mmu.c 59.1 KB
Newer Older
J
Jeremy Fitzhardinge 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
/*
 * Xen mmu operations
 *
 * This file contains the various mmu fetch and update operations.
 * The most important job they must perform is the mapping between the
 * domain's pfn and the overall machine mfns.
 *
 * Xen allows guests to directly update the pagetable, in a controlled
 * fashion.  In other words, the guest modifies the same pagetable
 * that the CPU actually uses, which eliminates the overhead of having
 * a separate shadow pagetable.
 *
 * In order to allow this, it falls on the guest domain to map its
 * notion of a "physical" pfn - which is just a domain-local linear
 * address - into a real "machine address" which the CPU's MMU can
 * use.
 *
 * A pgd_t/pmd_t/pte_t will typically contain an mfn, and so can be
 * inserted directly into the pagetable.  When creating a new
 * pte/pmd/pgd, it converts the passed pfn into an mfn.  Conversely,
 * when reading the content back with __(pgd|pmd|pte)_val, it converts
 * the mfn back into a pfn.
 *
 * The other constraint is that all pages which make up a pagetable
 * must be mapped read-only in the guest.  This prevents uncontrolled
 * guest updates to the pagetable.  Xen strictly enforces this, and
 * will disallow any pagetable update which will end up mapping a
 * pagetable page RW, and will disallow using any writable page as a
 * pagetable.
 *
 * Naively, when loading %cr3 with the base of a new pagetable, Xen
 * would need to validate the whole pagetable before going on.
 * Naturally, this is quite slow.  The solution is to "pin" a
 * pagetable, which enforces all the constraints on the pagetable even
 * when it is not actively in use.  This menas that Xen can be assured
 * that it is still valid when you do load it into %cr3, and doesn't
 * need to revalidate it.
 *
 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
 */
41
#include <linux/sched.h>
42
#include <linux/highmem.h>
J
Jeremy Fitzhardinge 已提交
43
#include <linux/debugfs.h>
J
Jeremy Fitzhardinge 已提交
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>
J
Jeremy Fitzhardinge 已提交
49 50 51

#include <asm/pgtable.h>
#include <asm/tlbflush.h>
52
#include <asm/fixmap.h>
J
Jeremy Fitzhardinge 已提交
53
#include <asm/mmu_context.h>
54
#include <asm/setup.h>
55
#include <asm/paravirt.h>
56
#include <asm/e820.h>
57
#include <asm/linkage.h>
58
#include <asm/page.h>
59
#include <asm/init.h>
J
Jeremy Fitzhardinge 已提交
60
#include <asm/pat.h>
J
Jeremy Fitzhardinge 已提交
61 62

#include <asm/xen/hypercall.h>
63
#include <asm/xen/hypervisor.h>
J
Jeremy Fitzhardinge 已提交
64

65
#include <xen/xen.h>
J
Jeremy Fitzhardinge 已提交
66 67
#include <xen/page.h>
#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>
J
Jeremy Fitzhardinge 已提交
72

73
#include "multicalls.h"
J
Jeremy Fitzhardinge 已提交
74
#include "mmu.h"
J
Jeremy Fitzhardinge 已提交
75 76 77 78
#include "debugfs.h"

#define MMU_UPDATE_HISTO	30

A
Alex Nixon 已提交
79 80 81 82 83 84 85
/*
 * Protects atomic reservation decrease/increase against concurrent increases.
 * Also protects non-atomic updates of current_pages and driver_pages, and
 * balloon lists.
 */
DEFINE_SPINLOCK(xen_reservation_lock);

J
Jeremy Fitzhardinge 已提交
86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136
#ifdef CONFIG_XEN_DEBUG_FS

static struct {
	u32 pgd_update;
	u32 pgd_update_pinned;
	u32 pgd_update_batched;

	u32 pud_update;
	u32 pud_update_pinned;
	u32 pud_update_batched;

	u32 pmd_update;
	u32 pmd_update_pinned;
	u32 pmd_update_batched;

	u32 pte_update;
	u32 pte_update_pinned;
	u32 pte_update_batched;

	u32 mmu_update;
	u32 mmu_update_extended;
	u32 mmu_update_histo[MMU_UPDATE_HISTO];

	u32 prot_commit;
	u32 prot_commit_batched;

	u32 set_pte_at;
	u32 set_pte_at_batched;
	u32 set_pte_at_pinned;
	u32 set_pte_at_current;
	u32 set_pte_at_kernel;
} mmu_stats;

static u8 zero_stats;

static inline void check_zero(void)
{
	if (unlikely(zero_stats)) {
		memset(&mmu_stats, 0, sizeof(mmu_stats));
		zero_stats = 0;
	}
}

#define ADD_STATS(elem, val)			\
	do { check_zero(); mmu_stats.elem += (val); } while(0)

#else  /* !CONFIG_XEN_DEBUG_FS */

#define ADD_STATS(elem, val)	do { (void)(val); } while(0)

#endif /* CONFIG_XEN_DEBUG_FS */
J
Jeremy Fitzhardinge 已提交
137

138 139 140 141 142 143

/*
 * Identity map, in addition to plain kernel map.  This needs to be
 * large enough to allocate page table pages to allocate the rest.
 * Each page can map 2MB.
 */
144 145
#define LEVEL1_IDENT_ENTRIES	(PTRS_PER_PTE * 4)
static RESERVE_BRK_ARRAY(pte_t, level1_ident_pgt, LEVEL1_IDENT_ENTRIES);
146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169

#ifdef CONFIG_X86_64
/* l3 pud for userspace vsyscall mapping */
static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss;
#endif /* CONFIG_X86_64 */

/*
 * Note about cr3 (pagetable base) values:
 *
 * xen_cr3 contains the current logical cr3 value; it contains the
 * last set cr3.  This may not be the current effective cr3, because
 * its update may be being lazily deferred.  However, a vcpu looking
 * at its own cr3 can use this value knowing that it everything will
 * be self-consistent.
 *
 * xen_current_cr3 contains the actual vcpu cr3; it is set once the
 * hypercall to set the vcpu cr3 is complete (so it may be a little
 * out of date, but it will never be set early).  If one vcpu is
 * looking at another vcpu's cr3 value, it should use this variable.
 */
DEFINE_PER_CPU(unsigned long, xen_cr3);	 /* cr3 stored as physaddr */
DEFINE_PER_CPU(unsigned long, xen_current_cr3);	 /* actual vcpu cr3 */


170 171 172 173 174 175
/*
 * Just beyond the highest usermode address.  STACK_TOP_MAX has a
 * redzone above it, so round it up to a PGD boundary.
 */
#define USER_LIMIT	((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK)

176 177 178 179 180 181 182
unsigned long arbitrary_virt_to_mfn(void *vaddr)
{
	xmaddr_t maddr = arbitrary_virt_to_machine(vaddr);

	return PFN_DOWN(maddr.maddr);
}

183
xmaddr_t arbitrary_virt_to_machine(void *vaddr)
J
Jeremy Fitzhardinge 已提交
184
{
185
	unsigned long address = (unsigned long)vaddr;
186
	unsigned int level;
187 188
	pte_t *pte;
	unsigned offset;
J
Jeremy Fitzhardinge 已提交
189

190 191 192 193 194 195 196 197
	/*
	 * if the PFN is in the linear mapped vaddr range, we can just use
	 * the (quick) virt_to_machine() p2m lookup
	 */
	if (virt_addr_valid(vaddr))
		return virt_to_machine(vaddr);

	/* otherwise we have to do a (slower) full page-table walk */
J
Jeremy Fitzhardinge 已提交
198

199 200 201
	pte = lookup_address(address, &level);
	BUG_ON(pte == NULL);
	offset = address & ~PAGE_MASK;
202
	return XMADDR(((phys_addr_t)pte_mfn(*pte) << PAGE_SHIFT) + offset);
J
Jeremy Fitzhardinge 已提交
203 204 205 206 207 208
}

void make_lowmem_page_readonly(void *vaddr)
{
	pte_t *pte, ptev;
	unsigned long address = (unsigned long)vaddr;
209
	unsigned int level;
J
Jeremy Fitzhardinge 已提交
210

211
	pte = lookup_address(address, &level);
212 213
	if (pte == NULL)
		return;		/* vaddr missing */
J
Jeremy Fitzhardinge 已提交
214 215 216 217 218 219 220 221 222 223 224

	ptev = pte_wrprotect(*pte);

	if (HYPERVISOR_update_va_mapping(address, ptev, 0))
		BUG();
}

void make_lowmem_page_readwrite(void *vaddr)
{
	pte_t *pte, ptev;
	unsigned long address = (unsigned long)vaddr;
225
	unsigned int level;
J
Jeremy Fitzhardinge 已提交
226

227
	pte = lookup_address(address, &level);
228 229
	if (pte == NULL)
		return;		/* vaddr missing */
J
Jeremy Fitzhardinge 已提交
230 231 232 233 234 235 236 237

	ptev = pte_mkwrite(*pte);

	if (HYPERVISOR_update_va_mapping(address, ptev, 0))
		BUG();
}


238
static bool xen_page_pinned(void *ptr)
239 240 241 242 243 244
{
	struct page *page = virt_to_page(ptr);

	return PagePinned(page);
}

245 246
static bool xen_iomap_pte(pte_t pte)
{
247
	return pte_flags(pte) & _PAGE_IOMAP;
248 249
}

250
void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid)
251 252 253 254 255 256 257 258 259 260 261
{
	struct multicall_space mcs;
	struct mmu_update *u;

	mcs = xen_mc_entry(sizeof(*u));
	u = mcs.args;

	/* ptep might be kmapped when using 32-bit HIGHPTE */
	u->ptr = arbitrary_virt_to_machine(ptep).maddr;
	u->val = pte_val_ma(pteval);

262
	MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, domid);
263 264 265

	xen_mc_issue(PARAVIRT_LAZY_MMU);
}
266 267 268 269 270 271
EXPORT_SYMBOL_GPL(xen_set_domain_pte);

static void xen_set_iomap_pte(pte_t *ptep, pte_t pteval)
{
	xen_set_domain_pte(ptep, pteval, DOMID_IO);
}
272

273
static void xen_extend_mmu_update(const struct mmu_update *update)
J
Jeremy Fitzhardinge 已提交
274
{
J
Jeremy Fitzhardinge 已提交
275 276
	struct multicall_space mcs;
	struct mmu_update *u;
J
Jeremy Fitzhardinge 已提交
277

