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>
49 #include <linux/seq_file.h>
51 #include <trace/events/xen.h>
53 #include <asm/pgtable.h>
54 #include <asm/tlbflush.h>
55 #include <asm/fixmap.h>
56 #include <asm/mmu_context.h>
57 #include <asm/setup.h>
58 #include <asm/paravirt.h>
60 #include <asm/linkage.h>
66 #include <asm/xen/hypercall.h>
67 #include <asm/xen/hypervisor.h>
71 #include <xen/interface/xen.h>
72 #include <xen/interface/hvm/hvm_op.h>
73 #include <xen/interface/version.h>
74 #include <xen/interface/memory.h>
75 #include <xen/hvc-console.h>
77 #include "multicalls.h"
82 * Protects atomic reservation decrease/increase against concurrent increases.
83 * Also protects non-atomic updates of current_pages and balloon lists.
85 DEFINE_SPINLOCK(xen_reservation_lock
);
88 * Identity map, in addition to plain kernel map. This needs to be
89 * large enough to allocate page table pages to allocate the rest.
90 * Each page can map 2MB.
92 #define LEVEL1_IDENT_ENTRIES (PTRS_PER_PTE * 4)
93 static RESERVE_BRK_ARRAY(pte_t
, level1_ident_pgt
, LEVEL1_IDENT_ENTRIES
);
96 /* l3 pud for userspace vsyscall mapping */
97 static pud_t level3_user_vsyscall
[PTRS_PER_PUD
] __page_aligned_bss
;
98 #endif /* CONFIG_X86_64 */
101 * Note about cr3 (pagetable base) values:
103 * xen_cr3 contains the current logical cr3 value; it contains the
104 * last set cr3. This may not be the current effective cr3, because
105 * its update may be being lazily deferred. However, a vcpu looking
106 * at its own cr3 can use this value knowing that it everything will
107 * be self-consistent.
109 * xen_current_cr3 contains the actual vcpu cr3; it is set once the
110 * hypercall to set the vcpu cr3 is complete (so it may be a little
111 * out of date, but it will never be set early). If one vcpu is
112 * looking at another vcpu's cr3 value, it should use this variable.
114 DEFINE_PER_CPU(unsigned long, xen_cr3
); /* cr3 stored as physaddr */
115 DEFINE_PER_CPU(unsigned long, xen_current_cr3
); /* actual vcpu cr3 */
119 * Just beyond the highest usermode address. STACK_TOP_MAX has a
120 * redzone above it, so round it up to a PGD boundary.
122 #define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK)
124 unsigned long arbitrary_virt_to_mfn(void *vaddr
)
126 xmaddr_t maddr
= arbitrary_virt_to_machine(vaddr
);
128 return PFN_DOWN(maddr
.maddr
);
131 xmaddr_t
arbitrary_virt_to_machine(void *vaddr
)
133 unsigned long address
= (unsigned long)vaddr
;
139 * if the PFN is in the linear mapped vaddr range, we can just use
140 * the (quick) virt_to_machine() p2m lookup
142 if (virt_addr_valid(vaddr
))
143 return virt_to_machine(vaddr
);
145 /* otherwise we have to do a (slower) full page-table walk */
147 pte
= lookup_address(address
, &level
);
149 offset
= address
& ~PAGE_MASK
;
150 return XMADDR(((phys_addr_t
)pte_mfn(*pte
) << PAGE_SHIFT
) + offset
);
152 EXPORT_SYMBOL_GPL(arbitrary_virt_to_machine
);
154 void make_lowmem_page_readonly(void *vaddr
)
157 unsigned long address
= (unsigned long)vaddr
;
160 pte
= lookup_address(address
, &level
);
162 return; /* vaddr missing */
164 ptev
= pte_wrprotect(*pte
);
166 if (HYPERVISOR_update_va_mapping(address
, ptev
, 0))
170 void make_lowmem_page_readwrite(void *vaddr
)
173 unsigned long address
= (unsigned long)vaddr
;
176 pte
= lookup_address(address
, &level
);
178 return; /* vaddr missing */
180 ptev
= pte_mkwrite(*pte
);
182 if (HYPERVISOR_update_va_mapping(address
, ptev
, 0))
187 static bool xen_page_pinned(void *ptr
)
189 struct page
*page
= virt_to_page(ptr
);
191 return PagePinned(page
);
194 void xen_set_domain_pte(pte_t
*ptep
, pte_t pteval
, unsigned domid
)
196 struct multicall_space mcs
;
197 struct mmu_update
*u
;
199 trace_xen_mmu_set_domain_pte(ptep
, pteval
, domid
);
201 mcs
= xen_mc_entry(sizeof(*u
));
204 /* ptep might be kmapped when using 32-bit HIGHPTE */
205 u
->ptr
= virt_to_machine(ptep
).maddr
;
206 u
->val
= pte_val_ma(pteval
);
208 MULTI_mmu_update(mcs
.mc
, mcs
.args
, 1, NULL
, domid
);
210 xen_mc_issue(PARAVIRT_LAZY_MMU
);
212 EXPORT_SYMBOL_GPL(xen_set_domain_pte
);
214 static void xen_extend_mmu_update(const struct mmu_update
*update
)
216 struct multicall_space mcs
;
217 struct mmu_update
*u
;
219 mcs
= xen_mc_extend_args(__HYPERVISOR_mmu_update
, sizeof(*u
));
221 if (mcs
.mc
!= NULL
) {
224 mcs
= __xen_mc_entry(sizeof(*u
));
225 MULTI_mmu_update(mcs
.mc
, mcs
.args
, 1, NULL
, DOMID_SELF
);
232 static void xen_set_pmd_hyper(pmd_t
*ptr
, pmd_t val
)
240 /* ptr may be ioremapped for 64-bit pagetable setup */
241 u
.ptr
= arbitrary_virt_to_machine(ptr
).maddr
;
242 u
.val
= pmd_val_ma(val
);
243 xen_extend_mmu_update(&u
);
245 xen_mc_issue(PARAVIRT_LAZY_MMU
);
250 static void xen_set_pmd(pmd_t
*ptr
, pmd_t val
)
252 trace_xen_mmu_set_pmd(ptr
, val
);
254 /* If page is not pinned, we can just update the entry
256 if (!xen_page_pinned(ptr
)) {
261 xen_set_pmd_hyper(ptr
, val
);
265 * Associate a virtual page frame with a given physical page frame
266 * and protection flags for that frame.
268 void set_pte_mfn(unsigned long vaddr
, unsigned long mfn
, pgprot_t flags
)
270 set_pte_vaddr(vaddr
, mfn_pte(mfn
, flags
));
273 static bool xen_batched_set_pte(pte_t
*ptep
, pte_t pteval
)
277 if (paravirt_get_lazy_mode() != PARAVIRT_LAZY_MMU
)
282 u
.ptr
= virt_to_machine(ptep
).maddr
| MMU_NORMAL_PT_UPDATE
;
283 u
.val
= pte_val_ma(pteval
);
284 xen_extend_mmu_update(&u
);
286 xen_mc_issue(PARAVIRT_LAZY_MMU
);
291 static inline void __xen_set_pte(pte_t
*ptep
, pte_t pteval
)
293 if (!xen_batched_set_pte(ptep
, pteval
))
294 native_set_pte(ptep
, pteval
);
297 static void xen_set_pte(pte_t
*ptep
, pte_t pteval
)
299 trace_xen_mmu_set_pte(ptep
, pteval
);
300 __xen_set_pte(ptep
, pteval
);
303 static void xen_set_pte_at(struct mm_struct
*mm
, unsigned long addr
,
304 pte_t
*ptep
, pte_t pteval
)
306 trace_xen_mmu_set_pte_at(mm
, addr
, ptep
, pteval
);
307 __xen_set_pte(ptep
, pteval
);
310 pte_t
xen_ptep_modify_prot_start(struct mm_struct
*mm
,
311 unsigned long addr
, pte_t
*ptep
)
313 /* Just return the pte as-is. We preserve the bits on commit */
314 trace_xen_mmu_ptep_modify_prot_start(mm
, addr
, ptep
, *ptep
);
318 void xen_ptep_modify_prot_commit(struct mm_struct
*mm
, unsigned long addr
,
319 pte_t
*ptep
, pte_t pte
)
323 trace_xen_mmu_ptep_modify_prot_commit(mm
, addr
, ptep
, pte
);
326 u
.ptr
= virt_to_machine(ptep
).maddr
| MMU_PT_UPDATE_PRESERVE_AD
;
327 u
.val
= pte_val_ma(pte
);
328 xen_extend_mmu_update(&u
);
330 xen_mc_issue(PARAVIRT_LAZY_MMU
);
333 /* Assume pteval_t is equivalent to all the other *val_t types. */
334 static pteval_t
pte_mfn_to_pfn(pteval_t val
)
336 if (val
& _PAGE_PRESENT
) {
337 unsigned long mfn
= (val
& PTE_PFN_MASK
) >> PAGE_SHIFT
;
338 pteval_t flags
= val
& PTE_FLAGS_MASK
;
339 val
= ((pteval_t
)mfn_to_pfn(mfn
) << PAGE_SHIFT
) | flags
;
345 static pteval_t
pte_pfn_to_mfn(pteval_t val
)
347 if (val
& _PAGE_PRESENT
) {
348 unsigned long pfn
= (val
& PTE_PFN_MASK
) >> PAGE_SHIFT
;
349 pteval_t flags
= val
& PTE_FLAGS_MASK
;
352 if (!xen_feature(XENFEAT_auto_translated_physmap
))
353 mfn
= get_phys_to_machine(pfn
);
357 * If there's no mfn for the pfn, then just create an
358 * empty non-present pte. Unfortunately this loses
359 * information about the original pfn, so
360 * pte_mfn_to_pfn is asymmetric.
