4 * This file contains the various mmu fetch and update operations.
5 * The most important job they must perform is the mapping between the
6 * domain's pfn and the overall machine mfns.
8 * Xen allows guests to directly update the pagetable, in a controlled
9 * fashion. In other words, the guest modifies the same pagetable
10 * that the CPU actually uses, which eliminates the overhead of having
11 * a separate shadow pagetable.
13 * In order to allow this, it falls on the guest domain to map its
14 * notion of a "physical" pfn - which is just a domain-local linear
15 * address - into a real "machine address" which the CPU's MMU can
18 * A pgd_t/pmd_t/pte_t will typically contain an mfn, and so can be
19 * inserted directly into the pagetable. When creating a new
20 * pte/pmd/pgd, it converts the passed pfn into an mfn. Conversely,
21 * when reading the content back with __(pgd|pmd|pte)_val, it converts
22 * the mfn back into a pfn.
24 * The other constraint is that all pages which make up a pagetable
25 * must be mapped read-only in the guest. This prevents uncontrolled
26 * guest updates to the pagetable. Xen strictly enforces this, and
27 * will disallow any pagetable update which will end up mapping a
28 * pagetable page RW, and will disallow using any writable page as a
31 * Naively, when loading %cr3 with the base of a new pagetable, Xen
32 * would need to validate the whole pagetable before going on.
33 * Naturally, this is quite slow. The solution is to "pin" a
34 * pagetable, which enforces all the constraints on the pagetable even
35 * when it is not actively in use. This menas that Xen can be assured
36 * that it is still valid when you do load it into %cr3, and doesn't
37 * need to revalidate it.
39 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
41 #include <linux/sched.h>
42 #include <linux/highmem.h>
43 #include <linux/debugfs.h>
44 #include <linux/bug.h>
45 #include <linux/vmalloc.h>
46 #include <linux/module.h>
47 #include <linux/gfp.h>
48 #include <linux/memblock.h>
50 #include <asm/pgtable.h>
51 #include <asm/tlbflush.h>
52 #include <asm/fixmap.h>
53 #include <asm/mmu_context.h>
54 #include <asm/setup.h>
55 #include <asm/paravirt.h>
57 #include <asm/linkage.h>
62 #include <asm/xen/hypercall.h>
63 #include <asm/xen/hypervisor.h>
67 #include <xen/interface/xen.h>
68 #include <xen/interface/hvm/hvm_op.h>
69 #include <xen/interface/version.h>
70 #include <xen/interface/memory.h>
71 #include <xen/hvc-console.h>
73 #include "multicalls.h"
77 #define MMU_UPDATE_HISTO 30
80 * Protects atomic reservation decrease/increase against concurrent increases.
81 * Also protects non-atomic updates of current_pages and driver_pages, and
84 DEFINE_SPINLOCK(xen_reservation_lock
);
86 #ifdef CONFIG_XEN_DEBUG_FS
90 u32 pgd_update_pinned
;
91 u32 pgd_update_batched
;
94 u32 pud_update_pinned
;
95 u32 pud_update_batched
;
98 u32 pmd_update_pinned
;
99 u32 pmd_update_batched
;
102 u32 pte_update_pinned
;
103 u32 pte_update_batched
;
106 u32 mmu_update_extended
;
107 u32 mmu_update_histo
[MMU_UPDATE_HISTO
];
110 u32 prot_commit_batched
;
113 u32 set_pte_at_batched
;
114 u32 set_pte_at_pinned
;
115 u32 set_pte_at_current
;
116 u32 set_pte_at_kernel
;
119 static u8 zero_stats
;
121 static inline void check_zero(void)
123 if (unlikely(zero_stats
)) {
124 memset(&mmu_stats
, 0, sizeof(mmu_stats
));
129 #define ADD_STATS(elem, val) \
130 do { check_zero(); mmu_stats.elem += (val); } while(0)
132 #else /* !CONFIG_XEN_DEBUG_FS */
134 #define ADD_STATS(elem, val) do { (void)(val); } while(0)
136 #endif /* CONFIG_XEN_DEBUG_FS */
140 * Identity map, in addition to plain kernel map. This needs to be
141 * large enough to allocate page table pages to allocate the rest.
142 * Each page can map 2MB.
144 #define LEVEL1_IDENT_ENTRIES (PTRS_PER_PTE * 4)
145 static RESERVE_BRK_ARRAY(pte_t
, level1_ident_pgt
, LEVEL1_IDENT_ENTRIES
);
148 /* l3 pud for userspace vsyscall mapping */
149 static pud_t level3_user_vsyscall
[PTRS_PER_PUD
] __page_aligned_bss
;
150 #endif /* CONFIG_X86_64 */
153 * Note about cr3 (pagetable base) values:
155 * xen_cr3 contains the current logical cr3 value; it contains the
156 * last set cr3. This may not be the current effective cr3, because
157 * its update may be being lazily deferred. However, a vcpu looking
158 * at its own cr3 can use this value knowing that it everything will
159 * be self-consistent.
161 * xen_current_cr3 contains the actual vcpu cr3; it is set once the
162 * hypercall to set the vcpu cr3 is complete (so it may be a little
163 * out of date, but it will never be set early). If one vcpu is
164 * looking at another vcpu's cr3 value, it should use this variable.
166 DEFINE_PER_CPU(unsigned long, xen_cr3
); /* cr3 stored as physaddr */
167 DEFINE_PER_CPU(unsigned long, xen_current_cr3
); /* actual vcpu cr3 */
171 * Just beyond the highest usermode address. STACK_TOP_MAX has a
172 * redzone above it, so round it up to a PGD boundary.
174 #define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK)
176 unsigned long arbitrary_virt_to_mfn(void *vaddr
)
178 xmaddr_t maddr
= arbitrary_virt_to_machine(vaddr
);
180 return PFN_DOWN(maddr
.maddr
);
183 xmaddr_t
arbitrary_virt_to_machine(void *vaddr
)
185 unsigned long address
= (unsigned long)vaddr
;
191 * if the PFN is in the linear mapped vaddr range, we can just use
192 * the (quick) virt_to_machine() p2m lookup
194 if (virt_addr_valid(vaddr
))
195 return virt_to_machine(vaddr
);
197 /* otherwise we have to do a (slower) full page-table walk */
199 pte
= lookup_address(address
, &level
);
201 offset
= address
& ~PAGE_MASK
;
202 return XMADDR(((phys_addr_t
)pte_mfn(*pte
) << PAGE_SHIFT
) + offset
);
204 EXPORT_SYMBOL_GPL(arbitrary_virt_to_machine
);
206 void make_lowmem_page_readonly(void *vaddr
)
209 unsigned long address
= (unsigned long)vaddr
;
212 pte
= lookup_address(address
, &level
);
214 return; /* vaddr missing */
216 ptev
= pte_wrprotect(*pte
);
218 if (HYPERVISOR_update_va_mapping(address
, ptev
, 0))
222 void make_lowmem_page_readwrite(void *vaddr
)
225 unsigned long address
= (unsigned long)vaddr
;
228 pte
= lookup_address(address
, &level
);
230 return; /* vaddr missing */
232 ptev
= pte_mkwrite(*pte
);
234 if (HYPERVISOR_update_va_mapping(address
, ptev
, 0))
239 static bool xen_page_pinned(void *ptr
)
241 struct page
*page
= virt_to_page(ptr
);
243 return PagePinned(page
);
246 static bool xen_iomap_pte(pte_t pte
)
248 return pte_flags(pte
) & _PAGE_IOMAP
;
251 void xen_set_domain_pte(pte_t
*ptep
, pte_t pteval
, unsigned domid
)
253 struct multicall_space mcs
;
254 struct mmu_update
*u
;
256 mcs
= xen_mc_entry(sizeof(*u
));
259 /* ptep might be kmapped when using 32-bit HIGHPTE */
260 u
->ptr
= arbitrary_virt_to_machine(ptep
).maddr
;
261 u
->val
= pte_val_ma(pteval
);
263 MULTI_mmu_update(mcs
.mc
, mcs
.args
, 1, NULL
, domid
);
265 xen_mc_issue(PARAVIRT_LAZY_MMU
);
267 EXPORT_SYMBOL_GPL(xen_set_domain_pte
);
269 static void xen_set_iomap_pte(pte_t
*ptep
, pte_t pteval
)
271 xen_set_domain_pte(ptep
, pteval
, DOMID_IO
);
274 static void xen_extend_mmu_update(const struct mmu_update
*update
)
276 struct multicall_space mcs
;
277 struct mmu_update
*u
;
279 mcs
= xen_mc_extend_args(__HYPERVISOR_mmu_update
, sizeof(*u
));
281 if (mcs
.mc
!= NULL
) {
282 ADD_STATS(mmu_update_extended
, 1);
283 ADD_STATS(mmu_update_histo
[mcs
.mc
->args
[1]], -1);
287 if (mcs
.mc
->args
[1] < MMU_UPDATE_HISTO
)
288 ADD_STATS(mmu_update_histo
[mcs
.mc
->args
[1]], 1);
290 ADD_STATS(mmu_update_histo
[0], 1);
292 ADD_STATS(mmu_update
, 1);
293 mcs
= __xen_mc_entry(sizeof(*u
));
294 MULTI_mmu_update(mcs
.mc
, mcs
.args
, 1, NULL
, DOMID_SELF
);
295 ADD_STATS(mmu_update_histo
[1], 1);
302 void xen_set_pmd_hyper(pmd_t
*ptr
, pmd_t val
)
310 /* ptr may be ioremapped for 64-bit pagetable setup */
311 u
.ptr
= arbitrary_virt_to_machine(ptr
).maddr
;
312 u
.val
= pmd_val_ma(val
);
313 xen_extend_mmu_update(&u
);
315 ADD_STATS(pmd_update_batched
, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU
);
317 xen_mc_issue(PARAVIRT_LAZY_MMU
);
322 void xen_set_pmd(pmd_t
*ptr
, pmd_t val
)
324 ADD_STATS(pmd_update
, 1);
326 /* If page is not pinned, we can just update the entry
328 if (!xen_page_pinned(ptr
)) {
333 ADD_STATS(pmd_update_pinned
, 1);
335 xen_set_pmd_hyper(ptr
, val
);
339 * Associate a virtual page frame with a given physical page frame
340 * and protection flags for that frame.
