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);
205 void make_lowmem_page_readonly(void *vaddr)
208 unsigned long address = (unsigned long)vaddr;
211 pte = lookup_address(address, &level);
213 return; /* vaddr missing */
215 ptev = pte_wrprotect(*pte);
217 if (HYPERVISOR_update_va_mapping(address, ptev, 0))
221 void make_lowmem_page_readwrite(void *vaddr)
224 unsigned long address = (unsigned long)vaddr;
227 pte = lookup_address(address, &level);
229 return; /* vaddr missing */
231 ptev = pte_mkwrite(*pte);
233 if (HYPERVISOR_update_va_mapping(address, ptev, 0))
238 static bool xen_page_pinned(void *ptr)
240 struct page *page = virt_to_page(ptr);
242 return PagePinned(page);
245 static bool xen_iomap_pte(pte_t pte)
247 return pte_flags(pte) & _PAGE_IOMAP;
250 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid)
252 struct multicall_space mcs;
253 struct mmu_update *u;
255 mcs = xen_mc_entry(sizeof(*u));
258 /* ptep might be kmapped when using 32-bit HIGHPTE */
259 u->ptr = arbitrary_virt_to_machine(ptep).maddr;
260 u->val = pte_val_ma(pteval);
262 MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, domid);
264 xen_mc_issue(PARAVIRT_LAZY_MMU);
266 EXPORT_SYMBOL_GPL(xen_set_domain_pte);
268 static void xen_set_iomap_pte(pte_t *ptep, pte_t pteval)
270 xen_set_domain_pte(ptep, pteval, DOMID_IO);
273 static void xen_extend_mmu_update(const struct mmu_update *update)
275 struct multicall_space mcs;
276 struct mmu_update *u;
278 mcs = xen_mc_extend_args(__HYPERVISOR_mmu_update, sizeof(*u));
280 if (mcs.mc != NULL) {
281 ADD_STATS(mmu_update_extended, 1);
282 ADD_STATS(mmu_update_histo[mcs.mc->args[1]], -1);
286 if (mcs.mc->args[1] < MMU_UPDATE_HISTO)
287 ADD_STATS(mmu_update_histo[mcs.mc->args[1]], 1);
289 ADD_STATS(mmu_update_histo[0], 1);
291 ADD_STATS(mmu_update, 1);
292 mcs = __xen_mc_entry(sizeof(*u));
293 MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
294 ADD_STATS(mmu_update_histo[1], 1);
301 void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
309 /* ptr may be ioremapped for 64-bit pagetable setup */
310 u.ptr = arbitrary_virt_to_machine(ptr).maddr;
311 u.val = pmd_val_ma(val);
312 xen_extend_mmu_update(&u);
314 ADD_STATS(pmd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
316 xen_mc_issue(PARAVIRT_LAZY_MMU);
321 void xen_set_pmd(pmd_t *ptr, pmd_t val)
323 ADD_STATS(pmd_update, 1);
325 /* If page is not pinned, we can just update the entry
327 if (!xen_page_pinned(ptr)) {
332 ADD_STATS(pmd_update_pinned, 1);
334 xen_set_pmd_hyper(ptr, val);
338 * Associate a virtual page frame with a given physical page frame
339 * and protection flags for that frame.
341 void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
343 set_pte_vaddr(vaddr, mfn_pte(mfn, flags));
346 void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
347 pte_t *ptep, pte_t pteval)
349 if (xen_iomap_pte(pteval)) {
350 xen_set_iomap_pte(ptep, pteval);
354 ADD_STATS(set_pte_at, 1);
355 // ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
356 ADD_STATS(set_pte_at_current, mm == current->mm);
357 ADD_STATS(set_pte_at_kernel, mm == &init_mm);
359 if (mm == current->mm || mm == &init_mm) {
360 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
361 struct multicall_space mcs;
362 mcs = xen_mc_entry(0);
364 MULTI_update_va_mapping(mcs.mc, addr, pteval, 0);
365 ADD_STATS(set_pte_at_batched, 1);
366 xen_mc_issue(PARAVIRT_LAZY_MMU);
369 if (HYPERVISOR_update_va_mapping(addr, pteval, 0) == 0)
372 xen_set_pte(ptep, pteval);
377 pte_t xen_ptep_modify_prot_start(struct mm_struct *mm,
378 unsigned long addr, pte_t *ptep)
380 /* Just return the pte as-is. We preserve the bits on commit */
384 void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
385 pte_t *ptep, pte_t pte)
391 u.ptr = arbitrary_virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
392 u.val = pte_val_ma(pte);
393 xen_extend_mmu_update(&u);
395 ADD_STATS(prot_commit, 1);
396 ADD_STATS(prot_commit_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
398 xen_mc_issue(PARAVIRT_LAZY_MMU);
401 /* Assume pteval_t is equivalent to all the other *val_t types. */
402 static pteval_t pte_mfn_to_pfn(pteval_t val)
404 if (val & _PAGE_PRESENT) {
405 unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
406 pteval_t flags = val & PTE_FLAGS_MASK;
407 val = ((pteval_t)mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
413 static pteval_t pte_pfn_to_mfn(pteval_t val)
415 if (val & _PAGE_PRESENT) {
416 unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
417 pteval_t flags = val & PTE_FLAGS_MASK;
418 unsigned long mfn = pfn_to_mfn(pfn);
421 * If there's no mfn for the pfn, then just create an
422 * empty non-present pte. Unfortunately this loses
423 * information about the original pfn, so
424 * pte_mfn_to_pfn is asymmetric.
426 if (unlikely(mfn == INVALID_P2M_ENTRY)) {
431 val = ((pteval_t)mfn << PAGE_SHIFT) | flags;
437 static pteval_t iomap_pte(pteval_t val)
439 if (val & _PAGE_PRESENT) {
440 unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
441 pteval_t flags = val & PTE_FLAGS_MASK;
443 /* We assume the pte frame number is a MFN, so
444 just use it as-is. */
445 val = ((pteval_t)pfn << PAGE_SHIFT) | flags;
451 pteval_t xen_pte_val(pte_t pte)
453 pteval_t pteval = pte.pte;
455 /* If this is a WC pte, convert back from Xen WC to Linux WC */
456 if ((pteval & (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT)) == _PAGE_PAT) {
457 WARN_ON(!pat_enabled);
458 pteval = (pteval & ~_PAGE_PAT) | _PAGE_PWT;
461 if (xen_initial_domain() && (pteval & _PAGE_IOMAP))
464 return pte_mfn_to_pfn(pteval);
466 PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val);
468 pgdval_t xen_pgd_val(pgd_t pgd)
470 return pte_mfn_to_pfn(pgd.pgd);
472 PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val);
475 * Xen's PAT setup is part of its ABI, though I assume entries 6 & 7
476 * are reserved for now, to correspond to the Intel-reserved PAT
479 * We expect Linux's PAT set as follows:
481 * Idx PTE flags Linux Xen Default
488 * 6 PAT PCD UC- UC UC-
489 * 7 PAT PCD PWT UC UC UC
492 void xen_set_pat(u64 pat)
494 /* We expect Linux to use a PAT setting of
495 * UC UC- WC WB (ignoring the PAT flag) */
496 WARN_ON(pat != 0x0007010600070106ull);
499 pte_t xen_make_pte(pteval_t pte)
501 phys_addr_t addr = (pte & PTE_PFN_MASK);
503 /* If Linux is trying to set a WC pte, then map to the Xen WC.