362 if (unlikely(mfn
== INVALID_P2M_ENTRY
)) {
367 * Paramount to do this test _after_ the
368 * INVALID_P2M_ENTRY as INVALID_P2M_ENTRY &
369 * IDENTITY_FRAME_BIT resolves to true.
371 mfn
&= ~FOREIGN_FRAME_BIT
;
372 if (mfn
& IDENTITY_FRAME_BIT
) {
373 mfn
&= ~IDENTITY_FRAME_BIT
;
374 flags
|= _PAGE_IOMAP
;
377 val
= ((pteval_t
)mfn
<< PAGE_SHIFT
) | flags
;
383 static pteval_t
iomap_pte(pteval_t val
)
385 if (val
& _PAGE_PRESENT
) {
386 unsigned long pfn
= (val
& PTE_PFN_MASK
) >> PAGE_SHIFT
;
387 pteval_t flags
= val
& PTE_FLAGS_MASK
;
389 /* We assume the pte frame number is a MFN, so
390 just use it as-is. */
391 val
= ((pteval_t
)pfn
<< PAGE_SHIFT
) | flags
;
397 static pteval_t
xen_pte_val(pte_t pte
)
399 pteval_t pteval
= pte
.pte
;
401 /* If this is a WC pte, convert back from Xen WC to Linux WC */
402 if ((pteval
& (_PAGE_PAT
| _PAGE_PCD
| _PAGE_PWT
)) == _PAGE_PAT
) {
403 WARN_ON(!pat_enabled
);
404 pteval
= (pteval
& ~_PAGE_PAT
) | _PAGE_PWT
;
407 if (xen_initial_domain() && (pteval
& _PAGE_IOMAP
))
410 return pte_mfn_to_pfn(pteval
);
412 PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val
);
414 static pgdval_t
xen_pgd_val(pgd_t pgd
)
416 return pte_mfn_to_pfn(pgd
.pgd
);
418 PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val
);
421 * Xen's PAT setup is part of its ABI, though I assume entries 6 & 7
422 * are reserved for now, to correspond to the Intel-reserved PAT
425 * We expect Linux's PAT set as follows:
427 * Idx PTE flags Linux Xen Default
434 * 6 PAT PCD UC- UC UC-
435 * 7 PAT PCD PWT UC UC UC
438 void xen_set_pat(u64 pat
)
440 /* We expect Linux to use a PAT setting of
441 * UC UC- WC WB (ignoring the PAT flag) */
442 WARN_ON(pat
!= 0x0007010600070106ull
);
445 static pte_t
xen_make_pte(pteval_t pte
)
447 phys_addr_t addr
= (pte
& PTE_PFN_MASK
);
449 /* If Linux is trying to set a WC pte, then map to the Xen WC.
450 * If _PAGE_PAT is set, then it probably means it is really
451 * _PAGE_PSE, so avoid fiddling with the PAT mapping and hope
452 * things work out OK...
454 * (We should never see kernel mappings with _PAGE_PSE set,
455 * but we could see hugetlbfs mappings, I think.).
457 if (pat_enabled
&& !WARN_ON(pte
& _PAGE_PAT
)) {
458 if ((pte
& (_PAGE_PCD
| _PAGE_PWT
)) == _PAGE_PWT
)
459 pte
= (pte
& ~(_PAGE_PCD
| _PAGE_PWT
)) | _PAGE_PAT
;
463 * Unprivileged domains are allowed to do IOMAPpings for
464 * PCI passthrough, but not map ISA space. The ISA
465 * mappings are just dummy local mappings to keep other
466 * parts of the kernel happy.
468 if (unlikely(pte
& _PAGE_IOMAP
) &&
469 (xen_initial_domain() || addr
>= ISA_END_ADDRESS
)) {
470 pte
= iomap_pte(pte
);
473 pte
= pte_pfn_to_mfn(pte
);
476 return native_make_pte(pte
);
478 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte
);
480 #ifdef CONFIG_XEN_DEBUG
481 pte_t
xen_make_pte_debug(pteval_t pte
)
483 phys_addr_t addr
= (pte
& PTE_PFN_MASK
);
484 phys_addr_t other_addr
;
485 bool io_page
= false;
488 if (pte
& _PAGE_IOMAP
)
491 _pte
= xen_make_pte(pte
);
497 (xen_initial_domain() || addr
>= ISA_END_ADDRESS
)) {
498 other_addr
= pfn_to_mfn(addr
>> PAGE_SHIFT
) << PAGE_SHIFT
;
499 WARN_ONCE(addr
!= other_addr
,
500 "0x%lx is using VM_IO, but it is 0x%lx!\n",
501 (unsigned long)addr
, (unsigned long)other_addr
);
503 pteval_t iomap_set
= (_pte
.pte
& PTE_FLAGS_MASK
) & _PAGE_IOMAP
;
504 other_addr
= (_pte
.pte
& PTE_PFN_MASK
);
505 WARN_ONCE((addr
== other_addr
) && (!io_page
) && (!iomap_set
),
506 "0x%lx is missing VM_IO (and wasn't fixed)!\n",
507 (unsigned long)addr
);
512 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_debug
);
515 static pgd_t
xen_make_pgd(pgdval_t pgd
)
517 pgd
= pte_pfn_to_mfn(pgd
);
518 return native_make_pgd(pgd
);
520 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pgd
);
522 static pmdval_t
xen_pmd_val(pmd_t pmd
)
524 return pte_mfn_to_pfn(pmd
.pmd
);
526 PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val
);
528 static void xen_set_pud_hyper(pud_t
*ptr
, pud_t val
)
536 /* ptr may be ioremapped for 64-bit pagetable setup */
537 u
.ptr
= arbitrary_virt_to_machine(ptr
).maddr
;
538 u
.val
= pud_val_ma(val
);
539 xen_extend_mmu_update(&u
);
541 xen_mc_issue(PARAVIRT_LAZY_MMU
);
546 static void xen_set_pud(pud_t
*ptr
, pud_t val
)
548 trace_xen_mmu_set_pud(ptr
, val
);
550 /* If page is not pinned, we can just update the entry
552 if (!xen_page_pinned(ptr
)) {
557 xen_set_pud_hyper(ptr
, val
);
560 #ifdef CONFIG_X86_PAE
561 static void xen_set_pte_atomic(pte_t
*ptep
, pte_t pte
)
563 trace_xen_mmu_set_pte_atomic(ptep
, pte
);
564 set_64bit((u64
*)ptep
, native_pte_val(pte
));
567 static void xen_pte_clear(struct mm_struct
*mm
, unsigned long addr
, pte_t
*ptep
)
569 trace_xen_mmu_pte_clear(mm
, addr
, ptep
);
570 if (!xen_batched_set_pte(ptep
, native_make_pte(0)))
571 native_pte_clear(mm
, addr
, ptep
);
574 static void xen_pmd_clear(pmd_t
*pmdp
)
576 trace_xen_mmu_pmd_clear(pmdp
);
577 set_pmd(pmdp
, __pmd(0));
579 #endif /* CONFIG_X86_PAE */
581 static pmd_t
xen_make_pmd(pmdval_t pmd
)
583 pmd
= pte_pfn_to_mfn(pmd
);
584 return native_make_pmd(pmd
);
586 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd
);
588 #if PAGETABLE_LEVELS == 4
589 static pudval_t
xen_pud_val(pud_t pud
)
591 return pte_mfn_to_pfn(pud
.pud
);
593 PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val
);
595 static pud_t
xen_make_pud(pudval_t pud
)
597 pud
= pte_pfn_to_mfn(pud
);
599 return native_make_pud(pud
);
601 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pud
);
603 static pgd_t
*xen_get_user_pgd(pgd_t
*pgd
)
605 pgd_t
*pgd_page
= (pgd_t
*)(((unsigned long)pgd
) & PAGE_MASK
);
606 unsigned offset
= pgd
- pgd_page
;
607 pgd_t
*user_ptr
= NULL
;
609 if (offset
< pgd_index(USER_LIMIT
)) {
610 struct page
*page
= virt_to_page(pgd_page
);
611 user_ptr
= (pgd_t
*)page
->private;
619 static void __xen_set_pgd_hyper(pgd_t
*ptr
, pgd_t val
)
623 u
.ptr
= virt_to_machine(ptr
).maddr
;
624 u
.val
= pgd_val_ma(val
);
625 xen_extend_mmu_update(&u
);
629 * Raw hypercall-based set_pgd, intended for in early boot before
630 * there's a page structure. This implies:
631 * 1. The only existing pagetable is the kernel's
632 * 2. It is always pinned
633 * 3. It has no user pagetable attached to it
635 static void __init
xen_set_pgd_hyper(pgd_t
*ptr
, pgd_t val
)
641 __xen_set_pgd_hyper(ptr
, val
);
643 xen_mc_issue(PARAVIRT_LAZY_MMU
);
648 static void xen_set_pgd(pgd_t
*ptr
, pgd_t val
)
650 pgd_t
*user_ptr
= xen_get_user_pgd(ptr
);
652 trace_xen_mmu_set_pgd(ptr
, user_ptr
, val
);
654 /* If page is not pinned, we can just update the entry
656 if (!xen_page_pinned(ptr
)) {
659 WARN_ON(xen_page_pinned(user_ptr
));
665 /* If it's pinned, then we can at least batch the kernel and
666 user updates together. */
669 __xen_set_pgd_hyper(ptr
, val
);
671 __xen_set_pgd_hyper(user_ptr
, val
);
673 xen_mc_issue(PARAVIRT_LAZY_MMU
);
675 #endif /* PAGETABLE_LEVELS == 4 */
678 * (Yet another) pagetable walker. This one is intended for pinning a
679 * pagetable. This means that it walks a pagetable and calls the
680 * callback function on each page it finds making up the page table,
681 * at every level. It walks the entire pagetable, but it only bothers
682 * pinning pte pages which are below limit. In the normal case this
683 * will be STACK_TOP_MAX, but at boot we need to pin up to
686 * For 32-bit the important bit is that we don't pin beyond there,
687 * because then we start getting into Xen's ptes.