342 void set_pte_mfn(unsigned long vaddr
, unsigned long mfn
, pgprot_t flags
)
344 set_pte_vaddr(vaddr
, mfn_pte(mfn
, flags
));
347 void xen_set_pte_at(struct mm_struct
*mm
, unsigned long addr
,
348 pte_t
*ptep
, pte_t pteval
)
350 if (xen_iomap_pte(pteval
)) {
351 xen_set_iomap_pte(ptep
, pteval
);
355 ADD_STATS(set_pte_at
, 1);
356 // ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
357 ADD_STATS(set_pte_at_current
, mm
== current
->mm
);
358 ADD_STATS(set_pte_at_kernel
, mm
== &init_mm
);
360 if (mm
== current
->mm
|| mm
== &init_mm
) {
361 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU
) {
362 struct multicall_space mcs
;
363 mcs
= xen_mc_entry(0);
365 MULTI_update_va_mapping(mcs
.mc
, addr
, pteval
, 0);
366 ADD_STATS(set_pte_at_batched
, 1);
367 xen_mc_issue(PARAVIRT_LAZY_MMU
);
370 if (HYPERVISOR_update_va_mapping(addr
, pteval
, 0) == 0)
373 xen_set_pte(ptep
, pteval
);
378 pte_t
xen_ptep_modify_prot_start(struct mm_struct
*mm
,
379 unsigned long addr
, pte_t
*ptep
)
381 /* Just return the pte as-is. We preserve the bits on commit */
385 void xen_ptep_modify_prot_commit(struct mm_struct
*mm
, unsigned long addr
,
386 pte_t
*ptep
, pte_t pte
)
392 u
.ptr
= arbitrary_virt_to_machine(ptep
).maddr
| MMU_PT_UPDATE_PRESERVE_AD
;
393 u
.val
= pte_val_ma(pte
);
394 xen_extend_mmu_update(&u
);
396 ADD_STATS(prot_commit
, 1);
397 ADD_STATS(prot_commit_batched
, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU
);
399 xen_mc_issue(PARAVIRT_LAZY_MMU
);
402 /* Assume pteval_t is equivalent to all the other *val_t types. */
403 static pteval_t
pte_mfn_to_pfn(pteval_t val
)
405 if (val
& _PAGE_PRESENT
) {
406 unsigned long mfn
= (val
& PTE_PFN_MASK
) >> PAGE_SHIFT
;
407 pteval_t flags
= val
& PTE_FLAGS_MASK
;
408 val
= ((pteval_t
)mfn_to_pfn(mfn
) << PAGE_SHIFT
) | flags
;
414 static pteval_t
pte_pfn_to_mfn(pteval_t val
)
416 if (val
& _PAGE_PRESENT
) {
417 unsigned long pfn
= (val
& PTE_PFN_MASK
) >> PAGE_SHIFT
;
418 pteval_t flags
= val
& PTE_FLAGS_MASK
;
419 unsigned long mfn
= pfn_to_mfn(pfn
);
422 * If there's no mfn for the pfn, then just create an
423 * empty non-present pte. Unfortunately this loses
424 * information about the original pfn, so
425 * pte_mfn_to_pfn is asymmetric.
427 if (unlikely(mfn
== INVALID_P2M_ENTRY
)) {
432 val
= ((pteval_t
)mfn
<< PAGE_SHIFT
) | flags
;
438 static pteval_t
iomap_pte(pteval_t val
)
440 if (val
& _PAGE_PRESENT
) {
441 unsigned long pfn
= (val
& PTE_PFN_MASK
) >> PAGE_SHIFT
;
442 pteval_t flags
= val
& PTE_FLAGS_MASK
;
444 /* We assume the pte frame number is a MFN, so
445 just use it as-is. */
446 val
= ((pteval_t
)pfn
<< PAGE_SHIFT
) | flags
;
452 pteval_t
xen_pte_val(pte_t pte
)
454 pteval_t pteval
= pte
.pte
;
456 /* If this is a WC pte, convert back from Xen WC to Linux WC */
457 if ((pteval
& (_PAGE_PAT
| _PAGE_PCD
| _PAGE_PWT
)) == _PAGE_PAT
) {
458 WARN_ON(!pat_enabled
);
459 pteval
= (pteval
& ~_PAGE_PAT
) | _PAGE_PWT
;
462 if (xen_initial_domain() && (pteval
& _PAGE_IOMAP
))
465 return pte_mfn_to_pfn(pteval
);
467 PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val
);
469 pgdval_t
xen_pgd_val(pgd_t pgd
)
471 return pte_mfn_to_pfn(pgd
.pgd
);
473 PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val
);
476 * Xen's PAT setup is part of its ABI, though I assume entries 6 & 7
477 * are reserved for now, to correspond to the Intel-reserved PAT
480 * We expect Linux's PAT set as follows:
482 * Idx PTE flags Linux Xen Default
489 * 6 PAT PCD UC- UC UC-
490 * 7 PAT PCD PWT UC UC UC
493 void xen_set_pat(u64 pat
)
495 /* We expect Linux to use a PAT setting of
496 * UC UC- WC WB (ignoring the PAT flag) */
497 WARN_ON(pat
!= 0x0007010600070106ull
);
500 pte_t
xen_make_pte(pteval_t pte
)
502 phys_addr_t addr
= (pte
& PTE_PFN_MASK
);
504 /* If Linux is trying to set a WC pte, then map to the Xen WC.
505 * If _PAGE_PAT is set, then it probably means it is really
506 * _PAGE_PSE, so avoid fiddling with the PAT mapping and hope
507 * things work out OK...
509 * (We should never see kernel mappings with _PAGE_PSE set,
510 * but we could see hugetlbfs mappings, I think.).
512 if (pat_enabled
&& !WARN_ON(pte
& _PAGE_PAT
)) {
513 if ((pte
& (_PAGE_PCD
| _PAGE_PWT
)) == _PAGE_PWT
)
514 pte
= (pte
& ~(_PAGE_PCD
| _PAGE_PWT
)) | _PAGE_PAT
;
518 * Unprivileged domains are allowed to do IOMAPpings for
519 * PCI passthrough, but not map ISA space. The ISA
520 * mappings are just dummy local mappings to keep other
521 * parts of the kernel happy.
523 if (unlikely(pte
& _PAGE_IOMAP
) &&
524 (xen_initial_domain() || addr
>= ISA_END_ADDRESS
)) {
525 pte
= iomap_pte(pte
);
528 pte
= pte_pfn_to_mfn(pte
);
531 return native_make_pte(pte
);
533 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte
);
535 pgd_t
xen_make_pgd(pgdval_t pgd
)
537 pgd
= pte_pfn_to_mfn(pgd
);
538 return native_make_pgd(pgd
);
540 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pgd
);
542 pmdval_t
xen_pmd_val(pmd_t pmd
)
544 return pte_mfn_to_pfn(pmd
.pmd
);
546 PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val
);
548 void xen_set_pud_hyper(pud_t
*ptr
, pud_t val
)
556 /* ptr may be ioremapped for 64-bit pagetable setup */
557 u
.ptr
= arbitrary_virt_to_machine(ptr
).maddr
;
558 u
.val
= pud_val_ma(val
);
559 xen_extend_mmu_update(&u
);
561 ADD_STATS(pud_update_batched
, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU
);
563 xen_mc_issue(PARAVIRT_LAZY_MMU
);
568 void xen_set_pud(pud_t
*ptr
, pud_t val
)
570 ADD_STATS(pud_update
, 1);
572 /* If page is not pinned, we can just update the entry
574 if (!xen_page_pinned(ptr
)) {
579 ADD_STATS(pud_update_pinned
, 1);
581 xen_set_pud_hyper(ptr
, val
);
584 void xen_set_pte(pte_t
*ptep
, pte_t pte
)
586 if (xen_iomap_pte(pte
)) {
587 xen_set_iomap_pte(ptep
, pte
);
591 ADD_STATS(pte_update
, 1);
592 // ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
593 ADD_STATS(pte_update_batched
, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU
);
595 #ifdef CONFIG_X86_PAE
596 ptep
->pte_high
= pte
.pte_high
;
598 ptep
->pte_low
= pte
.pte_low
;
604 #ifdef CONFIG_X86_PAE
605 void xen_set_pte_atomic(pte_t
*ptep
, pte_t pte
)
607 if (xen_iomap_pte(pte
)) {
608 xen_set_iomap_pte(ptep
, pte
);
612 set_64bit((u64
*)ptep
, native_pte_val(pte
));
615 void xen_pte_clear(struct mm_struct
*mm
, unsigned long addr
, pte_t
*ptep
)
618 smp_wmb(); /* make sure low gets written first */
622 void xen_pmd_clear(pmd_t
*pmdp
)
624 set_pmd(pmdp
, __pmd(0));
626 #endif /* CONFIG_X86_PAE */
628 pmd_t
xen_make_pmd(pmdval_t pmd
)
630 pmd
= pte_pfn_to_mfn(pmd
);
631 return native_make_pmd(pmd
);
633 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd
);
635 #if PAGETABLE_LEVELS == 4
636 pudval_t
xen_pud_val(pud_t pud
)
638 return pte_mfn_to_pfn(pud
.pud
);
640 PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val
);
642 pud_t
xen_make_pud(pudval_t pud
)
644 pud
= pte_pfn_to_mfn(pud
);
646 return native_make_pud(pud
);
648 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pud
);
650 pgd_t
*xen_get_user_pgd(pgd_t
*pgd
)
652 pgd_t
*pgd_page
= (pgd_t
*)(((unsigned long)pgd
) & PAGE_MASK
);
653 unsigned offset
= pgd
- pgd_page
;
654 pgd_t
*user_ptr
= NULL
;
656 if (offset
< pgd_index(USER_LIMIT
)) {
657 struct page
*page
= virt_to_page(pgd_page
);
658 user_ptr
= (pgd_t
*)page
->private;
666 static void __xen_set_pgd_hyper(pgd_t
*ptr
, pgd_t val
)
670 u
.ptr
= virt_to_machine(ptr
).maddr
;
671 u
.val
= pgd_val_ma(val
);
672 xen_extend_mmu_update(&u
);
676 * Raw hypercall-based set_pgd, intended for in early boot before
677 * there's a page structure. This implies:
678 * 1. The only existing pagetable is the kernel's
679 * 2. It is always pinned
680 * 3. It has no user pagetable attached to it
682 void __init
xen_set_pgd_hyper(pgd_t
*ptr
, pgd_t val
)
688 __xen_set_pgd_hyper(ptr
, val
);
690 xen_mc_issue(PARAVIRT_LAZY_MMU
);
695 void xen_set_pgd(pgd_t
*ptr
, pgd_t val
)
697 pgd_t
*user_ptr
= xen_get_user_pgd(ptr
);
699 ADD_STATS(pgd_update
, 1);
701 /* If page is not pinned, we can just update the entry
703 if (!xen_page_pinned(ptr
)) {
706 WARN_ON(xen_page_pinned(user_ptr
));
712 ADD_STATS(pgd_update_pinned
, 1);
713 ADD_STATS(pgd_update_batched
, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU
);
715 /* If it's pinned, then we can at least batch the kernel and
716 user updates together. */
719 __xen_set_pgd_hyper(ptr
, val
);
721 __xen_set_pgd_hyper(user_ptr
, val
);
723 xen_mc_issue(PARAVIRT_LAZY_MMU
);
725 #endif /* PAGETABLE_LEVELS == 4 */
728 * (Yet another) pagetable walker. This one is intended for pinning a
729 * pagetable. This means that it walks a pagetable and calls the
730 * callback function on each page it finds making up the page table,
731 * at every level. It walks the entire pagetable, but it only bothers
732 * pinning pte pages which are below limit. In the normal case this
733 * will be STACK_TOP_MAX, but at boot we need to pin up to
736 * For 32-bit the important bit is that we don't pin beyond there,
737 * because then we start getting into Xen's ptes.