504 * If _PAGE_PAT is set, then it probably means it is really
505 * _PAGE_PSE, so avoid fiddling with the PAT mapping and hope
506 * things work out OK...
508 * (We should never see kernel mappings with _PAGE_PSE set,
509 * but we could see hugetlbfs mappings, I think.).
511 if (pat_enabled && !WARN_ON(pte & _PAGE_PAT)) {
512 if ((pte & (_PAGE_PCD | _PAGE_PWT)) == _PAGE_PWT)
513 pte = (pte & ~(_PAGE_PCD | _PAGE_PWT)) | _PAGE_PAT;
517 * Unprivileged domains are allowed to do IOMAPpings for
518 * PCI passthrough, but not map ISA space. The ISA
519 * mappings are just dummy local mappings to keep other
520 * parts of the kernel happy.
522 if (unlikely(pte & _PAGE_IOMAP) &&
523 (xen_initial_domain() || addr >= ISA_END_ADDRESS)) {
524 pte = iomap_pte(pte);
527 pte = pte_pfn_to_mfn(pte);
530 return native_make_pte(pte);
532 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
534 pgd_t xen_make_pgd(pgdval_t pgd)
536 pgd = pte_pfn_to_mfn(pgd);
537 return native_make_pgd(pgd);
539 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pgd);
541 pmdval_t xen_pmd_val(pmd_t pmd)
543 return pte_mfn_to_pfn(pmd.pmd);
545 PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val);
547 void xen_set_pud_hyper(pud_t *ptr, pud_t val)
555 /* ptr may be ioremapped for 64-bit pagetable setup */
556 u.ptr = arbitrary_virt_to_machine(ptr).maddr;
557 u.val = pud_val_ma(val);
558 xen_extend_mmu_update(&u);
560 ADD_STATS(pud_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
562 xen_mc_issue(PARAVIRT_LAZY_MMU);
567 void xen_set_pud(pud_t *ptr, pud_t val)
569 ADD_STATS(pud_update, 1);
571 /* If page is not pinned, we can just update the entry
573 if (!xen_page_pinned(ptr)) {
578 ADD_STATS(pud_update_pinned, 1);
580 xen_set_pud_hyper(ptr, val);
583 void xen_set_pte(pte_t *ptep, pte_t pte)
585 if (xen_iomap_pte(pte)) {
586 xen_set_iomap_pte(ptep, pte);
590 ADD_STATS(pte_update, 1);
591 // ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
592 ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
594 #ifdef CONFIG_X86_PAE
595 ptep->pte_high = pte.pte_high;
597 ptep->pte_low = pte.pte_low;
603 #ifdef CONFIG_X86_PAE
604 void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
606 if (xen_iomap_pte(pte)) {
607 xen_set_iomap_pte(ptep, pte);
611 set_64bit((u64 *)ptep, native_pte_val(pte));
614 void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
617 smp_wmb(); /* make sure low gets written first */
621 void xen_pmd_clear(pmd_t *pmdp)
623 set_pmd(pmdp, __pmd(0));
625 #endif /* CONFIG_X86_PAE */
627 pmd_t xen_make_pmd(pmdval_t pmd)
629 pmd = pte_pfn_to_mfn(pmd);
630 return native_make_pmd(pmd);
632 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd);
634 #if PAGETABLE_LEVELS == 4
635 pudval_t xen_pud_val(pud_t pud)
637 return pte_mfn_to_pfn(pud.pud);
639 PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val);
641 pud_t xen_make_pud(pudval_t pud)
643 pud = pte_pfn_to_mfn(pud);
645 return native_make_pud(pud);
647 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pud);
649 pgd_t *xen_get_user_pgd(pgd_t *pgd)
651 pgd_t *pgd_page = (pgd_t *)(((unsigned long)pgd) & PAGE_MASK);
652 unsigned offset = pgd - pgd_page;
653 pgd_t *user_ptr = NULL;
655 if (offset < pgd_index(USER_LIMIT)) {
656 struct page *page = virt_to_page(pgd_page);
657 user_ptr = (pgd_t *)page->private;
665 static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
669 u.ptr = virt_to_machine(ptr).maddr;
670 u.val = pgd_val_ma(val);
671 xen_extend_mmu_update(&u);
675 * Raw hypercall-based set_pgd, intended for in early boot before
676 * there's a page structure. This implies:
677 * 1. The only existing pagetable is the kernel's
678 * 2. It is always pinned
679 * 3. It has no user pagetable attached to it
681 void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
687 __xen_set_pgd_hyper(ptr, val);
689 xen_mc_issue(PARAVIRT_LAZY_MMU);
694 void xen_set_pgd(pgd_t *ptr, pgd_t val)
696 pgd_t *user_ptr = xen_get_user_pgd(ptr);
698 ADD_STATS(pgd_update, 1);
700 /* If page is not pinned, we can just update the entry
702 if (!xen_page_pinned(ptr)) {
705 WARN_ON(xen_page_pinned(user_ptr));
711 ADD_STATS(pgd_update_pinned, 1);
712 ADD_STATS(pgd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
714 /* If it's pinned, then we can at least batch the kernel and
715 user updates together. */
718 __xen_set_pgd_hyper(ptr, val);
720 __xen_set_pgd_hyper(user_ptr, val);
722 xen_mc_issue(PARAVIRT_LAZY_MMU);
724 #endif /* PAGETABLE_LEVELS == 4 */
727 * (Yet another) pagetable walker. This one is intended for pinning a
728 * pagetable. This means that it walks a pagetable and calls the
729 * callback function on each page it finds making up the page table,
730 * at every level. It walks the entire pagetable, but it only bothers
731 * pinning pte pages which are below limit. In the normal case this
732 * will be STACK_TOP_MAX, but at boot we need to pin up to
735 * For 32-bit the important bit is that we don't pin beyond there,
736 * because then we start getting into Xen's ptes.
