xen_remap_buf.target_pfn) {
527 len += xen_remap_buf.size;
529 xen_del_extra_mem(pfn_s, len);
530 pfn_s = xen_remap_buf.target_pfn;
531 len = xen_remap_buf.size;
535 xen_remap_mfn = xen_remap_buf.next_area_mfn;
538 if (pfn_s != ~0UL && len)
539 xen_del_extra_mem(pfn_s, len);
541 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
543 pr_info("Remapped %ld page(s)\n", remapped);
546 static unsigned long __init xen_get_pages_limit(void)
551 limit = GB(64) / PAGE_SIZE;
553 limit = MAXMEM / PAGE_SIZE;
554 if (!xen_initial_domain() && xen_512gb_limit)
555 limit = GB(512) / PAGE_SIZE;
560 static unsigned long __init xen_get_max_pages(void)
562 unsigned long max_pages, limit;
563 domid_t domid = DOMID_SELF;
566 limit = xen_get_pages_limit();
570 * For the initial domain we use the maximum reservation as
573 * For guest domains the current maximum reservation reflects
574 * the current maximum rather than the static maximum. In this
575 * case the e820 map provided to us will cover the static
578 if (xen_initial_domain()) {
579 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
584 return min(max_pages, limit);
587 static void __init xen_align_and_add_e820_region(phys_addr_t start,
588 phys_addr_t size, int type)
590 phys_addr_t end = start + size;
592 /* Align RAM regions to page boundaries. */
593 if (type == E820_TYPE_RAM) {
594 start = PAGE_ALIGN(start);
595 end &= ~((phys_addr_t)PAGE_SIZE - 1);
598 e820__range_add(start, end - start, type);
601 static void __init xen_ignore_unusable(void)
603 struct e820_entry *entry = xen_e820_table.entries;
606 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
607 if (entry->type == E820_TYPE_UNUSABLE)
608 entry->type = E820_TYPE_RAM;
612 bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
614 struct e820_entry *entry;
622 entry = xen_e820_table.entries;
624 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
625 if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
626 (entry->addr + entry->size) >= end)
636 * Find a free area in physical memory not yet reserved and compliant with
638 * Used to relocate pre-allocated areas like initrd or p2m list which are in
639 * conflict with the to be used E820 map.
640 * In case no area is found, return 0. Otherwise return the physical address
641 * of the area which is already reserved for convenience.
643 phys_addr_t __init xen_find_free_area(phys_addr_t size)
646 phys_addr_t addr, start;
647 struct e820_entry *entry = xen_e820_table.entries;
649 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
650 if (entry->type != E820_TYPE_RAM || entry->size < size)
653 for (addr = start; addr < start + size; addr += PAGE_SIZE) {
654 if (!memblock_is_reserved(addr))
656 start = addr + PAGE_SIZE;
657 if (start + size > entry->addr + entry->size)
660 if (addr >= start + size) {
661 memblock_reserve(start, size);
670 * Like memcpy, but with physical addresses for dest and src.
672 static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
675 phys_addr_t dest_off, src_off, dest_len, src_len, len;
679 dest_off = dest & ~PAGE_MASK;
680 src_off = src & ~PAGE_MASK;
682 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
683 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
685 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
686 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
687 len = min(dest_len, src_len);
688 to = early_memremap(dest - dest_off, dest_len + dest_off);
689 from = early_memremap(src - src_off, src_len + src_off);
690 memcpy(to, from, len);
691 early_memunmap(to, dest_len + dest_off);
692 early_memunmap(from, src_len + src_off);
700 * Reserve Xen mfn_list.
702 static void __init xen_reserve_xen_mfnlist(void)
704 phys_addr_t start, size;
706 if (xen_start_info->mfn_list >= __START_KERNEL_map) {
707 start = __pa(xen_start_info->mfn_list);
708 size = PFN_ALIGN(xen_start_info->nr_pages *
709 sizeof(unsigned long));
711 start = PFN_PHYS(xen_start_info->first_p2m_pfn);
712 size = PFN_PHYS(xen_start_info->nr_p2m_frames);
715 memblock_reserve(start, size);
716 if (!xen_is_e820_reserved(start, size))
721 * Relocating the p2m on 32 bit system to an arbitrary virtual address
722 * is not supported, so just give up.