689 * For 64-bit, we must skip the Xen hole in the middle of the address
690 * space, just after the big x86-64 virtual hole.
692 static int __xen_pgd_walk(struct mm_struct
*mm
, pgd_t
*pgd
,
693 int (*func
)(struct mm_struct
*mm
, struct page
*,
698 unsigned hole_low
, hole_high
;
699 unsigned pgdidx_limit
, pudidx_limit
, pmdidx_limit
;
700 unsigned pgdidx
, pudidx
, pmdidx
;
702 /* The limit is the last byte to be touched */
704 BUG_ON(limit
>= FIXADDR_TOP
);
706 if (xen_feature(XENFEAT_auto_translated_physmap
))
710 * 64-bit has a great big hole in the middle of the address
711 * space, which contains the Xen mappings. On 32-bit these
712 * will end up making a zero-sized hole and so is a no-op.
714 hole_low
= pgd_index(USER_LIMIT
);
715 hole_high
= pgd_index(PAGE_OFFSET
);
717 pgdidx_limit
= pgd_index(limit
);
719 pudidx_limit
= pud_index(limit
);
724 pmdidx_limit
= pmd_index(limit
);
729 for (pgdidx
= 0; pgdidx
<= pgdidx_limit
; pgdidx
++) {
732 if (pgdidx
>= hole_low
&& pgdidx
< hole_high
)
735 if (!pgd_val(pgd
[pgdidx
]))
738 pud
= pud_offset(&pgd
[pgdidx
], 0);
740 if (PTRS_PER_PUD
> 1) /* not folded */
741 flush
|= (*func
)(mm
, virt_to_page(pud
), PT_PUD
);
743 for (pudidx
= 0; pudidx
< PTRS_PER_PUD
; pudidx
++) {
746 if (pgdidx
== pgdidx_limit
&&
747 pudidx
> pudidx_limit
)
750 if (pud_none(pud
[pudidx
]))
753 pmd
= pmd_offset(&pud
[pudidx
], 0);
755 if (PTRS_PER_PMD
> 1) /* not folded */
756 flush
|= (*func
)(mm
, virt_to_page(pmd
), PT_PMD
);
758 for (pmdidx
= 0; pmdidx
< PTRS_PER_PMD
; pmdidx
++) {
761 if (pgdidx
== pgdidx_limit
&&
762 pudidx
== pudidx_limit
&&
763 pmdidx
> pmdidx_limit
)
766 if (pmd_none(pmd
[pmdidx
]))
769 pte
= pmd_page(pmd
[pmdidx
]);
770 flush
|= (*func
)(mm
, pte
, PT_PTE
);
776 /* Do the top level last, so that the callbacks can use it as
777 a cue to do final things like tlb flushes. */
778 flush
|= (*func
)(mm
, virt_to_page(pgd
), PT_PGD
);
783 static int xen_pgd_walk(struct mm_struct
*mm
,
784 int (*func
)(struct mm_struct
*mm
, struct page
*,
788 return __xen_pgd_walk(mm
, mm
->pgd
, func
, limit
);
791 /* If we're using split pte locks, then take the page's lock and
792 return a pointer to it. Otherwise return NULL. */
793 static spinlock_t
*xen_pte_lock(struct page
*page
, struct mm_struct
*mm
)
795 spinlock_t
*ptl
= NULL
;
797 #if USE_SPLIT_PTLOCKS
798 ptl
= __pte_lockptr(page
);
799 spin_lock_nest_lock(ptl
, &mm
->page_table_lock
);
805 static void xen_pte_unlock(void *v
)
811 static void xen_do_pin(unsigned level
, unsigned long pfn
)
813 struct mmuext_op
*op
;
814 struct multicall_space mcs
;
816 mcs
= __xen_mc_entry(sizeof(*op
));
819 op
->arg1
.mfn
= pfn_to_mfn(pfn
);
820 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
823 static int xen_pin_page(struct mm_struct
*mm
, struct page
*page
,
826 unsigned pgfl
= TestSetPagePinned(page
);
830 flush
= 0; /* already pinned */
831 else if (PageHighMem(page
))
832 /* kmaps need flushing if we found an unpinned
836 void *pt
= lowmem_page_address(page
);
837 unsigned long pfn
= page_to_pfn(page
);
838 struct multicall_space mcs
= __xen_mc_entry(0);
844 * We need to hold the pagetable lock between the time
845 * we make the pagetable RO and when we actually pin
846 * it. If we don't, then other users may come in and
847 * attempt to update the pagetable by writing it,
848 * which will fail because the memory is RO but not
849 * pinned, so Xen won't do the trap'n'emulate.
851 * If we're using split pte locks, we can't hold the
852 * entire pagetable's worth of locks during the
853 * traverse, because we may wrap the preempt count (8
854 * bits). The solution is to mark RO and pin each PTE
855 * page while holding the lock. This means the number
856 * of locks we end up holding is never more than a
857 * batch size (~32 entries, at present).
859 * If we're not using split pte locks, we needn't pin
860 * the PTE pages independently, because we're
861 * protected by the overall pagetable lock.
865 ptl
= xen_pte_lock(page
, mm
);
867 MULTI_update_va_mapping(mcs
.mc
, (unsigned long)pt
,
868 pfn_pte(pfn
, PAGE_KERNEL_RO
),
869 level
== PT_PGD
? UVMF_TLB_FLUSH
: 0);
872 xen_do_pin(MMUEXT_PIN_L1_TABLE
, pfn
);
874 /* Queue a deferred unlock for when this batch
876 xen_mc_callback(xen_pte_unlock
, ptl
);
883 /* This is called just after a mm has been created, but it has not
884 been used yet. We need to make sure that its pagetable is all
885 read-only, and can be pinned. */
886 static void __xen_pgd_pin(struct mm_struct
*mm
, pgd_t
*pgd
)
888 trace_xen_mmu_pgd_pin(mm
, pgd
);
892 if (__xen_pgd_walk(mm
, pgd
, xen_pin_page
, USER_LIMIT
)) {
893 /* re-enable interrupts for flushing */
903 pgd_t
*user_pgd
= xen_get_user_pgd(pgd
);
905 xen_do_pin(MMUEXT_PIN_L4_TABLE
, PFN_DOWN(__pa(pgd
)));
908 xen_pin_page(mm
, virt_to_page(user_pgd
), PT_PGD
);
909 xen_do_pin(MMUEXT_PIN_L4_TABLE
,
910 PFN_DOWN(__pa(user_pgd
)));
913 #else /* CONFIG_X86_32 */
914 #ifdef CONFIG_X86_PAE
915 /* Need to make sure unshared kernel PMD is pinnable */
916 xen_pin_page(mm
, pgd_page(pgd
[pgd_index(TASK_SIZE
)]),
919 xen_do_pin(MMUEXT_PIN_L3_TABLE
, PFN_DOWN(__pa(pgd
)));
920 #endif /* CONFIG_X86_64 */
924 static void xen_pgd_pin(struct mm_struct
*mm
)
926 __xen_pgd_pin(mm
, mm
->pgd
);
930 * On save, we need to pin all pagetables to make sure they get their
931 * mfns turned into pfns. Search the list for any unpinned pgds and pin
932 * them (unpinned pgds are not currently in use, probably because the
933 * process is under construction or destruction).
935 * Expected to be called in stop_machine() ("equivalent to taking
936 * every spinlock in the system"), so the locking doesn't really
937 * matter all that much.
939 void xen_mm_pin_all(void)
943 spin_lock(&pgd_lock
);
945 list_for_each_entry(page
, &pgd_list
, lru
) {
946 if (!PagePinned(page
)) {
947 __xen_pgd_pin(&init_mm
, (pgd_t
*)page_address(page
));
948 SetPageSavePinned(page
);
952 spin_unlock(&pgd_lock
);
956 * The init_mm pagetable is really pinned as soon as its created, but
957 * that's before we have page structures to store the bits. So do all
958 * the book-keeping now.
960 static int __init
xen_mark_pinned(struct mm_struct
*mm
, struct page
*page
,
967 static void __init
xen_mark_init_mm_pinned(void)
969 xen_pgd_walk(&init_mm
, xen_mark_pinned
, FIXADDR_TOP
);
972 static int xen_unpin_page(struct mm_struct
*mm
, struct page
*page
,
975 unsigned pgfl
= TestClearPagePinned(page
);
977 if (pgfl
&& !PageHighMem(page
)) {
978 void *pt
= lowmem_page_address(page
);
979 unsigned long pfn
= page_to_pfn(page
);
980 spinlock_t
*ptl
= NULL
;
981 struct multicall_space mcs
;
984 * Do the converse to pin_page. If we're using split
985 * pte locks, we must be holding the lock for while
986 * the pte page is unpinned but still RO to prevent
987 * concurrent updates from seeing it in this
988 * partially-pinned state.