738 * For 64-bit, we must skip the Xen hole in the middle of the address
739 * space, just after the big x86-64 virtual hole.
741 static int __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd,
742 int (*func)(struct mm_struct *mm, struct page *,
747 unsigned hole_low, hole_high;
748 unsigned pgdidx_limit, pudidx_limit, pmdidx_limit;
749 unsigned pgdidx, pudidx, pmdidx;
751 /* The limit is the last byte to be touched */
753 BUG_ON(limit >= FIXADDR_TOP);
755 if (xen_feature(XENFEAT_auto_translated_physmap))
759 * 64-bit has a great big hole in the middle of the address
760 * space, which contains the Xen mappings. On 32-bit these
761 * will end up making a zero-sized hole and so is a no-op.
763 hole_low = pgd_index(USER_LIMIT);
764 hole_high = pgd_index(PAGE_OFFSET);
766 pgdidx_limit = pgd_index(limit);
768 pudidx_limit = pud_index(limit);
773 pmdidx_limit = pmd_index(limit);
778 for (pgdidx = 0; pgdidx <= pgdidx_limit; pgdidx++) {
781 if (pgdidx >= hole_low && pgdidx < hole_high)
784 if (!pgd_val(pgd[pgdidx]))
787 pud = pud_offset(&pgd[pgdidx], 0);
789 if (PTRS_PER_PUD > 1) /* not folded */
790 flush |= (*func)(mm, virt_to_page(pud), PT_PUD);
792 for (pudidx = 0; pudidx < PTRS_PER_PUD; pudidx++) {
795 if (pgdidx == pgdidx_limit &&
796 pudidx > pudidx_limit)
799 if (pud_none(pud[pudidx]))
802 pmd = pmd_offset(&pud[pudidx], 0);
804 if (PTRS_PER_PMD > 1) /* not folded */
805 flush |= (*func)(mm, virt_to_page(pmd), PT_PMD);
807 for (pmdidx = 0; pmdidx < PTRS_PER_PMD; pmdidx++) {
810 if (pgdidx == pgdidx_limit &&
811 pudidx == pudidx_limit &&
812 pmdidx > pmdidx_limit)
815 if (pmd_none(pmd[pmdidx]))
818 pte = pmd_page(pmd[pmdidx]);
819 flush |= (*func)(mm, pte, PT_PTE);
825 /* Do the top level last, so that the callbacks can use it as
826 a cue to do final things like tlb flushes. */
827 flush |= (*func)(mm, virt_to_page(pgd), PT_PGD);
832 static int xen_pgd_walk(struct mm_struct *mm,
833 int (*func)(struct mm_struct *mm, struct page *,
837 return __xen_pgd_walk(mm, mm->pgd, func, limit);
840 /* If we're using split pte locks, then take the page's lock and
841 return a pointer to it. Otherwise return NULL. */
842 static spinlock_t *xen_pte_lock(struct page *page, struct mm_struct *mm)
844 spinlock_t *ptl = NULL;
846 #if USE_SPLIT_PTLOCKS
847 ptl = __pte_lockptr(page);
848 spin_lock_nest_lock(ptl, &mm->page_table_lock);
854 static void xen_pte_unlock(void *v)
860 static void xen_do_pin(unsigned level, unsigned long pfn)
862 struct mmuext_op *op;
863 struct multicall_space mcs;
865 mcs = __xen_mc_entry(sizeof(*op));
868 op->arg1.mfn = pfn_to_mfn(pfn);
869 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
872 static int xen_pin_page(struct mm_struct *mm, struct page *page,
875 unsigned pgfl = TestSetPagePinned(page);
879 flush = 0; /* already pinned */
880 else if (PageHighMem(page))
881 /* kmaps need flushing if we found an unpinned
885 void *pt = lowmem_page_address(page);
886 unsigned long pfn = page_to_pfn(page);
887 struct multicall_space mcs = __xen_mc_entry(0);
893 * We need to hold the pagetable lock between the time
894 * we make the pagetable RO and when we actually pin
895 * it. If we don't, then other users may come in and
896 * attempt to update the pagetable by writing it,
897 * which will fail because the memory is RO but not
898 * pinned, so Xen won't do the trap'n'emulate.
900 * If we're using split pte locks, we can't hold the
901 * entire pagetable's worth of locks during the
902 * traverse, because we may wrap the preempt count (8
903 * bits). The solution is to mark RO and pin each PTE
904 * page while holding the lock. This means the number
905 * of locks we end up holding is never more than a
906 * batch size (~32 entries, at present).
908 * If we're not using split pte locks, we needn't pin
909 * the PTE pages independently, because we're
910 * protected by the overall pagetable lock.
914 ptl = xen_pte_lock(page, mm);
916 MULTI_update_va_mapping(mcs.mc, (unsigned long)pt,
917 pfn_pte(pfn, PAGE_KERNEL_RO),
918 level == PT_PGD ? UVMF_TLB_FLUSH : 0);
921 xen_do_pin(MMUEXT_PIN_L1_TABLE, pfn);
923 /* Queue a deferred unlock for when this batch
925 xen_mc_callback(xen_pte_unlock, ptl);
932 /* This is called just after a mm has been created, but it has not
933 been used yet. We need to make sure that its pagetable is all
934 read-only, and can be pinned. */
935 static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
939 if (__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT)) {
940 /* re-enable interrupts for flushing */
950 pgd_t *user_pgd = xen_get_user_pgd(pgd);
952 xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));
955 xen_pin_page(mm, virt_to_page(user_pgd), PT_PGD);
956 xen_do_pin(MMUEXT_PIN_L4_TABLE,
957 PFN_DOWN(__pa(user_pgd)));
960 #else /* CONFIG_X86_32 */
961 #ifdef CONFIG_X86_PAE
962 /* Need to make sure unshared kernel PMD is pinnable */
963 xen_pin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
966 xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
967 #endif /* CONFIG_X86_64 */
971 static void xen_pgd_pin(struct mm_struct *mm)
973 __xen_pgd_pin(mm, mm->pgd);
977 * On save, we need to pin all pagetables to make sure they get their
978 * mfns turned into pfns. Search the list for any unpinned pgds and pin
979 * them (unpinned pgds are not currently in use, probably because the
980 * process is under construction or destruction).
982 * Expected to be called in stop_machine() ("equivalent to taking
983 * every spinlock in the system"), so the locking doesn't really
984 * matter all that much.
986 void xen_mm_pin_all(void)
991 spin_lock_irqsave(&pgd_lock, flags);
993 list_for_each_entry(page, &pgd_list, lru) {
994 if (!PagePinned(page)) {
995 __xen_pgd_pin(&init_mm, (pgd_t *)page_address(page));
996 SetPageSavePinned(page);
1000 spin_unlock_irqrestore(&pgd_lock, flags);
1004 * The init_mm pagetable is really pinned as soon as its created, but
1005 * that's before we have page structures to store the bits. So do all
1006 * the book-keeping now.
