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>
71 #include <asm/cache.h>
72 #include <asm/setup.h>
73 #include <asm/uaccess.h>
75 #include <asm/xen/page.h>
76 #include <asm/xen/hypercall.h>
77 #include <asm/xen/hypervisor.h>
78 #include <xen/balloon.h>
79 #include <xen/grant_table.h>
82 #include "multicalls.h"
85 #define PMDS_PER_MID_PAGE (P2M_MID_PER_PAGE / PTRS_PER_PTE)
87 unsigned long *xen_p2m_addr __read_mostly
;
88 EXPORT_SYMBOL_GPL(xen_p2m_addr
);
89 unsigned long xen_p2m_size __read_mostly
;
90 EXPORT_SYMBOL_GPL(xen_p2m_size
);
91 unsigned long xen_max_p2m_pfn __read_mostly
;
92 EXPORT_SYMBOL_GPL(xen_max_p2m_pfn
);
94 static DEFINE_SPINLOCK(p2m_update_lock
);
96 static unsigned long *p2m_mid_missing_mfn
;
97 static unsigned long *p2m_top_mfn
;
98 static unsigned long **p2m_top_mfn_p
;
99 static unsigned long *p2m_missing
;
100 static unsigned long *p2m_identity
;
101 static pte_t
*p2m_missing_pte
;
102 static pte_t
*p2m_identity_pte
;
104 static inline unsigned p2m_top_index(unsigned long pfn
)
106 BUG_ON(pfn
>= MAX_P2M_PFN
);
107 return pfn
/ (P2M_MID_PER_PAGE
* P2M_PER_PAGE
);
110 static inline unsigned p2m_mid_index(unsigned long pfn
)
112 return (pfn
/ P2M_PER_PAGE
) % P2M_MID_PER_PAGE
;
115 static inline unsigned p2m_index(unsigned long pfn
)
117 return pfn
% P2M_PER_PAGE
;
120 static void p2m_top_mfn_init(unsigned long *top
)
124 for (i
= 0; i
< P2M_TOP_PER_PAGE
; i
++)
125 top
[i
] = virt_to_mfn(p2m_mid_missing_mfn
);
128 static void p2m_top_mfn_p_init(unsigned long **top
)
132 for (i
= 0; i
< P2M_TOP_PER_PAGE
; i
++)
133 top
[i
] = p2m_mid_missing_mfn
;
136 static void p2m_mid_mfn_init(unsigned long *mid
, unsigned long *leaf
)
140 for (i
= 0; i
< P2M_MID_PER_PAGE
; i
++)
141 mid
[i
] = virt_to_mfn(leaf
);
144 static void p2m_init(unsigned long *p2m
)
148 for (i
= 0; i
< P2M_PER_PAGE
; i
++)
149 p2m
[i
] = INVALID_P2M_ENTRY
;
152 static void p2m_init_identity(unsigned long *p2m
, unsigned long pfn
)
156 for (i
= 0; i
< P2M_PER_PAGE
; i
++)
157 p2m
[i
] = IDENTITY_FRAME(pfn
+ i
);
160 static void * __ref
alloc_p2m_page(void)
162 if (unlikely(!slab_is_available()))
163 return alloc_bootmem_align(PAGE_SIZE
, PAGE_SIZE
);
165 return (void *)__get_free_page(GFP_KERNEL
| __GFP_REPEAT
);
168 static void __ref
free_p2m_page(void *p
)
170 if (unlikely(!slab_is_available())) {
171 free_bootmem((unsigned long)p
, PAGE_SIZE
);
175 free_page((unsigned long)p
);
179 * Build the parallel p2m_top_mfn and p2m_mid_mfn structures
181 * This is called both at boot time, and after resuming from suspend:
182 * - At boot time we're called rather early, and must use alloc_bootmem*()
183 * to allocate memory.
185 * - After resume we're called from within stop_machine, but the mfn
186 * tree should already be completely allocated.
