2 * Xen leaves the responsibility for maintaining p2m mappings to the
3 * guests themselves, but it must also access and update the p2m array
4 * during suspend/resume when all the pages are reallocated.
6 * The logical flat p2m table is mapped to a linear kernel memory area.
7 * For accesses by Xen a three-level tree linked via mfns only is set up to
8 * allow the address space to be sparse.
14 * p2m_mid_mfn p2m_mid_mfn
18 * The p2m_mid_mfn pages are mapped by p2m_top_mfn_p.
20 * The p2m_top_mfn level is limited to 1 page, so the maximum representable
21 * pseudo-physical address space is:
22 * P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages
24 * P2M_PER_PAGE depends on the architecture, as a mfn is always
25 * unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to
26 * 512 and 1024 entries respectively.
28 * In short, these structures contain the Machine Frame Number (MFN) of the PFN.
30 * However not all entries are filled with MFNs. Specifically for all other
31 * leaf entries, or for the top root, or middle one, for which there is a void
32 * entry, we assume it is "missing". So (for example)
33 * pfn_to_mfn(0x90909090)=INVALID_P2M_ENTRY.
34 * We have a dedicated page p2m_missing with all entries being
35 * INVALID_P2M_ENTRY. This page may be referenced multiple times in the p2m
36 * list/tree in case there are multiple areas with P2M_PER_PAGE invalid pfns.
38 * We also have the possibility of setting 1-1 mappings on certain regions, so
40 * pfn_to_mfn(0xc0000)=0xc0000
42 * The benefit of this is, that we can assume for non-RAM regions (think
43 * PCI BARs, or ACPI spaces), we can create mappings easily because we
44 * get the PFN value to match the MFN.
46 * For this to work efficiently we have one new page p2m_identity. All entries
47 * in p2m_identity are set to INVALID_P2M_ENTRY type (Xen toolstack only
48 * recognizes that and MFNs, no other fancy value).
50 * On lookup we spot that the entry points to p2m_identity and return the
51 * identity value instead of dereferencing and returning INVALID_P2M_ENTRY.
52 * If the entry points to an allocated page, we just proceed as before and
53 * return the PFN. If the PFN has IDENTITY_FRAME_BIT set we unmask that in
54 * appropriate functions (pfn_to_mfn).
56 * The reason for having the IDENTITY_FRAME_BIT instead of just returning the
57 * PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a
58 * non-identity pfn. To protect ourselves against we elect to set (and get) the
59 * IDENTITY_FRAME_BIT on all identity mapped PFNs.
62 #include <linux/init.h>
63 #include <linux/module.h>
64 #include <linux/list.h>
65 #include <linux/hash.h>
66 #include <linux/sched.h>
67 #include <linux/seq_file.h>
68 #include <linux/bootmem.h>
69 #include <linux/slab.h>
70 #include <linux/vmalloc.h>
72 #include <asm/cache.h>
73 #include <asm/setup.h>
74 #include <asm/uaccess.h>
76 #include <asm/xen/page.h>
77 #include <asm/xen/hypercall.h>
78 #include <asm/xen/hypervisor.h>
79 #include <xen/balloon.h>
80 #include <xen/grant_table.h>
83 #include "multicalls.h"
86 #define PMDS_PER_MID_PAGE (P2M_MID_PER_PAGE / PTRS_PER_PTE)
88 unsigned long *xen_p2m_addr __read_mostly;
89 EXPORT_SYMBOL_GPL(xen_p2m_addr);
90 unsigned long xen_p2m_size __read_mostly;
91 EXPORT_SYMBOL_GPL(xen_p2m_size);
92 unsigned long xen_max_p2m_pfn __read_mostly;
93 EXPORT_SYMBOL_GPL(xen_max_p2m_pfn);
95 #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT
96 #define P2M_LIMIT CONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT
101 static DEFINE_SPINLOCK(p2m_update_lock);
103 static unsigned long *p2m_mid_missing_mfn;
104 static unsigned long *p2m_top_mfn;
105 static unsigned long **p2m_top_mfn_p;
106 static unsigned long *p2m_missing;
107 static unsigned long *p2m_identity;
108 static pte_t *p2m_missing_pte;
109 static pte_t *p2m_identity_pte;
111 static inline unsigned p2m_top_index(unsigned long pfn)
113 BUG_ON(pfn >= MAX_P2M_PFN);
114 return pfn / (P2M_MID_PER_PAGE * P2M_PER_PAGE);
117 static inline unsigned p2m_mid_index(unsigned long pfn)
119 return (pfn / P2M_PER_PAGE) % P2M_MID_PER_PAGE;
122 static inline unsigned p2m_index(unsigned long pfn)
124 return pfn % P2M_PER_PAGE;
127 static void p2m_top_mfn_init(unsigned long *top)
131 for (i = 0; i < P2M_TOP_PER_PAGE; i++)
132 top[i] = virt_to_mfn(p2m_mid_missing_mfn);
135 static void p2m_top_mfn_p_init(unsigned long **top)
139 for (i = 0; i < P2M_TOP_PER_PAGE; i++)
140 top[i] = p2m_mid_missing_mfn;
143 static void p2m_mid_mfn_init(unsigned long *mid, unsigned long *leaf)
147 for (i = 0; i < P2M_MID_PER_PAGE; i++)
148 mid[i] = virt_to_mfn(leaf);
151 static void p2m_init(unsigned long *p2m)
155 for (i = 0; i < P2M_PER_PAGE; i++)
156 p2m[i] = INVALID_P2M_ENTRY;
159 static void p2m_init_identity(unsigned long *p2m, unsigned long pfn)
163 for (i = 0; i < P2M_PER_PAGE; i++)
164 p2m[i] = IDENTITY_FRAME(pfn + i);
167 static void * __ref alloc_p2m_page(void)
169 if (unlikely(!slab_is_available()))
170 return alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
172 return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
175 static void __ref free_p2m_page(void *p)
177 if (unlikely(!slab_is_available())) {
178 free_bootmem((unsigned long)p, PAGE_SIZE);
182 free_page((unsigned long)p);
186 * Build the parallel p2m_top_mfn and p2m_mid_mfn structures
188 * This is called both at boot time, and after resuming from suspend:
189 * - At boot time we're called rather early, and must use alloc_bootmem*()
190 * to allocate memory.
192 * - After resume we're called from within stop_machine, but the mfn
193 * tree should already be completely allocated.
195 void __ref xen_build_mfn_list_list(void)
197 unsigned long pfn, mfn;
199 unsigned int level, topidx, mididx;
200 unsigned long *mid_mfn_p;
202 if (xen_feature(XENFEAT_auto_translated_physmap))
205 /* Pre-initialize p2m_top_mfn to be completely missing */
206 if (p2m_top_mfn == NULL) {
207 p2m_mid_missing_mfn = alloc_p2m_page();
208 p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
210 p2m_top_mfn_p = alloc_p2m_page();
211 p2m_top_mfn_p_init(p2m_top_mfn_p);
213 p2m_top_mfn = alloc_p2m_page();
214 p2m_top_mfn_init(p2m_top_mfn);
216 /* Reinitialise, mfn's all change after migration */
217 p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
220 for (pfn = 0; pfn < xen_max_p2m_pfn && pfn < MAX_P2M_PFN;
221 pfn += P2M_PER_PAGE) {
222 topidx = p2m_top_index(pfn);
223 mididx = p2m_mid_index(pfn);
225 mid_mfn_p = p2m_top_mfn_p[topidx];
226 ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn),
228 BUG_ON(!ptep || level != PG_LEVEL_4K);
229 mfn = pte_mfn(*ptep);
230 ptep = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));
232 /* Don't bother allocating any mfn mid levels if
233 * they're just missing, just update the stored mfn,
234 * since all could have changed over a migrate.