1008 static __init int xen_mark_pinned(struct mm_struct *mm, struct page *page,
1009 enum pt_level level)
1011 SetPagePinned(page);
1015 static void __init xen_mark_init_mm_pinned(void)
1017 xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
1020 static int xen_unpin_page(struct mm_struct *mm, struct page *page,
1021 enum pt_level level)
1023 unsigned pgfl = TestClearPagePinned(page);
1025 if (pgfl && !PageHighMem(page)) {
1026 void *pt = lowmem_page_address(page);
1027 unsigned long pfn = page_to_pfn(page);
1028 spinlock_t *ptl = NULL;
1029 struct multicall_space mcs;
1032 * Do the converse to pin_page. If we're using split
1033 * pte locks, we must be holding the lock for while
1034 * the pte page is unpinned but still RO to prevent
1035 * concurrent updates from seeing it in this
1036 * partially-pinned state.
1038 if (level == PT_PTE) {
1039 ptl = xen_pte_lock(page, mm);
1042 xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
1045 mcs = __xen_mc_entry(0);
1047 MULTI_update_va_mapping(mcs.mc, (unsigned long)pt,
1048 pfn_pte(pfn, PAGE_KERNEL),
1049 level == PT_PGD ? UVMF_TLB_FLUSH : 0);
1052 /* unlock when batch completed */
1053 xen_mc_callback(xen_pte_unlock, ptl);
1057 return 0; /* never need to flush on unpin */
1060 /* Release a pagetables pages back as normal RW */
1061 static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
1065 xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
1067 #ifdef CONFIG_X86_64
1069 pgd_t *user_pgd = xen_get_user_pgd(pgd);
1072 xen_do_pin(MMUEXT_UNPIN_TABLE,
1073 PFN_DOWN(__pa(user_pgd)));
1074 xen_unpin_page(mm, virt_to_page(user_pgd), PT_PGD);
1079 #ifdef CONFIG_X86_PAE
1080 /* Need to make sure unshared kernel PMD is unpinned */
1081 xen_unpin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
1085 __xen_pgd_walk(mm, pgd, xen_unpin_page, USER_LIMIT);
1090 static void xen_pgd_unpin(struct mm_struct *mm)
1092 __xen_pgd_unpin(mm, mm->pgd);
1096 * On resume, undo any pinning done at save, so that the rest of the
1097 * kernel doesn't see any unexpected pinned pagetables.
1099 void xen_mm_unpin_all(void)
1101 unsigned long flags;
1104 spin_lock_irqsave(&pgd_lock, flags);
1106 list_for_each_entry(page, &pgd_list, lru) {
1107 if (PageSavePinned(page)) {
1108 BUG_ON(!PagePinned(page));
1109 __xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page));
1110 ClearPageSavePinned(page);
1114 spin_unlock_irqrestore(&pgd_lock, flags);
1117 void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
1119 spin_lock(&next->page_table_lock);
1121 spin_unlock(&next->page_table_lock);
1124 void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
1126 spin_lock(&mm->page_table_lock);
1128 spin_unlock(&mm->page_table_lock);
1133 /* Another cpu may still have their %cr3 pointing at the pagetable, so
1134 we need to repoint it somewhere else before we can unpin it. */
1135 static void drop_other_mm_ref(void *info)
1137 struct mm_struct *mm = info;
1138 struct mm_struct *active_mm;
1140 active_mm = percpu_read(cpu_tlbstate.active_mm);
1142 if (active_mm == mm)
1143 leave_mm(smp_processor_id());
1145 /* If this cpu still has a stale cr3 reference, then make sure
1146 it has been flushed. */
1147 if (percpu_read(xen_current_cr3) == __pa(mm->pgd))
1148 load_cr3(swapper_pg_dir);
1151 static void xen_drop_mm_ref(struct mm_struct *mm)
1156 if (current->active_mm == mm) {
1157 if (current->mm == mm)
1158 load_cr3(swapper_pg_dir);
1160 leave_mm(smp_processor_id());
1163 /* Get the "official" set of cpus referring to our pagetable. */
1164 if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) {
1165 for_each_online_cpu(cpu) {
1166 if (!cpumask_test_cpu(cpu, mm_cpumask(mm))
1167 && per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd))
1169 smp_call_function_single(cpu, drop_other_mm_ref, mm, 1);
1173 cpumask_copy(mask, mm_cpumask(mm));
1175 /* It's possible that a vcpu may have a stale reference to our
1176 cr3, because its in lazy mode, and it hasn't yet flushed
1177 its set of pending hypercalls yet. In this case, we can
1178 look at its actual current cr3 value, and force it to flush
1180 for_each_online_cpu(cpu) {
1181 if (per_cpu(xen_current_cr3, cpu) == __pa(mm->pgd))
1182 cpumask_set_cpu(cpu, mask);
1185 if (!cpumask_empty(mask))
1186 smp_call_function_many(mask, drop_other_mm_ref, mm, 1);
1187 free_cpumask_var(mask);
1190 static void xen_drop_mm_ref(struct mm_struct *mm)
1192 if (current->active_mm == mm)
1193 load_cr3(swapper_pg_dir);
1198 * While a process runs, Xen pins its pagetables, which means that the
1199 * hypervisor forces it to be read-only, and it controls all updates
1200 * to it. This means that all pagetable updates have to go via the
1201 * hypervisor, which is moderately expensive.
1203 * Since we're pulling the pagetable down, we switch to use init_mm,
1204 * unpin old process pagetable and mark it all read-write, which
1205 * allows further operations on it to be simple memory accesses.
1207 * The only subtle point is that another CPU may be still using the
1208 * pagetable because of lazy tlb flushing. This means we need need to
1209 * switch all CPUs off this pagetable before we can unpin it.