724 xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with E820 map\n");
728 memblock_free(start, size);
733 * machine_specific_memory_setup - Hook for machine specific memory setup.
735 char * __init xen_memory_setup(void)
737 unsigned long max_pfn, pfn_s, n_pfns;
738 phys_addr_t mem_end, addr, size, chunk_size;
741 struct xen_memory_map memmap;
742 unsigned long max_pages;
743 unsigned long extra_pages = 0;
748 max_pfn = xen_get_pages_limit();
749 max_pfn = min(max_pfn, xen_start_info->nr_pages);
750 mem_end = PFN_PHYS(max_pfn);
752 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
753 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
755 op = xen_initial_domain() ?
756 XENMEM_machine_memory_map :
758 rc = HYPERVISOR_memory_op(op, &memmap);
760 BUG_ON(xen_initial_domain());
761 memmap.nr_entries = 1;
762 xen_e820_table.entries[0].addr = 0ULL;
763 xen_e820_table.entries[0].size = mem_end;
764 /* 8MB slack (to balance backend allocations). */
765 xen_e820_table.entries[0].size += 8ULL << 20;
766 xen_e820_table.entries[0].type = E820_TYPE_RAM;
770 BUG_ON(memmap.nr_entries == 0);
771 xen_e820_table.nr_entries = memmap.nr_entries;
774 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
775 * regions, so if we're using the machine memory map leave the
776 * region as RAM as it is in the pseudo-physical map.
778 * UNUSABLE regions in domUs are not handled and will need
779 * a patch in the future.
781 if (xen_initial_domain())
782 xen_ignore_unusable();
784 /* Make sure the Xen-supplied memory map is well-ordered. */
785 e820__update_table(&xen_e820_table);
787 max_pages = xen_get_max_pages();
789 /* How many extra pages do we need due to remapping? */
790 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages);
792 if (max_pages > max_pfn)
793 extra_pages += max_pages - max_pfn;
796 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
797 * factor the base size. On non-highmem systems, the base
798 * size is the full initial memory allocation; on highmem it
799 * is limited to the max size of lowmem, so that it doesn't
800 * get completely filled.
802 * Make sure we have no memory above max_pages, as this area
803 * isn't handled by the p2m management.
805 * In principle there could be a problem in lowmem systems if
806 * the initial memory is also very large with respect to
807 * lowmem, but we won't try to deal with that here.
809 extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
810 extra_pages, max_pages - max_pfn);
812 addr = xen_e820_table.entries[0].addr;
813 size = xen_e820_table.entries[0].size;
814 while (i < xen_e820_table.nr_entries) {
815 bool discard = false;
818 type = xen_e820_table.entries[i].type;
820 if (type == E820_TYPE_RAM) {
821 if (addr < mem_end) {
822 chunk_size = min(size, mem_end - addr);
823 } else if (extra_pages) {
824 chunk_size = min(size, PFN_PHYS(extra_pages));
825 pfn_s = PFN_UP(addr);
826 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
827 extra_pages -= n_pfns;
828 xen_add_extra_mem(pfn_s, n_pfns);
829 xen_max_p2m_pfn = pfn_s + n_pfns;
835 xen_align_and_add_e820_region(addr, chunk_size, type);
841 if (i < xen_e820_table.nr_entries) {
842 addr = xen_e820_table.entries[i].addr;
843 size = xen_e820_table.entries[i].size;
849 * Set the rest as identity mapped, in case PCI BARs are
852 set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
855 * In domU, the ISA region is normal, usable memory, but we
856 * reserve ISA memory anyway because too many things poke
859 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
861 e820__update_table(e820_table);
864 * Check whether the kernel itself conflicts with the target E820 map.