278 279
	mcs = xen_mc_extend_args(__HYPERVISOR_mmu_update, sizeof(*u));

J
Jeremy Fitzhardinge 已提交
280 281 282 283
	if (mcs.mc != NULL) {
		ADD_STATS(mmu_update_extended, 1);
		ADD_STATS(mmu_update_histo[mcs.mc->args[1]], -1);

284
		mcs.mc->args[1]++;
J
Jeremy Fitzhardinge 已提交
285 286 287 288 289 290 291

		if (mcs.mc->args[1] < MMU_UPDATE_HISTO)
			ADD_STATS(mmu_update_histo[mcs.mc->args[1]], 1);
		else
			ADD_STATS(mmu_update_histo[0], 1);
	} else {
		ADD_STATS(mmu_update, 1);
292 293
		mcs = __xen_mc_entry(sizeof(*u));
		MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
J
Jeremy Fitzhardinge 已提交
294
		ADD_STATS(mmu_update_histo[1], 1);
295
	}
J
Jeremy Fitzhardinge 已提交
296 297

	u = mcs.args;
298 299 300 301 302 303 304 305 306 307 308
	*u = *update;
}

void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
{
	struct mmu_update u;

	preempt_disable();

	xen_mc_batch();

309 310
	/* ptr may be ioremapped for 64-bit pagetable setup */
	u.ptr = arbitrary_virt_to_machine(ptr).maddr;
311
	u.val = pmd_val_ma(val);
312
	xen_extend_mmu_update(&u);
J
Jeremy Fitzhardinge 已提交
313

J
Jeremy Fitzhardinge 已提交
314 315
	ADD_STATS(pmd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);

J
Jeremy Fitzhardinge 已提交
316 317 318
	xen_mc_issue(PARAVIRT_LAZY_MMU);

	preempt_enable();
J
Jeremy Fitzhardinge 已提交
319 320
}

321 322
void xen_set_pmd(pmd_t *ptr, pmd_t val)
{
J
Jeremy Fitzhardinge 已提交
323 324
	ADD_STATS(pmd_update, 1);

325 326
	/* If page is not pinned, we can just update the entry
	   directly */
327
	if (!xen_page_pinned(ptr)) {
328 329 330 331
		*ptr = val;
		return;
	}

J
Jeremy Fitzhardinge 已提交
332 333
	ADD_STATS(pmd_update_pinned, 1);

334 335 336
	xen_set_pmd_hyper(ptr, val);
}

J
Jeremy Fitzhardinge 已提交
337 338 339 340 341 342
/*
 * Associate a virtual page frame with a given physical page frame
 * and protection flags for that frame.
 */
void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
{
J
Jeremy Fitzhardinge 已提交
343
	set_pte_vaddr(vaddr, mfn_pte(mfn, flags));
J
Jeremy Fitzhardinge 已提交
344 345 346 347 348
}

void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
		    pte_t *ptep, pte_t pteval)
{
349 350 351 352 353
	if (xen_iomap_pte(pteval)) {
		xen_set_iomap_pte(ptep, pteval);
		goto out;
	}

J
Jeremy Fitzhardinge 已提交
354 355 356 357 358
	ADD_STATS(set_pte_at, 1);
//	ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
	ADD_STATS(set_pte_at_current, mm == current->mm);
	ADD_STATS(set_pte_at_kernel, mm == &init_mm);

J
Jeremy Fitzhardinge 已提交
359
	if (mm == current->mm || mm == &init_mm) {
360
		if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
J
Jeremy Fitzhardinge 已提交
361 362 363 364
			struct multicall_space mcs;
			mcs = xen_mc_entry(0);

			MULTI_update_va_mapping(mcs.mc, addr, pteval, 0);
J
Jeremy Fitzhardinge 已提交
365
			ADD_STATS(set_pte_at_batched, 1);
J
Jeremy Fitzhardinge 已提交
366
			xen_mc_issue(PARAVIRT_LAZY_MMU);
367
			goto out;
J
Jeremy Fitzhardinge 已提交
368 369
		} else
			if (HYPERVISOR_update_va_mapping(addr, pteval, 0) == 0)
370
				goto out;
J
Jeremy Fitzhardinge 已提交
371 372
	}
	xen_set_pte(ptep, pteval);
373

374
out:	return;
J
Jeremy Fitzhardinge 已提交
375 376
}

T
Tej 已提交
377 378
pte_t xen_ptep_modify_prot_start(struct mm_struct *mm,
				 unsigned long addr, pte_t *ptep)
J
Jeremy Fitzhardinge 已提交
379
{
380 381 382 383 384 385 386
	/* Just return the pte as-is.  We preserve the bits on commit */
	return *ptep;
}

void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
				 pte_t *ptep, pte_t pte)
{
387
	struct mmu_update u;
388

389
	xen_mc_batch();
J
Jeremy Fitzhardinge 已提交
390

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);
J
Jeremy Fitzhardinge 已提交
394

J
Jeremy Fitzhardinge 已提交
395 396 397
	ADD_STATS(prot_commit, 1);
	ADD_STATS(prot_commit_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);

398
	xen_mc_issue(PARAVIRT_LAZY_MMU);
J
Jeremy Fitzhardinge 已提交
399 400
}

J
Jeremy Fitzhardinge 已提交
401 402
/* Assume pteval_t is equivalent to all the other *val_t types. */
static pteval_t pte_mfn_to_pfn(pteval_t val)
J
Jeremy Fitzhardinge 已提交
403
{
J
Jeremy Fitzhardinge 已提交
404
	if (val & _PAGE_PRESENT) {
405
		unsigned long mfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
J
Jeremy Fitzhardinge 已提交
406
		pteval_t flags = val & PTE_FLAGS_MASK;
407
		val = ((pteval_t)mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
J
Jeremy Fitzhardinge 已提交
408
	}
J
Jeremy Fitzhardinge 已提交
409

J
Jeremy Fitzhardinge 已提交
410
	return val;
J
Jeremy Fitzhardinge 已提交
411 412
}

J
Jeremy Fitzhardinge 已提交
413
static pteval_t pte_pfn_to_mfn(pteval_t val)
J
Jeremy Fitzhardinge 已提交
414
{
J
Jeremy Fitzhardinge 已提交
415
	if (val & _PAGE_PRESENT) {
416
		unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
J
Jeremy Fitzhardinge 已提交
417
		pteval_t flags = val & PTE_FLAGS_MASK;
418 419 420 421 422 423 424 425 426 427 428 429 430 431
		unsigned long mfn = pfn_to_mfn(pfn);

		/*
		 * If there's no mfn for the pfn, then just create an
		 * empty non-present pte.  Unfortunately this loses
		 * information about the original pfn, so
		 * pte_mfn_to_pfn is asymmetric.
		 */
		if (unlikely(mfn == INVALID_P2M_ENTRY)) {
			mfn = 0;
			flags = 0;
		}

		val = ((pteval_t)mfn << PAGE_SHIFT) | flags;
J
Jeremy Fitzhardinge 已提交
432 433
	}

J
Jeremy Fitzhardinge 已提交
434
	return val;
J
Jeremy Fitzhardinge 已提交
435 436
}

437 438 439 440 441 442 443 444 445 446 447 448 449 450
static pteval_t iomap_pte(pteval_t val)
{
	if (val & _PAGE_PRESENT) {
		unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
		pteval_t flags = val & PTE_FLAGS_MASK;

		/* We assume the pte frame number is a MFN, so
		   just use it as-is. */
		val = ((pteval_t)pfn << PAGE_SHIFT) | flags;
	}

	return val;
}

J
Jeremy Fitzhardinge 已提交
451
pteval_t xen_pte_val(pte_t pte)
J
Jeremy Fitzhardinge 已提交
452
{
J
Jeremy Fitzhardinge 已提交
453
	pteval_t pteval = pte.pte;
454

J
Jeremy Fitzhardinge 已提交
455 456 457 458 459
	/* If this is a WC pte, convert back from Xen WC to Linux WC */
	if ((pteval & (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT)) == _PAGE_PAT) {
		WARN_ON(!pat_enabled);
		pteval = (pteval & ~_PAGE_PAT) | _PAGE_PWT;
	}
460

J
Jeremy Fitzhardinge 已提交
461 462 463 464
	if (xen_initial_domain() && (pteval & _PAGE_IOMAP))
		return pteval;

	return pte_mfn_to_pfn(pteval);
J
Jeremy Fitzhardinge 已提交
465
}
466
PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val);
J
Jeremy Fitzhardinge 已提交
467 468 469

pgdval_t xen_pgd_val(pgd_t pgd)
{
J
Jeremy Fitzhardinge 已提交
470
	return pte_mfn_to_pfn(pgd.pgd);
J
Jeremy Fitzhardinge 已提交
471
}
472
PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val);
J
Jeremy Fitzhardinge 已提交
473

J
Jeremy Fitzhardinge 已提交
474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498
/*
 * Xen's PAT setup is part of its ABI, though I assume entries 6 & 7
 * are reserved for now, to correspond to the Intel-reserved PAT
 * types.
 *
 * We expect Linux's PAT set as follows:
 *
 * Idx  PTE flags        Linux    Xen    Default
 * 0                     WB       WB     WB
 * 1            PWT      WC       WT     WT
 * 2        PCD          UC-      UC-    UC-
 * 3        PCD PWT      UC       UC     UC
 * 4    PAT              WB       WC     WB
 * 5    PAT     PWT      WC       WP     WT
 * 6    PAT PCD          UC-      UC     UC-
 * 7    PAT PCD PWT      UC       UC     UC
 */

void xen_set_pat(u64 pat)
{
	/* We expect Linux to use a PAT setting of
	 * UC UC- WC WB (ignoring the PAT flag) */
	WARN_ON(pat != 0x0007010600070106ull);
}

J
Jeremy Fitzhardinge 已提交
499 500
pte_t xen_make_pte(pteval_t pte)
{
501 502
	phys_addr_t addr = (pte & PTE_PFN_MASK);