1211 void xen_exit_mmap(struct mm_struct *mm)
1213 get_cpu(); /* make sure we don't move around */
1214 xen_drop_mm_ref(mm);
1217 spin_lock(&mm->page_table_lock);
1219 /* pgd may not be pinned in the error exit path of execve */
1220 if (xen_page_pinned(mm->pgd))
1223 spin_unlock(&mm->page_table_lock);
1226 static __init void xen_pagetable_setup_start(pgd_t *base)
1230 static void xen_post_allocator_init(void);
1232 static __init void xen_pagetable_setup_done(pgd_t *base)
1234 xen_setup_shared_info();
1235 xen_post_allocator_init();
1238 static void xen_write_cr2(unsigned long cr2)
1240 percpu_read(xen_vcpu)->arch.cr2 = cr2;
1243 static unsigned long xen_read_cr2(void)
1245 return percpu_read(xen_vcpu)->arch.cr2;
1248 unsigned long xen_read_cr2_direct(void)
1250 return percpu_read(xen_vcpu_info.arch.cr2);
1253 static void xen_flush_tlb(void)
1255 struct mmuext_op *op;
1256 struct multicall_space mcs;
1260 mcs = xen_mc_entry(sizeof(*op));
1263 op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
1264 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
1266 xen_mc_issue(PARAVIRT_LAZY_MMU);
1271 static void xen_flush_tlb_single(unsigned long addr)
1273 struct mmuext_op *op;
1274 struct multicall_space mcs;
1278 mcs = xen_mc_entry(sizeof(*op));
1280 op->cmd = MMUEXT_INVLPG_LOCAL;
1281 op->arg1.linear_addr = addr & PAGE_MASK;
1282 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
1284 xen_mc_issue(PARAVIRT_LAZY_MMU);
1289 static void xen_flush_tlb_others(const struct cpumask *cpus,
1290 struct mm_struct *mm, unsigned long va)
1293 struct mmuext_op op;
1294 DECLARE_BITMAP(mask, NR_CPUS);
1296 struct multicall_space mcs;
1298 if (cpumask_empty(cpus))
1299 return; /* nothing to do */
1301 mcs = xen_mc_entry(sizeof(*args));
1303 args->op.arg2.vcpumask = to_cpumask(args->mask);
1305 /* Remove us, and any offline CPUS. */
1306 cpumask_and(to_cpumask(args->mask), cpus, cpu_online_mask);
1307 cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
1309 if (va == TLB_FLUSH_ALL) {
1310 args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
1312 args->op.cmd = MMUEXT_INVLPG_MULTI;
1313 args->op.arg1.linear_addr = va;
1316 MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
1318 xen_mc_issue(PARAVIRT_LAZY_MMU);
1321 static unsigned long xen_read_cr3(void)
1323 return percpu_read(xen_cr3);
1326 static void set_current_cr3(void *v)
1328 percpu_write(xen_current_cr3, (unsigned long)v);
1331 static void __xen_write_cr3(bool kernel, unsigned long cr3)
1333 struct mmuext_op *op;
1334 struct multicall_space mcs;
1338 mfn = pfn_to_mfn(PFN_DOWN(cr3));
1342 WARN_ON(mfn == 0 && kernel);
1344 mcs = __xen_mc_entry(sizeof(*op));
1347 op->cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR;
1350 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
1353 percpu_write(xen_cr3, cr3);
1355 /* Update xen_current_cr3 once the batch has actually
1357 xen_mc_callback(set_current_cr3, (void *)cr3);
1361 static void xen_write_cr3(unsigned long cr3)
1363 BUG_ON(preemptible());
1365 xen_mc_batch(); /* disables interrupts */
1367 /* Update while interrupts are disabled, so its atomic with
1369 percpu_write(xen_cr3, cr3);
1371 __xen_write_cr3(true, cr3);
1373 #ifdef CONFIG_X86_64
1375 pgd_t *user_pgd = xen_get_user_pgd(__va(cr3));
1377 __xen_write_cr3(false, __pa(user_pgd));
1379 __xen_write_cr3(false, 0);
1383 xen_mc_issue(PARAVIRT_LAZY_CPU); /* interrupts restored */
1386 static int xen_pgd_alloc(struct mm_struct *mm)
1388 pgd_t *pgd = mm->pgd;
1391 BUG_ON(PagePinned(virt_to_page(pgd)));
1393 #ifdef CONFIG_X86_64
1395 struct page *page = virt_to_page(pgd);
1398 BUG_ON(page->private != 0);
1402 user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
1403 page->private = (unsigned long)user_pgd;
1405 if (user_pgd != NULL) {
1406 user_pgd[pgd_index(VSYSCALL_START)] =
1407 __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
1411 BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
1418 static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
1420 #ifdef CONFIG_X86_64
1421 pgd_t *user_pgd = xen_get_user_pgd(pgd);
1424 free_page((unsigned long)user_pgd);
1428 static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
1430 unsigned long pfn = pte_pfn(pte);
1432 #ifdef CONFIG_X86_32
1433 /* If there's an existing pte, then don't allow _PAGE_RW to be set */
1434 if (pte_val_ma(*ptep) & _PAGE_PRESENT)
1435 pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
1440 * If the new pfn is within the range of the newly allocated
1441 * kernel pagetable, and it isn't being mapped into an
1442 * early_ioremap fixmap slot, make sure it is RO.
1444 if (!is_early_ioremap_ptep(ptep) &&
1445 pfn >= e820_table_start && pfn < e820_table_end)
1446 pte = pte_wrprotect(pte);
1451 /* Init-time set_pte while constructing initial pagetables, which
1452 doesn't allow RO pagetable pages to be remapped RW */
1453 static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
1455 pte = mask_rw_pte(ptep, pte);
1457 xen_set_pte(ptep, pte);
1460 static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
1462 struct mmuext_op op;
1464 op.arg1.mfn = pfn_to_mfn(pfn);
1465 if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
1469 /* Early in boot, while setting up the initial pagetable, assume
1470 everything is pinned. */
1471 static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
1473 #ifdef CONFIG_FLATMEM
1474 BUG_ON(mem_map); /* should only be used early */
1476 make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
1477 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
1480 /* Used for pmd and pud */
1481 static __init void xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn)
1483 #ifdef CONFIG_FLATMEM
1484 BUG_ON(mem_map); /* should only be used early */
1486 make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
1489 /* Early release_pte assumes that all pts are pinned, since there's
1490 only init_mm and anything attached to that is pinned. */
1491 static __init void xen_release_pte_init(unsigned long pfn)
1493 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
1494 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
1497 static __init void xen_release_pmd_init(unsigned long pfn)
1499 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
1502 /* This needs to make sure the new pte page is pinned iff its being
1503 attached to a pinned pagetable. */
1504 static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned level)
1506 struct page *page = pfn_to_page(pfn);
1508 if (PagePinned(virt_to_page(mm->pgd))) {
1509 SetPagePinned(page);
1511 if (!PageHighMem(page)) {
1512 make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn)));
1513 if (level == PT_PTE && USE_SPLIT_PTLOCKS)
1514 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
1516 /* make sure there are no stray mappings of
1518 kmap_flush_unused();
1523 static void xen_alloc_pte(struct mm_struct *mm, unsigned long pfn)
1525 xen_alloc_ptpage(mm, pfn, PT_PTE);
1528 static void xen_alloc_pmd(struct mm_struct *mm, unsigned long pfn)
1530 xen_alloc_ptpage(mm, pfn, PT_PMD);
1533 /* This should never happen until we're OK to use struct page */
1534 static void xen_release_ptpage(unsigned long pfn, unsigned level)
1536 struct page *page = pfn_to_page(pfn);
1538 if (PagePinned(page)) {
1539 if (!PageHighMem(page)) {
1540 if (level == PT_PTE && USE_SPLIT_PTLOCKS)
1541 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
1542 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
1544 ClearPagePinned(page);
1548 static void xen_release_pte(unsigned long pfn)
1550 xen_release_ptpage(pfn, PT_PTE);
1553 static void xen_release_pmd(unsigned long pfn)
1555 xen_release_ptpage(pfn, PT_PMD);
1558 #if PAGETABLE_LEVELS == 4
1559 static void xen_alloc_pud(struct mm_struct *mm, unsigned long pfn)
1561 xen_alloc_ptpage(mm, pfn, PT_PUD);
1564 static void xen_release_pud(unsigned long pfn)
1566 xen_release_ptpage(pfn, PT_PUD);
1570 void __init xen_reserve_top(void)
1572 #ifdef CONFIG_X86_32
1573 unsigned long top = HYPERVISOR_VIRT_START;
1574 struct xen_platform_parameters pp;
1576 if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
1577 top = pp.virt_start;
1579 reserve_top_address(-top);
1580 #endif /* CONFIG_X86_32 */
1584 * Like __va(), but returns address in the kernel mapping (which is
1585 * all we have until the physical memory mapping has been set up.