188 void __ref
xen_build_mfn_list_list(void)
190 unsigned long pfn
, mfn
;
192 unsigned int level
, topidx
, mididx
;
193 unsigned long *mid_mfn_p
;
195 if (xen_feature(XENFEAT_auto_translated_physmap
))
198 /* Pre-initialize p2m_top_mfn to be completely missing */
199 if (p2m_top_mfn
== NULL
) {
200 p2m_mid_missing_mfn
= alloc_p2m_page();
201 p2m_mid_mfn_init(p2m_mid_missing_mfn
, p2m_missing
);
203 p2m_top_mfn_p
= alloc_p2m_page();
204 p2m_top_mfn_p_init(p2m_top_mfn_p
);
206 p2m_top_mfn
= alloc_p2m_page();
207 p2m_top_mfn_init(p2m_top_mfn
);
209 /* Reinitialise, mfn's all change after migration */
210 p2m_mid_mfn_init(p2m_mid_missing_mfn
, p2m_missing
);
213 for (pfn
= 0; pfn
< xen_max_p2m_pfn
&& pfn
< MAX_P2M_PFN
;
214 pfn
+= P2M_PER_PAGE
) {
215 topidx
= p2m_top_index(pfn
);
216 mididx
= p2m_mid_index(pfn
);
218 mid_mfn_p
= p2m_top_mfn_p
[topidx
];
219 ptep
= lookup_address((unsigned long)(xen_p2m_addr
+ pfn
),
221 BUG_ON(!ptep
|| level
!= PG_LEVEL_4K
);
222 mfn
= pte_mfn(*ptep
);
223 ptep
= (pte_t
*)((unsigned long)ptep
& ~(PAGE_SIZE
- 1));
225 /* Don't bother allocating any mfn mid levels if
226 * they're just missing, just update the stored mfn,
227 * since all could have changed over a migrate.
229 if (ptep
== p2m_missing_pte
|| ptep
== p2m_identity_pte
) {
231 BUG_ON(mid_mfn_p
!= p2m_mid_missing_mfn
);
232 p2m_top_mfn
[topidx
] = virt_to_mfn(p2m_mid_missing_mfn
);
233 pfn
+= (P2M_MID_PER_PAGE
- 1) * P2M_PER_PAGE
;
237 if (mid_mfn_p
== p2m_mid_missing_mfn
) {
238 mid_mfn_p
= alloc_p2m_page();
239 p2m_mid_mfn_init(mid_mfn_p
, p2m_missing
);
241 p2m_top_mfn_p
[topidx
] = mid_mfn_p
;
244 p2m_top_mfn
[topidx
] = virt_to_mfn(mid_mfn_p
);
245 mid_mfn_p
[mididx
] = mfn
;
249 void xen_setup_mfn_list_list(void)
251 if (xen_feature(XENFEAT_auto_translated_physmap
))
254 BUG_ON(HYPERVISOR_shared_info
== &xen_dummy_shared_info
);
256 HYPERVISOR_shared_info
->arch
.pfn_to_mfn_frame_list_list
=
257 virt_to_mfn(p2m_top_mfn
);
258 HYPERVISOR_shared_info
->arch
.max_pfn
= xen_max_p2m_pfn
;
261 /* Set up p2m_top to point to the domain-builder provided p2m pages */
262 void __init
xen_build_dynamic_phys_to_machine(void)
266 if (xen_feature(XENFEAT_auto_translated_physmap
))
269 xen_p2m_addr
= (unsigned long *)xen_start_info
->mfn_list
;
270 xen_p2m_size
= ALIGN(xen_start_info
->nr_pages
, P2M_PER_PAGE
);
272 for (pfn
= xen_start_info
->nr_pages
; pfn
< xen_p2m_size
; pfn
++)
273 xen_p2m_addr
[pfn
] = INVALID_P2M_ENTRY
;
275 xen_max_p2m_pfn
= xen_p2m_size
;
278 #define P2M_TYPE_IDENTITY 0