J
Jeremy Fitzhardinge 已提交
503 504 505 506 507 508 509 510 511 512 513 514 515
	/* If Linux is trying to set a WC pte, then map to the Xen WC.
	 * If _PAGE_PAT is set, then it probably means it is really
	 * _PAGE_PSE, so avoid fiddling with the PAT mapping and hope
	 * things work out OK...
	 *
	 * (We should never see kernel mappings with _PAGE_PSE set,
	 * but we could see hugetlbfs mappings, I think.).
	 */
	if (pat_enabled && !WARN_ON(pte & _PAGE_PAT)) {
		if ((pte & (_PAGE_PCD | _PAGE_PWT)) == _PAGE_PWT)
			pte = (pte & ~(_PAGE_PCD | _PAGE_PWT)) | _PAGE_PAT;
	}

516 517 518 519 520 521 522 523
	/*
	 * Unprivileged domains are allowed to do IOMAPpings for
	 * PCI passthrough, but not map ISA space.  The ISA
	 * mappings are just dummy local mappings to keep other
	 * parts of the kernel happy.
	 */
	if (unlikely(pte & _PAGE_IOMAP) &&
	    (xen_initial_domain() || addr >= ISA_END_ADDRESS)) {
524
		pte = iomap_pte(pte);
525 526
	} else {
		pte &= ~_PAGE_IOMAP;
527
		pte = pte_pfn_to_mfn(pte);
528
	}
529

J
Jeremy Fitzhardinge 已提交
530
	return native_make_pte(pte);
J
Jeremy Fitzhardinge 已提交
531
}
532
PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
J
Jeremy Fitzhardinge 已提交
533 534 535

pgd_t xen_make_pgd(pgdval_t pgd)
{
J
Jeremy Fitzhardinge 已提交
536 537
	pgd = pte_pfn_to_mfn(pgd);
	return native_make_pgd(pgd);
J
Jeremy Fitzhardinge 已提交
538
}
539
PV_CALLEE_SAVE_REGS_THUNK(xen_make_pgd);
J
Jeremy Fitzhardinge 已提交
540 541 542

pmdval_t xen_pmd_val(pmd_t pmd)
{
J
Jeremy Fitzhardinge 已提交
543
	return pte_mfn_to_pfn(pmd.pmd);
J
Jeremy Fitzhardinge 已提交
544
}
545
PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val);
546

547
void xen_set_pud_hyper(pud_t *ptr, pud_t val)
548
{
549
	struct mmu_update u;
550

J
Jeremy Fitzhardinge 已提交
551 552
	preempt_disable();

553 554
	xen_mc_batch();

555 556
	/* ptr may be ioremapped for 64-bit pagetable setup */
	u.ptr = arbitrary_virt_to_machine(ptr).maddr;
557
	u.val = pud_val_ma(val);
558
	xen_extend_mmu_update(&u);
J
Jeremy Fitzhardinge 已提交
559

J
Jeremy Fitzhardinge 已提交
560 561
	ADD_STATS(pud_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);

J
Jeremy Fitzhardinge 已提交
562 563 564
	xen_mc_issue(PARAVIRT_LAZY_MMU);

	preempt_enable();
565 566
}

567 568
void xen_set_pud(pud_t *ptr, pud_t val)
{
J
Jeremy Fitzhardinge 已提交
569 570
	ADD_STATS(pud_update, 1);

571 572
	/* If page is not pinned, we can just update the entry
	   directly */
573
	if (!xen_page_pinned(ptr)) {
574 575 576 577
		*ptr = val;
		return;
	}

J
Jeremy Fitzhardinge 已提交
578 579
	ADD_STATS(pud_update_pinned, 1);

580 581 582
	xen_set_pud_hyper(ptr, val);
}

583 584
void xen_set_pte(pte_t *ptep, pte_t pte)
{
585 586 587 588 589
	if (xen_iomap_pte(pte)) {
		xen_set_iomap_pte(ptep, pte);
		return;
	}

J
Jeremy Fitzhardinge 已提交
590 591 592 593
	ADD_STATS(pte_update, 1);
//	ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
	ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);

594
#ifdef CONFIG_X86_PAE
595 596 597
	ptep->pte_high = pte.pte_high;
	smp_wmb();
	ptep->pte_low = pte.pte_low;
598 599 600
#else
	*ptep = pte;
#endif
601 602
}

603
#ifdef CONFIG_X86_PAE
J
Jeremy Fitzhardinge 已提交
604 605
void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
{
606 607 608 609 610
	if (xen_iomap_pte(pte)) {
		xen_set_iomap_pte(ptep, pte);
		return;
	}

611
	set_64bit((u64 *)ptep, native_pte_val(pte));
J
Jeremy Fitzhardinge 已提交
612 613 614 615 616 617 618 619 620 621 622
}

void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
	ptep->pte_low = 0;
	smp_wmb();		/* make sure low gets written first */
	ptep->pte_high = 0;
}

void xen_pmd_clear(pmd_t *pmdp)
{
623
	set_pmd(pmdp, __pmd(0));
J
Jeremy Fitzhardinge 已提交
624
}
625
#endif	/* CONFIG_X86_PAE */
J
Jeremy Fitzhardinge 已提交
626

627
pmd_t xen_make_pmd(pmdval_t pmd)
J
Jeremy Fitzhardinge 已提交
628
{
J
Jeremy Fitzhardinge 已提交
629
	pmd = pte_pfn_to_mfn(pmd);
J
Jeremy Fitzhardinge 已提交
630
	return native_make_pmd(pmd);
J
Jeremy Fitzhardinge 已提交
631
}
632
PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd);
J
Jeremy Fitzhardinge 已提交
633

634 635 636 637 638
#if PAGETABLE_LEVELS == 4
pudval_t xen_pud_val(pud_t pud)
{
	return pte_mfn_to_pfn(pud.pud);
}
639
PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val);
640 641 642 643 644 645 646

pud_t xen_make_pud(pudval_t pud)
{
	pud = pte_pfn_to_mfn(pud);

	return native_make_pud(pud);
}
647
PV_CALLEE_SAVE_REGS_THUNK(xen_make_pud);
648

649
pgd_t *xen_get_user_pgd(pgd_t *pgd)
650
{
651 652 653
	pgd_t *pgd_page = (pgd_t *)(((unsigned long)pgd) & PAGE_MASK);
	unsigned offset = pgd - pgd_page;
	pgd_t *user_ptr = NULL;
654

655 656 657 658 659 660
	if (offset < pgd_index(USER_LIMIT)) {
		struct page *page = virt_to_page(pgd_page);
		user_ptr = (pgd_t *)page->private;
		if (user_ptr)
			user_ptr += offset;
	}
661

662 663 664 665 666 667
	return user_ptr;
}

static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
{
	struct mmu_update u;
668 669 670

	u.ptr = virt_to_machine(ptr).maddr;
	u.val = pgd_val_ma(val);
671
	xen_extend_mmu_update(&u);
672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687
}

/*
 * Raw hypercall-based set_pgd, intended for in early boot before
 * there's a page structure.  This implies:
 *  1. The only existing pagetable is the kernel's
 *  2. It is always pinned
 *  3. It has no user pagetable attached to it
 */
void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
{
	preempt_disable();

	xen_mc_batch();

	__xen_set_pgd_hyper(ptr, val);
688 689 690 691 692 693 694 695

	xen_mc_issue(PARAVIRT_LAZY_MMU);

	preempt_enable();
}

void xen_set_pgd(pgd_t *ptr, pgd_t val)
{
696 697
	pgd_t *user_ptr = xen_get_user_pgd(ptr);

J
Jeremy Fitzhardinge 已提交
698 699
	ADD_STATS(pgd_update, 1);

700 701
	/* If page is not pinned, we can just update the entry
	   directly */
702
	if (!xen_page_pinned(ptr)) {
703
		*ptr = val;
704
		if (user_ptr) {
705
			WARN_ON(xen_page_pinned(user_ptr));
706 707
			*user_ptr = val;
		}
708 709 710
		return;
	}

J
Jeremy Fitzhardinge 已提交
711 712 713
	ADD_STATS(pgd_update_pinned, 1);
	ADD_STATS(pgd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);

714 715 716 717 718 719 720 721 722
	/* If it's pinned, then we can at least batch the kernel and
	   user updates together. */
	xen_mc_batch();

	__xen_set_pgd_hyper(ptr, val);
	if (user_ptr)
		__xen_set_pgd_hyper(user_ptr, val);

	xen_mc_issue(PARAVIRT_LAZY_MMU);
723 724 725
}
#endif	/* PAGETABLE_LEVELS == 4 */

726
/*
727 728 729 730 731 732 733 734 735 736 737 738 739 740
 * (Yet another) pagetable walker.  This one is intended for pinning a
 * pagetable.  This means that it walks a pagetable and calls the
 * callback function on each page it finds making up the page table,
 * at every level.  It walks the entire pagetable, but it only bothers
 * pinning pte pages which are below limit.  In the normal case this
 * will be STACK_TOP_MAX, but at boot we need to pin up to
 * FIXADDR_TOP.
 *
 * For 32-bit the important bit is that we don't pin beyond there,
 * because then we start getting into Xen's ptes.
 *
 * For 64-bit, we must skip the Xen hole in the middle of the address
 * space, just after the big x86-64 virtual hole.
 */
I
Ian Campbell 已提交
741 742 743 744
static int __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd,
			  int (*func)(struct mm_struct *mm, struct page *,
				      enum pt_level),
			  unsigned long limit)
J
Jeremy Fitzhardinge 已提交
745
{
746
	int flush = 0;
747 748 749
	unsigned hole_low, hole_high;
	unsigned pgdidx_limit, pudidx_limit, pmdidx_limit;
	unsigned pgdidx, pudidx, pmdidx;
750

751 752 753
	/* The limit is the last byte to be touched */
	limit--;
	BUG_ON(limit >= FIXADDR_TOP);
J
Jeremy Fitzhardinge 已提交
754 755

	if (xen_feature(XENFEAT_auto_translated_physmap))
756 757
		return 0;

758 759 760 761 762
	/*
	 * 64-bit has a great big hole in the middle of the address
	 * space, which contains the Xen mappings.  On 32-bit these
	 * will end up making a zero-sized hole and so is a no-op.
	 */
763
	hole_low = pgd_index(USER_LIMIT);
764 765 766 767 768 769 770 771 772 773 774 775 776 777 778
	hole_high = pgd_index(PAGE_OFFSET);

	pgdidx_limit = pgd_index(limit);
#if PTRS_PER_PUD > 1
	pudidx_limit = pud_index(limit);
#else
	pudidx_limit = 0;
#endif
#if PTRS_PER_PMD > 1
	pmdidx_limit = pmd_index(limit);
#else
	pmdidx_limit = 0;
#endif

	for (pgdidx = 0; pgdidx <= pgdidx_limit; pgdidx++) {
779
		pud_t *pud;
J
Jeremy Fitzhardinge 已提交
780