990 if (level
== PT_PTE
) {
991 ptl
= xen_pte_lock(page
, mm
);
994 xen_do_pin(MMUEXT_UNPIN_TABLE
, pfn
);
997 mcs
= __xen_mc_entry(0);
999 MULTI_update_va_mapping(mcs
.mc
, (unsigned long)pt
,
1000 pfn_pte(pfn
, PAGE_KERNEL
),
1001 level
== PT_PGD
? UVMF_TLB_FLUSH
: 0);
1004 /* unlock when batch completed */
1005 xen_mc_callback(xen_pte_unlock
, ptl
);
1009 return 0; /* never need to flush on unpin */
1012 /* Release a pagetables pages back as normal RW */
1013 static void __xen_pgd_unpin(struct mm_struct
*mm
, pgd_t
*pgd
)
1015 trace_xen_mmu_pgd_unpin(mm
, pgd
);
1019 xen_do_pin(MMUEXT_UNPIN_TABLE
, PFN_DOWN(__pa(pgd
)));
1021 #ifdef CONFIG_X86_64
1023 pgd_t
*user_pgd
= xen_get_user_pgd(pgd
);
1026 xen_do_pin(MMUEXT_UNPIN_TABLE
,
1027 PFN_DOWN(__pa(user_pgd
)));
1028 xen_unpin_page(mm
, virt_to_page(user_pgd
), PT_PGD
);
1033 #ifdef CONFIG_X86_PAE
1034 /* Need to make sure unshared kernel PMD is unpinned */
1035 xen_unpin_page(mm
, pgd_page(pgd
[pgd_index(TASK_SIZE
)]),
1039 __xen_pgd_walk(mm
, pgd
, xen_unpin_page
, USER_LIMIT
);
1044 static void xen_pgd_unpin(struct mm_struct
*mm
)
1046 __xen_pgd_unpin(mm
, mm
->pgd
);
1050 * On resume, undo any pinning done at save, so that the rest of the
1051 * kernel doesn't see any unexpected pinned pagetables.
1053 void xen_mm_unpin_all(void)
1057 spin_lock(&pgd_lock
);
1059 list_for_each_entry(page
, &pgd_list
, lru
) {
1060 if (PageSavePinned(page
)) {
1061 BUG_ON(!PagePinned(page
));
1062 __xen_pgd_unpin(&init_mm
, (pgd_t
*)page_address(page
));
1063 ClearPageSavePinned(page
);
1067 spin_unlock(&pgd_lock
);
1070 static void xen_activate_mm(struct mm_struct
*prev
, struct mm_struct
*next
)
1072 spin_lock(&next
->page_table_lock
);
1074 spin_unlock(&next
->page_table_lock
);
1077 static void xen_dup_mmap(struct mm_struct
*oldmm
, struct mm_struct
*mm
)
1079 spin_lock(&mm
->page_table_lock
);
1081 spin_unlock(&mm
->page_table_lock
);
1086 /* Another cpu may still have their %cr3 pointing at the pagetable, so
1087 we need to repoint it somewhere else before we can unpin it. */
1088 static void drop_other_mm_ref(void *info
)
1090 struct mm_struct
*mm
= info
;
1091 struct mm_struct
*active_mm
;
1093 active_mm
= percpu_read(cpu_tlbstate
.active_mm
);
1095 if (active_mm
== mm
&& percpu_read(cpu_tlbstate
.state
) != TLBSTATE_OK
)
1096 leave_mm(smp_processor_id());
1098 /* If this cpu still has a stale cr3 reference, then make sure
1099 it has been flushed. */
1100 if (percpu_read(xen_current_cr3
) == __pa(mm
->pgd
))
1101 load_cr3(swapper_pg_dir
);
1104 static void xen_drop_mm_ref(struct mm_struct
*mm
)
1109 if (current
->active_mm
== mm
) {
1110 if (current
->mm
== mm
)
1111 load_cr3(swapper_pg_dir
);
1113 leave_mm(smp_processor_id());
1116 /* Get the "official" set of cpus referring to our pagetable. */
1117 if (!alloc_cpumask_var(&mask
, GFP_ATOMIC
)) {
1118 for_each_online_cpu(cpu
) {
1119 if (!cpumask_test_cpu(cpu
, mm_cpumask(mm
))
1120 && per_cpu(xen_current_cr3
, cpu
) != __pa(mm
->pgd
))
1122 smp_call_function_single(cpu
, drop_other_mm_ref
, mm
, 1);
1126 cpumask_copy(mask
, mm_cpumask(mm
));
1128 /* It's possible that a vcpu may have a stale reference to our
1129 cr3, because its in lazy mode, and it hasn't yet flushed
1130 its set of pending hypercalls yet. In this case, we can
1131 look at its actual current cr3 value, and force it to flush
1133 for_each_online_cpu(cpu
) {
1134 if (per_cpu(xen_current_cr3
, cpu
) == __pa(mm
->pgd
))
1135 cpumask_set_cpu(cpu
, mask
);
1138 if (!cpumask_empty(mask
))
1139 smp_call_function_many(mask
, drop_other_mm_ref
, mm
, 1);
1140 free_cpumask_var(mask
);
1143 static void xen_drop_mm_ref(struct mm_struct
*mm
)
1145 if (current
->active_mm
== mm
)
1146 load_cr3(swapper_pg_dir
);
1151 * While a process runs, Xen pins its pagetables, which means that the
1152 * hypervisor forces it to be read-only, and it controls all updates
1153 * to it. This means that all pagetable updates have to go via the
1154 * hypervisor, which is moderately expensive.
1156 * Since we're pulling the pagetable down, we switch to use init_mm,
1157 * unpin old process pagetable and mark it all read-write, which
1158 * allows further operations on it to be simple memory accesses.
1160 * The only subtle point is that another CPU may be still using the
1161 * pagetable because of lazy tlb flushing. This means we need need to
1162 * switch all CPUs off this pagetable before we can unpin it.
1164 static void xen_exit_mmap(struct mm_struct
*mm
)
1166 get_cpu(); /* make sure we don't move around */
1167 xen_drop_mm_ref(mm
);
1170 spin_lock(&mm
->page_table_lock
);
1172 /* pgd may not be pinned in the error exit path of execve */
1173 if (xen_page_pinned(mm
->pgd
))
1176 spin_unlock(&mm
->page_table_lock
);
1179 static void __init
xen_pagetable_setup_start(pgd_t
*base
)
1183 static __init
void xen_mapping_pagetable_reserve(u64 start
, u64 end
)
1185 /* reserve the range used */
1186 native_pagetable_reserve(start
, end
);
1188 /* set as RW the rest */
1189 printk(KERN_DEBUG
"xen: setting RW the range %llx - %llx\n", end
,
1190 PFN_PHYS(pgt_buf_top
));
1191 while (end
< PFN_PHYS(pgt_buf_top
)) {
1192 make_lowmem_page_readwrite(__va(end
));
1197 static void xen_post_allocator_init(void);
1199 static void __init
xen_pagetable_setup_done(pgd_t
*base
)
1201 xen_setup_shared_info();
1202 xen_post_allocator_init();
1205 static void xen_write_cr2(unsigned long cr2
)
1207 percpu_read(xen_vcpu
)->arch
.cr2
= cr2
;
1210 static unsigned long xen_read_cr2(void)
1212 return percpu_read(xen_vcpu
)->arch
.cr2
;
1215 unsigned long xen_read_cr2_direct(void)
1217 return percpu_read(xen_vcpu_info
.arch
.cr2
);
1220 static void xen_flush_tlb(void)
1222 struct mmuext_op
*op
;
1223 struct multicall_space mcs
;
1225 trace_xen_mmu_flush_tlb(0);
1229 mcs
= xen_mc_entry(sizeof(*op
));
1232 op
->cmd
= MMUEXT_TLB_FLUSH_LOCAL
;
1233 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
1235 xen_mc_issue(PARAVIRT_LAZY_MMU
);
1240 static void xen_flush_tlb_single(unsigned long addr
)
1242 struct mmuext_op
*op
;
1243 struct multicall_space mcs
;
1245 trace_xen_mmu_flush_tlb_single(addr
);
1249 mcs
= xen_mc_entry(sizeof(*op
));
1251 op
->cmd
= MMUEXT_INVLPG_LOCAL
;
1252 op
->arg1
.linear_addr
= addr
& PAGE_MASK
;
1253 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
1255 xen_mc_issue(PARAVIRT_LAZY_MMU
);
1260 static void xen_flush_tlb_others(const struct cpumask
*cpus
,
1261 struct mm_struct
*mm
, unsigned long va
)
1264 struct mmuext_op op
;
1266 DECLARE_BITMAP(mask
, num_processors
);
1268 DECLARE_BITMAP(mask
, NR_CPUS
);
1271 struct multicall_space mcs
;
1273 trace_xen_mmu_flush_tlb_others(cpus
, mm
, va
);
1275 if (cpumask_empty(cpus
))
1276 return; /* nothing to do */
1278 mcs
= xen_mc_entry(sizeof(*args
));
1280 args
->op
.arg2
.vcpumask
= to_cpumask(args
->mask
);
1282 /* Remove us, and any offline CPUS. */
1283 cpumask_and(to_cpumask(args
->mask
), cpus
, cpu_online_mask
);
1284 cpumask_clear_cpu(smp_processor_id(), to_cpumask(args