1587 static void *__ka(phys_addr_t paddr)
1589 #ifdef CONFIG_X86_64
1590 return (void *)(paddr + __START_KERNEL_map);
1596 /* Convert a machine address to physical address */
1597 static unsigned long m2p(phys_addr_t maddr)
1601 maddr &= PTE_PFN_MASK;
1602 paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT;
1607 /* Convert a machine address to kernel virtual */
1608 static void *m2v(phys_addr_t maddr)
1610 return __ka(m2p(maddr));
1613 /* Set the page permissions on an identity-mapped pages */
1614 static void set_page_prot(void *addr, pgprot_t prot)
1616 unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
1617 pte_t pte = pfn_pte(pfn, prot);
1619 if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
1623 static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
1625 unsigned pmdidx, pteidx;
1629 level1_ident_pgt = extend_brk(sizeof(pte_t) * LEVEL1_IDENT_ENTRIES,
1634 for (pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) {
1637 /* Reuse or allocate a page of ptes */
1638 if (pmd_present(pmd[pmdidx]))
1639 pte_page = m2v(pmd[pmdidx].pmd);
1641 /* Check for free pte pages */
1642 if (ident_pte == LEVEL1_IDENT_ENTRIES)
1645 pte_page = &level1_ident_pgt[ident_pte];
1646 ident_pte += PTRS_PER_PTE;
1648 pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);
1651 /* Install mappings */
1652 for (pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
1655 if (pfn > max_pfn_mapped)
1656 max_pfn_mapped = pfn;
1658 if (!pte_none(pte_page[pteidx]))
1661 pte = pfn_pte(pfn, PAGE_KERNEL_EXEC);
1662 pte_page[pteidx] = pte;
1666 for (pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE)
1667 set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO);
1669 set_page_prot(pmd, PAGE_KERNEL_RO);
1672 void __init xen_setup_machphys_mapping(void)
1674 struct xen_machphys_mapping mapping;
1675 unsigned long machine_to_phys_nr_ents;
1677 if (HYPERVISOR_memory_op(XENMEM_machphys_mapping, &mapping) == 0) {
1678 machine_to_phys_mapping = (unsigned long *)mapping.v_start;
1679 machine_to_phys_nr_ents = mapping.max_mfn + 1;
1681 machine_to_phys_nr_ents = MACH2PHYS_NR_ENTRIES;
1683 machine_to_phys_order = fls(machine_to_phys_nr_ents - 1);
1686 #ifdef CONFIG_X86_64
1687 static void convert_pfn_mfn(void *v)
1692 /* All levels are converted the same way, so just treat them
1694 for (i = 0; i < PTRS_PER_PTE; i++)
1695 pte[i] = xen_make_pte(pte[i].pte);
1699 * Set up the inital kernel pagetable.
1701 * We can construct this by grafting the Xen provided pagetable into
1702 * head_64.S's preconstructed pagetables. We copy the Xen L2's into
1703 * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt. This
1704 * means that only the kernel has a physical mapping to start with -
1705 * but that's enough to get __va working. We need to fill in the rest
1706 * of the physical mapping once some sort of allocator has been set
1709 __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
1710 unsigned long max_pfn)
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 __init void 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 __init pgd_t *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 __init void 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 __init void xen_post_allocator_init(void)
1944 pv_mmu_ops.set_pte = xen_set_pte;
1945 pv_mmu_ops.set_pmd = xen_set_pmd;
1946 pv_mmu_ops.set_pud = xen_set_pud;
1947 #if PAGETABLE_LEVELS == 4
1948 pv_mmu_ops.set_pgd = xen_set_pgd;
1951 /* This will work as long as patching hasn't happened yet
1952 (which it hasn't) */
1953 pv_mmu_ops.alloc_pte = xen_alloc_pte;
1954 pv_mmu_ops.alloc_pmd = xen_alloc_pmd;
1955 pv_mmu_ops.release_pte = xen_release_pte;
1956 pv_mmu_ops.release_pmd = xen_release_pmd;
1957 #if PAGETABLE_LEVELS == 4
1958 pv_mmu_ops.alloc_pud = xen_alloc_pud;
1959 pv_mmu_ops.release_pud = xen_release_pud;
1962 #ifdef CONFIG_X86_64
1963 SetPagePinned(virt_to_page(level3_user_vsyscall));
1965 xen_mark_init_mm_pinned();
1968 static void xen_leave_lazy_mmu(void)
1972 paravirt_leave_lazy_mmu();
1976 static const struct pv_mmu_ops xen_mmu_ops __initdata = {
1977 .read_cr2 = xen_read_cr2,
1978 .write_cr2 = xen_write_cr2,
1980 .read_cr3 = xen_read_cr3,
1981 #ifdef CONFIG_X86_32
1982 .write_cr3 = xen_write_cr3_init,
1984 .write_cr3 = xen_write_cr3,
1987 .flush_tlb_user = xen_flush_tlb,
1988 .flush_tlb_kernel = xen_flush_tlb,
1989 .flush_tlb_single = xen_flush_tlb_single,
1990 .flush_tlb_others = xen_flush_tlb_others,
1992 .pte_update = paravirt_nop,
1993 .pte_update_defer = paravirt_nop,
1995 .pgd_alloc = xen_pgd_alloc,