781 782
		if (pgdidx >= hole_low && pgdidx < hole_high)
			continue;
783

784
		if (!pgd_val(pgd[pgdidx]))
J
Jeremy Fitzhardinge 已提交
785
			continue;
786

787
		pud = pud_offset(&pgd[pgdidx], 0);
J
Jeremy Fitzhardinge 已提交
788 789

		if (PTRS_PER_PUD > 1) /* not folded */
790
			flush |= (*func)(mm, virt_to_page(pud), PT_PUD);
791

792
		for (pudidx = 0; pudidx < PTRS_PER_PUD; pudidx++) {
793 794
			pmd_t *pmd;

795 796 797
			if (pgdidx == pgdidx_limit &&
			    pudidx > pudidx_limit)
				goto out;
J
Jeremy Fitzhardinge 已提交
798

799
			if (pud_none(pud[pudidx]))
J
Jeremy Fitzhardinge 已提交
800
				continue;
801

802
			pmd = pmd_offset(&pud[pudidx], 0);
J
Jeremy Fitzhardinge 已提交
803 804

			if (PTRS_PER_PMD > 1) /* not folded */
805
				flush |= (*func)(mm, virt_to_page(pmd), PT_PMD);
806

807 808 809 810 811 812 813
			for (pmdidx = 0; pmdidx < PTRS_PER_PMD; pmdidx++) {
				struct page *pte;

				if (pgdidx == pgdidx_limit &&
				    pudidx == pudidx_limit &&
				    pmdidx > pmdidx_limit)
					goto out;
J
Jeremy Fitzhardinge 已提交
814

815
				if (pmd_none(pmd[pmdidx]))
J
Jeremy Fitzhardinge 已提交
816 817
					continue;

818
				pte = pmd_page(pmd[pmdidx]);
819
				flush |= (*func)(mm, pte, PT_PTE);
J
Jeremy Fitzhardinge 已提交
820 821 822
			}
		}
	}
823

824
out:
825 826
	/* Do the top level last, so that the callbacks can use it as
	   a cue to do final things like tlb flushes. */
827
	flush |= (*func)(mm, virt_to_page(pgd), PT_PGD);
828 829

	return flush;
J
Jeremy Fitzhardinge 已提交
830 831
}

I
Ian Campbell 已提交
832 833 834 835 836 837 838 839
static int xen_pgd_walk(struct mm_struct *mm,
			int (*func)(struct mm_struct *mm, struct page *,
				    enum pt_level),
			unsigned long limit)
{
	return __xen_pgd_walk(mm, mm->pgd, func, limit);
}

840 841
/* If we're using split pte locks, then take the page's lock and
   return a pointer to it.  Otherwise return NULL. */
842
static spinlock_t *xen_pte_lock(struct page *page, struct mm_struct *mm)
843 844 845
{
	spinlock_t *ptl = NULL;

846
#if USE_SPLIT_PTLOCKS
847
	ptl = __pte_lockptr(page);
848
	spin_lock_nest_lock(ptl, &mm->page_table_lock);
849 850 851 852 853
#endif

	return ptl;
}

854
static void xen_pte_unlock(void *v)
855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871
{
	spinlock_t *ptl = v;
	spin_unlock(ptl);
}

static void xen_do_pin(unsigned level, unsigned long pfn)
{
	struct mmuext_op *op;
	struct multicall_space mcs;

	mcs = __xen_mc_entry(sizeof(*op));
	op = mcs.args;
	op->cmd = level;
	op->arg1.mfn = pfn_to_mfn(pfn);
	MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
}

872 873
static int xen_pin_page(struct mm_struct *mm, struct page *page,
			enum pt_level level)
874
{
875
	unsigned pgfl = TestSetPagePinned(page);
876 877 878 879 880 881 882 883 884 885 886 887
	int flush;

	if (pgfl)
		flush = 0;		/* already pinned */
	else if (PageHighMem(page))
		/* kmaps need flushing if we found an unpinned
		   highpage */
		flush = 1;
	else {
		void *pt = lowmem_page_address(page);
		unsigned long pfn = page_to_pfn(page);
		struct multicall_space mcs = __xen_mc_entry(0);
888
		spinlock_t *ptl;
889 890 891

		flush = 0;

892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911
		/*
		 * We need to hold the pagetable lock between the time
		 * we make the pagetable RO and when we actually pin
		 * it.  If we don't, then other users may come in and
		 * attempt to update the pagetable by writing it,
		 * which will fail because the memory is RO but not
		 * pinned, so Xen won't do the trap'n'emulate.
		 *
		 * If we're using split pte locks, we can't hold the
		 * entire pagetable's worth of locks during the
		 * traverse, because we may wrap the preempt count (8
		 * bits).  The solution is to mark RO and pin each PTE
		 * page while holding the lock.  This means the number
		 * of locks we end up holding is never more than a
		 * batch size (~32 entries, at present).
		 *
		 * If we're not using split pte locks, we needn't pin
		 * the PTE pages independently, because we're
		 * protected by the overall pagetable lock.
		 */
912 913
		ptl = NULL;
		if (level == PT_PTE)
914
			ptl = xen_pte_lock(page, mm);
915

916 917
		MULTI_update_va_mapping(mcs.mc, (unsigned long)pt,
					pfn_pte(pfn, PAGE_KERNEL_RO),
918 919
					level == PT_PGD ? UVMF_TLB_FLUSH : 0);

920
		if (ptl) {
921 922 923 924
			xen_do_pin(MMUEXT_PIN_L1_TABLE, pfn);

			/* Queue a deferred unlock for when this batch
			   is completed. */
925
			xen_mc_callback(xen_pte_unlock, ptl);
926
		}
927 928 929 930
	}

	return flush;
}
J
Jeremy Fitzhardinge 已提交
931

932 933 934
/* This is called just after a mm has been created, but it has not
   been used yet.  We need to make sure that its pagetable is all
   read-only, and can be pinned. */
935
static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
J
Jeremy Fitzhardinge 已提交
936
{
937
	xen_mc_batch();
J
Jeremy Fitzhardinge 已提交
938

I
Ian Campbell 已提交
939
	if (__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT)) {
940
		/* re-enable interrupts for flushing */
J
Jeremy Fitzhardinge 已提交
941
		xen_mc_issue(0);
942

943
		kmap_flush_unused();
944

J
Jeremy Fitzhardinge 已提交
945 946
		xen_mc_batch();
	}
947

948 949 950 951 952 953 954
#ifdef CONFIG_X86_64
	{
		pgd_t *user_pgd = xen_get_user_pgd(pgd);

		xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));

		if (user_pgd) {
955
			xen_pin_page(mm, virt_to_page(user_pgd), PT_PGD);
T
Tej 已提交
956 957
			xen_do_pin(MMUEXT_PIN_L4_TABLE,
				   PFN_DOWN(__pa(user_pgd)));
958 959 960
		}
	}
#else /* CONFIG_X86_32 */
961 962
#ifdef CONFIG_X86_PAE
	/* Need to make sure unshared kernel PMD is pinnable */
963
	xen_pin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
964
		     PT_PMD);
965
#endif
966
	xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
967
#endif /* CONFIG_X86_64 */
968
	xen_mc_issue(0);
J
Jeremy Fitzhardinge 已提交
969 970
}

971 972 973 974 975
static void xen_pgd_pin(struct mm_struct *mm)
{
	__xen_pgd_pin(mm, mm->pgd);
}

976 977 978 979 980
/*
 * On save, we need to pin all pagetables to make sure they get their
 * mfns turned into pfns.  Search the list for any unpinned pgds and pin
 * them (unpinned pgds are not currently in use, probably because the
 * process is under construction or destruction).
981 982 983 984
 *
 * Expected to be called in stop_machine() ("equivalent to taking
 * every spinlock in the system"), so the locking doesn't really
 * matter all that much.
985 986 987 988 989
 */
void xen_mm_pin_all(void)
{
	unsigned long flags;
	struct page *page;
990

991
	spin_lock_irqsave(&pgd_lock, flags);
992

993 994
	list_for_each_entry(page, &pgd_list, lru) {
		if (!PagePinned(page)) {
995
			__xen_pgd_pin(&init_mm, (pgd_t *)page_address(page));
996 997 998 999 1000
			SetPageSavePinned(page);
		}
	}

	spin_unlock_irqrestore(&pgd_lock, flags);
J
Jeremy Fitzhardinge 已提交
1001 1002
}

1003 1004 1005 1006 1007
/*
 * The init_mm pagetable is really pinned as soon as its created, but
 * that's before we have page structures to store the bits.  So do all
 * the book-keeping now.
 */
1008 1009
static __init int xen_mark_pinned(struct mm_struct *mm, struct page *page,
				  enum pt_level level)
J
Jeremy Fitzhardinge 已提交
1010
{
1011 1012 1013
	SetPagePinned(page);
	return 0;
}
J
Jeremy Fitzhardinge 已提交
1014

1015
static void __init xen_mark_init_mm_pinned(void)
1016
{
1017
	xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
1018
}
J
Jeremy Fitzhardinge 已提交
1019

1020 1021
static int xen_unpin_page(struct mm_struct *mm, struct page *page,
			  enum pt_level level)
1022
{
1023
	unsigned pgfl = TestClearPagePinned(page);
J
Jeremy Fitzhardinge 已提交
1024

1025 1026 1027
	if (pgfl && !PageHighMem(page)) {
		void *pt = lowmem_page_address(page);
		unsigned long pfn = page_to_pfn(page);
1028 1029 1030
		spinlock_t *ptl = NULL;
		struct multicall_space mcs;

1031 1032 1033 1034 1035 1036 1037
		/*
		 * Do the converse to pin_page.  If we're using split
		 * pte locks, we must be holding the lock for while
		 * the pte page is unpinned but still RO to prevent
		 * concurrent updates from seeing it in this
		 * partially-pinned state.
		 */
1038
		if (level == PT_PTE) {
1039
			ptl = xen_pte_lock(page, mm);
1040