279 #define P2M_TYPE_MISSING 1
280 #define P2M_TYPE_PFN 2
281 #define P2M_TYPE_UNKNOWN 3
283 static int xen_p2m_elem_type(unsigned long pfn
)
287 if (pfn
>= xen_p2m_size
)
288 return P2M_TYPE_IDENTITY
;
290 mfn
= xen_p2m_addr
[pfn
];
292 if (mfn
== INVALID_P2M_ENTRY
)
293 return P2M_TYPE_MISSING
;
295 if (mfn
& IDENTITY_FRAME_BIT
)
296 return P2M_TYPE_IDENTITY
;
301 static void __init
xen_rebuild_p2m_list(unsigned long *p2m
)
303 unsigned int i
, chunk
;
310 p2m_missing
= alloc_p2m_page();
311 p2m_init(p2m_missing
);
312 p2m_identity
= alloc_p2m_page();
313 p2m_init(p2m_identity
);
315 p2m_missing_pte
= alloc_p2m_page();
316 paravirt_alloc_pte(&init_mm
, __pa(p2m_missing_pte
) >> PAGE_SHIFT
);
317 p2m_identity_pte
= alloc_p2m_page();
318 paravirt_alloc_pte(&init_mm
, __pa(p2m_identity_pte
) >> PAGE_SHIFT
);
319 for (i
= 0; i
< PTRS_PER_PTE
; i
++) {
320 set_pte(p2m_missing_pte
+ i
,
321 pfn_pte(PFN_DOWN(__pa(p2m_missing
)), PAGE_KERNEL_RO
));
322 set_pte(p2m_identity_pte
+ i
,
323 pfn_pte(PFN_DOWN(__pa(p2m_identity
)), PAGE_KERNEL_RO
));
326 for (pfn
= 0; pfn
< xen_max_p2m_pfn
; pfn
+= chunk
) {
328 * Try to map missing/identity PMDs or p2m-pages if possible.
329 * We have to respect the structure of the mfn_list_list
330 * which will be built just afterwards.
331 * Chunk size to test is one p2m page if we are in the middle
332 * of a mfn_list_list mid page and the complete mid page area
333 * if we are at index 0 of the mid page. Please note that a
334 * mid page might cover more than one PMD, e.g. on 32 bit PAE
337 chunk
= (pfn
& (P2M_PER_PAGE
* P2M_MID_PER_PAGE
- 1)) ?
338 P2M_PER_PAGE
: P2M_PER_PAGE
* P2M_MID_PER_PAGE
;
340 type
= xen_p2m_elem_type(pfn
);
342 if (type
!= P2M_TYPE_PFN
)
343 for (i
= 1; i
< chunk
; i
++)
344 if (xen_p2m_elem_type(pfn
+ i
) != type
)
347 /* Reset to minimal chunk size. */
348 chunk
= P2M_PER_PAGE
;
350 if (type
== P2M_TYPE_PFN
|| i
< chunk
) {
351 /* Use initial p2m page contents. */
353 mfns
= alloc_p2m_page();
354 copy_page(mfns
, xen_p2m_addr
+ pfn
);
356 mfns
= xen_p2m_addr
+ pfn
;
358 ptep
= populate_extra_pte((unsigned long)(p2m
+ pfn
));
360 pfn_pte(PFN_DOWN(__pa(mfns
)), PAGE_KERNEL
));
364 if (chunk
== P2M_PER_PAGE
) {
365 /* Map complete missing or identity p2m-page. */
366 mfns
= (type
== P2M_TYPE_MISSING
) ?
367 p2m_missing
: p2m_identity
;
368 ptep
= populate_extra_pte((unsigned long)(p2m
+ pfn
));
370 pfn_pte(PFN_DOWN(__pa(mfns
)), PAGE_KERNEL_RO
));
374 /* Complete missing or identity PMD(s) can be mapped. */
375 ptep
= (type
== P2M_TYPE_MISSING
) ?