1996 .pgd_free = xen_pgd_free,
1998 .alloc_pte = xen_alloc_pte_init,
1999 .release_pte = xen_release_pte_init,
2000 .alloc_pmd = xen_alloc_pmd_init,
2001 .release_pmd = xen_release_pmd_init,
2003 .set_pte = xen_set_pte_init,
2004 .set_pte_at = xen_set_pte_at,
2005 .set_pmd = xen_set_pmd_hyper,
2007 .ptep_modify_prot_start = __ptep_modify_prot_start,
2008 .ptep_modify_prot_commit = __ptep_modify_prot_commit,
2010 .pte_val = PV_CALLEE_SAVE(xen_pte_val),
2011 .pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
2013 .make_pte = PV_CALLEE_SAVE(xen_make_pte),
2014 .make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
2016 #ifdef CONFIG_X86_PAE
2017 .set_pte_atomic = xen_set_pte_atomic,
2018 .pte_clear = xen_pte_clear,
2019 .pmd_clear = xen_pmd_clear,
2020 #endif /* CONFIG_X86_PAE */
2021 .set_pud = xen_set_pud_hyper,
2023 .make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
2024 .pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
2026 #if PAGETABLE_LEVELS == 4
2027 .pud_val = PV_CALLEE_SAVE(xen_pud_val),
2028 .make_pud = PV_CALLEE_SAVE(xen_make_pud),
2029 .set_pgd = xen_set_pgd_hyper,
2031 .alloc_pud = xen_alloc_pmd_init,
2032 .release_pud = xen_release_pmd_init,
2033 #endif /* PAGETABLE_LEVELS == 4 */
2035 .activate_mm = xen_activate_mm,
2036 .dup_mmap = xen_dup_mmap,
2037 .exit_mmap = xen_exit_mmap,
2040 .enter = paravirt_enter_lazy_mmu,
2041 .leave = xen_leave_lazy_mmu,
2044 .set_fixmap = xen_set_fixmap,
2047 void __init xen_init_mmu_ops(void)
2049 x86_init.paging.pagetable_setup_start = xen_pagetable_setup_start;
2050 x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done;
2051 pv_mmu_ops = xen_mmu_ops;
2053 memset(dummy_mapping, 0xff, PAGE_SIZE);
2056 /* Protected by xen_reservation_lock. */
2057 #define MAX_CONTIG_ORDER 9 /* 2MB */
2058 static unsigned long discontig_frames[1<<MAX_CONTIG_ORDER];
2060 #define VOID_PTE (mfn_pte(0, __pgprot(0)))
2061 static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order,
2062 unsigned long *in_frames,
2063 unsigned long *out_frames)
2066 struct multicall_space mcs;
2069 for (i = 0; i < (1UL<<order); i++, vaddr += PAGE_SIZE) {
2070 mcs = __xen_mc_entry(0);
2073 in_frames[i] = virt_to_mfn(vaddr);
2075 MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0);
2076 set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);
2079 out_frames[i] = virt_to_pfn(vaddr);
2085 * Update the pfn-to-mfn mappings for a virtual address range, either to
2086 * point to an array of mfns, or contiguously from a single starting
2089 static void xen_remap_exchanged_ptes(unsigned long vaddr, int order,
2090 unsigned long *mfns,
2091 unsigned long first_mfn)
2098 limit = 1u << order;
2099 for (i = 0; i < limit; i++, vaddr += PAGE_SIZE) {
2100 struct multicall_space mcs;
2103 mcs = __xen_mc_entry(0);
2107 mfn = first_mfn + i;
2109 if (i < (limit - 1))
2113 flags = UVMF_INVLPG | UVMF_ALL;
2115 flags = UVMF_TLB_FLUSH | UVMF_ALL;
2118 MULTI_update_va_mapping(mcs.mc, vaddr,
2119 mfn_pte(mfn, PAGE_KERNEL), flags);
2121 set_phys_to_machine(virt_to_pfn(vaddr), mfn);
2128 * Perform the hypercall to exchange a region of our pfns to point to
2129 * memory with the required contiguous alignment. Takes the pfns as
2130 * input, and populates mfns as output.
2132 * Returns a success code indicating whether the hypervisor was able to
2133 * satisfy the request or not.
2135 static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in,
2136 unsigned long *pfns_in,
2137 unsigned long extents_out,
2138 unsigned int order_out,
2139 unsigned long *mfns_out,
2140 unsigned int address_bits)
2145 struct xen_memory_exchange exchange = {
2147 .nr_extents = extents_in,
2148 .extent_order = order_in,
2149 .extent_start = pfns_in,
2153 .nr_extents = extents_out,
2154 .extent_order = order_out,
2155 .extent_start = mfns_out,
2156 .address_bits = address_bits,
2161 BUG_ON(extents_in << order_in != extents_out << order_out);
2163 rc = HYPERVISOR_memory_op(XENMEM_exchange, &exchange);
2164 success = (exchange.nr_exchanged == extents_in);
2166 BUG_ON(!success && ((exchange.nr_exchanged != 0) || (rc == 0)));
2167 BUG_ON(success && (rc != 0));
2172 int xen_create_contiguous_region(unsigned long vstart, unsigned int order,
2173 unsigned int address_bits)
2175 unsigned long *in_frames = discontig_frames, out_frame;
2176 unsigned long flags;
2180 * Currently an auto-translated guest will not perform I/O, nor will
2181 * it require PAE page directories below 4GB. Therefore any calls to
2182 * this function are redundant and can be ignored.