739 * For 64-bit, we must skip the Xen hole in the middle of the address
740 * space, just after the big x86-64 virtual hole.
742 static int __xen_pgd_walk(struct mm_struct
*mm
, pgd_t
*pgd
,
743 int (*func
)(struct mm_struct
*mm
, struct page
*,
748 unsigned hole_low
, hole_high
;
749 unsigned pgdidx_limit
, pudidx_limit
, pmdidx_limit
;
750 unsigned pgdidx
, pudidx
, pmdidx
;
752 /* The limit is the last byte to be touched */
754 BUG_ON(limit
>= FIXADDR_TOP
);
756 if (xen_feature(XENFEAT_auto_translated_physmap
))
760 * 64-bit has a great big hole in the middle of the address
761 * space, which contains the Xen mappings. On 32-bit these
762 * will end up making a zero-sized hole and so is a no-op.
764 hole_low
= pgd_index(USER_LIMIT
);
765 hole_high
= pgd_index(PAGE_OFFSET
);
767 pgdidx_limit
= pgd_index(limit
);
769 pudidx_limit
= pud_index(limit
);
774 pmdidx_limit
= pmd_index(limit
);
779 for (pgdidx
= 0; pgdidx
<= pgdidx_limit
; pgdidx
++) {
782 if (pgdidx
>= hole_low
&& pgdidx
< hole_high
)
785 if (!pgd_val(pgd
[pgdidx
]))
788 pud
= pud_offset(&pgd
[pgdidx
], 0);
790 if (PTRS_PER_PUD
> 1) /* not folded */
791 flush
|= (*func
)(mm
, virt_to_page(pud
), PT_PUD
);
793 for (pudidx
= 0; pudidx
< PTRS_PER_PUD
; pudidx
++) {
796 if (pgdidx
== pgdidx_limit
&&
797 pudidx
> pudidx_limit
)
800 if (pud_none(pud
[pudidx
]))
803 pmd
= pmd_offset(&pud
[pudidx
], 0);
805 if (PTRS_PER_PMD
> 1) /* not folded */
806 flush
|= (*func
)(mm
, virt_to_page(pmd
), PT_PMD
);
808 for (pmdidx
= 0; pmdidx
< PTRS_PER_PMD
; pmdidx
++) {
811 if (pgdidx
== pgdidx_limit
&&
812 pudidx
== pudidx_limit
&&
813 pmdidx
> pmdidx_limit
)
816 if (pmd_none(pmd
[pmdidx
]))
819 pte
= pmd_page(pmd
[pmdidx
]);
820 flush
|= (*func
)(mm
, pte
, PT_PTE
);
826 /* Do the top level last, so that the callbacks can use it as
827 a cue to do final things like tlb flushes. */
828 flush
|= (*func
)(mm
, virt_to_page(pgd
), PT_PGD
);
833 static int xen_pgd_walk(struct mm_struct
*mm
,
834 int (*func
)(struct mm_struct
*mm
, struct page
*,
838 return __xen_pgd_walk(mm
, mm
->pgd
, func
, limit
);
841 /* If we're using split pte locks, then take the page's lock and
842 return a pointer to it. Otherwise return NULL. */
843 static spinlock_t
*xen_pte_lock(struct page
*page
, struct mm_struct
*mm
)
845 spinlock_t
*ptl
= NULL
;
847 #if USE_SPLIT_PTLOCKS
848 ptl
= __pte_lockptr(page
);
849 spin_lock_nest_lock(ptl
, &mm
->page_table_lock
);
855 static void xen_pte_unlock(void *v
)
861 static void xen_do_pin(unsigned level
, unsigned long pfn
)
863 struct mmuext_op
*op
;
864 struct multicall_space mcs
;
866 mcs
= __xen_mc_entry(sizeof(*op
));
869 op
->arg1
.mfn
= pfn_to_mfn(pfn
);
870 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
873 static int xen_pin_page(struct mm_struct
*mm
, struct page
*page
,
876 unsigned pgfl
= TestSetPagePinned(page
);
880 flush
= 0; /* already pinned */
881 else if (PageHighMem(page
))
882 /* kmaps need flushing if we found an unpinned
886 void *pt
= lowmem_page_address(page
);
887 unsigned long pfn
= page_to_pfn(page
);
888 struct multicall_space mcs
= __xen_mc_entry(0);
894 * We need to hold the pagetable lock between the time
895 * we make the pagetable RO and when we actually pin
896 * it. If we don't, then other users may come in and
897 * attempt to update the pagetable by writing it,
898 * which will fail because the memory is RO but not
899 * pinned, so Xen won't do the trap'n'emulate.
901 * If we're using split pte locks, we can't hold the
902 * entire pagetable's worth of locks during the
903 * traverse, because we may wrap the preempt count (8
904 * bits). The solution is to mark RO and pin each PTE
905 * page while holding the lock. This means the number
906 * of locks we end up holding is never more than a
907 * batch size (~32 entries, at present).
909 * If we're not using split pte locks, we needn't pin
910 * the PTE pages independently, because we're
911 * protected by the overall pagetable lock.
915 ptl
= xen_pte_lock(page
, mm
);
917 MULTI_update_va_mapping(mcs
.mc
, (unsigned long)pt
,
918 pfn_pte(pfn
, PAGE_KERNEL_RO
),
919 level
== PT_PGD
? UVMF_TLB_FLUSH
: 0);
922 xen_do_pin(MMUEXT_PIN_L1_TABLE
, pfn
);
924 /* Queue a deferred unlock for when this batch
926 xen_mc_callback(xen_pte_unlock
, ptl
);
933 /* This is called just after a mm has been created, but it has not
934 been used yet. We need to make sure that its pagetable is all
935 read-only, and can be pinned. */
936 static void __xen_pgd_pin(struct mm_struct
*mm
, pgd_t
*pgd
)
940 if (__xen_pgd_walk(mm
, pgd
, xen_pin_page
, USER_LIMIT
)) {
941 /* re-enable interrupts for flushing */
951 pgd_t
*user_pgd
= xen_get_user_pgd(pgd
);
953 xen_do_pin(MMUEXT_PIN_L4_TABLE
, PFN_DOWN(__pa(pgd
)));
956 xen_pin_page(mm
, virt_to_page(user_pgd
), PT_PGD
);
957 xen_do_pin(MMUEXT_PIN_L4_TABLE
,
958 PFN_DOWN(__pa(user_pgd
)));
961 #else /* CONFIG_X86_32 */
962 #ifdef CONFIG_X86_PAE
963 /* Need to make sure unshared kernel PMD is pinnable */
964 xen_pin_page(mm
, pgd_page(pgd
[pgd_index(TASK_SIZE
)]),
967 xen_do_pin(MMUEXT_PIN_L3_TABLE
, PFN_DOWN(__pa(pgd
)));
968 #endif /* CONFIG_X86_64 */
972 static void xen_pgd_pin(struct mm_struct
*mm
)
974 __xen_pgd_pin(mm
, mm
->pgd
);
978 * On save, we need to pin all pagetables to make sure they get their
979 * mfns turned into pfns. Search the list for any unpinned pgds and pin
980 * them (unpinned pgds are not currently in use, probably because the
981 * process is under construction or destruction).
983 * Expected to be called in stop_machine() ("equivalent to taking
984 * every spinlock in the system"), so the locking doesn't really
985 * matter all that much.