->mask
));
1286 if (va
== TLB_FLUSH_ALL
) {
1287 args
->op
.cmd
= MMUEXT_TLB_FLUSH_MULTI
;
1289 args
->op
.cmd
= MMUEXT_INVLPG_MULTI
;
1290 args
->op
.arg1
.linear_addr
= va
;
1293 MULTI_mmuext_op(mcs
.mc
, &args
->op
, 1, NULL
, DOMID_SELF
);
1295 xen_mc_issue(PARAVIRT_LAZY_MMU
);
1298 static unsigned long xen_read_cr3(void)
1300 return percpu_read(xen_cr3
);
1303 static void set_current_cr3(void *v
)
1305 percpu_write(xen_current_cr3
, (unsigned long)v
);
1308 static void __xen_write_cr3(bool kernel
, unsigned long cr3
)
1310 struct mmuext_op
*op
;
1311 struct multicall_space mcs
;
1314 trace_xen_mmu_write_cr3(kernel
, cr3
);
1317 mfn
= pfn_to_mfn(PFN_DOWN(cr3
));
1321 WARN_ON(mfn
== 0 && kernel
);
1323 mcs
= __xen_mc_entry(sizeof(*op
));
1326 op
->cmd
= kernel
? MMUEXT_NEW_BASEPTR
: MMUEXT_NEW_USER_BASEPTR
;
1329 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
1332 percpu_write(xen_cr3
, cr3
);
1334 /* Update xen_current_cr3 once the batch has actually
1336 xen_mc_callback(set_current_cr3
, (void *)cr3
);
1340 static void xen_write_cr3(unsigned long cr3
)
1342 BUG_ON(preemptible());
1344 xen_mc_batch(); /* disables interrupts */
1346 /* Update while interrupts are disabled, so its atomic with
1348 percpu_write(xen_cr3
, cr3
);
1350 __xen_write_cr3(true, cr3
);
1352 #ifdef CONFIG_X86_64
1354 pgd_t
*user_pgd
= xen_get_user_pgd(__va(cr3
));
1356 __xen_write_cr3(false, __pa(user_pgd
));
1358 __xen_write_cr3(false, 0);
1362 xen_mc_issue(PARAVIRT_LAZY_CPU
); /* interrupts restored */
1365 static int xen_pgd_alloc(struct mm_struct
*mm
)
1367 pgd_t
*pgd
= mm
->pgd
;
1370 BUG_ON(PagePinned(virt_to_page(pgd
)));
1372 #ifdef CONFIG_X86_64
1374 struct page
*page
= virt_to_page(pgd
);
1377 BUG_ON(page
->private != 0);
1381 user_pgd
= (pgd_t
*)__get_free_page(GFP_KERNEL
| __GFP_ZERO
);
1382 page
->private = (unsigned long)user_pgd
;
1384 if (user_pgd
!= NULL
) {
1385 user_pgd
[pgd_index(VSYSCALL_START
)] =
1386 __pgd(__pa(level3_user_vsyscall
) | _PAGE_TABLE
);
1390 BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd
))));
1397 static void xen_pgd_free(struct mm_struct
*mm
, pgd_t
*pgd
)
1399 #ifdef CONFIG_X86_64
1400 pgd_t
*user_pgd
= xen_get_user_pgd(pgd
);
1403 free_page((unsigned long)user_pgd
);
1407 #ifdef CONFIG_X86_32
1408 static pte_t __init
mask_rw_pte(pte_t
*ptep
, pte_t pte
)
1410 /* If there's an existing pte, then don't allow _PAGE_RW to be set */
1411 if (pte_val_ma(*ptep
) & _PAGE_PRESENT
)
1412 pte
= __pte_ma(((pte_val_ma(*ptep
) & _PAGE_RW
) | ~_PAGE_RW
) &
1417 #else /* CONFIG_X86_64 */
1418 static pte_t __init
mask_rw_pte(pte_t
*ptep
, pte_t pte
)
1420 unsigned long pfn
= pte_pfn(pte
);
1423 * If the new pfn is within the range of the newly allocated
1424 * kernel pagetable, and it isn't being mapped into an
1425 * early_ioremap fixmap slot as a freshly allocated page, make sure
1428 if (((!is_early_ioremap_ptep(ptep
) &&
1429 pfn
>= pgt_buf_start
&& pfn
< pgt_buf_top
)) ||
1430 (is_early_ioremap_ptep(ptep
) && pfn
!= (pgt_buf_end
- 1)))
1431 pte
= pte_wrprotect(pte
);
1435 #endif /* CONFIG_X86_64 */
1437 /* Init-time set_pte while constructing initial pagetables, which
1438 doesn't allow RO pagetable pages to be remapped RW */
1439 static void __init
xen_set_pte_init(pte_t
*ptep
, pte_t pte
)
1441 pte
= mask_rw_pte(ptep
, pte
);
1443 xen_set_pte(ptep
, pte
);
1446 static void pin_pagetable_pfn(unsigned cmd
, unsigned long pfn
)
1448 struct mmuext_op op
;
1450 op
.arg1
.mfn
= pfn_to_mfn(pfn
);
1451 if (HYPERVISOR_mmuext_op(&op
, 1, NULL
, DOMID_SELF
))
1455 /* Early in boot, while setting up the initial pagetable, assume
1456 everything is pinned. */
1457 static void __init
xen_alloc_pte_init(struct mm_struct
*mm
, unsigned long pfn
)
1459 #ifdef CONFIG_FLATMEM
1460 BUG_ON(mem_map
); /* should only be used early */
1462 make_lowmem_page_readonly(__va(PFN_PHYS(pfn
)));
1463 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE
, pfn
);
1466 /* Used for pmd and pud */
1467 static void __init
xen_alloc_pmd_init(struct mm_struct
*mm
, unsigned long pfn
)
1469 #ifdef CONFIG_FLATMEM
1470 BUG_ON(mem_map
); /* should only be used early */
1472 make_lowmem_page_readonly(__va(PFN_PHYS(pfn
)));
1475 /* Early release_pte assumes that all pts are pinned, since there's
1476 only init_mm and anything attached to that is pinned. */
1477 static void __init
xen_release_pte_init(unsigned long pfn
)
1479 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, pfn
);
1480 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
1483 static void __init
xen_release_pmd_init(unsigned long pfn
)
1485 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
1488 /* This needs to make sure the new pte page is pinned iff its being
1489 attached to a pinned pagetable. */
1490 static void xen_alloc_ptpage(struct mm_struct
*mm
, unsigned long pfn
, unsigned level
)
1492 struct page
*page
= pfn_to_page(pfn
);
1493 int pinned
= PagePinned(virt_to_page(mm
->pgd
));
1495 trace_xen_mmu_alloc_ptpage(mm
, pfn
, level
, pinned
);
1498 SetPagePinned(page
);
1500 if (!PageHighMem(page
)) {
1501 make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn
)));
1502 if (level
== PT_PTE
&& USE_SPLIT_PTLOCKS
)
1503 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE
, pfn
);
1505 /* make sure there are no stray mappings of
1507 kmap_flush_unused();
1512 static void xen_alloc_pte(struct mm_struct
*mm
, unsigned long pfn
)
1514 xen_alloc_ptpage(mm
, pfn
, PT_PTE
);
1517 static void xen_alloc_pmd(struct mm_struct
*mm
, unsigned long pfn
)
1519 xen_alloc_ptpage(mm
, pfn
, PT_PMD
);
1522 /* This should never happen until we're OK to use struct page */
1523 static void xen_release_ptpage(unsigned long pfn
, unsigned level
)
1525 struct page
*page
= pfn_to_page(pfn
);
1526 bool pinned
= PagePinned(page
);
1528 trace_xen_mmu_release_ptpage(pfn
, level
, pinned
);
1531 if (!PageHighMem(page
)) {
1532 if (level
== PT_PTE
&& USE_SPLIT_PTLOCKS
)
1533 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, pfn
);
1534 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
1536 ClearPagePinned(page
);
1540 static void xen_release_pte(unsigned long pfn
)
1542 xen_release_ptpage(pfn
, PT_PTE
);
1545 static void xen_release_pmd(unsigned long pfn
)
1547 xen_release_ptpage(pfn
, PT_PMD
);
1550 #if PAGETABLE_LEVELS == 4
1551 static void xen_alloc_pud(struct mm_struct
*mm
, unsigned long pfn
)
1553 xen_alloc_ptpage(mm
, pfn
, PT_PUD
);
1556 static void xen_release_pud(unsigned long pfn
)
1558 xen_release_ptpage(pfn
, PT_PUD
);
1562 void __init
xen_reserve_top(void)
1564 #ifdef CONFIG_X86_32
1565 unsigned long top
= HYPERVISOR_VIRT_START
;
1566 struct xen_platform_parameters pp
;
1568 if (HYPERVISOR_xen_version(XENVER_platform_parameters
, &pp
) == 0)
1569 top
= pp
.virt_start
;
1571 reserve_top_address(-top
);
1572 #endif /* CONFIG_X86_32 */
1576 * Like __va(), but returns address in the kernel mapping (which is
1577 * all we have until the physical memory mapping has been set up.