2185 if (xen_feature(XENFEAT_auto_translated_physmap))
2188 if (unlikely(order > MAX_CONTIG_ORDER))
2191 memset((void *) vstart, 0, PAGE_SIZE << order);
2193 spin_lock_irqsave(&xen_reservation_lock, flags);
2195 /* 1. Zap current PTEs, remembering MFNs. */
2196 xen_zap_pfn_range(vstart, order, in_frames, NULL);
2198 /* 2. Get a new contiguous memory extent. */
2199 out_frame = virt_to_pfn(vstart);
2200 success = xen_exchange_memory(1UL << order, 0, in_frames,
2201 1, order, &out_frame,
2204 /* 3. Map the new extent in place of old pages. */
2206 xen_remap_exchanged_ptes(vstart, order, NULL, out_frame);
2208 xen_remap_exchanged_ptes(vstart, order, in_frames, 0);
2210 spin_unlock_irqrestore(&xen_reservation_lock, flags);
2212 return success ? 0 : -ENOMEM;
2214 EXPORT_SYMBOL_GPL(xen_create_contiguous_region);
2216 void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order)
2218 unsigned long *out_frames = discontig_frames, in_frame;
2219 unsigned long flags;
2222 if (xen_feature(XENFEAT_auto_translated_physmap))
2225 if (unlikely(order > MAX_CONTIG_ORDER))
2228 memset((void *) vstart, 0, PAGE_SIZE << order);
2230 spin_lock_irqsave(&xen_reservation_lock, flags);
2232 /* 1. Find start MFN of contiguous extent. */
2233 in_frame = virt_to_mfn(vstart);
2235 /* 2. Zap current PTEs. */
2236 xen_zap_pfn_range(vstart, order, NULL, out_frames);
2238 /* 3. Do the exchange for non-contiguous MFNs. */
2239 success = xen_exchange_memory(1, order, &in_frame, 1UL << order,
2242 /* 4. Map new pages in place of old pages. */
2244 xen_remap_exchanged_ptes(vstart, order, out_frames, 0);
2246 xen_remap_exchanged_ptes(vstart, order, NULL, in_frame);
2248 spin_unlock_irqrestore(&xen_reservation_lock, flags);
2250 EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
2252 #ifdef CONFIG_XEN_PVHVM
2253 static void xen_hvm_exit_mmap(struct mm_struct *mm)
2255 struct xen_hvm_pagetable_dying a;
2258 a.domid = DOMID_SELF;
2259 a.gpa = __pa(mm->pgd);
2260 rc = HYPERVISOR_hvm_op(HVMOP_pagetable_dying, &a);
2261 WARN_ON_ONCE(rc < 0);
2264 static int is_pagetable_dying_supported(void)
2266 struct xen_hvm_pagetable_dying a;
2269 a.domid = DOMID_SELF;
2271 rc = HYPERVISOR_hvm_op(HVMOP_pagetable_dying, &a);
2273 printk(KERN_DEBUG "HVMOP_pagetable_dying not supported\n");
2279 void __init xen_hvm_init_mmu_ops(void)
2281 if (is_pagetable_dying_supported())
2282 pv_mmu_ops.exit_mmap = xen_hvm_exit_mmap;
2286 #define REMAP_BATCH_SIZE 16
2291 struct mmu_update *mmu_update;
2294 static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,
2295 unsigned long addr, void *data)
2297 struct remap_data *rmd = data;
2298 pte_t pte = pte_mkspecial(pfn_pte(rmd->mfn++, rmd->prot));
2300 rmd->mmu_update->ptr = arbitrary_virt_to_machine(ptep).maddr;
2301 rmd->mmu_update->val = pte_val_ma(pte);
2307 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
2309 unsigned long mfn, int nr,
2310 pgprot_t prot, unsigned domid)
2312 struct remap_data rmd;
2313 struct mmu_update mmu_update[REMAP_BATCH_SIZE];
2315 unsigned long range;
2318 prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP);
2320 BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_RESERVED | VM_IO)) ==
2321 (VM_PFNMAP | VM_RESERVED | VM_IO)));
2327 batch = min(REMAP_BATCH_SIZE, nr);
2328 range = (unsigned long)batch << PAGE_SHIFT;
2330 rmd.mmu_update = mmu_update;
2331 err = apply_to_page_range(vma->vm_mm, addr, range,
2332 remap_area_mfn_pte_fn, &rmd);
2337 if (HYPERVISOR_mmu_update(mmu_update, batch, NULL, domid) < 0)
2351 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
2353 #ifdef CONFIG_XEN_DEBUG_FS
2355 static struct dentry *d_mmu_debug;
2357 static int __init xen_mmu_debugfs(void)
2359 struct dentry *d_xen = xen_init_debugfs();
2364 d_mmu_debug = debugfs_create_dir("mmu", d_xen);
2366 debugfs_create_u8("zero_stats", 0644, d_mmu_debug, &zero_stats);
2368 debugfs_create_u32("pgd_update", 0444, d_mmu_debug, &mmu_stats.pgd_update);
2369 debugfs_create_u32("pgd_update_pinned", 0444, d_mmu_debug,
2370 &mmu_stats.pgd_update_pinned);
2371 debugfs_create_u32("pgd_update_batched", 0444, d_mmu_debug,
2372 &mmu_stats.pgd_update_pinned);
2374 debugfs_create_u32("pud_update", 0444, d_mmu_debug, &mmu_stats.pud_update);
2375 debugfs_create_u32("pud_update_pinned", 0444, d_mmu_debug,
2376 &mmu_stats.pud_update_pinned);
2377 debugfs_create_u32("pud_update_batched", 0444, d_mmu_debug,
2378 &mmu_stats.pud_update_pinned);
2380 debugfs_create_u32("pmd_update", 0444, d_mmu_debug, &mmu_stats.pmd_update);
2381 debugfs_create_u32("pmd_update_pinned", 0444, d_mmu_debug,
2382 &mmu_stats.pmd_update_pinned);
2383 debugfs_create_u32("pmd_update_batched", 0444, d_mmu_debug,
2384 &mmu_stats.pmd_update_pinned);
2386 debugfs_create_u32("pte_update", 0444, d_mmu_debug, &mmu_stats.pte_update);
2387 // debugfs_create_u32("pte_update_pinned", 0444, d_mmu_debug,
2388 // &mmu_stats.pte_update_pinned);
2389 debugfs_create_u32("pte_update_batched", 0444, d_mmu_debug,
2390 &mmu_stats.pte_update_pinned);
2392 debugfs_create_u32("mmu_update", 0444, d_mmu_debug, &mmu_stats.mmu_update);
2393 debugfs_create_u32("mmu_update_extended", 0444, d_mmu_debug,
2394 &mmu_stats.mmu_update_extended);
2395 xen_debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug,
2396 mmu_stats.mmu_update_histo, 20);
2398 debugfs_create_u32("set_pte_at", 0444, d_mmu_debug, &mmu_stats.set_pte_at);
2399 debugfs_create_u32("set_pte_at_batched", 0444, d_mmu_debug,
2400 &mmu_stats.set_pte_at_batched);
2401 debugfs_create_u32("set_pte_at_current", 0444, d_mmu_debug,
2402 &mmu_stats.set_pte_at_current);
2403 debugfs_create_u32("set_pte_at_kernel", 0444, d_mmu_debug,
2404 &mmu_stats.set_pte_at_kernel);
2406 debugfs_create_u32("prot_commit", 0444, d_mmu_debug, &mmu_stats.prot_commit);
2407 debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
2408 &mmu_stats.prot_commit_batched);
2412 fs_initcall(xen_mmu_debugfs);
2414 #endif /* CONFIG_XEN_DEBUG_FS */