236 if (ptep == p2m_missing_pte || ptep == p2m_identity_pte) {
238 BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
239 p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn);
240 pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE;
244 if (mid_mfn_p == p2m_mid_missing_mfn) {
245 mid_mfn_p = alloc_p2m_page();
246 p2m_mid_mfn_init(mid_mfn_p, p2m_missing);
248 p2m_top_mfn_p[topidx] = mid_mfn_p;
251 p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
252 mid_mfn_p[mididx] = mfn;
256 void xen_setup_mfn_list_list(void)
258 if (xen_feature(XENFEAT_auto_translated_physmap))
261 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
263 HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
264 virt_to_mfn(p2m_top_mfn);
265 HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn;
266 HYPERVISOR_shared_info->arch.p2m_generation = 0;
267 HYPERVISOR_shared_info->arch.p2m_vaddr = (unsigned long)xen_p2m_addr;
268 HYPERVISOR_shared_info->arch.p2m_cr3 =
269 xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
272 /* Set up p2m_top to point to the domain-builder provided p2m pages */
273 void __init xen_build_dynamic_phys_to_machine(void)
277 if (xen_feature(XENFEAT_auto_translated_physmap))
280 xen_p2m_addr = (unsigned long *)xen_start_info->mfn_list;
281 xen_p2m_size = ALIGN(xen_start_info->nr_pages, P2M_PER_PAGE);
283 for (pfn = xen_start_info->nr_pages; pfn < xen_p2m_size; pfn++)
284 xen_p2m_addr[pfn] = INVALID_P2M_ENTRY;
286 xen_max_p2m_pfn = xen_p2m_size;
289 #define P2M_TYPE_IDENTITY 0
290 #define P2M_TYPE_MISSING 1
291 #define P2M_TYPE_PFN 2
292 #define P2M_TYPE_UNKNOWN 3
294 static int xen_p2m_elem_type(unsigned long pfn)
298 if (pfn >= xen_p2m_size)
299 return P2M_TYPE_IDENTITY;
301 mfn = xen_p2m_addr[pfn];
303 if (mfn == INVALID_P2M_ENTRY)
304 return P2M_TYPE_MISSING;
306 if (mfn & IDENTITY_FRAME_BIT)
307 return P2M_TYPE_IDENTITY;
312 static void __init xen_rebuild_p2m_list(unsigned long *p2m)
314 unsigned int i, chunk;
321 p2m_missing = alloc_p2m_page();
322 p2m_init(p2m_missing);
323 p2m_identity = alloc_p2m_page();
324 p2m_init(p2m_identity);
326 p2m_missing_pte = alloc_p2m_page();
327 paravirt_alloc_pte(&init_mm, __pa(p2m_missing_pte) >> PAGE_SHIFT);
328 p2m_identity_pte = alloc_p2m_page();
329 paravirt_alloc_pte(&init_mm, __pa(p2m_identity_pte) >> PAGE_SHIFT);
330 for (i = 0; i < PTRS_PER_PTE; i++) {
331 set_pte(p2m_missing_pte + i,
332 pfn_pte(PFN_DOWN(__pa(p2m_missing)), PAGE_KERNEL_RO));
333 set_pte(p2m_identity_pte + i,
334 pfn_pte(PFN_DOWN(__pa(p2m_identity)), PAGE_KERNEL_RO));
337 for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += chunk) {
339 * Try to map missing/identity PMDs or p2m-pages if possible.
340 * We have to respect the structure of the mfn_list_list
341 * which will be built just afterwards.
342 * Chunk size to test is one p2m page if we are in the middle
343 * of a mfn_list_list mid page and the complete mid page area
344 * if we are at index 0 of the mid page. Please note that a
345 * mid page might cover more than one PMD, e.g. on 32 bit PAE
348 chunk = (pfn & (P2M_PER_PAGE * P2M_MID_PER_PAGE - 1)) ?