987 void xen_mm_pin_all(void)
992 spin_lock_irqsave(&pgd_lock
, flags
);
994 list_for_each_entry(page
, &pgd_list
, lru
) {
995 if (!PagePinned(page
)) {
996 __xen_pgd_pin(&init_mm
, (pgd_t
*)page_address(page
));
997 SetPageSavePinned(page
);
1001 spin_unlock_irqrestore(&pgd_lock
, flags
);
1005 * The init_mm pagetable is really pinned as soon as its created, but
1006 * that's before we have page structures to store the bits. So do all
1007 * the book-keeping now.
1009 static __init
int xen_mark_pinned(struct mm_struct
*mm
, struct page
*page
,
1010 enum pt_level level
)
1012 SetPagePinned(page
);
1016 static void __init
xen_mark_init_mm_pinned(void)
1018 xen_pgd_walk(&init_mm
, xen_mark_pinned
, FIXADDR_TOP
);
1021 static int xen_unpin_page(struct mm_struct
*mm
, struct page
*page
,
1022 enum pt_level level
)
1024 unsigned pgfl
= TestClearPagePinned(page
);
1026 if (pgfl
&& !PageHighMem(page
)) {
1027 void *pt
= lowmem_page_address(page
);
1028 unsigned long pfn
= page_to_pfn(page
);
1029 spinlock_t
*ptl
= NULL
;
1030 struct multicall_space mcs
;
1033 * Do the converse to pin_page. If we're using split
1034 * pte locks, we must be holding the lock for while
1035 * the pte page is unpinned but still RO to prevent
1036 * concurrent updates from seeing it in this
1037 * partially-pinned state.
1039 if (level
== PT_PTE
) {
1040 ptl
= xen_pte_lock(page
, mm
);
1043 xen_do_pin(MMUEXT_UNPIN_TABLE
, pfn
);
1046 mcs
= __xen_mc_entry(0);
1048 MULTI_update_va_mapping(mcs
.mc
, (unsigned long)pt
,
1049 pfn_pte(pfn
, PAGE_KERNEL
),
1050 level
== PT_PGD
? UVMF_TLB_FLUSH
: 0);
1053 /* unlock when batch completed */
1054 xen_mc_callback(xen_pte_unlock
, ptl
);
1058 return 0; /* never need to flush on unpin */
1061 /* Release a pagetables pages back as normal RW */
1062 static void __xen_pgd_unpin(struct mm_struct
*mm
, pgd_t
*pgd
)
1066 xen_do_pin(MMUEXT_UNPIN_TABLE
, PFN_DOWN(__pa(pgd
)));
1068 #ifdef CONFIG_X86_64
1070 pgd_t
*user_pgd
= xen_get_user_pgd(pgd
);
1073 xen_do_pin(MMUEXT_UNPIN_TABLE
,
1074 PFN_DOWN(__pa(user_pgd
)));
1075 xen_unpin_page(mm
, virt_to_page(user_pgd
), PT_PGD
);
1080 #ifdef CONFIG_X86_PAE
1081 /* Need to make sure unshared kernel PMD is unpinned */
1082 xen_unpin_page(mm
, pgd_page(pgd
[pgd_index(TASK_SIZE
)]),
1086 __xen_pgd_walk(mm
, pgd
, xen_unpin_page
, USER_LIMIT
);
1091 static void xen_pgd_unpin(struct mm_struct
*mm
)
1093 __xen_pgd_unpin(mm
, mm
->pgd
);
1097 * On resume, undo any pinning done at save, so that the rest of the
1098 * kernel doesn't see any unexpected pinned pagetables.
1100 void xen_mm_unpin_all(void)
1102 unsigned long flags
;
1105 spin_lock_irqsave(&pgd_lock
, flags
);
1107 list_for_each_entry(page
, &pgd_list
, lru
) {
1108 if (PageSavePinned(page
)) {
1109 BUG_ON(!PagePinned(page
));
1110 __xen_pgd_unpin(&init_mm
, (pgd_t
*)page_address(page
));
1111 ClearPageSavePinned(page
);
1115 spin_unlock_irqrestore(&pgd_lock
, flags
);
1118 void xen_activate_mm(struct mm_struct
*prev
, struct mm_struct
*next
)
1120 spin_lock(&next
->page_table_lock
);
1122 spin_unlock(&next
->page_table_lock
);
1125 void xen_dup_mmap(struct mm_struct
*oldmm
, struct mm_struct
*mm
)
1127 spin_lock(&mm
->page_table_lock
);
1129 spin_unlock(&mm
->page_table_lock
);
1134 /* Another cpu may still have their %cr3 pointing at the pagetable, so
1135 we need to repoint it somewhere else before we can unpin it. */
1136 static void drop_other_mm_ref(void *info
)
1138 struct mm_struct
*mm
= info
;
1139 struct mm_struct
*active_mm
;
1141 active_mm
= percpu_read(cpu_tlbstate
.active_mm
);
1143 if (active_mm
== mm
)
1144 leave_mm(smp_processor_id());
1146 /* If this cpu still has a stale cr3 reference, then make sure
1147 it has been flushed. */
1148 if (percpu_read(xen_current_cr3
) == __pa(mm
->pgd
))
1149 load_cr3(swapper_pg_dir
);
1152 static void xen_drop_mm_ref(struct mm_struct
*mm
)
1157 if (current
->active_mm
== mm
) {
1158 if (current
->mm
== mm
)
1159 load_cr3(swapper_pg_dir
);
1161 leave_mm(smp_processor_id());
1164 /* Get the "official" set of cpus referring to our pagetable. */
1165 if (!alloc_cpumask_var(&mask
, GFP_ATOMIC
)) {
1166 for_each_online_cpu(cpu
) {
1167 if (!cpumask_test_cpu(cpu
, mm_cpumask(mm
))
1168 && per_cpu(xen_current_cr3
, cpu
) != __pa(mm
->pgd
))
1170 smp_call_function_single(cpu
, drop_other_mm_ref
, mm
, 1);
1174 cpumask_copy(mask
, mm_cpumask(mm
));
1176 /* It's possible that a vcpu may have a stale reference to our
1177 cr3, because its in lazy mode, and it hasn't yet flushed
1178 its set of pending hypercalls yet. In this case, we can
1179 look at its actual current cr3 value, and force it to flush
1181 for_each_online_cpu(cpu
) {
1182 if (per_cpu(xen_current_cr3
, cpu
) == __pa(mm
->pgd
))
1183 cpumask_set_cpu(cpu
, mask
);
1186 if (!cpumask_empty(mask
))
1187 smp_call_function_many(mask
, drop_other_mm_ref
, mm
, 1);
1188 free_cpumask_var(mask
);
1191 static void xen_drop_mm_ref(struct mm_struct
*mm
)
1193 if (current
->active_mm
== mm
)
1194 load_cr3(swapper_pg_dir
);
1199 * While a process runs, Xen pins its pagetables, which means that the
1200 * hypervisor forces it to be read-only, and it controls all updates
1201 * to it. This means that all pagetable updates have to go via the
1202 * hypervisor, which is moderately expensive.
1204 * Since we're pulling the pagetable down, we switch to use init_mm,
1205 * unpin old process pagetable and mark it all read-write, which
1206 * allows further operations on it to be simple memory accesses.
1208 * The only subtle point is that another CPU may be still using the
1209 * pagetable because of lazy tlb flushing. This means we need need to
1210 * switch all CPUs off this pagetable before we can unpin it.