376 p2m_missing_pte
: p2m_identity_pte
;
377 for (i
= 0; i
< PMDS_PER_MID_PAGE
; i
++) {
378 pmdp
= populate_extra_pmd(
379 (unsigned long)(p2m
+ pfn
) + i
* PMD_SIZE
);
380 set_pmd(pmdp
, __pmd(__pa(ptep
) | _KERNPG_TABLE
));
385 void __init
xen_vmalloc_p2m_tree(void)
387 static struct vm_struct vm
;
390 vm
.size
= ALIGN(sizeof(unsigned long) * xen_max_p2m_pfn
,
391 PMD_SIZE
* PMDS_PER_MID_PAGE
);
392 vm_area_register_early(&vm
, PMD_SIZE
* PMDS_PER_MID_PAGE
);
393 pr_notice("p2m virtual area at %p, size is %lx\n", vm
.addr
, vm
.size
);
395 xen_max_p2m_pfn
= vm
.size
/ sizeof(unsigned long);
397 xen_rebuild_p2m_list(vm
.addr
);
399 xen_p2m_addr
= vm
.addr
;
400 xen_p2m_size
= xen_max_p2m_pfn
;
405 unsigned long get_phys_to_machine(unsigned long pfn
)
410 if (unlikely(pfn
>= xen_p2m_size
)) {
411 if (pfn
< xen_max_p2m_pfn
)
412 return xen_chk_extra_mem(pfn
);
414 return IDENTITY_FRAME(pfn
);
417 ptep
= lookup_address((unsigned long)(xen_p2m_addr
+ pfn
), &level
);
418 BUG_ON(!ptep
|| level
!= PG_LEVEL_4K
);
421 * The INVALID_P2M_ENTRY is filled in both p2m_*identity
422 * and in p2m_*missing, so returning the INVALID_P2M_ENTRY
425 if (pte_pfn(*ptep
) == PFN_DOWN(__pa(p2m_identity
)))
426 return IDENTITY_FRAME(pfn
);
428 return xen_p2m_addr
[pfn
];
430 EXPORT_SYMBOL_GPL(get_phys_to_machine
);
433 * Allocate new pmd(s). It is checked whether the old pmd is still in place.
434 * If not, nothing is changed. This is okay as the only reason for allocating
435 * a new pmd is to replace p2m_missing_pte or p2m_identity_pte by a individual
436 * pmd. In case of PAE/x86-32 there are multiple pmds to allocate!
438 static pte_t
*alloc_p2m_pmd(unsigned long addr
, pte_t
*pte_pg
)
441 pte_t
*pte_newpg
[PMDS_PER_MID_PAGE
];
448 /* Do all allocations first to bail out in error case. */
449 for (i
= 0; i
< PMDS_PER_MID_PAGE
; i
++) {
450 pte_newpg
[i
] = alloc_p2m_page();
452 for (i
--; i
>= 0; i
--)
453 free_p2m_page(pte_newpg
[i
]);
459 vaddr
= addr
& ~(PMD_SIZE
* PMDS_PER_MID_PAGE
- 1);
461 for (i
= 0; i
< PMDS_PER_MID_PAGE
; i
++) {
462 copy_page(pte_newpg
[i
], pte_pg
);
463 paravirt_alloc_pte(&init_mm
, __pa(pte_newpg
[i
]) >> PAGE_SHIFT
);
465 pmdp
= lookup_pmd_address(vaddr
);
468 spin_lock_irqsave(&p2m_update_lock
, flags
);
470 ptechk
= lookup_address(vaddr
, &level
);
471 if (ptechk
== pte_pg
) {
473 __pmd(__pa(pte_newpg
[i
]) | _KERNPG_TABLE
));
477 spin_unlock_irqrestore(&p2m_update_lock
, flags
);
480 paravirt_release_pte(__pa(pte_newpg
[i
]) >> PAGE_SHIFT
);
481 free_p2m_page(pte_newpg
[i
]);
487 return lookup_address(addr
, &level
);
491 * Fully allocate the p2m structure for a given pfn. We need to check
492 * that both the top and mid levels are allocated, and make sure the
493 * parallel mfn tree is kept in sync. We may race with other cpus, so
494 * the new pages are installed with cmpxchg; if we lose the race then
495 * simply free the page we allocated and use the one that's there.