349 P2M_PER_PAGE : P2M_PER_PAGE * P2M_MID_PER_PAGE;
351 type = xen_p2m_elem_type(pfn);
353 if (type != P2M_TYPE_PFN)
354 for (i = 1; i < chunk; i++)
355 if (xen_p2m_elem_type(pfn + i) != type)
358 /* Reset to minimal chunk size. */
359 chunk = P2M_PER_PAGE;
361 if (type == P2M_TYPE_PFN || i < chunk) {
362 /* Use initial p2m page contents. */
364 mfns = alloc_p2m_page();
365 copy_page(mfns, xen_p2m_addr + pfn);
367 mfns = xen_p2m_addr + pfn;
369 ptep = populate_extra_pte((unsigned long)(p2m + pfn));
371 pfn_pte(PFN_DOWN(__pa(mfns)), PAGE_KERNEL));
375 if (chunk == P2M_PER_PAGE) {
376 /* Map complete missing or identity p2m-page. */
377 mfns = (type == P2M_TYPE_MISSING) ?
378 p2m_missing : p2m_identity;
379 ptep = populate_extra_pte((unsigned long)(p2m + pfn));
381 pfn_pte(PFN_DOWN(__pa(mfns)), PAGE_KERNEL_RO));
385 /* Complete missing or identity PMD(s) can be mapped. */
386 ptep = (type == P2M_TYPE_MISSING) ?
387 p2m_missing_pte : p2m_identity_pte;
388 for (i = 0; i < PMDS_PER_MID_PAGE; i++) {
389 pmdp = populate_extra_pmd(
390 (unsigned long)(p2m + pfn) + i * PMD_SIZE);
391 set_pmd(pmdp, __pmd(__pa(ptep) | _KERNPG_TABLE));
396 void __init xen_vmalloc_p2m_tree(void)
398 static struct vm_struct vm;
399 unsigned long p2m_limit;
401 p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE;
403 vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit),
404 PMD_SIZE * PMDS_PER_MID_PAGE);
405 vm_area_register_early(&vm, PMD_SIZE * PMDS_PER_MID_PAGE);
406 pr_notice("p2m virtual area at %p, size is %lx\n", vm.addr, vm.size);
408 xen_max_p2m_pfn = vm.size / sizeof(unsigned long);
410 xen_rebuild_p2m_list(vm.addr);
412 xen_p2m_addr = vm.addr;
413 xen_p2m_size = xen_max_p2m_pfn;
418 unsigned long get_phys_to_machine(unsigned long pfn)
423 if (unlikely(pfn >= xen_p2m_size)) {
424 if (pfn < xen_max_p2m_pfn)
425 return xen_chk_extra_mem(pfn);
427 return IDENTITY_FRAME(pfn);
430 ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), &level);
431 BUG_ON(!ptep || level != PG_LEVEL_4K);
434 * The INVALID_P2M_ENTRY is filled in both p2m_*identity
435 * and in p2m_*missing, so returning the INVALID_P2M_ENTRY
438 if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_identity)))
439 return IDENTITY_FRAME(pfn);
441 return xen_p2m_addr[pfn];
443 EXPORT_SYMBOL_GPL(get_phys_to_machine);
446 * Allocate new pmd(s). It is checked whether the old pmd is still in place.
447 * If not, nothing is changed. This is okay as the only reason for allocating
448 * a new pmd is to replace p2m_missing_pte or p2m_identity_pte by a individual
449 * pmd. In case of PAE/x86-32 there are multiple pmds to allocate!