1212 void xen_exit_mmap(struct mm_struct
*mm
)
1214 get_cpu(); /* make sure we don't move around */
1215 xen_drop_mm_ref(mm
);
1218 spin_lock(&mm
->page_table_lock
);
1220 /* pgd may not be pinned in the error exit path of execve */
1221 if (xen_page_pinned(mm
->pgd
))
1224 spin_unlock(&mm
->page_table_lock
);
1227 static __init
void xen_pagetable_setup_start(pgd_t
*base
)
1231 static void xen_post_allocator_init(void);
1233 static __init
void xen_pagetable_setup_done(pgd_t
*base
)
1235 xen_setup_shared_info();
1236 xen_post_allocator_init();
1239 static void xen_write_cr2(unsigned long cr2
)
1241 percpu_read(xen_vcpu
)->arch
.cr2
= cr2
;
1244 static unsigned long xen_read_cr2(void)
1246 return percpu_read(xen_vcpu
)->arch
.cr2
;
1249 unsigned long xen_read_cr2_direct(void)
1251 return percpu_read(xen_vcpu_info
.arch
.cr2
);
1254 static void xen_flush_tlb(void)
1256 struct mmuext_op
*op
;
1257 struct multicall_space mcs
;
1261 mcs
= xen_mc_entry(sizeof(*op
));
1264 op
->cmd
= MMUEXT_TLB_FLUSH_LOCAL
;
1265 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
1267 xen_mc_issue(PARAVIRT_LAZY_MMU
);
1272 static void xen_flush_tlb_single(unsigned long addr
)
1274 struct mmuext_op
*op
;
1275 struct multicall_space mcs
;
1279 mcs
= xen_mc_entry(sizeof(*op
));
1281 op
->cmd
= MMUEXT_INVLPG_LOCAL
;
1282 op
->arg1
.linear_addr
= addr
& PAGE_MASK
;
1283 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
1285 xen_mc_issue(PARAVIRT_LAZY_MMU
);
1290 static void xen_flush_tlb_others(const struct cpumask
*cpus
,
1291 struct mm_struct
*mm
, unsigned long va
)
1294 struct mmuext_op op
;
1295 DECLARE_BITMAP(mask
, NR_CPUS
);
1297 struct multicall_space mcs
;
1299 if (cpumask_empty(cpus
))
1300 return; /* nothing to do */
1302 mcs
= xen_mc_entry(sizeof(*args
));
1304 args
->op
.arg2
.vcpumask
= to_cpumask(args
->mask
);
1306 /* Remove us, and any offline CPUS. */
1307 cpumask_and(to_cpumask(args
->mask
), cpus
, cpu_online_mask
);
1308 cpumask_clear_cpu(smp_processor_id(), to_cpumask(args
->mask
));
1310 if (va
== TLB_FLUSH_ALL
) {
1311 args
->op
.cmd
= MMUEXT_TLB_FLUSH_MULTI
;
1313 args
->op
.cmd
= MMUEXT_INVLPG_MULTI
;
1314 args
->op
.arg1
.linear_addr
= va
;
1317 MULTI_mmuext_op(mcs
.mc
, &args
->op
, 1, NULL
, DOMID_SELF
);
1319 xen_mc_issue(PARAVIRT_LAZY_MMU
);
1322 static unsigned long xen_read_cr3(void)
1324 return percpu_read(xen_cr3
);
1327 static void set_current_cr3(void *v
)
1329 percpu_write(xen_current_cr3
, (unsigned long)v
);
1332 static void __xen_write_cr3(bool kernel
, unsigned long cr3
)
1334 struct mmuext_op
*op
;
1335 struct multicall_space mcs
;
1339 mfn
= pfn_to_mfn(PFN_DOWN(cr3
));
1343 WARN_ON(mfn
== 0 && kernel
);
1345 mcs
= __xen_mc_entry(sizeof(*op
));
1348 op
->cmd
= kernel
? MMUEXT_NEW_BASEPTR
: MMUEXT_NEW_USER_BASEPTR
;
1351 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
1354 percpu_write(xen_cr3
, cr3
);
1356 /* Update xen_current_cr3 once the batch has actually
1358 xen_mc_callback(set_current_cr3
, (void *)cr3
);
1362 static void xen_write_cr3(unsigned long cr3
)
1364 BUG_ON(preemptible());
1366 xen_mc_batch(); /* disables interrupts */
1368 /* Update while interrupts are disabled, so its atomic with
1370 percpu_write(xen_cr3
, cr3
);
1372 __xen_write_cr3(true, cr3
);
1374 #ifdef CONFIG_X86_64
1376 pgd_t
*user_pgd
= xen_get_user_pgd(__va(cr3
));
1378 __xen_write_cr3(false, __pa(user_pgd
));
1380 __xen_write_cr3(false, 0);
1384 xen_mc_issue(PARAVIRT_LAZY_CPU
); /* interrupts restored */
1387 static int xen_pgd_alloc(struct mm_struct
*mm
)
1389 pgd_t
*pgd
= mm
->pgd
;
1392 BUG_ON(PagePinned(virt_to_page(pgd
)));
1394 #ifdef CONFIG_X86_64
1396 struct page
*page
= virt_to_page(pgd
);
1399 BUG_ON(page
->private != 0);
1403 user_pgd
= (pgd_t
*)__get_free_page(GFP_KERNEL
| __GFP_ZERO
);
1404 page
->private = (unsigned long)user_pgd
;
1406 if (user_pgd
!= NULL
) {
1407 user_pgd
[pgd_index(VSYSCALL_START
)] =
1408 __pgd(__pa(level3_user_vsyscall
) | _PAGE_TABLE
);
1412 BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd
))));
1419 static void xen_pgd_free(struct mm_struct
*mm
, pgd_t
*pgd
)
1421 #ifdef CONFIG_X86_64
1422 pgd_t
*user_pgd
= xen_get_user_pgd(pgd
);
1425 free_page((unsigned long)user_pgd
);
1429 static __init pte_t
mask_rw_pte(pte_t
*ptep
, pte_t pte
)
1431 unsigned long pfn
= pte_pfn(pte
);
1433 #ifdef CONFIG_X86_32
1434 /* If there's an existing pte, then don't allow _PAGE_RW to be set */
1435 if (pte_val_ma(*ptep
) & _PAGE_PRESENT
)
1436 pte
= __pte_ma(((pte_val_ma(*ptep
) & _PAGE_RW
) | ~_PAGE_RW
) &
1441 * If the new pfn is within the range of the newly allocated
1442 * kernel pagetable, and it isn't being mapped into an
1443 * early_ioremap fixmap slot, make sure it is RO.
1445 if (!is_early_ioremap_ptep(ptep
) &&
1446 pfn
>= e820_table_start
&& pfn
< e820_table_end
)
1447 pte
= pte_wrprotect(pte
);
1452 /* Init-time set_pte while constructing initial pagetables, which
1453 doesn't allow RO pagetable pages to be remapped RW */
1454 static __init
void xen_set_pte_init(pte_t
*ptep
, pte_t pte
)
1456 pte
= mask_rw_pte(ptep
, pte
);
1458 xen_set_pte(ptep
, pte
);
1461 static void pin_pagetable_pfn(unsigned cmd
, unsigned long pfn
)
1463 struct mmuext_op op
;
1465 op
.arg1
.mfn
= pfn_to_mfn(pfn
);
1466 if (HYPERVISOR_mmuext_op(&op
, 1, NULL
, DOMID_SELF
))
1470 /* Early in boot, while setting up the initial pagetable, assume
1471 everything is pinned. */
1472 static __init
void xen_alloc_pte_init(struct mm_struct
*mm
, unsigned long pfn
)
1474 #ifdef CONFIG_FLATMEM
1475 BUG_ON(mem_map
); /* should only be used early */
1477 make_lowmem_page_readonly(__va(PFN_PHYS(pfn
)));
1478 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE
, pfn
);
1481 /* Used for pmd and pud */
1482 static __init
void xen_alloc_pmd_init(struct mm_struct
*mm
, unsigned long pfn
)
1484 #ifdef CONFIG_FLATMEM
1485 BUG_ON(mem_map
); /* should only be used early */
1487 make_lowmem_page_readonly(__va(PFN_PHYS(pfn
)));
1490 /* Early release_pte assumes that all pts are pinned, since there's
1491 only init_mm and anything attached to that is pinned. */
1492 static __init
void xen_release_pte_init(unsigned long pfn
)
1494 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, pfn
);
1495 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
1498 static __init
void xen_release_pmd_init(unsigned long pfn
)
1500 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
1503 /* This needs to make sure the new pte page is pinned iff its being
1504 attached to a pinned pagetable. */
1505 static void xen_alloc_ptpage(struct mm_struct
*mm
, unsigned long pfn
, unsigned level
)
1507 struct page
*page
= pfn_to_page(pfn
);
1509 if (PagePinned(virt_to_page(mm
->pgd
))) {
1510 SetPagePinned(page
);
1512 if (!PageHighMem(page
)) {
1513 make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn
)));
1514 if (level
== PT_PTE
&& USE_SPLIT_PTLOCKS
)
1515 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE
, pfn
);
1517 /* make sure there are no stray mappings of
1519 kmap_flush_unused();
1524 static void xen_alloc_pte(struct mm_struct
*mm
, unsigned long pfn
)
1526 xen_alloc_ptpage(mm
, pfn
, PT_PTE
);
1529 static void xen_alloc_pmd(struct mm_struct
*mm
, unsigned long pfn
)
1531 xen_alloc_ptpage(mm
, pfn
, PT_PMD
);
1534 /* This should never happen until we're OK to use struct page */
1535 static void xen_release_ptpage(unsigned long pfn
, unsigned level
)
1537 struct page
*page
= pfn_to_page(pfn
);
1539 if (PagePinned(page
)) {
1540 if (!PageHighMem(page
)) {
1541 if (level
== PT_PTE
&& USE_SPLIT_PTLOCKS
)
1542 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, pfn
);
1543 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
1545 ClearPagePinned(page
);
1549 static void xen_release_pte(unsigned long pfn
)
1551 xen_release_ptpage(pfn
, PT_PTE
);
1554 static void xen_release_pmd(unsigned long pfn
)
1556 xen_release_ptpage(pfn
, PT_PMD
);
1559 #if PAGETABLE_LEVELS == 4
1560 static void xen_alloc_pud(struct mm_struct
*mm
, unsigned long pfn
)
1562 xen_alloc_ptpage(mm
, pfn
, PT_PUD
);
1565 static void xen_release_pud(unsigned long pfn
)
1567 xen_release_ptpage(pfn
, PT_PUD
);
1571 void __init
xen_reserve_top(void)
1573 #ifdef CONFIG_X86_32
1574 unsigned long top
= HYPERVISOR_VIRT_START
;
1575 struct xen_platform_parameters pp
;
1577 if (HYPERVISOR_xen_version(XENVER_platform_parameters
, &pp
) == 0)
1578 top
= pp
.virt_start
;
1580 reserve_top_address(-top
);
1581 #endif /* CONFIG_X86_32 */
1585 * Like __va(), but returns address in the kernel mapping (which is
1586 * all we have until the physical memory mapping has been set up.