1041 1042
			if (ptl)
				xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
1043 1044 1045
		}

		mcs = __xen_mc_entry(0);
1046 1047 1048

		MULTI_update_va_mapping(mcs.mc, (unsigned long)pt,
					pfn_pte(pfn, PAGE_KERNEL),
1049 1050 1051 1052
					level == PT_PGD ? UVMF_TLB_FLUSH : 0);

		if (ptl) {
			/* unlock when batch completed */
1053
			xen_mc_callback(xen_pte_unlock, ptl);
1054
		}
1055 1056 1057
	}

	return 0;		/* never need to flush on unpin */
J
Jeremy Fitzhardinge 已提交
1058 1059
}

1060
/* Release a pagetables pages back as normal RW */
1061
static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
1062 1063 1064
{
	xen_mc_batch();

1065
	xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
1066

1067 1068 1069 1070 1071
#ifdef CONFIG_X86_64
	{
		pgd_t *user_pgd = xen_get_user_pgd(pgd);

		if (user_pgd) {
T
Tej 已提交
1072 1073
			xen_do_pin(MMUEXT_UNPIN_TABLE,
				   PFN_DOWN(__pa(user_pgd)));
1074
			xen_unpin_page(mm, virt_to_page(user_pgd), PT_PGD);
1075 1076 1077 1078
		}
	}
#endif

1079 1080
#ifdef CONFIG_X86_PAE
	/* Need to make sure unshared kernel PMD is unpinned */
1081
	xen_unpin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]),
1082
		       PT_PMD);
1083
#endif
1084

I
Ian Campbell 已提交
1085
	__xen_pgd_walk(mm, pgd, xen_unpin_page, USER_LIMIT);
1086 1087 1088

	xen_mc_issue(0);
}
J
Jeremy Fitzhardinge 已提交
1089

1090 1091 1092 1093 1094
static void xen_pgd_unpin(struct mm_struct *mm)
{
	__xen_pgd_unpin(mm, mm->pgd);
}

1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108
/*
 * On resume, undo any pinning done at save, so that the rest of the
 * kernel doesn't see any unexpected pinned pagetables.
 */
void xen_mm_unpin_all(void)
{
	unsigned long flags;
	struct page *page;

	spin_lock_irqsave(&pgd_lock, flags);

	list_for_each_entry(page, &pgd_list, lru) {
		if (PageSavePinned(page)) {
			BUG_ON(!PagePinned(page));
1109
			__xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page));
1110 1111 1112 1113 1114 1115 1116
			ClearPageSavePinned(page);
		}
	}

	spin_unlock_irqrestore(&pgd_lock, flags);
}

J
Jeremy Fitzhardinge 已提交
1117 1118
void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
1119
	spin_lock(&next->page_table_lock);
1120
	xen_pgd_pin(next);
1121
	spin_unlock(&next->page_table_lock);
J
Jeremy Fitzhardinge 已提交
1122 1123 1124 1125
}

void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
{
1126
	spin_lock(&mm->page_table_lock);
1127
	xen_pgd_pin(mm);
1128
	spin_unlock(&mm->page_table_lock);
J
Jeremy Fitzhardinge 已提交
1129 1130 1131
}


J
Jeremy Fitzhardinge 已提交
1132 1133 1134 1135 1136 1137
#ifdef CONFIG_SMP
/* Another cpu may still have their %cr3 pointing at the pagetable, so
   we need to repoint it somewhere else before we can unpin it. */
static void drop_other_mm_ref(void *info)
{
	struct mm_struct *mm = info;
1138
	struct mm_struct *active_mm;
J
Jeremy Fitzhardinge 已提交
1139

1140
	active_mm = percpu_read(cpu_tlbstate.active_mm);
1141 1142

	if (active_mm == mm)
J
Jeremy Fitzhardinge 已提交
1143
		leave_mm(smp_processor_id());
1144 1145 1146

	/* If this cpu still has a stale cr3 reference, then make sure
	   it has been flushed. */
1147
	if (percpu_read(xen_current_cr3) == __pa(mm->pgd))
1148
		load_cr3(swapper_pg_dir);
J
Jeremy Fitzhardinge 已提交
1149
}
J
Jeremy Fitzhardinge 已提交
1150

1151
static void xen_drop_mm_ref(struct mm_struct *mm)
J
Jeremy Fitzhardinge 已提交
1152
{
1153
	cpumask_var_t mask;
1154 1155
	unsigned cpu;

J
Jeremy Fitzhardinge 已提交
1156 1157 1158 1159 1160
	if (current->active_mm == mm) {
		if (current->mm == mm)
			load_cr3(swapper_pg_dir);
		else
			leave_mm(smp_processor_id());
1161 1162 1163
	}

	/* Get the "official" set of cpus referring to our pagetable. */
1164 1165
	if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) {
		for_each_online_cpu(cpu) {
1166
			if (!cpumask_test_cpu(cpu, mm_cpumask(mm))
1167 1168 1169 1170 1171 1172
			    && per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd))
				continue;
			smp_call_function_single(cpu, drop_other_mm_ref, mm, 1);
		}
		return;
	}
1173
	cpumask_copy(mask, mm_cpumask(mm));
1174 1175 1176 1177 1178 1179 1180 1181

	/* It's possible that a vcpu may have a stale reference to our
	   cr3, because its in lazy mode, and it hasn't yet flushed
	   its set of pending hypercalls yet.  In this case, we can
	   look at its actual current cr3 value, and force it to flush
	   if needed. */
	for_each_online_cpu(cpu) {
		if (per_cpu(xen_current_cr3, cpu) == __pa(mm->pgd))
1182
			cpumask_set_cpu(cpu, mask);
J
Jeremy Fitzhardinge 已提交
1183 1184
	}

1185 1186 1187
	if (!cpumask_empty(mask))
		smp_call_function_many(mask, drop_other_mm_ref, mm, 1);
	free_cpumask_var(mask);
J
Jeremy Fitzhardinge 已提交
1188 1189
}
#else
1190
static void xen_drop_mm_ref(struct mm_struct *mm)
J
Jeremy Fitzhardinge 已提交
1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
{
	if (current->active_mm == mm)
		load_cr3(swapper_pg_dir);
}
#endif

/*
 * While a process runs, Xen pins its pagetables, which means that the
 * hypervisor forces it to be read-only, and it controls all updates
 * to it.  This means that all pagetable updates have to go via the
 * hypervisor, which is moderately expensive.
 *
 * Since we're pulling the pagetable down, we switch to use init_mm,
 * unpin old process pagetable and mark it all read-write, which
 * allows further operations on it to be simple memory accesses.
 *
 * The only subtle point is that another CPU may be still using the
 * pagetable because of lazy tlb flushing.  This means we need need to
 * switch all CPUs off this pagetable before we can unpin it.
 */
void xen_exit_mmap(struct mm_struct *mm)
{
	get_cpu();		/* make sure we don't move around */
1214
	xen_drop_mm_ref(mm);
J
Jeremy Fitzhardinge 已提交
1215
	put_cpu();
J
Jeremy Fitzhardinge 已提交
1216

1217
	spin_lock(&mm->page_table_lock);
1218 1219

	/* pgd may not be pinned in the error exit path of execve */
1220
	if (xen_page_pinned(mm->pgd))
1221
		xen_pgd_unpin(mm);
1222

1223
	spin_unlock(&mm->page_table_lock);
J
Jeremy Fitzhardinge 已提交
1224
}
J
Jeremy Fitzhardinge 已提交
1225

1226 1227 1228 1229
static __init void xen_pagetable_setup_start(pgd_t *base)
{
}

1230 1231
static void xen_post_allocator_init(void);

1232 1233 1234
static __init void xen_pagetable_setup_done(pgd_t *base)
{
	xen_setup_shared_info();
1235
	xen_post_allocator_init();
1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297
}

static void xen_write_cr2(unsigned long cr2)
{
	percpu_read(xen_vcpu)->arch.cr2 = cr2;
}

static unsigned long xen_read_cr2(void)
{
	return percpu_read(xen_vcpu)->arch.cr2;
}

unsigned long xen_read_cr2_direct(void)
{
	return percpu_read(xen_vcpu_info.arch.cr2);
}

static void xen_flush_tlb(void)
{
	struct mmuext_op *op;
	struct multicall_space mcs;

	preempt_disable();

	mcs = xen_mc_entry(sizeof(*op));

	op = mcs.args;
	op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
	MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);

	xen_mc_issue(PARAVIRT_LAZY_MMU);

	preempt_enable();
}

static void xen_flush_tlb_single(unsigned long addr)
{
	struct mmuext_op *op;
	struct multicall_space mcs;

	preempt_disable();

	mcs = xen_mc_entry(sizeof(*op));
	op = mcs.args;
	op->cmd = MMUEXT_INVLPG_LOCAL;
	op->arg1.linear_addr = addr & PAGE_MASK;
	MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);

	xen_mc_issue(PARAVIRT_LAZY_MMU);

	preempt_enable();
}

static void xen_flush_tlb_others(const struct cpumask *cpus,
				 struct mm_struct *mm, unsigned long va)
{
	struct {
		struct mmuext_op op;
		DECLARE_BITMAP(mask, NR_CPUS);
	} *args;
	struct multicall_space mcs;

1298 1299
	if (cpumask_empty(cpus))
		return;		/* nothing to do */
1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427

	mcs = xen_mc_entry(sizeof(*args));
	args = mcs.args;
	args->op.arg2.vcpumask = to_cpumask(args->mask);

	/* Remove us, and any offline CPUS. */
	cpumask_and(to_cpumask(args->mask), cpus, cpu_online_mask);
	cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));

	if (va == TLB_FLUSH_ALL) {
		args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
	} else {
		args->op.cmd = MMUEXT_INVLPG_MULTI;
		args->op.arg1.linear_addr = va;
	}

	MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);

	xen_mc_issue(PARAVIRT_LAZY_MMU);
}

static unsigned long xen_read_cr3(void)
{
	return percpu_read(xen_cr3);
}

static void set_current_cr3(void *v)
{
	percpu_write(xen_current_cr3, (unsigned long)v);
}

static void __xen_write_cr3(bool kernel, unsigned long cr3)
{
	struct mmuext_op *op;
	struct multicall_space mcs;
	unsigned long mfn;

	if (cr3)
		mfn = pfn_to_mfn(PFN_DOWN(cr3));
	else
		mfn = 0;

	WARN_ON(mfn == 0 && kernel);

	mcs = __xen_mc_entry(sizeof(*op));

	op = mcs.args;
	op->cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR;
	op->arg1.mfn = mfn;

	MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);

	if (kernel) {
		percpu_write(xen_cr3, cr3);

		/* Update xen_current_cr3 once the batch has actually
		   been submitted. */
		xen_mc_callback(set_current_cr3, (void *)cr3);
	}
}

static void xen_write_cr3(unsigned long cr3)
{
	BUG_ON(preemptible());

	xen_mc_batch();  /* disables interrupts */

	/* Update while interrupts are disabled, so its atomic with
	   respect to ipis */
	percpu_write(xen_cr3, cr3);

	__xen_write_cr3(true, cr3);

#ifdef CONFIG_X86_64
	{
		pgd_t *user_pgd = xen_get_user_pgd(__va(cr3));
		if (user_pgd)
			__xen_write_cr3(false, __pa(user_pgd));
		else
			__xen_write_cr3(false, 0);
	}
#endif

	xen_mc_issue(PARAVIRT_LAZY_CPU);  /* interrupts restored */
}

static int xen_pgd_alloc(struct mm_struct *mm)
{
	pgd_t *pgd = mm->pgd;
	int ret = 0;

	BUG_ON(PagePinned(virt_to_page(pgd)));

#ifdef CONFIG_X86_64
	{
		struct page *page = virt_to_page(pgd);
		pgd_t *user_pgd;

		BUG_ON(page->private != 0);

		ret = -ENOMEM;

		user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
		page->private = (unsigned long)user_pgd;

		if (user_pgd != NULL) {
			user_pgd[pgd_index(VSYSCALL_START)] =
				__pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
			ret = 0;
		}

		BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
	}
#endif

	return ret;
}

static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
#ifdef CONFIG_X86_64
	pgd_t *user_pgd = xen_get_user_pgd(pgd);

	if (user_pgd)
		free_page((unsigned long)user_pgd);
#endif
}

1428 1429
static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
{
1430 1431 1432
	unsigned long pfn = pte_pfn(pte);

#ifdef CONFIG_X86_32
1433 1434 1435 1436
	/* If there's an existing pte, then don't allow _PAGE_RW to be set */
	if (pte_val_ma(*ptep) & _PAGE_PRESENT)
		pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
			       pte_val_ma(pte));
1437 1438 1439 1440 1441 1442 1443 1444 1445 1446
#endif

	/*
	 * If the new pfn is within the range of the newly allocated
	 * kernel pagetable, and it isn't being mapped into an
	 * early_ioremap fixmap slot, make sure it is RO.
	 */
	if (!is_early_ioremap_ptep(ptep) &&
	    pfn >= e820_table_start && pfn < e820_table_end)
		pte = pte_wrprotect(pte);
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458

	return pte;
}

/* Init-time set_pte while constructing initial pagetables, which
   doesn't allow RO pagetable pages to be remapped RW */
static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
{
	pte = mask_rw_pte(ptep, pte);

	xen_set_pte(ptep, pte);
}
1459

1460 1461 1462 1463 1464 1465 1466 1467 1468
static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
{
	struct mmuext_op op;
	op.cmd = cmd;
	op.arg1.mfn = pfn_to_mfn(pfn);
	if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
		BUG();
}

1469 1470 1471 1472
/* Early in boot, while setting up the initial pagetable, assume
   everything is pinned. */
static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
{
1473 1474 1475 1476 1477 1478 1479 1480 1481 1482
#ifdef CONFIG_FLATMEM
	BUG_ON(mem_map);	/* should only be used early */
#endif
	make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
	pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
}

/* Used for pmd and pud */
static __init void xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn)
{
1483 1484 1485 1486 1487 1488 1489 1490
#ifdef CONFIG_FLATMEM
	BUG_ON(mem_map);	/* should only be used early */
#endif
	make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
}

/* Early release_pte assumes that all pts are pinned, since there's
   only init_mm and anything attached to that is pinned. */
1491
static __init void xen_release_pte_init(unsigned long pfn)
1492
{
1493
	pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
1494 1495 1496
	make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
}

1497
static __init void xen_release_pmd_init(unsigned long pfn)
1498
{
1499
	make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612
}

/* This needs to make sure the new pte page is pinned iff its being
   attached to a pinned pagetable. */
static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned level)
{
	struct page *page = pfn_to_page(pfn);

	if (PagePinned(virt_to_page(mm->pgd))) {
		SetPagePinned(page);

		if (!PageHighMem(page)) {
			make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn)));
			if (level == PT_PTE && USE_SPLIT_PTLOCKS)
				pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
		} else {
			/* make sure there are no stray mappings of
			   this page */
			kmap_flush_unused();
		}
	}
}

static void xen_alloc_pte(struct mm_struct *mm, unsigned long pfn)
{
	xen_alloc_ptpage(mm, pfn, PT_PTE);
}

static void xen_alloc_pmd(struct mm_struct *mm, unsigned long pfn)
{
	xen_alloc_ptpage(mm, pfn, PT_PMD);
}

/* This should never happen until we're OK to use struct page */
static void xen_release_ptpage(unsigned long pfn, unsigned level)
{
	struct page *page = pfn_to_page(pfn);

	if (PagePinned(page)) {
		if (!PageHighMem(page)) {
			if (level == PT_PTE && USE_SPLIT_PTLOCKS)
				pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
			make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
		}
		ClearPagePinned(page);
	}
}

static void xen_release_pte(unsigned long pfn)
{
	xen_release_ptpage(pfn, PT_PTE);
}

static void xen_release_pmd(unsigned long pfn)
{
	xen_release_ptpage(pfn, PT_PMD);
}

#if PAGETABLE_LEVELS == 4
static void xen_alloc_pud(struct mm_struct *mm, unsigned long pfn)
{
	xen_alloc_ptpage(mm, pfn, PT_PUD);
}

static void xen_release_pud(unsigned long pfn)
{
	xen_release_ptpage(pfn, PT_PUD);
}
#endif

void __init xen_reserve_top(void)
{
#ifdef CONFIG_X86_32
	unsigned long top = HYPERVISOR_VIRT_START;
	struct xen_platform_parameters pp;

	if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
		top = pp.virt_start;

	reserve_top_address(-top);
#endif	/* CONFIG_X86_32 */
}

/*
 * Like __va(), but returns address in the kernel mapping (which is
 * all we have until the physical memory mapping has been set up.
 */
static void *__ka(phys_addr_t paddr)
{
#ifdef CONFIG_X86_64
	return (void *)(paddr + __START_KERNEL_map);
#else
	return __va(paddr);
#endif
}

/* Convert a machine address to physical address */
static unsigned long m2p(phys_addr_t maddr)
{
	phys_addr_t paddr;

	maddr &= PTE_PFN_MASK;
	paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT;

	return paddr;
}

/* Convert a machine address to kernel virtual */
static void *m2v(phys_addr_t maddr)
{
	return __ka(m2p(maddr));
}

1613
/* Set the page permissions on an identity-mapped pages */
1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628
static void set_page_prot(void *addr, pgprot_t prot)
{
	unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
	pte_t pte = pfn_pte(pfn, prot);

	if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
		BUG();
}

static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
{
	unsigned pmdidx, pteidx;
	unsigned ident_pte;
	unsigned long pfn;

1629 1630 1631
	level1_ident_pgt = extend_brk(sizeof(pte_t) * LEVEL1_IDENT_ENTRIES,
				      PAGE_SIZE);

1632 1633 1634 1635 1636 1637 1638 1639 1640 1641
	ident_pte = 0;
	pfn = 0;
	for (pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) {
		pte_t *pte_page;

		/* Reuse or allocate a page of ptes */
		if (pmd_present(pmd[pmdidx]))
			pte_page = m2v(pmd[pmdidx].pmd);
		else {
			/* Check for free pte pages */
1642
			if (ident_pte == LEVEL1_IDENT_ENTRIES)
1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671
				break;

			pte_page = &level1_ident_pgt[ident_pte];
			ident_pte += PTRS_PER_PTE;

			pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);
		}

		/* Install mappings */
		for (pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
			pte_t pte;

			if (pfn > max_pfn_mapped)
				max_pfn_mapped = pfn;

			if (!pte_none(pte_page[pteidx]))
				continue;

			pte = pfn_pte(pfn, PAGE_KERNEL_EXEC);
			pte_page[pteidx] = pte;
		}
	}

	for (pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE)
		set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO);

	set_page_prot(pmd, PAGE_KERNEL_RO);
}

1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685
void __init xen_setup_machphys_mapping(void)
{
	struct xen_machphys_mapping mapping;
	unsigned long machine_to_phys_nr_ents;

	if (HYPERVISOR_memory_op(XENMEM_machphys_mapping, &mapping) == 0) {
		machine_to_phys_mapping = (unsigned long *)mapping.v_start;
		machine_to_phys_nr_ents = mapping.max_mfn + 1;
	} else {
		machine_to_phys_nr_ents = MACH2PHYS_NR_ENTRIES;
	}
	machine_to_phys_order = fls(machine_to_phys_nr_ents - 1);
}

1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762
#ifdef CONFIG_X86_64
static void convert_pfn_mfn(void *v)
{
	pte_t *pte = v;
	int i;

	/* All levels are converted the same way, so just treat them
	   as ptes. */
	for (i = 0; i < PTRS_PER_PTE; i++)
		pte[i] = xen_make_pte(pte[i].pte);
}

/*
 * Set up the inital kernel pagetable.
 *
 * We can construct this by grafting the Xen provided pagetable into
 * head_64.S's preconstructed pagetables.  We copy the Xen L2's into
 * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt.  This
 * means that only the kernel has a physical mapping to start with -
 * but that's enough to get __va working.  We need to fill in the rest
 * of the physical mapping once some sort of allocator has been set
 * up.
 */
__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
					 unsigned long max_pfn)
{
	pud_t *l3;
	pmd_t *l2;

	/* Zap identity mapping */
	init_level4_pgt[0] = __pgd(0);

	/* Pre-constructed entries are in pfn, so convert to mfn */
	convert_pfn_mfn(init_level4_pgt);
	convert_pfn_mfn(level3_ident_pgt);
	convert_pfn_mfn(level3_kernel_pgt);

	l3 = m2v(pgd[pgd_index(__START_KERNEL_map)].pgd);
	l2 = m2v(l3[pud_index(__START_KERNEL_map)].pud);

	memcpy(level2_ident_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
	memcpy(level2_kernel_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);

	l3 = m2v(pgd[pgd_index(__START_KERNEL_map + PMD_SIZE)].pgd);
	l2 = m2v(l3[pud_index(__START_KERNEL_map + PMD_SIZE)].pud);
	memcpy(level2_fixmap_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);