451 static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg)
454 pte_t *pte_newpg[PMDS_PER_MID_PAGE];
461 /* Do all allocations first to bail out in error case. */
462 for (i = 0; i < PMDS_PER_MID_PAGE; i++) {
463 pte_newpg[i] = alloc_p2m_page();
465 for (i--; i >= 0; i--)
466 free_p2m_page(pte_newpg[i]);
472 vaddr = addr & ~(PMD_SIZE * PMDS_PER_MID_PAGE - 1);
474 for (i = 0; i < PMDS_PER_MID_PAGE; i++) {
475 copy_page(pte_newpg[i], pte_pg);
476 paravirt_alloc_pte(&init_mm, __pa(pte_newpg[i]) >> PAGE_SHIFT);
478 pmdp = lookup_pmd_address(vaddr);
481 spin_lock_irqsave(&p2m_update_lock, flags);
483 ptechk = lookup_address(vaddr, &level);
484 if (ptechk == pte_pg) {
485 HYPERVISOR_shared_info->arch.p2m_generation++;
486 wmb(); /* Tools are synchronizing via p2m_generation. */
488 __pmd(__pa(pte_newpg[i]) | _KERNPG_TABLE));
489 wmb(); /* Tools are synchronizing via p2m_generation. */
490 HYPERVISOR_shared_info->arch.p2m_generation++;
494 spin_unlock_irqrestore(&p2m_update_lock, flags);
497 paravirt_release_pte(__pa(pte_newpg[i]) >> PAGE_SHIFT);
498 free_p2m_page(pte_newpg[i]);
504 return lookup_address(addr, &level);
508 * Fully allocate the p2m structure for a given pfn. We need to check
509 * that both the top and mid levels are allocated, and make sure the
510 * parallel mfn tree is kept in sync. We may race with other cpus, so
511 * the new pages are installed with cmpxchg; if we lose the race then
512 * simply free the page we allocated and use the one that's there.
514 static bool alloc_p2m(unsigned long pfn)
516 unsigned topidx, mididx;
517 unsigned long *top_mfn_p, *mid_mfn;
518 pte_t *ptep, *pte_pg;
521 unsigned long addr = (unsigned long)(xen_p2m_addr + pfn);
522 unsigned long p2m_pfn;
524 topidx = p2m_top_index(pfn);
525 mididx = p2m_mid_index(pfn);
527 ptep = lookup_address(addr, &level);
528 BUG_ON(!ptep || level != PG_LEVEL_4K);
529 pte_pg = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));
531 if (pte_pg == p2m_missing_pte || pte_pg == p2m_identity_pte) {
532 /* PMD level is missing, allocate a new one */
533 ptep = alloc_p2m_pmd(addr, pte_pg);
539 top_mfn_p = &p2m_top_mfn[topidx];
540 mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]);
542 BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p);
544 if (mid_mfn == p2m_mid_missing_mfn) {
545 /* Separately check the mid mfn level */
546 unsigned long missing_mfn;
547 unsigned long mid_mfn_mfn;
548 unsigned long old_mfn;
550 mid_mfn = alloc_p2m_page();
554 p2m_mid_mfn_init(mid_mfn, p2m_missing);
556 missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
557 mid_mfn_mfn = virt_to_mfn(mid_mfn);
558 old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn);
559 if (old_mfn != missing_mfn) {
560 free_p2m_page(mid_mfn);
561 mid_mfn = mfn_to_virt(old_mfn);
563 p2m_top_mfn_p[topidx] = mid_mfn;
570 p2m_pfn = pte_pfn(READ_ONCE(*ptep));
571 if (p2m_pfn == PFN_DOWN(__pa(p2m_identity)) ||
572 p2m_pfn == PFN_DOWN(__pa(p2m_missing))) {
573 /* p2m leaf page is missing */
576 p2m = alloc_p2m_page();
580 if (p2m_pfn == PFN_DOWN(__pa(p2m_missing)))
583 p2m_init_identity(p2m, pfn & ~(P2M_PER_PAGE - 1));
585 spin_lock_irqsave(&p2m_update_lock, flags);
587 if (pte_pfn(*ptep) == p2m_pfn) {
588 HYPERVISOR_shared_info->arch.p2m_generation++;
589 wmb(); /* Tools are synchronizing via p2m_generation. */
591 pfn_pte(PFN_DOWN(__pa(p2m)), PAGE_KERNEL));
592 wmb(); /* Tools are synchronizing via p2m_generation. */
593 HYPERVISOR_shared_info->arch.p2m_generation++;
595 mid_mfn[mididx] = virt_to_mfn(p2m);
599 spin_unlock_irqrestore(&p2m_update_lock, flags);
608 unsigned long __init set_phys_range_identity(unsigned long pfn_s,
613 if (unlikely(pfn_s >= xen_p2m_size))
616 if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
617 return pfn_e - pfn_s;
622 if (pfn_e > xen_p2m_size)
623 pfn_e = xen_p2m_size;
625 for (pfn = pfn_s; pfn < pfn_e; pfn++)
626 xen_p2m_addr[pfn] = IDENTITY_FRAME(pfn);
631 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
636 /* don't track P2M changes in autotranslate guests */
637 if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
640 if (unlikely(pfn >= xen_p2m_size)) {
641 BUG_ON(mfn != INVALID_P2M_ENTRY);
646 * The interface requires atomic updates on p2m elements.