1588 static void *__ka(phys_addr_t paddr
)
1590 #ifdef CONFIG_X86_64
1591 return (void *)(paddr
+ __START_KERNEL_map
);
1597 /* Convert a machine address to physical address */
1598 static unsigned long m2p(phys_addr_t maddr
)
1602 maddr
&= PTE_PFN_MASK
;
1603 paddr
= mfn_to_pfn(maddr
>> PAGE_SHIFT
) << PAGE_SHIFT
;
1608 /* Convert a machine address to kernel virtual */
1609 static void *m2v(phys_addr_t maddr
)
1611 return __ka(m2p(maddr
));
1614 /* Set the page permissions on an identity-mapped pages */
1615 static void set_page_prot(void *addr
, pgprot_t prot
)
1617 unsigned long pfn
= __pa(addr
) >> PAGE_SHIFT
;
1618 pte_t pte
= pfn_pte(pfn
, prot
);
1620 if (HYPERVISOR_update_va_mapping((unsigned long)addr
, pte
, 0))
1624 static __init
void xen_map_identity_early(pmd_t
*pmd
, unsigned long max_pfn
)
1626 unsigned pmdidx
, pteidx
;
1630 level1_ident_pgt
= extend_brk(sizeof(pte_t
) * LEVEL1_IDENT_ENTRIES
,
1635 for (pmdidx
= 0; pmdidx
< PTRS_PER_PMD
&& pfn
< max_pfn
; pmdidx
++) {
1638 /* Reuse or allocate a page of ptes */
1639 if (pmd_present(pmd
[pmdidx
]))
1640 pte_page
= m2v(pmd
[pmdidx
].pmd
);
1642 /* Check for free pte pages */
1643 if (ident_pte
== LEVEL1_IDENT_ENTRIES
)
1646 pte_page
= &level1_ident_pgt
[ident_pte
];
1647 ident_pte
+= PTRS_PER_PTE
;
1649 pmd
[pmdidx
] = __pmd(__pa(pte_page
) | _PAGE_TABLE
);
1652 /* Install mappings */
1653 for (pteidx
= 0; pteidx
< PTRS_PER_PTE
; pteidx
++, pfn
++) {
1656 if (pfn
> max_pfn_mapped
)
1657 max_pfn_mapped
= pfn
;
1659 if (!pte_none(pte_page
[pteidx
]))
1662 pte
= pfn_pte(pfn
, PAGE_KERNEL_EXEC
);
1663 pte_page
[pteidx
] = pte
;
1667 for (pteidx
= 0; pteidx
< ident_pte
; pteidx
+= PTRS_PER_PTE
)
1668 set_page_prot(&level1_ident_pgt
[pteidx
], PAGE_KERNEL_RO
);
1670 set_page_prot(pmd
, PAGE_KERNEL_RO
);
1673 void __init
xen_setup_machphys_mapping(void)
1675 struct xen_machphys_mapping mapping
;
1676 unsigned long machine_to_phys_nr_ents
;
1678 if (HYPERVISOR_memory_op(XENMEM_machphys_mapping
, &mapping
) == 0) {
1679 machine_to_phys_mapping
= (unsigned long *)mapping
.v_start
;
1680 machine_to_phys_nr_ents
= mapping
.max_mfn
+ 1;
1682 machine_to_phys_nr_ents
= MACH2PHYS_NR_ENTRIES
;
1684 machine_to_phys_order
= fls(machine_to_phys_nr_ents
- 1);
1687 #ifdef CONFIG_X86_64
1688 static void convert_pfn_mfn(void *v
)
1693 /* All levels are converted the same way, so just treat them
1695 for (i
= 0; i
< PTRS_PER_PTE
; i
++)
1696 pte
[i
] = xen_make_pte(pte
[i
].pte
);
1700 * Set up the inital kernel pagetable.
1702 * We can construct this by grafting the Xen provided pagetable into
1703 * head_64.S's preconstructed pagetables. We copy the Xen L2's into
1704 * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt. This
1705 * means that only the kernel has a physical mapping to start with -
1706 * but that's enough to get __va working. We need to fill in the rest
1707 * of the physical mapping once some sort of allocator has been set
1710 __init pgd_t
*xen_setup_kernel_pagetable(pgd_t
*pgd
,
1711 unsigned long max_pfn
)
1716 /* Zap identity mapping */
1717 init_level4_pgt
[0] = __pgd(0);
1719 /* Pre-constructed entries are in pfn, so convert to mfn */
1720 convert_pfn_mfn(init_level4_pgt
);
1721 convert_pfn_mfn(level3_ident_pgt
);
1722 convert_pfn_mfn(level3_kernel_pgt
);
1724 l3
= m2v(pgd
[pgd_index(__START_KERNEL_map
)].pgd
);
1725 l2
= m2v(l3
[pud_index(__START_KERNEL_map
)].pud
);
1727 memcpy(level2_ident_pgt
, l2
, sizeof(pmd_t
) * PTRS_PER_PMD
);
1728 memcpy(level2_kernel_pgt
, l2
, sizeof(pmd_t
) * PTRS_PER_PMD
);
1730 l3
= m2v(pgd
[pgd_index(__START_KERNEL_map
+ PMD_SIZE
)].pgd
);
1731 l2
= m2v(l3
[pud_index(__START_KERNEL_map
+ PMD_SIZE
)].pud
);
1732 memcpy(level2_fixmap_pgt
, l2
, sizeof(pmd_t
) * PTRS_PER_PMD
);
1734 /* Set up identity map */
1735 xen_map_identity_early(level2_ident_pgt
, max_pfn
);
1737 /* Make pagetable pieces RO */
1738 set_page_prot(init_level4_pgt
, PAGE_KERNEL_RO
);
1739 set_page_prot(level3_ident_pgt
, PAGE_KERNEL_RO
);
1740 set_page_prot(level3_kernel_pgt
, PAGE_KERNEL_RO
);
1741 set_page_prot(level3_user_vsyscall
, PAGE_KERNEL_RO
);
1742 set_page_prot(level2_kernel_pgt
, PAGE_KERNEL_RO
);
1743 set_page_prot(level2_fixmap_pgt
, PAGE_KERNEL_RO
);
1745 /* Pin down new L4 */
1746 pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE
,
1747 PFN_DOWN(__pa_symbol(init_level4_pgt
)));
1749 /* Unpin Xen-provided one */
1750 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, PFN_DOWN(__pa(pgd
)));
1753 pgd
= init_level4_pgt
;
1756 * At this stage there can be no user pgd, and no page
1757 * structure to attach it to, so make sure we just set kernel
1761 __xen_write_cr3(true, __pa(pgd
));
1762 xen_mc_issue(PARAVIRT_LAZY_CPU
);
1764 memblock_x86_reserve_range(__pa(xen_start_info
->pt_base
),
1765 __pa(xen_start_info
->pt_base
+
1766 xen_start_info
->nr_pt_frames
* PAGE_SIZE
),
1771 #else /* !CONFIG_X86_64 */
1772 static RESERVE_BRK_ARRAY(pmd_t
, initial_kernel_pmd
, PTRS_PER_PMD
);
1773 static RESERVE_BRK_ARRAY(pmd_t
, swapper_kernel_pmd
, PTRS_PER_PMD
);
1775 static __init
void xen_write_cr3_init(unsigned long cr3
)
1777 unsigned long pfn
= PFN_DOWN(__pa(swapper_pg_dir
));
1779 BUG_ON(read_cr3() != __pa(initial_page_table
));
1780 BUG_ON(cr3
!= __pa(swapper_pg_dir
));
1783 * We are switching to swapper_pg_dir for the first time (from
1784 * initial_page_table) and therefore need to mark that page
1785 * read-only and then pin it.
1787 * Xen disallows sharing of kernel PMDs for PAE
1788 * guests. Therefore we must copy the kernel PMD from
1789 * initial_page_table into a new kernel PMD to be used in
1792 swapper_kernel_pmd
=
1793 extend_brk(sizeof(pmd_t
) * PTRS_PER_PMD
, PAGE_SIZE
);
1794 memcpy(swapper_kernel_pmd
, initial_kernel_pmd
,
1795 sizeof(pmd_t
) * PTRS_PER_PMD
);
1796 swapper_pg_dir
[KERNEL_PGD_BOUNDARY
] =
1797 __pgd(__pa(swapper_kernel_pmd
) | _PAGE_PRESENT
);
1798 set_page_prot(swapper_kernel_pmd
, PAGE_KERNEL_RO
);
1800 set_page_prot(swapper_pg_dir
, PAGE_KERNEL_RO
);
1802 pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE
, pfn
);
1804 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
,
1805 PFN_DOWN(__pa(initial_page_table
)));
1806 set_page_prot(initial_page_table
, PAGE_KERNEL
);
1807 set_page_prot(initial_kernel_pmd
, PAGE_KERNEL
);
1809 pv_mmu_ops
.write_cr3
= &xen_write_cr3
;
1812 __init pgd_t
*xen_setup_kernel_pagetable(pgd_t
*pgd
,
1813 unsigned long max_pfn
)
1817 initial_kernel_pmd
=
1818 extend_brk(sizeof(pmd_t
) * PTRS_PER_PMD
, PAGE_SIZE
);
1820 max_pfn_mapped
= PFN_DOWN(__pa(xen_start_info
->pt_base
) +
1821 xen_start_info
->nr_pt_frames
* PAGE_SIZE
+
1824 kernel_pmd
= m2v(pgd
[KERNEL_PGD_BOUNDARY
].pgd
);
1825 memcpy(initial_kernel_pmd
, kernel_pmd
, sizeof(pmd_t
) * PTRS_PER_PMD
);
1827 xen_map_identity_early(initial_kernel_pmd
, max_pfn
);
1829 memcpy(initial_page_table
, pgd
, sizeof(pgd_t
) * PTRS_PER_PGD
);
1830 initial_page_table
[KERNEL_PGD_BOUNDARY
] =
1831 __pgd(__pa(initial_kernel_pmd
) | _PAGE_PRESENT
);
1833 set_page_prot(initial_kernel_pmd
, PAGE_KERNEL_RO
);
1834 set_page_prot(initial_page_table
, PAGE_KERNEL_RO
);
1835 set_page_prot(empty_zero_page
, PAGE_KERNEL_RO
);
1837 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, PFN_DOWN(__pa(pgd
)));
1839 pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE
,
1840 PFN_DOWN(__pa(initial_page_table
)));
1841 xen_write_cr3(__pa(initial_page_table
));
1843 memblock_x86_reserve_range(__pa(xen_start_info
->pt_base
),
1844 __pa(xen_start_info
->pt_base
+
1845 xen_start_info
->nr_pt_frames
* PAGE_SIZE
),
1848 return initial_page_table
;
1850 #endif /* CONFIG_X86_64 */
1852 static unsigned char dummy_mapping
[PAGE_SIZE
] __page_aligned_bss
;
1854 static void xen_set_fixmap(unsigned idx
, phys_addr_t phys
, pgprot_t prot
)
1858 phys
>>= PAGE_SHIFT
;
1861 case FIX_BTMAP_END
... FIX_BTMAP_BEGIN
:
1862 #ifdef CONFIG_X86_F00F_BUG
1865 #ifdef CONFIG_X86_32
1868 # ifdef CONFIG_HIGHMEM
1869 case FIX_KMAP_BEGIN
... FIX_KMAP_END
:
1872 case VSYSCALL_LAST_PAGE
... VSYSCALL_FIRST_PAGE
:
1874 case FIX_TEXT_POKE0
:
1875 case FIX_TEXT_POKE1
:
1876 /* All local page mappings */
1877 pte
= pfn_pte(phys
, prot
);
1880 #ifdef CONFIG_X86_LOCAL_APIC
1881 case FIX_APIC_BASE
: /* maps dummy local APIC */
1882 pte
= pfn_pte(PFN_DOWN(__pa(dummy_mapping
)), PAGE_KERNEL
);
1886 #ifdef CONFIG_X86_IO_APIC
1887 case FIX_IO_APIC_BASE_0
... FIX_IO_APIC_BASE_END
:
1889 * We just don't map the IO APIC - all access is via
1890 * hypercalls. Keep the address in the pte for reference.