	/* Set up identity map */
	xen_map_identity_early(level2_ident_pgt, max_pfn);

	/* Make pagetable pieces RO */
	set_page_prot(init_level4_pgt, PAGE_KERNEL_RO);
	set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO);
	set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO);
	set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO);
	set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
	set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO);

	/* Pin down new L4 */
	pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE,
			  PFN_DOWN(__pa_symbol(init_level4_pgt)));

	/* Unpin Xen-provided one */
	pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));

	/* Switch over */
	pgd = init_level4_pgt;

	/*
	 * At this stage there can be no user pgd, and no page
	 * structure to attach it to, so make sure we just set kernel
	 * pgd.
	 */
	xen_mc_batch();
	__xen_write_cr3(true, __pa(pgd));
	xen_mc_issue(PARAVIRT_LAZY_CPU);

1763
	memblock_x86_reserve_range(__pa(xen_start_info->pt_base),
1764 1765 1766 1767 1768 1769 1770
		      __pa(xen_start_info->pt_base +
			   xen_start_info->nr_pt_frames * PAGE_SIZE),
		      "XEN PAGETABLES");

	return pgd;
}
#else	/* !CONFIG_X86_64 */
1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809
static RESERVE_BRK_ARRAY(pmd_t, initial_kernel_pmd, PTRS_PER_PMD);
static RESERVE_BRK_ARRAY(pmd_t, swapper_kernel_pmd, PTRS_PER_PMD);

static __init void xen_write_cr3_init(unsigned long cr3)
{
	unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));

	BUG_ON(read_cr3() != __pa(initial_page_table));
	BUG_ON(cr3 != __pa(swapper_pg_dir));

	/*
	 * We are switching to swapper_pg_dir for the first time (from
	 * initial_page_table) and therefore need to mark that page
	 * read-only and then pin it.
	 *
	 * Xen disallows sharing of kernel PMDs for PAE
	 * guests. Therefore we must copy the kernel PMD from
	 * initial_page_table into a new kernel PMD to be used in
	 * swapper_pg_dir.
	 */
	swapper_kernel_pmd =
		extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
	memcpy(swapper_kernel_pmd, initial_kernel_pmd,
	       sizeof(pmd_t) * PTRS_PER_PMD);
	swapper_pg_dir[KERNEL_PGD_BOUNDARY] =
		__pgd(__pa(swapper_kernel_pmd) | _PAGE_PRESENT);
	set_page_prot(swapper_kernel_pmd, PAGE_KERNEL_RO);

	set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
	xen_write_cr3(cr3);
	pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, pfn);

	pin_pagetable_pfn(MMUEXT_UNPIN_TABLE,
			  PFN_DOWN(__pa(initial_page_table)));
	set_page_prot(initial_page_table, PAGE_KERNEL);
	set_page_prot(initial_kernel_pmd, PAGE_KERNEL);

	pv_mmu_ops.write_cr3 = &xen_write_cr3;
}
1810 1811 1812 1813 1814 1815

__init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
					 unsigned long max_pfn)
{
	pmd_t *kernel_pmd;

1816 1817
	initial_kernel_pmd =
		extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
1818

1819 1820 1821
	max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->pt_base) +
				  xen_start_info->nr_pt_frames * PAGE_SIZE +
				  512*1024);
1822 1823

	kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);
1824
	memcpy(initial_kernel_pmd, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD);
1825

1826
	xen_map_identity_early(initial_kernel_pmd, max_pfn);
1827

1828 1829 1830
	memcpy(initial_page_table, pgd, sizeof(pgd_t) * PTRS_PER_PGD);
	initial_page_table[KERNEL_PGD_BOUNDARY] =
		__pgd(__pa(initial_kernel_pmd) | _PAGE_PRESENT);
1831

1832 1833
	set_page_prot(initial_kernel_pmd, PAGE_KERNEL_RO);
	set_page_prot(initial_page_table, PAGE_KERNEL_RO);
1834 1835 1836 1837
	set_page_prot(empty_zero_page, PAGE_KERNEL_RO);

	pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));

1838 1839 1840
	pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE,
			  PFN_DOWN(__pa(initial_page_table)));
	xen_write_cr3(__pa(initial_page_table));
1841

1842
	memblock_x86_reserve_range(__pa(xen_start_info->pt_base),
1843 1844 1845 1846
		      __pa(xen_start_info->pt_base +
			   xen_start_info->nr_pt_frames * PAGE_SIZE),
		      "XEN PAGETABLES");

1847
	return initial_page_table;
1848 1849 1850
}
#endif	/* CONFIG_X86_64 */

1851 1852
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)
1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872
{
	pte_t pte;

	phys >>= PAGE_SHIFT;

	switch (idx) {
	case FIX_BTMAP_END ... FIX_BTMAP_BEGIN:
#ifdef CONFIG_X86_F00F_BUG
	case FIX_F00F_IDT:
#endif
#ifdef CONFIG_X86_32
	case FIX_WP_TEST:
	case FIX_VDSO:
# ifdef CONFIG_HIGHMEM
	case FIX_KMAP_BEGIN ... FIX_KMAP_END:
# endif
#else
	case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
#endif
1873 1874 1875
	case FIX_TEXT_POKE0:
	case FIX_TEXT_POKE1:
		/* All local page mappings */
1876 1877 1878
		pte = pfn_pte(phys, prot);
		break;

1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894
#ifdef CONFIG_X86_LOCAL_APIC
	case FIX_APIC_BASE:	/* maps dummy local APIC */
		pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
		break;
#endif

#ifdef CONFIG_X86_IO_APIC
	case FIX_IO_APIC_BASE_0 ... FIX_IO_APIC_BASE_END:
		/*
		 * We just don't map the IO APIC - all access is via
		 * hypercalls.  Keep the address in the pte for reference.
		 */
		pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
		break;
#endif

1895 1896 1897
	case FIX_PARAVIRT_BOOTMAP:
		/* This is an MFN, but it isn't an IO mapping from the
		   IO domain */
1898 1899
		pte = mfn_pte(phys, prot);
		break;
1900 1901 1902 1903 1904

	default:
		/* By default, set_fixmap is used for hardware mappings */
		pte = mfn_pte(phys, __pgprot(pgprot_val(prot) | _PAGE_IOMAP));
		break;
1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918
	}

	__native_set_fixmap(idx, pte);

#ifdef CONFIG_X86_64
	/* Replicate changes to map the vsyscall page into the user
	   pagetable vsyscall mapping. */
	if (idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) {
		unsigned long vaddr = __fix_to_virt(idx);
		set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
	}
#endif
}

1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941
__init void xen_ident_map_ISA(void)
{
	unsigned long pa;

	/*
	 * If we're dom0, then linear map the ISA machine addresses into
	 * the kernel's address space.
	 */
	if (!xen_initial_domain())
		return;

	xen_raw_printk("Xen: setup ISA identity maps\n");

	for (pa = ISA_START_ADDRESS; pa < ISA_END_ADDRESS; pa += PAGE_SIZE) {
		pte_t pte = mfn_pte(PFN_DOWN(pa), PAGE_KERNEL_IO);

		if (HYPERVISOR_update_va_mapping(PAGE_OFFSET + pa, pte, 0))
			BUG();
	}

	xen_flush_tlb();
}

1942
static __init void xen_post_allocator_init(void)
1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967
{
	pv_mmu_ops.set_pte = xen_set_pte;
	pv_mmu_ops.set_pmd = xen_set_pmd;
	pv_mmu_ops.set_pud = xen_set_pud;
#if PAGETABLE_LEVELS == 4
	pv_mmu_ops.set_pgd = xen_set_pgd;
#endif

	/* This will work as long as patching hasn't happened yet
	   (which it hasn't) */
	pv_mmu_ops.alloc_pte = xen_alloc_pte;
	pv_mmu_ops.alloc_pmd = xen_alloc_pmd;
	pv_mmu_ops.release_pte = xen_release_pte;
	pv_mmu_ops.release_pmd = xen_release_pmd;
#if PAGETABLE_LEVELS == 4
	pv_mmu_ops.alloc_pud = xen_alloc_pud;
	pv_mmu_ops.release_pud = xen_release_pud;
#endif

#ifdef CONFIG_X86_64
	SetPagePinned(virt_to_page(level3_user_vsyscall));
#endif
	xen_mark_init_mm_pinned();
}

1968 1969
static void xen_leave_lazy_mmu(void)
{
1970
	preempt_disable();
1971 1972
	xen_mc_flush();
	paravirt_leave_lazy_mmu();
1973
	preempt_enable();
1974
}
1975

1976
static const struct pv_mmu_ops xen_mmu_ops __initdata = {
1977 1978 1979 1980
	.read_cr2 = xen_read_cr2,
	.write_cr2 = xen_write_cr2,

	.read_cr3 = xen_read_cr3,
1981 1982 1983
#ifdef CONFIG_X86_32
	.write_cr3 = xen_write_cr3_init,
#else
1984
	.write_cr3 = xen_write_cr3,
1985
#endif
1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

	.flush_tlb_user = xen_flush_tlb,
	.flush_tlb_kernel = xen_flush_tlb,
	.flush_tlb_single = xen_flush_tlb_single,
	.flush_tlb_others = xen_flush_tlb_others,

	.pte_update = paravirt_nop,
	.pte_update_defer = paravirt_nop,

	.pgd_alloc = xen_pgd_alloc,
	.pgd_free = xen_pgd_free,

	.alloc_pte = xen_alloc_pte_init,
	.release_pte = xen_release_pte_init,
2000 2001
	.alloc_pmd = xen_alloc_pmd_init,
	.release_pmd = xen_release_pmd_init,
2002 2003 2004 2005 2006 2007 2008 2009

	.set_pte = xen_set_pte_init,
	.set_pte_at = xen_set_pte_at,
	.set_pmd = xen_set_pmd_hyper,

	.ptep_modify_prot_start = __ptep_modify_prot_start,
	.ptep_modify_prot_commit = __ptep_modify_prot_commit,

2010 2011
	.pte_val = PV_CALLEE_SAVE(xen_pte_val),
	.pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
2012

2013 2014
	.make_pte = PV_CALLEE_SAVE(xen_make_pte),
	.make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
2015 2016 2017 2018 2019 2020 2021 2022