1579 static void *__ka(phys_addr_t paddr
)
1581 #ifdef CONFIG_X86_64
1582 return (void *)(paddr
+ __START_KERNEL_map
);
1588 /* Convert a machine address to physical address */
1589 static unsigned long m2p(phys_addr_t maddr
)
1593 maddr
&= PTE_PFN_MASK
;
1594 paddr
= mfn_to_pfn(maddr
>> PAGE_SHIFT
) << PAGE_SHIFT
;
1599 /* Convert a machine address to kernel virtual */
1600 static void *m2v(phys_addr_t maddr
)
1602 return __ka(m2p(maddr
));
1605 /* Set the page permissions on an identity-mapped pages */
1606 static void set_page_prot(void *addr
, pgprot_t prot
)
1608 unsigned long pfn
= __pa(addr
) >> PAGE_SHIFT
;
1609 pte_t pte
= pfn_pte(pfn
, prot
);
1611 if (HYPERVISOR_update_va_mapping((unsigned long)addr
, pte
, 0))
1615 static void __init
xen_map_identity_early(pmd_t
*pmd
, unsigned long max_pfn
)
1617 unsigned pmdidx
, pteidx
;
1621 level1_ident_pgt
= extend_brk(sizeof(pte_t
) * LEVEL1_IDENT_ENTRIES
,
1626 for (pmdidx
= 0; pmdidx
< PTRS_PER_PMD
&& pfn
< max_pfn
; pmdidx
++) {
1629 /* Reuse or allocate a page of ptes */
1630 if (pmd_present(pmd
[pmdidx
]))
1631 pte_page
= m2v(pmd
[pmdidx
].pmd
);
1633 /* Check for free pte pages */
1634 if (ident_pte
== LEVEL1_IDENT_ENTRIES
)
1637 pte_page
= &level1_ident_pgt
[ident_pte
];
1638 ident_pte
+= PTRS_PER_PTE
;
1640 pmd
[pmdidx
] = __pmd(__pa(pte_page
) | _PAGE_TABLE
);
1643 /* Install mappings */
1644 for (pteidx
= 0; pteidx
< PTRS_PER_PTE
; pteidx
++, pfn
++) {
1647 #ifdef CONFIG_X86_32
1648 if (pfn
> max_pfn_mapped
)
1649 max_pfn_mapped
= pfn
;
1652 if (!pte_none(pte_page
[pteidx
]))
1655 pte
= pfn_pte(pfn
, PAGE_KERNEL_EXEC
);
1656 pte_page
[pteidx
] = pte
;
1660 for (pteidx
= 0; pteidx
< ident_pte
; pteidx
+= PTRS_PER_PTE
)
1661 set_page_prot(&level1_ident_pgt
[pteidx
], PAGE_KERNEL_RO
);
1663 set_page_prot(pmd
, PAGE_KERNEL_RO
);
1666 void __init
xen_setup_machphys_mapping(void)
1668 struct xen_machphys_mapping mapping
;
1669 unsigned long machine_to_phys_nr_ents
;
1671 if (HYPERVISOR_memory_op(XENMEM_machphys_mapping
, &mapping
) == 0) {
1672 machine_to_phys_mapping
= (unsigned long *)mapping
.v_start
;
1673 machine_to_phys_nr_ents
= mapping
.max_mfn
+ 1;
1675 machine_to_phys_nr_ents
= MACH2PHYS_NR_ENTRIES
;
1677 machine_to_phys_order
= fls(machine_to_phys_nr_ents
- 1);
1680 #ifdef CONFIG_X86_64
1681 static void convert_pfn_mfn(void *v
)
1686 /* All levels are converted the same way, so just treat them
1688 for (i
= 0; i
< PTRS_PER_PTE
; i
++)
1689 pte
[i
] = xen_make_pte(pte
[i
].pte
);
1693 * Set up the initial kernel pagetable.
1695 * We can construct this by grafting the Xen provided pagetable into
1696 * head_64.S's preconstructed pagetables. We copy the Xen L2's into
1697 * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt. This
1698 * means that only the kernel has a physical mapping to start with -
1699 * but that's enough to get __va working. We need to fill in the rest
1700 * of the physical mapping once some sort of allocator has been set
1703 pgd_t
* __init
xen_setup_kernel_pagetable(pgd_t
*pgd
,
1704 unsigned long max_pfn
)
1709 /* max_pfn_mapped is the last pfn mapped in the initial memory
1710 * mappings. Considering that on Xen after the kernel mappings we
1711 * have the mappings of some pages that don't exist in pfn space, we
1712 * set max_pfn_mapped to the last real pfn mapped. */
1713 max_pfn_mapped
= PFN_DOWN(__pa(xen_start_info
->mfn_list
));
1715 /* Zap identity mapping */
1716 init_level4_pgt
[0] = __pgd(0);
1718 /* Pre-constructed entries are in pfn, so convert to mfn */
1719 convert_pfn_mfn(init_level4_pgt
);
1720 convert_pfn_mfn(level3_ident_pgt
);
1721 convert_pfn_mfn(level3_kernel_pgt
);
1723 l3
= m2v(pgd
[pgd_index(__START_KERNEL_map
)].pgd
);
1724 l2
= m2v(l3
[pud_index(__START_KERNEL_map
)].pud
);
1726 memcpy(level2_ident_pgt
, l2
, sizeof(pmd_t
) * PTRS_PER_PMD
);
1727 memcpy(level2_kernel_pgt
, l2
, sizeof(pmd_t
) * PTRS_PER_PMD
);
1729 l3
= m2v(pgd
[pgd_index(__START_KERNEL_map
+ PMD_SIZE
)].pgd
);
1730 l2
= m2v(l3
[pud_index(__START_KERNEL_map
+ PMD_SIZE
)].pud
);
1731 memcpy(level2_fixmap_pgt
, l2
, sizeof(pmd_t
) * PTRS_PER_PMD
);
1733 /* Set up identity map */
1734 xen_map_identity_early(level2_ident_pgt
, max_pfn
);
1736 /* Make pagetable pieces RO */
1737 set_page_prot(init_level4_pgt
, PAGE_KERNEL_RO
);
1738 set_page_prot(level3_ident_pgt
, PAGE_KERNEL_RO
);
1739 set_page_prot(level3_kernel_pgt
, PAGE_KERNEL_RO
);
1740 set_page_prot(level3_user_vsyscall
, PAGE_KERNEL_RO
);
1741 set_page_prot(level2_kernel_pgt
, PAGE_KERNEL_RO
);
1742 set_page_prot(level2_fixmap_pgt
, PAGE_KERNEL_RO
);
1744 /* Pin down new L4 */
1745 pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE
,
1746 PFN_DOWN(__pa_symbol(init_level4_pgt
)));
1748 /* Unpin Xen-provided one */
1749 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, PFN_DOWN(__pa(pgd
)));
1752 pgd
= init_level4_pgt
;
1755 * At this stage there can be no user pgd, and no page
1756 * structure to attach it to, so make sure we just set kernel
1760 __xen_write_cr3(true, __pa(pgd
));
1761 xen_mc_issue(PARAVIRT_LAZY_CPU
);
1763 memblock_x86_reserve_range(__pa(xen_start_info
->pt_base
),
1764 __pa(xen_start_info
->pt_base
+
1765 xen_start_info
->nr_pt_frames
* PAGE_SIZE
),
1770 #else /* !CONFIG_X86_64 */
1771 static RESERVE_BRK_ARRAY(pmd_t
, initial_kernel_pmd
, PTRS_PER_PMD
);
1772 static RESERVE_BRK_ARRAY(pmd_t
, swapper_kernel_pmd
, PTRS_PER_PMD
);
1774 static void __init
xen_write_cr3_init(unsigned long cr3
)
1776 unsigned long pfn
= PFN_DOWN(__pa(swapper_pg_dir
));
1778 BUG_ON(read_cr3() != __pa(initial_page_table
));
1779 BUG_ON(cr3
!= __pa(swapper_pg_dir
));
1782 * We are switching to swapper_pg_dir for the first time (from
1783 * initial_page_table) and therefore need to mark that page
1784 * read-only and then pin it.