1892 pte
= pfn_pte(PFN_DOWN(__pa(dummy_mapping
)), PAGE_KERNEL
);
1896 case FIX_PARAVIRT_BOOTMAP
:
1897 /* This is an MFN, but it isn't an IO mapping from the
1899 pte
= mfn_pte(phys
, prot
);
1903 /* By default, set_fixmap is used for hardware mappings */
1904 pte
= mfn_pte(phys
, __pgprot(pgprot_val(prot
) | _PAGE_IOMAP
));
1908 __native_set_fixmap(idx
, pte
);
1910 #ifdef CONFIG_X86_64
1911 /* Replicate changes to map the vsyscall page into the user
1912 pagetable vsyscall mapping. */
1913 if (idx
>= VSYSCALL_LAST_PAGE
&& idx
<= VSYSCALL_FIRST_PAGE
) {
1914 unsigned long vaddr
= __fix_to_virt(idx
);
1915 set_pte_vaddr_pud(level3_user_vsyscall
, vaddr
, pte
);
1920 __init
void xen_ident_map_ISA(void)
1925 * If we're dom0, then linear map the ISA machine addresses into
1926 * the kernel's address space.
1928 if (!xen_initial_domain())
1931 xen_raw_printk("Xen: setup ISA identity maps\n");
1933 for (pa
= ISA_START_ADDRESS
; pa
< ISA_END_ADDRESS
; pa
+= PAGE_SIZE
) {
1934 pte_t pte
= mfn_pte(PFN_DOWN(pa
), PAGE_KERNEL_IO
);
1936 if (HYPERVISOR_update_va_mapping(PAGE_OFFSET
+ pa
, pte
, 0))
1943 static __init
void xen_post_allocator_init(void)
1945 pv_mmu_ops
.set_pte
= xen_set_pte
;
1946 pv_mmu_ops
.set_pmd
= xen_set_pmd
;
1947 pv_mmu_ops
.set_pud
= xen_set_pud
;
1948 #if PAGETABLE_LEVELS == 4
1949 pv_mmu_ops
.set_pgd
= xen_set_pgd
;
1952 /* This will work as long as patching hasn't happened yet
1953 (which it hasn't) */
1954 pv_mmu_ops
.alloc_pte
= xen_alloc_pte
;
1955 pv_mmu_ops
.alloc_pmd
= xen_alloc_pmd
;
1956 pv_mmu_ops
.release_pte
= xen_release_pte
;
1957 pv_mmu_ops
.release_pmd
= xen_release_pmd
;
1958 #if PAGETABLE_LEVELS == 4
1959 pv_mmu_ops
.alloc_pud
= xen_alloc_pud
;
1960 pv_mmu_ops
.release_pud
= xen_release_pud
;
1963 #ifdef CONFIG_X86_64
1964 SetPagePinned(virt_to_page(level3_user_vsyscall
));
1966 xen_mark_init_mm_pinned();
1969 static void xen_leave_lazy_mmu(void)
1973 paravirt_leave_lazy_mmu();
1977 static const struct pv_mmu_ops xen_mmu_ops __initdata
= {
1978 .read_cr2
= xen_read_cr2
,
1979 .write_cr2
= xen_write_cr2
,
1981 .read_cr3
= xen_read_cr3
,
1982 #ifdef CONFIG_X86_32
1983 .write_cr3
= xen_write_cr3_init
,
1985 .write_cr3
= xen_write_cr3
,
1988 .flush_tlb_user
= xen_flush_tlb
,
1989 .flush_tlb_kernel
= xen_flush_tlb
,
1990 .flush_tlb_single
= xen_flush_tlb_single
,
1991 .flush_tlb_others
= xen_flush_tlb_others
,
1993 .pte_update
= paravirt_nop
,
1994 .pte_update_defer
= paravirt_nop
,
1996 .pgd_alloc
= xen_pgd_alloc
,
1997 .pgd_free
= xen_pgd_free
,
1999 .alloc_pte
= xen_alloc_pte_init
,
2000 .release_pte
= xen_release_pte_init
,
2001 .alloc_pmd
= xen_alloc_pmd_init
,
2002 .release_pmd
= xen_release_pmd_init
,
2004 .set_pte
= xen_set_pte_init
,
2005 .set_pte_at
= xen_set_pte_at
,
2006 .set_pmd
= xen_set_pmd_hyper
,
2008 .ptep_modify_prot_start
= __ptep_modify_prot_start
,
2009 .ptep_modify_prot_commit
= __ptep_modify_prot_commit
,
2011 .pte_val
= PV_CALLEE_SAVE(xen_pte_val
),
2012 .pgd_val
= PV_CALLEE_SAVE(xen_pgd_val
),
2014 .make_pte
= PV_CALLEE_SAVE(xen_make_pte
),
2015 .make_pgd
= PV_CALLEE_SAVE(xen_make_pgd
),
2017 #ifdef CONFIG_X86_PAE
2018 .set_pte_atomic
= xen_set_pte_atomic
,
2019 .pte_clear
= xen_pte_clear
,
2020 .pmd_clear
= xen_pmd_clear
,
2021 #endif /* CONFIG_X86_PAE */
2022 .set_pud
= xen_set_pud_hyper
,
2024 .make_pmd
= PV_CALLEE_SAVE(xen_make_pmd
),
2025 .pmd_val
= PV_CALLEE_SAVE(xen_pmd_val
),
2027 #if PAGETABLE_LEVELS == 4
2028 .pud_val
= PV_CALLEE_SAVE(xen_pud_val
),
2029 .make_pud
= PV_CALLEE_SAVE(xen_make_pud
),
2030 .set_pgd
= xen_set_pgd_hyper
,
2032 .alloc_pud
= xen_alloc_pmd_init
,
2033 .release_pud
= xen_release_pmd_init
,
2034 #endif /* PAGETABLE_LEVELS == 4 */
2036 .activate_mm
= xen_activate_mm
,
2037 .dup_mmap
= xen_dup_mmap
,
2038 .exit_mmap
= xen_exit_mmap
,
2041 .enter
= paravirt_enter_lazy_mmu
,
2042 .leave
= xen_leave_lazy_mmu
,
2045 .set_fixmap
= xen_set_fixmap
,
2048 void __init
xen_init_mmu_ops(void)
2050 x86_init
.paging
.pagetable_setup_start
= xen_pagetable_setup_start
;
2051 x86_init
.paging
.pagetable_setup_done
= xen_pagetable_setup_done
;
2052 pv_mmu_ops
= xen_mmu_ops
;
2054 memset(dummy_mapping
, 0xff, PAGE_SIZE
);
2057 /* Protected by xen_reservation_lock. */
2058 #define MAX_CONTIG_ORDER 9 /* 2MB */
2059 static unsigned long discontig_frames
[1<<MAX_CONTIG_ORDER
];
2061 #define VOID_PTE (mfn_pte(0, __pgprot(0)))
2062 static void xen_zap_pfn_range(unsigned long vaddr
, unsigned int order
,
2063 unsigned long *in_frames
,
2064 unsigned long *out_frames
)
2067 struct multicall_space mcs
;
2070 for (i
= 0; i
< (1UL<<order
); i
++, vaddr
+= PAGE_SIZE
) {
2071 mcs
= __xen_mc_entry(0);
2074 in_frames
[i
] = virt_to_mfn(vaddr
);
2076 MULTI_update_va_mapping(mcs
.mc
, vaddr
, VOID_PTE
, 0);
2077 set_phys_to_machine(virt_to_pfn(vaddr
), INVALID_P2M_ENTRY
);
2080 out_frames
[i
] = virt_to_pfn(vaddr
);
2086 * Update the pfn-to-mfn mappings for a virtual address range, either to
2087 * point to an array of mfns, or contiguously from a single starting
2090 static void xen_remap_exchanged_ptes(unsigned long vaddr
, int order
,
2091 unsigned long *mfns
,
2092 unsigned long first_mfn
)
2099 limit
= 1u << order
;
2100 for (i
= 0; i
< limit
; i
++, vaddr
+= PAGE_SIZE
) {
2101 struct multicall_space mcs
;
2104 mcs
= __xen_mc_entry(0);
2108 mfn
= first_mfn
+ i
;
2110 if (i
< (limit
- 1))
2114 flags
= UVMF_INVLPG
| UVMF_ALL
;
2116 flags
= UVMF_TLB_FLUSH
| UVMF_ALL
;
2119 MULTI_update_va_mapping(mcs
.mc
, vaddr
,
2120 mfn_pte(mfn
, PAGE_KERNEL
), flags
);
2122 set_phys_to_machine(virt_to_pfn(vaddr
), mfn
);
2129 * Perform the hypercall to exchange a region of our pfns to point to
2130 * memory with the required contiguous alignment. Takes the pfns as
2131 * input, and populates mfns as output.
2133 * Returns a success code indicating whether the hypervisor was able to
2134 * satisfy the request or not.