647 * xen_safe_write_ulong() is using __put_user which does an atomic
650 if (likely(!xen_safe_write_ulong(xen_p2m_addr + pfn, mfn)))
653 ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), &level);
654 BUG_ON(!ptep || level != PG_LEVEL_4K);
656 if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_missing)))
657 return mfn == INVALID_P2M_ENTRY;
659 if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_identity)))
660 return mfn == IDENTITY_FRAME(pfn);
665 bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
667 if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
671 return __set_phys_to_machine(pfn, mfn);
677 int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
678 struct gnttab_map_grant_ref *kmap_ops,
679 struct page **pages, unsigned int count)
684 if (xen_feature(XENFEAT_auto_translated_physmap))
688 ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
694 for (i = 0; i < count; i++) {
695 unsigned long mfn, pfn;
697 /* Do not add to override if the map failed. */
698 if (map_ops[i].status)
701 if (map_ops[i].flags & GNTMAP_contains_pte) {
702 pte = (pte_t *)(mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) +
703 (map_ops[i].host_addr & ~PAGE_MASK));
706 mfn = PFN_DOWN(map_ops[i].dev_bus_addr);
708 pfn = page_to_pfn(pages[i]);
710 WARN(pfn_to_mfn(pfn) != INVALID_P2M_ENTRY, "page must be ballooned");
712 if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
721 EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping);
723 int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
724 struct gnttab_unmap_grant_ref *kunmap_ops,
725 struct page **pages, unsigned int count)
729 if (xen_feature(XENFEAT_auto_translated_physmap))
732 for (i = 0; i < count; i++) {
733 unsigned long mfn = __pfn_to_mfn(page_to_pfn(pages[i]));
734 unsigned long pfn = page_to_pfn(pages[i]);
736 if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) {
741 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
744 ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
749 EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
751 #ifdef CONFIG_XEN_DEBUG_FS
752 #include <linux/debugfs.h>
754 static int p2m_dump_show(struct seq_file *m, void *v)
756 static const char * const type_name[] = {
757 [P2M_TYPE_IDENTITY] = "identity",
758 [P2M_TYPE_MISSING] = "missing",
759 [P2M_TYPE_PFN] = "pfn",
760 [P2M_TYPE_UNKNOWN] = "abnormal"};
761 unsigned long pfn, first_pfn;
764 prev_type = xen_p2m_elem_type(0);
767 for (pfn = 0; pfn < xen_p2m_size; pfn++) {
768 type = xen_p2m_elem_type(pfn);
769 if (type != prev_type) {
770 seq_printf(m, " [0x%lx->0x%lx] %s\n", first_pfn, pfn,
771 type_name[prev_type]);
776 seq_printf(m, " [0x%lx->0x%lx] %s\n", first_pfn, pfn,
777 type_name[prev_type]);
781 static int p2m_dump_open(struct inode *inode, struct file *filp)
783 return single_open(filp, p2m_dump_show, NULL);
786 static const struct file_operations p2m_dump_fops = {
787 .open = p2m_dump_open,
790 .release = single_release,
793 static struct dentry *d_mmu_debug;
795 static int __init xen_p2m_debugfs(void)
797 struct dentry *d_xen = xen_init_debugfs();
802 d_mmu_debug = debugfs_create_dir("mmu", d_xen);
804 debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops);
807 fs_initcall(xen_p2m_debugfs);
808 #endif /* CONFIG_XEN_DEBUG_FS */