1786 * Xen disallows sharing of kernel PMDs for PAE
1787 * guests. Therefore we must copy the kernel PMD from
1788 * initial_page_table into a new kernel PMD to be used in
1791 swapper_kernel_pmd
=
1792 extend_brk(sizeof(pmd_t
) * PTRS_PER_PMD
, PAGE_SIZE
);
1793 memcpy(swapper_kernel_pmd
, initial_kernel_pmd
,
1794 sizeof(pmd_t
) * PTRS_PER_PMD
);
1795 swapper_pg_dir
[KERNEL_PGD_BOUNDARY
] =
1796 __pgd(__pa(swapper_kernel_pmd
) | _PAGE_PRESENT
);
1797 set_page_prot(swapper_kernel_pmd
, PAGE_KERNEL_RO
);
1799 set_page_prot(swapper_pg_dir
, PAGE_KERNEL_RO
);
1801 pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE
, pfn
);
1803 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
,
1804 PFN_DOWN(__pa(initial_page_table
)));
1805 set_page_prot(initial_page_table
, PAGE_KERNEL
);
1806 set_page_prot(initial_kernel_pmd
, PAGE_KERNEL
);
1808 pv_mmu_ops
.write_cr3
= &xen_write_cr3
;
1811 pgd_t
* __init
xen_setup_kernel_pagetable(pgd_t
*pgd
,
1812 unsigned long max_pfn
)
1816 initial_kernel_pmd
=
1817 extend_brk(sizeof(pmd_t
) * PTRS_PER_PMD
, PAGE_SIZE
);
1819 max_pfn_mapped
= PFN_DOWN(__pa(xen_start_info
->pt_base
) +
1820 xen_start_info
->nr_pt_frames
* PAGE_SIZE
+
1823 kernel_pmd
= m2v(pgd
[KERNEL_PGD_BOUNDARY
].pgd
);
1824 memcpy(initial_kernel_pmd
, kernel_pmd
, sizeof(pmd_t
) * PTRS_PER_PMD
);
1826 xen_map_identity_early(initial_kernel_pmd
, max_pfn
);
1828 memcpy(initial_page_table
, pgd
, sizeof(pgd_t
) * PTRS_PER_PGD
);
1829 initial_page_table
[KERNEL_PGD_BOUNDARY
] =
1830 __pgd(__pa(initial_kernel_pmd
) | _PAGE_PRESENT
);
1832 set_page_prot(initial_kernel_pmd
, PAGE_KERNEL_RO
);
1833 set_page_prot(initial_page_table
, PAGE_KERNEL_RO
);
1834 set_page_prot(empty_zero_page
, PAGE_KERNEL_RO
);
1836 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, PFN_DOWN(__pa(pgd
)));
1838 pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE
,
1839 PFN_DOWN(__pa(initial_page_table
)));
1840 xen_write_cr3(__pa(initial_page_table
));
1842 memblock_x86_reserve_range(__pa(xen_start_info
->pt_base
),
1843 __pa(xen_start_info
->pt_base
+
1844 xen_start_info
->nr_pt_frames
* PAGE_SIZE
),
1847 return initial_page_table
;
1849 #endif /* CONFIG_X86_64 */
1851 static unsigned char dummy_mapping
[PAGE_SIZE
] __page_aligned_bss
;
1853 static void xen_set_fixmap(unsigned idx
, phys_addr_t phys
, pgprot_t prot
)
1857 phys
>>= PAGE_SHIFT
;
1860 case FIX_BTMAP_END
... FIX_BTMAP_BEGIN
:
1861 #ifdef CONFIG_X86_F00F_BUG
1864 #ifdef CONFIG_X86_32
1867 # ifdef CONFIG_HIGHMEM
1868 case FIX_KMAP_BEGIN
... FIX_KMAP_END
:
1871 case VSYSCALL_LAST_PAGE
... VSYSCALL_FIRST_PAGE
:
1873 case FIX_TEXT_POKE0
:
1874 case FIX_TEXT_POKE1
:
1875 /* All local page mappings */
1876 pte
= pfn_pte(phys
, prot
);
1879 #ifdef CONFIG_X86_LOCAL_APIC
1880 case FIX_APIC_BASE
: /* maps dummy local APIC */
1881 pte
= pfn_pte(PFN_DOWN(__pa(dummy_mapping
)), PAGE_KERNEL
);
1885 #ifdef CONFIG_X86_IO_APIC
1886 case FIX_IO_APIC_BASE_0
... FIX_IO_APIC_BASE_END
:
1888 * We just don't map the IO APIC - all access is via
1889 * hypercalls. Keep the address in the pte for reference.
1891 pte
= pfn_pte(PFN_DOWN(__pa(dummy_mapping
)), PAGE_KERNEL
);
1895 case FIX_PARAVIRT_BOOTMAP
:
1896 /* This is an MFN, but it isn't an IO mapping from the
1898 pte
= mfn_pte(phys
, prot
);
1902 /* By default, set_fixmap is used for hardware mappings */
1903 pte
= mfn_pte(phys
, __pgprot(pgprot_val(prot
) | _PAGE_IOMAP
));
1907 __native_set_fixmap(idx
, pte
);
1909 #ifdef CONFIG_X86_64
1910 /* Replicate changes to map the vsyscall page into the user
1911 pagetable vsyscall mapping. */
1912 if (idx
>= VSYSCALL_LAST_PAGE
&& idx
<= VSYSCALL_FIRST_PAGE
) {
1913 unsigned long vaddr
= __fix_to_virt(idx
);
1914 set_pte_vaddr_pud(level3_user_vsyscall
, vaddr
, pte
);
1919 void __init
xen_ident_map_ISA(void)
1924 * If we're dom0, then linear map the ISA machine addresses into
1925 * the kernel's address space.
1927 if (!xen_initial_domain())
1930 xen_raw_printk("Xen: setup ISA identity maps\n");
1932 for (pa
= ISA_START_ADDRESS
; pa
< ISA_END_ADDRESS
; pa
+= PAGE_SIZE
) {
1933 pte_t pte
= mfn_pte(PFN_DOWN(pa
), PAGE_KERNEL_IO
);
1935 if (HYPERVISOR_update_va_mapping(PAGE_OFFSET
+ pa
, pte
, 0))
1942 static void __init
xen_post_allocator_init(void)
1944 #ifdef CONFIG_XEN_DEBUG
1945 pv_mmu_ops
.make_pte
= PV_CALLEE_SAVE(xen_make_pte_debug
);
1947 pv_mmu_ops
.set_pte
= xen_set_pte
;
1948 pv_mmu_ops
.set_pmd
= xen_set_pmd
;
1949 pv_mmu_ops
.set_pud
= xen_set_pud
;
1950 #if PAGETABLE_LEVELS == 4
1951 pv_mmu_ops
.set_pgd
= xen_set_pgd
;
1954 /* This will work as long as patching hasn't happened yet
1955 (which it hasn't) */
1956 pv_mmu_ops
.alloc_pte
= xen_alloc_pte
;
1957 pv_mmu_ops
.alloc_pmd
= xen_alloc_pmd
;
1958 pv_mmu_ops
.release_pte
= xen_release_pte
;
1959 pv_mmu_ops
.release_pmd
= xen_release_pmd
;
1960 #if PAGETABLE_LEVELS == 4
1961 pv_mmu_ops
.alloc_pud
= xen_alloc_pud
;
1962 pv_mmu_ops
.release_pud
= xen_release_pud
;
1965 #ifdef CONFIG_X86_64
1966 SetPagePinned(virt_to_page(level3_user_vsyscall
));
1968 xen_mark_init_mm_pinned();
1971 static void xen_leave_lazy_mmu(void)
1975 paravirt_leave_lazy_mmu();
1979 static const struct pv_mmu_ops xen_mmu_ops __initconst
= {
1980 .read_cr2
= xen_read_cr2
,
1981 .write_cr2
= xen_write_cr2
,
1983 .read_cr3
= xen_read_cr3
,
1984 #ifdef CONFIG_X86_32
1985 .write_cr3
= xen_write_cr3_init
,
1987 .write_cr3
= xen_write_cr3
,
1990 .flush_tlb_user
= xen_flush_tlb
,
1991 .flush_tlb_kernel
= xen_flush_tlb
,
1992 .flush_tlb_single
= xen_flush_tlb_single
,
1993 .flush_tlb_others
= xen_flush_tlb_others
,
1995 .pte_update
= paravirt_nop
,
1996 .pte_update_defer
= paravirt_nop
,
1998 .pgd_alloc
= xen_pgd_alloc
,
1999 .pgd_free
= xen_pgd_free
,
2001 .alloc_pte
= xen_alloc_pte_init
,
2002 .release_pte
= xen_release_pte_init
,
2003 .alloc_pmd
= xen_alloc_pmd_init
,
2004 .release_pmd
= xen_release_pmd_init
,
2006 .set_pte
= xen_set_pte_init
,
2007 .set_pte_at
= xen_set_pte_at
,
2008 .set_pmd
= xen_set_pmd_hyper
,
2010 .ptep_modify_prot_start
= __ptep_modify_prot_start
,
2011 .ptep_modify_prot_commit
= __ptep_modify_prot_commit
,
2013 .pte_val
= PV_CALLEE_SAVE(xen_pte_val
),
2014 .pgd_val
= PV_CALLEE_SAVE(xen_pgd_val
),
2016 .make_pte
= PV_CALLEE_SAVE(xen_make_pte
),
2017 .make_pgd
= PV_CALLEE_SAVE(xen_make_pgd
),
2019 #ifdef CONFIG_X86_PAE
2020 .set_pte_atomic
= xen_set_pte_atomic
,
2021 .pte_clear
= xen_pte_clear
,
2022 .pmd_clear
= xen_pmd_clear
,
2023 #endif /* CONFIG_X86_PAE */
2024 .set_pud
= xen_set_pud_hyper
,
2026 .make_pmd
= PV_CALLEE_SAVE(xen_make_pmd
),
2027 .pmd_val
= PV_CALLEE_SAVE(xen_pmd_val
),
2029 #if PAGETABLE_LEVELS == 4
2030 .pud_val
= PV_CALLEE_SAVE(xen_pud_val
),
2031 .make_pud
= PV_CALLEE_SAVE(xen_make_pud
),
2032 .set_pgd
= xen_set_pgd_hyper
,
2034 .alloc_pud
= xen_alloc_pmd_init
,
2035 .release_pud
= xen_release_pmd_init
,
2036 #endif /* PAGETABLE_LEVELS == 4 */
2038 .activate_mm
= xen_activate_mm
,
2039 .dup_mmap
= xen_dup_mmap
,
2040 .exit_mmap
= xen_exit_mmap
,
2043 .enter
= paravirt_enter_lazy_mmu
,
2044 .leave
= xen_leave_lazy_mmu
,
2047 .set_fixmap
= xen_set_fixmap
,
2050 void __init
xen_init_mmu_ops(void)
2052 x86_init
.mapping
.pagetable_reserve
= xen_mapping_pagetable_reserve
;
2053 x86_init
.paging
.pagetable_setup_start
= xen_pagetable_setup_start
;
2054 x86_init
.paging
.pagetable_setup_done
= xen_pagetable_setup_done
;
2055 pv_mmu_ops
= xen_mmu_ops
;
2057 memset(dummy_mapping
, 0xff, PAGE_SIZE
);
2060 /* Protected by xen_reservation_lock. */
2061 #define MAX_CONTIG_ORDER 9 /* 2MB */
2062 static unsigned long discontig_frames
[1<<MAX_CONTIG_ORDER
];
2064 #define VOID_PTE (mfn_pte(0, __pgprot(0)))
2065 static void xen_zap_pfn_range(unsigned long vaddr
, unsigned int order
,
2066 unsigned long *in_frames
,
2067 unsigned long *out_frames
)
2070 struct multicall_space mcs
;
2073 for (i
= 0; i
< (1UL<<order
); i
++, vaddr
+= PAGE_SIZE
) {
2074 mcs
= __xen_mc_entry(0);
2077 in_frames
[i
] = virt_to_mfn(vaddr
);
2079 MULTI_update_va_mapping(mcs
.mc
, vaddr
, VOID_PTE
, 0);
2080 __set_phys_to_machine(virt_to_pfn(vaddr
), INVALID_P2M_ENTRY
);
2083 out_frames
[i
] = virt_to_pfn(vaddr
);
2089 * Update the pfn-to-mfn mappings for a virtual address range, either to
2090 * point to an array of mfns, or contiguously from a single starting
2093 static void xen_remap_exchanged_ptes(unsigned long vaddr
, int order
,
2094 unsigned long *mfns
,
2095 unsigned long first_mfn
)
2102 limit
= 1u << order
;
2103 for (i
= 0; i
< limit
; i
++, vaddr
+= PAGE_SIZE
) {
2104 struct multicall_space mcs
;
2107 mcs
= __xen_mc_entry(0);
2111 mfn
= first_mfn
+ i
;
2113 if (i
< (limit
- 1))
2117 flags
= UVMF_INVLPG
| UVMF_ALL
;
2119 flags
= UVMF_TLB_FLUSH
| UVMF_ALL
;
2122 MULTI_update_va_mapping(mcs
.mc
, vaddr
,
2123 mfn_pte(mfn
, PAGE_KERNEL
), flags
);
2125 set_phys_to_machine(virt_to_pfn(vaddr
), mfn
);
2132 * Perform the hypercall to exchange a region of our pfns to point to
2133 * memory with the required contiguous alignment. Takes the pfns as
2134 * input, and populates mfns as output.