2136 static int xen_exchange_memory(unsigned long extents_in
, unsigned int order_in
,
2137 unsigned long *pfns_in
,
2138 unsigned long extents_out
,
2139 unsigned int order_out
,
2140 unsigned long *mfns_out
,
2141 unsigned int address_bits
)
2146 struct xen_memory_exchange exchange
= {
2148 .nr_extents
= extents_in
,
2149 .extent_order
= order_in
,
2150 .extent_start
= pfns_in
,
2154 .nr_extents
= extents_out
,
2155 .extent_order
= order_out
,
2156 .extent_start
= mfns_out
,
2157 .address_bits
= address_bits
,
2162 BUG_ON(extents_in
<< order_in
!= extents_out
<< order_out
);
2164 rc
= HYPERVISOR_memory_op(XENMEM_exchange
, &exchange
);
2165 success
= (exchange
.nr_exchanged
== extents_in
);
2167 BUG_ON(!success
&& ((exchange
.nr_exchanged
!= 0) || (rc
== 0)));
2168 BUG_ON(success
&& (rc
!= 0));
2173 int xen_create_contiguous_region(unsigned long vstart
, unsigned int order
,
2174 unsigned int address_bits
)
2176 unsigned long *in_frames
= discontig_frames
, out_frame
;
2177 unsigned long flags
;
2181 * Currently an auto-translated guest will not perform I/O, nor will
2182 * it require PAE page directories below 4GB. Therefore any calls to
2183 * this function are redundant and can be ignored.
2186 if (xen_feature(XENFEAT_auto_translated_physmap
))
2189 if (unlikely(order
> MAX_CONTIG_ORDER
))
2192 memset((void *) vstart
, 0, PAGE_SIZE
<< order
);
2194 spin_lock_irqsave(&xen_reservation_lock
, flags
);
2196 /* 1. Zap current PTEs, remembering MFNs. */
2197 xen_zap_pfn_range(vstart
, order
, in_frames
, NULL
);
2199 /* 2. Get a new contiguous memory extent. */
2200 out_frame
= virt_to_pfn(vstart
);
2201 success
= xen_exchange_memory(1UL << order
, 0, in_frames
,
2202 1, order
, &out_frame
,
2205 /* 3. Map the new extent in place of old pages. */
2207 xen_remap_exchanged_ptes(vstart
, order
, NULL
, out_frame
);
2209 xen_remap_exchanged_ptes(vstart
, order
, in_frames
, 0);
2211 spin_unlock_irqrestore(&xen_reservation_lock
, flags
);
2213 return success
? 0 : -ENOMEM
;
2215 EXPORT_SYMBOL_GPL(xen_create_contiguous_region
);
2217 void xen_destroy_contiguous_region(unsigned long vstart
, unsigned int order
)
2219 unsigned long *out_frames
= discontig_frames
, in_frame
;
2220 unsigned long flags
;
2223 if (xen_feature(XENFEAT_auto_translated_physmap
))
2226 if (unlikely(order
> MAX_CONTIG_ORDER
))
2229 memset((void *) vstart
, 0, PAGE_SIZE
<< order
);
2231 spin_lock_irqsave(&xen_reservation_lock
, flags
);
2233 /* 1. Find start MFN of contiguous extent. */
2234 in_frame
= virt_to_mfn(vstart
);
2236 /* 2. Zap current PTEs. */
2237 xen_zap_pfn_range(vstart
, order
, NULL
, out_frames
);
2239 /* 3. Do the exchange for non-contiguous MFNs. */
2240 success
= xen_exchange_memory(1, order
, &in_frame
, 1UL << order
,
2243 /* 4. Map new pages in place of old pages. */
2245 xen_remap_exchanged_ptes(vstart
, order
, out_frames
, 0);
2247 xen_remap_exchanged_ptes(vstart
, order
, NULL
, in_frame
);
2249 spin_unlock_irqrestore(&xen_reservation_lock
, flags
);
2251 EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region
);
2253 #ifdef CONFIG_XEN_PVHVM
2254 static void xen_hvm_exit_mmap(struct mm_struct
*mm
)
2256 struct xen_hvm_pagetable_dying a
;
2259 a
.domid
= DOMID_SELF
;
2260 a
.gpa
= __pa(mm
->pgd
);
2261 rc
= HYPERVISOR_hvm_op(HVMOP_pagetable_dying
, &a
);
2262 WARN_ON_ONCE(rc
< 0);
2265 static int is_pagetable_dying_supported(void)
2267 struct xen_hvm_pagetable_dying a
;
2270 a
.domid
= DOMID_SELF
;
2272 rc
= HYPERVISOR_hvm_op(HVMOP_pagetable_dying
, &a
);
2274 printk(KERN_DEBUG
"HVMOP_pagetable_dying not supported\n");
2280 void __init
xen_hvm_init_mmu_ops(void)
2282 if (is_pagetable_dying_supported())
2283 pv_mmu_ops
.exit_mmap
= xen_hvm_exit_mmap
;
2287 #define REMAP_BATCH_SIZE 16
2292 struct mmu_update
*mmu_update
;
2295 static int remap_area_mfn_pte_fn(pte_t
*ptep
, pgtable_t token
,
2296 unsigned long addr
, void *data
)
2298 struct remap_data
*rmd
= data
;
2299 pte_t pte
= pte_mkspecial(pfn_pte(rmd
->mfn
++, rmd
->prot
));
2301 rmd
->mmu_update
->ptr
= arbitrary_virt_to_machine(ptep
).maddr
;
2302 rmd
->mmu_update
->val
= pte_val_ma(pte
);
2308 int xen_remap_domain_mfn_range(struct vm_area_struct
*vma
,
2310 unsigned long mfn
, int nr
,
2311 pgprot_t prot
, unsigned domid
)
2313 struct remap_data rmd
;
2314 struct mmu_update mmu_update
[REMAP_BATCH_SIZE
];
2316 unsigned long range
;
2319 prot
= __pgprot(pgprot_val(prot
) | _PAGE_IOMAP
);
2321 BUG_ON(!((vma
->vm_flags
& (VM_PFNMAP
| VM_RESERVED
| VM_IO
)) ==
2322 (VM_PFNMAP
| VM_RESERVED
| VM_IO
)));
2328 batch
= min(REMAP_BATCH_SIZE
, nr
);
2329 range
= (unsigned long)batch
<< PAGE_SHIFT
;
2331 rmd
.mmu_update
= mmu_update
;
2332 err
= apply_to_page_range(vma
->vm_mm
, addr
, range
,
2333 remap_area_mfn_pte_fn
, &rmd
);
2338 if (HYPERVISOR_mmu_update(mmu_update
, batch
, NULL
, domid
) < 0)
2352 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range
);
2354 #ifdef CONFIG_XEN_DEBUG_FS
2356 static struct dentry
*d_mmu_debug
;
2358 static int __init
xen_mmu_debugfs(void)
2360 struct dentry
*d_xen
= xen_init_debugfs();
2365 d_mmu_debug
= debugfs_create_dir("mmu", d_xen
);
2367 debugfs_create_u8("zero_stats", 0644, d_mmu_debug
, &zero_stats
);
2369 debugfs_create_u32("pgd_update", 0444, d_mmu_debug
, &mmu_stats
.pgd_update
);
2370 debugfs_create_u32("pgd_update_pinned", 0444, d_mmu_debug
,
2371 &mmu_stats
.pgd_update_pinned
);
2372 debugfs_create_u32("pgd_update_batched", 0444, d_mmu_debug
,
2373 &mmu_stats
.pgd_update_pinned
);
2375 debugfs_create_u32("pud_update", 0444, d_mmu_debug
, &mmu_stats
.pud_update
);
2376 debugfs_create_u32("pud_update_pinned", 0444, d_mmu_debug
,
2377 &mmu_stats
.pud_update_pinned
);
2378 debugfs_create_u32("pud_update_batched", 0444, d_mmu_debug
,
2379 &mmu_stats
.pud_update_pinned
);
2381 debugfs_create_u32("pmd_update", 0444, d_mmu_debug
, &mmu_stats
.pmd_update
);
2382 debugfs_create_u32("pmd_update_pinned", 0444, d_mmu_debug
,
2383 &mmu_stats
.pmd_update_pinned
);
2384 debugfs_create_u32("pmd_update_batched", 0444, d_mmu_debug
,
2385 &mmu_stats
.pmd_update_pinned
);
2387 debugfs_create_u32("pte_update", 0444, d_mmu_debug
, &mmu_stats
.pte_update
);
2388 // debugfs_create_u32("pte_update_pinned", 0444, d_mmu_debug,
2389 // &mmu_stats.pte_update_pinned);
2390 debugfs_create_u32("pte_update_batched", 0444, d_mmu_debug
,
2391 &mmu_stats
.pte_update_pinned
);
2393 debugfs_create_u32("mmu_update", 0444, d_mmu_debug
, &mmu_stats
.mmu_update
);
2394 debugfs_create_u32("mmu_update_extended", 0444, d_mmu_debug
,
2395 &mmu_stats
.mmu_update_extended
);
2396 xen_debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug
,
2397 mmu_stats
.mmu_update_histo
, 20);
2399 debugfs_create_u32("set_pte_at", 0444, d_mmu_debug
, &mmu_stats
.set_pte_at
);
2400 debugfs_create_u32("set_pte_at_batched", 0444, d_mmu_debug
,
2401 &mmu_stats
.set_pte_at_batched
);
2402 debugfs_create_u32("set_pte_at_current", 0444, d_mmu_debug
,
2403 &mmu_stats
.set_pte_at_current
);
2404 debugfs_create_u32("set_pte_at_kernel", 0444, d_mmu_debug
,
2405 &mmu_stats
.set_pte_at_kernel
);
2407 debugfs_create_u32("prot_commit", 0444, d_mmu_debug
, &mmu_stats
.prot_commit
);
2408 debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug
,
2409 &mmu_stats
.prot_commit_batched
);
2413 fs_initcall(xen_mmu_debugfs
);
2415 #endif /* CONFIG_XEN_DEBUG_FS */