497 static bool alloc_p2m(unsigned long pfn
)
499 unsigned topidx
, mididx
;
500 unsigned long *top_mfn_p
, *mid_mfn
;
501 pte_t
*ptep
, *pte_pg
;
504 unsigned long addr
= (unsigned long)(xen_p2m_addr
+ pfn
);
505 unsigned long p2m_pfn
;
507 topidx
= p2m_top_index(pfn
);
508 mididx
= p2m_mid_index(pfn
);
510 ptep
= lookup_address(addr
, &level
);
511 BUG_ON(!ptep
|| level
!= PG_LEVEL_4K
);
512 pte_pg
= (pte_t
*)((unsigned long)ptep
& ~(PAGE_SIZE
- 1));
514 if (pte_pg
== p2m_missing_pte
|| pte_pg
== p2m_identity_pte
) {
515 /* PMD level is missing, allocate a new one */
516 ptep
= alloc_p2m_pmd(addr
, pte_pg
);
522 top_mfn_p
= &p2m_top_mfn
[topidx
];
523 mid_mfn
= ACCESS_ONCE(p2m_top_mfn_p
[topidx
]);
525 BUG_ON(virt_to_mfn(mid_mfn
) != *top_mfn_p
);
527 if (mid_mfn
== p2m_mid_missing_mfn
) {
528 /* Separately check the mid mfn level */
529 unsigned long missing_mfn
;
530 unsigned long mid_mfn_mfn
;
531 unsigned long old_mfn
;
533 mid_mfn
= alloc_p2m_page();
537 p2m_mid_mfn_init(mid_mfn
, p2m_missing
);
539 missing_mfn
= virt_to_mfn(p2m_mid_missing_mfn
);
540 mid_mfn_mfn
= virt_to_mfn(mid_mfn
);
541 old_mfn
= cmpxchg(top_mfn_p
, missing_mfn
, mid_mfn_mfn
);
542 if (old_mfn
!= missing_mfn
) {
543 free_p2m_page(mid_mfn
);
544 mid_mfn
= mfn_to_virt(old_mfn
);
546 p2m_top_mfn_p
[topidx
] = mid_mfn
;
553 p2m_pfn
= pte_pfn(READ_ONCE(*ptep
));
554 if (p2m_pfn
== PFN_DOWN(__pa(p2m_identity
)) ||
555 p2m_pfn
== PFN_DOWN(__pa(p2m_missing
))) {
556 /* p2m leaf page is missing */
559 p2m
= alloc_p2m_page();
563 if (p2m_pfn
== PFN_DOWN(__pa(p2m_missing
)))
566 p2m_init_identity(p2m
, pfn
);
568 spin_lock_irqsave(&p2m_update_lock
, flags
);
570 if (pte_pfn(*ptep
) == p2m_pfn
) {
572 pfn_pte(PFN_DOWN(__pa(p2m
)), PAGE_KERNEL
));
574 mid_mfn
[mididx
] = virt_to_mfn(p2m
);
578 spin_unlock_irqrestore(&p2m_update_lock
, flags
);
587 unsigned long __init
set_phys_range_identity(unsigned long pfn_s
,
592 if (unlikely(pfn_s
>= xen_p2m_size
))
595 if (unlikely(xen_feature(XENFEAT_auto_translated_physmap
)))
596 return pfn_e
- pfn_s
;
601 if (pfn_e
> xen_p2m_size
)
602 pfn_e
= xen_p2m_size
;
604 for (pfn
= pfn_s
; pfn
< pfn_e
; pfn
++)
605 xen_p2m_addr
[pfn
] = IDENTITY_FRAME(pfn
);
610 bool __set_phys_to_machine(unsigned long pfn
, unsigned long mfn
)
615 /* don't track P2M changes in autotranslate guests */
616 if (unlikely(xen_feature(XENFEAT_auto_translated_physmap
)))
619 if (unlikely(pfn
>= xen_p2m_size
)) {
620 BUG_ON(mfn
!= INVALID_P2M_ENTRY
);
624 if (likely(!xen_safe_write_ulong(xen_p2m_addr
+ pfn
, mfn
)))
627 ptep
= lookup_address((unsigned long)(xen_p2m_addr
+ pfn
), &level
);
628 BUG_ON(!ptep
|| level
!= PG_LEVEL_4K
);
630 if (pte_pfn(*ptep
) == PFN_DOWN(__pa(p2m_missing
)))
631 return mfn
== INVALID_P2M_ENTRY
;
633 if (pte_pfn(*ptep
) == PFN_DOWN(__pa(p2m_identity
)))
634 return mfn
== IDENTITY_FRAME(pfn
);
639 bool set_phys_to_machine(unsigned long pfn