865 * Failing now is better than running into weird problems later due
866 * to relocating (and even reusing) pages with kernel text or data.
868 if (xen_is_e820_reserved(__pa_symbol(_text),
869 __pa_symbol(__bss_stop) - __pa_symbol(_text))) {
870 xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
875 * Check for a conflict of the hypervisor supplied page tables with
876 * the target E820 map.
880 xen_reserve_xen_mfnlist();
882 /* Check for a conflict of the initrd with the target E820 map. */
883 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
884 boot_params.hdr.ramdisk_size)) {
885 phys_addr_t new_area, start, size;
887 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
889 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
893 start = boot_params.hdr.ramdisk_image;
894 size = boot_params.hdr.ramdisk_size;
895 xen_phys_memcpy(new_area, start, size);
896 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
897 start, start + size, new_area, new_area + size);
898 memblock_free(start, size);
899 boot_params.hdr.ramdisk_image = new_area;
900 boot_params.ext_ramdisk_image = new_area >> 32;
904 * Set identity map on non-RAM pages and prepare remapping the
907 xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk);
909 pr_info("Released %ld page(s)\n", xen_released_pages);
915 * Machine specific memory setup for auto-translated guests.
917 char * __init xen_auto_xlated_memory_setup(void)
919 struct xen_memory_map memmap;
923 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
924 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
926 rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
928 panic("No memory map (%d)\n", rc);
930 xen_e820_table.nr_entries = memmap.nr_entries;
932 e820__update_table(&xen_e820_table);
934 for (i = 0; i < xen_e820_table.nr_entries; i++)
935 e820__range_add(xen_e820_table.entries[i].addr, xen_e820_table.entries[i].size, xen_e820_table.entries[i].type);
937 /* Remove p2m info, it is not needed. */
938 xen_start_info->mfn_list = 0;
939 xen_start_info->first_p2m_pfn = 0;
940 xen_start_info->nr_p2m_frames = 0;
946 * Set the bit indicating "nosegneg" library variants should be used.
947 * We only need to bother in pure 32-bit mode; compat 32-bit processes
948 * can have un-truncated segments, so wrapping around is allowed.
950 static void __init fiddle_vdso(void)
953 u32 *mask = vdso_image_32.data +
954 vdso_image_32.sym_VDSO32_NOTE_MASK;
955 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
959 static int register_callback(unsigned type, const void *func)
961 struct callback_register callback = {
963 .address = XEN_CALLBACK(__KERNEL_CS, func),
964 .flags = CALLBACKF_mask_events,
967 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
970 void xen_enable_sysenter(void)
973 unsigned sysenter_feature;
976 sysenter_feature = X86_FEATURE_SEP;
978 sysenter_feature = X86_FEATURE_SYSENTER32;
981 if (!boot_cpu_has(sysenter_feature))
984 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
986 setup_clear_cpu_cap(sysenter_feature);
989 void xen_enable_syscall(void)
994 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
996 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
997 /* Pretty fatal; 64-bit userspace has no other
998 mechanism for syscalls. */
1001 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
1002 ret = register_callback(CALLBACKTYPE_syscall32,
1003 xen_syscall32_target);
1005 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
1007 #endif /* CONFIG_X86_64 */
1010 void __init xen_pvmmu_arch_setup(void)
1012 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
1013 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
1015 HYPERVISOR_vm_assist(VMASST_CMD_enable,
1016 VMASST_TYPE_pae_extended_cr3);
1018 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
1019 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
1022 xen_enable_sysenter();
1023 xen_enable_syscall();
1026 /* This function is not called for HVM domains */
1027 void __init xen_arch_setup(void)
1029 xen_panic_handler_init();
1030 if (!xen_feature(XENFEAT_auto_translated_physmap))
1031 xen_pvmmu_arch_setup();
1034 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
1035 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
1040 memcpy(boot_command_line, xen_start_info->cmd_line,
1041 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
1042 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
1044 /* Set up idle, making sure it calls safe_halt() pvop */
1047 WARN_ON(xen_set_default_idle());