2136 * Returns a success code indicating whether the hypervisor was able to
2137 * satisfy the request or not.
2139 static int xen_exchange_memory(unsigned long extents_in
, unsigned int order_in
,
2140 unsigned long *pfns_in
,
2141 unsigned long extents_out
,
2142 unsigned int order_out
,
2143 unsigned long *mfns_out
,
2144 unsigned int address_bits
)
2149 struct xen_memory_exchange exchange
= {
2151 .nr_extents
= extents_in
,
2152 .extent_order
= order_in
,
2153 .extent_start
= pfns_in
,
2157 .nr_extents
= extents_out
,
2158 .extent_order
= order_out
,
2159 .extent_start
= mfns_out
,
2160 .address_bits
= address_bits
,
2165 BUG_ON(extents_in
<< order_in
!= extents_out
<< order_out
);
2167 rc
= HYPERVISOR_memory_op(XENMEM_exchange
, &exchange
);
2168 success
= (exchange
.nr_exchanged
== extents_in
);
2170 BUG_ON(!success
&& ((exchange
.nr_exchanged
!= 0) || (rc
== 0)));
2171 BUG_ON(success
&& (rc
!= 0));
2176 int xen_create_contiguous_region(unsigned long vstart
, unsigned int order
,
2177 unsigned int address_bits
)
2179 unsigned long *in_frames
= discontig_frames
, out_frame
;
2180 unsigned long flags
;
2184 * Currently an auto-translated guest will not perform I/O, nor will
2185 * it require PAE page directories below 4GB. Therefore any calls to
2186 * this function are redundant and can be ignored.
2189 if (xen_feature(XENFEAT_auto_translated_physmap
))
2192 if (unlikely(order
> MAX_CONTIG_ORDER
))
2195 memset((void *) vstart
, 0, PAGE_SIZE
<< order
);
2197 spin_lock_irqsave(&xen_reservation_lock
, flags
);
2199 /* 1. Zap current PTEs, remembering MFNs. */
2200 xen_zap_pfn_range(vstart
, order
, in_frames
, NULL
);
2202 /* 2. Get a new contiguous memory extent. */
2203 out_frame
= virt_to_pfn(vstart
);
2204 success
= xen_exchange_memory(1UL << order
, 0, in_frames
,
2205 1, order
, &out_frame
,
2208 /* 3. Map the new extent in place of old pages. */
2210 xen_remap_exchanged_ptes(vstart
, order
, NULL
, out_frame
);
2212 xen_remap_exchanged_ptes(vstart
, order
, in_frames
, 0);
2214 spin_unlock_irqrestore(&xen_reservation_lock
, flags
);
2216 return success
? 0 : -ENOMEM
;
2218 EXPORT_SYMBOL_GPL(xen_create_contiguous_region
);
2220 void xen_destroy_contiguous_region(unsigned long vstart
, unsigned int order
)
2222 unsigned long *out_frames
= discontig_frames
, in_frame
;
2223 unsigned long flags
;
2226 if (xen_feature(XENFEAT_auto_translated_physmap
))
2229 if (unlikely(order
> MAX_CONTIG_ORDER
))
2232 memset((void *) vstart
, 0, PAGE_SIZE
<< order
);
2234 spin_lock_irqsave(&xen_reservation_lock
, flags
);
2236 /* 1. Find start MFN of contiguous extent. */
2237 in_frame
= virt_to_mfn(vstart
);
2239 /* 2. Zap current PTEs. */
2240 xen_zap_pfn_range(vstart
, order
, NULL
, out_frames
);
2242 /* 3. Do the exchange for non-contiguous MFNs. */
2243 success
= xen_exchange_memory(1, order
, &in_frame
, 1UL << order
,
2246 /* 4. Map new pages in place of old pages. */
2248 xen_remap_exchanged_ptes(vstart
, order
, out_frames
, 0);
2250 xen_remap_exchanged_ptes(vstart
, order
, NULL
, in_frame
);
2252 spin_unlock_irqrestore(&xen_reservation_lock
, flags
);
2254 EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region
);
2256 #ifdef CONFIG_XEN_PVHVM
2257 static void xen_hvm_exit_mmap(struct mm_struct
*mm
)
2259 struct xen_hvm_pagetable_dying a
;
2262 a
.domid
= DOMID_SELF
;
2263 a
.gpa
= __pa(mm
->pgd
);
2264 rc
= HYPERVISOR_hvm_op(HVMOP_pagetable_dying
, &a
);
2265 WARN_ON_ONCE(rc
< 0);
2268 static int is_pagetable_dying_supported(void)
2270 struct xen_hvm_pagetable_dying a
;
2273 a
.domid
= DOMID_SELF
;
2275 rc
= HYPERVISOR_hvm_op(HVMOP_pagetable_dying
, &a
);
2277 printk(KERN_DEBUG
"HVMOP_pagetable_dying not supported\n");
2283 void __init
xen_hvm_init_mmu_ops(void)
2285 if (is_pagetable_dying_supported())
2286 pv_mmu_ops
.exit_mmap
= xen_hvm_exit_mmap
;
2290 #define REMAP_BATCH_SIZE 16
2295 struct mmu_update
*mmu_update
;
2298 static int remap_area_mfn_pte_fn(pte_t
*ptep
, pgtable_t token
,
2299 unsigned long addr
, void *data
)
2301 struct remap_data
*rmd
= data
;
2302 pte_t pte
= pte_mkspecial(pfn_pte(rmd
->mfn
++, rmd
->prot
));
2304 rmd
->mmu_update
->ptr
= virt_to_machine(ptep
).maddr
;
2305 rmd
->mmu_update
->val
= pte_val_ma(pte
);
2311 int xen_remap_domain_mfn_range(struct vm_area_struct
*vma
,
2313 unsigned long mfn
, int nr
,
2314 pgprot_t prot
, unsigned domid
)
2316 struct remap_data rmd
;
2317 struct mmu_update mmu_update
[REMAP_BATCH_SIZE
];
2319 unsigned long range
;
2322 prot
= __pgprot(pgprot_val(prot
) | _PAGE_IOMAP
);
2324 BUG_ON(!((vma
->vm_flags
& (VM_PFNMAP
| VM_RESERVED
| VM_IO
)) ==
2325 (VM_PFNMAP
| VM_RESERVED
| VM_IO
)));
2331 batch
= min(REMAP_BATCH_SIZE
, nr
);
2332 range
= (unsigned long)batch
<< PAGE_SHIFT
;
2334 rmd
.mmu_update
= mmu_update
;
2335 err
= apply_to_page_range(vma
->vm_mm
, addr
, range
,
2336 remap_area_mfn_pte_fn
, &rmd
);
2341 if (HYPERVISOR_mmu_update(mmu_update
, batch
, NULL
, domid
) < 0)
2355 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range
);
2357 #ifdef CONFIG_XEN_DEBUG_FS
2358 static int p2m_dump_open(struct inode
*inode
, struct file
*filp
)
2360 return single_open(filp
, p2m_dump_show
, NULL
);
2363 static const struct file_operations p2m_dump_fops
= {
2364 .open
= p2m_dump_open
,
2366 .llseek
= seq_lseek
,
2367 .release
= single_release
,
2369 #endif /* CONFIG_XEN_DEBUG_FS */