, unsigned long mfn
)
641 if (unlikely(!__set_phys_to_machine(pfn
, mfn
))) {
645 return __set_phys_to_machine(pfn
, mfn
);
651 int set_foreign_p2m_mapping(struct gnttab_map_grant_ref
*map_ops
,
652 struct gnttab_map_grant_ref
*kmap_ops
,
653 struct page
**pages
, unsigned int count
)
658 if (xen_feature(XENFEAT_auto_translated_physmap
))
662 ret
= HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref
,
668 for (i
= 0; i
< count
; i
++) {
669 unsigned long mfn
, pfn
;
671 /* Do not add to override if the map failed. */
672 if (map_ops
[i
].status
)
675 if (map_ops
[i
].flags
& GNTMAP_contains_pte
) {
676 pte
= (pte_t
*)(mfn_to_virt(PFN_DOWN(map_ops
[i
].host_addr
)) +
677 (map_ops
[i
].host_addr
& ~PAGE_MASK
));
680 mfn
= PFN_DOWN(map_ops
[i
].dev_bus_addr
);
682 pfn
= page_to_pfn(pages
[i
]);
684 WARN(pfn_to_mfn(pfn
) != INVALID_P2M_ENTRY
, "page must be ballooned");
686 if (unlikely(!set_phys_to_machine(pfn
, FOREIGN_FRAME(mfn
)))) {
695 EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping
);
697 int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref
*unmap_ops
,
698 struct gnttab_unmap_grant_ref
*kunmap_ops
,
699 struct page
**pages
, unsigned int count
)
703 if (xen_feature(XENFEAT_auto_translated_physmap
))
706 for (i
= 0; i
< count
; i
++) {
707 unsigned long mfn
= __pfn_to_mfn(page_to_pfn(pages
[i
]));
708 unsigned long pfn
= page_to_pfn(pages
[i
]);
710 if (mfn
== INVALID_P2M_ENTRY
|| !(mfn
& FOREIGN_FRAME_BIT
)) {
715 set_phys_to_machine(pfn
, INVALID_P2M_ENTRY
);
718 ret
= HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref
,
723 EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping
);
725 #ifdef CONFIG_XEN_DEBUG_FS
726 #include <linux/debugfs.h>
728 static int p2m_dump_show(struct seq_file
*m
, void *v
)
730 static const char * const type_name
[] = {
731 [P2M_TYPE_IDENTITY
] = "identity",
732 [P2M_TYPE_MISSING
] = "missing",
733 [P2M_TYPE_PFN
] = "pfn",
734 [P2M_TYPE_UNKNOWN
] = "abnormal"};
735 unsigned long pfn
, first_pfn
;
738 prev_type
= xen_p2m_elem_type(0);
741 for (pfn
= 0; pfn
< xen_p2m_size
; pfn
++) {
742 type
= xen_p2m_elem_type(pfn
);
743 if (type
!= prev_type
) {
744 seq_printf(m
, " [0x%lx->0x%lx] %s\n", first_pfn
, pfn
,
745 type_name
[prev_type
]);
750 seq_printf(m
, " [0x%lx->0x%lx] %s\n", first_pfn
, pfn
,
751 type_name
[prev_type
]);
755 static int p2m_dump_open(struct inode
*inode
, struct file
*filp
)
757 return single_open(filp
, p2m_dump_show
, NULL
);
760 static const struct file_operations p2m_dump_fops
= {
761 .open
= p2m_dump_open
,
764 .release
= single_release
,
767 static struct dentry
*d_mmu_debug
;
769 static int __init
xen_p2m_debugfs(void)
771 struct dentry
*d_xen
= xen_init_debugfs();
776 d_mmu_debug
= debugfs_create_dir("mmu", d_xen
);
778 debugfs_create_file("p2m", 0600, d_mmu_debug
, NULL
, &p2m_dump_fops
);
781 fs_initcall(xen_p2m_debugfs
);
782 #endif /* CONFIG_XEN_DEBUG_FS */