#ifdef CONFIG_X86_PAE
	.set_pte_atomic = xen_set_pte_atomic,
	.pte_clear = xen_pte_clear,
	.pmd_clear = xen_pmd_clear,
#endif	/* CONFIG_X86_PAE */
	.set_pud = xen_set_pud_hyper,

2023 2024
	.make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
	.pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
2025 2026

#if PAGETABLE_LEVELS == 4
2027 2028
	.pud_val = PV_CALLEE_SAVE(xen_pud_val),
	.make_pud = PV_CALLEE_SAVE(xen_make_pud),
2029 2030
	.set_pgd = xen_set_pgd_hyper,

2031 2032
	.alloc_pud = xen_alloc_pmd_init,
	.release_pud = xen_release_pmd_init,
2033 2034 2035 2036 2037 2038 2039 2040
#endif	/* PAGETABLE_LEVELS == 4 */

	.activate_mm = xen_activate_mm,
	.dup_mmap = xen_dup_mmap,
	.exit_mmap = xen_exit_mmap,

	.lazy_mode = {
		.enter = paravirt_enter_lazy_mmu,
2041
		.leave = xen_leave_lazy_mmu,
2042 2043 2044 2045 2046
	},

	.set_fixmap = xen_set_fixmap,
};

2047 2048 2049 2050 2051
void __init xen_init_mmu_ops(void)
{
	x86_init.paging.pagetable_setup_start = xen_pagetable_setup_start;
	x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done;
	pv_mmu_ops = xen_mmu_ops;
2052

2053
	memset(dummy_mapping, 0xff, PAGE_SIZE);
2054
}
2055

2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248
/* Protected by xen_reservation_lock. */
#define MAX_CONTIG_ORDER 9 /* 2MB */
static unsigned long discontig_frames[1<<MAX_CONTIG_ORDER];

#define VOID_PTE (mfn_pte(0, __pgprot(0)))
static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order,
				unsigned long *in_frames,
				unsigned long *out_frames)
{
	int i;
	struct multicall_space mcs;

	xen_mc_batch();
	for (i = 0; i < (1UL<<order); i++, vaddr += PAGE_SIZE) {
		mcs = __xen_mc_entry(0);

		if (in_frames)
			in_frames[i] = virt_to_mfn(vaddr);

		MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0);
		set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY);

		if (out_frames)
			out_frames[i] = virt_to_pfn(vaddr);
	}
	xen_mc_issue(0);
}

/*
 * Update the pfn-to-mfn mappings for a virtual address range, either to
 * point to an array of mfns, or contiguously from a single starting
 * mfn.
 */
static void xen_remap_exchanged_ptes(unsigned long vaddr, int order,
				     unsigned long *mfns,
				     unsigned long first_mfn)
{
	unsigned i, limit;
	unsigned long mfn;

	xen_mc_batch();

	limit = 1u << order;
	for (i = 0; i < limit; i++, vaddr += PAGE_SIZE) {
		struct multicall_space mcs;
		unsigned flags;

		mcs = __xen_mc_entry(0);
		if (mfns)
			mfn = mfns[i];
		else
			mfn = first_mfn + i;

		if (i < (limit - 1))
			flags = 0;
		else {
			if (order == 0)
				flags = UVMF_INVLPG | UVMF_ALL;
			else
				flags = UVMF_TLB_FLUSH | UVMF_ALL;
		}

		MULTI_update_va_mapping(mcs.mc, vaddr,
				mfn_pte(mfn, PAGE_KERNEL), flags);

		set_phys_to_machine(virt_to_pfn(vaddr), mfn);
	}

	xen_mc_issue(0);
}

/*
 * Perform the hypercall to exchange a region of our pfns to point to
 * memory with the required contiguous alignment.  Takes the pfns as
 * input, and populates mfns as output.
 *
 * Returns a success code indicating whether the hypervisor was able to
 * satisfy the request or not.
 */
static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in,
			       unsigned long *pfns_in,
			       unsigned long extents_out,
			       unsigned int order_out,
			       unsigned long *mfns_out,
			       unsigned int address_bits)
{
	long rc;
	int success;

	struct xen_memory_exchange exchange = {
		.in = {
			.nr_extents   = extents_in,
			.extent_order = order_in,
			.extent_start = pfns_in,
			.domid        = DOMID_SELF
		},
		.out = {
			.nr_extents   = extents_out,
			.extent_order = order_out,
			.extent_start = mfns_out,
			.address_bits = address_bits,
			.domid        = DOMID_SELF
		}
	};

	BUG_ON(extents_in << order_in != extents_out << order_out);

	rc = HYPERVISOR_memory_op(XENMEM_exchange, &exchange);
	success = (exchange.nr_exchanged == extents_in);

	BUG_ON(!success && ((exchange.nr_exchanged != 0) || (rc == 0)));
	BUG_ON(success && (rc != 0));

	return success;
}

int xen_create_contiguous_region(unsigned long vstart, unsigned int order,
				 unsigned int address_bits)
{
	unsigned long *in_frames = discontig_frames, out_frame;
	unsigned long  flags;
	int            success;

	/*
	 * Currently an auto-translated guest will not perform I/O, nor will
	 * it require PAE page directories below 4GB. Therefore any calls to
	 * this function are redundant and can be ignored.
	 */

	if (xen_feature(XENFEAT_auto_translated_physmap))
		return 0;

	if (unlikely(order > MAX_CONTIG_ORDER))
		return -ENOMEM;

	memset((void *) vstart, 0, PAGE_SIZE << order);

	spin_lock_irqsave(&xen_reservation_lock, flags);

	/* 1. Zap current PTEs, remembering MFNs. */
	xen_zap_pfn_range(vstart, order, in_frames, NULL);

	/* 2. Get a new contiguous memory extent. */
	out_frame = virt_to_pfn(vstart);
	success = xen_exchange_memory(1UL << order, 0, in_frames,
				      1, order, &out_frame,
				      address_bits);

	/* 3. Map the new extent in place of old pages. */
	if (success)
		xen_remap_exchanged_ptes(vstart, order, NULL, out_frame);
	else
		xen_remap_exchanged_ptes(vstart, order, in_frames, 0);

	spin_unlock_irqrestore(&xen_reservation_lock, flags);

	return success ? 0 : -ENOMEM;
}
EXPORT_SYMBOL_GPL(xen_create_contiguous_region);

void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order)
{
	unsigned long *out_frames = discontig_frames, in_frame;
	unsigned long  flags;
	int success;

	if (xen_feature(XENFEAT_auto_translated_physmap))
		return;

	if (unlikely(order > MAX_CONTIG_ORDER))
		return;

	memset((void *) vstart, 0, PAGE_SIZE << order);

	spin_lock_irqsave(&xen_reservation_lock, flags);

	/* 1. Find start MFN of contiguous extent. */
	in_frame = virt_to_mfn(vstart);

	/* 2. Zap current PTEs. */
	xen_zap_pfn_range(vstart, order, NULL, out_frames);

	/* 3. Do the exchange for non-contiguous MFNs. */
	success = xen_exchange_memory(1, order, &in_frame, 1UL << order,
					0, out_frames, 0);

	/* 4. Map new pages in place of old pages. */
	if (success)
		xen_remap_exchanged_ptes(vstart, order, out_frames, 0);
	else
		xen_remap_exchanged_ptes(vstart, order, NULL, in_frame);

	spin_unlock_irqrestore(&xen_reservation_lock, flags);
2249
}
2250
EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
2251

2252
#ifdef CONFIG_XEN_PVHVM
2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283
static void xen_hvm_exit_mmap(struct mm_struct *mm)
{
	struct xen_hvm_pagetable_dying a;
	int rc;

	a.domid = DOMID_SELF;
	a.gpa = __pa(mm->pgd);
	rc = HYPERVISOR_hvm_op(HVMOP_pagetable_dying, &a);
	WARN_ON_ONCE(rc < 0);
}

static int is_pagetable_dying_supported(void)
{
	struct xen_hvm_pagetable_dying a;
	int rc = 0;

	a.domid = DOMID_SELF;
	a.gpa = 0x00;
	rc = HYPERVISOR_hvm_op(HVMOP_pagetable_dying, &a);
	if (rc < 0) {
		printk(KERN_DEBUG "HVMOP_pagetable_dying not supported\n");
		return 0;
	}
	return 1;
}

void __init xen_hvm_init_mmu_ops(void)
{
	if (is_pagetable_dying_supported())
		pv_mmu_ops.exit_mmap = xen_hvm_exit_mmap;
}
2284
#endif
2285

2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319
#define REMAP_BATCH_SIZE 16

struct remap_data {
	unsigned long mfn;
	pgprot_t prot;
	struct mmu_update *mmu_update;
};

static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,
				 unsigned long addr, void *data)
{
	struct remap_data *rmd = data;
	pte_t pte = pte_mkspecial(pfn_pte(rmd->mfn++, rmd->prot));

	rmd->mmu_update->ptr = arbitrary_virt_to_machine(ptep).maddr;
	rmd->mmu_update->val = pte_val_ma(pte);
	rmd->mmu_update++;

	return 0;
}

int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
			       unsigned long addr,
			       unsigned long mfn, int nr,
			       pgprot_t prot, unsigned domid)
{
	struct remap_data rmd;
	struct mmu_update mmu_update[REMAP_BATCH_SIZE];
	int batch;
	unsigned long range;
	int err = 0;

	prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP);

2320 2321
	BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_RESERVED | VM_IO)) ==
				(VM_PFNMAP | VM_RESERVED | VM_IO)));
2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352

	rmd.mfn = mfn;
	rmd.prot = prot;

	while (nr) {
		batch = min(REMAP_BATCH_SIZE, nr);
		range = (unsigned long)batch << PAGE_SHIFT;

		rmd.mmu_update = mmu_update;
		err = apply_to_page_range(vma->vm_mm, addr, range,
					  remap_area_mfn_pte_fn, &rmd);
		if (err)
			goto out;

		err = -EFAULT;
		if (HYPERVISOR_mmu_update(mmu_update, batch, NULL, domid) < 0)
			goto out;

		nr -= batch;
		addr += range;
	}

	err = 0;
out:

	flush_tlb_all();

	return err;
}
EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);

J
Jeremy Fitzhardinge 已提交
2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414
#ifdef CONFIG_XEN_DEBUG_FS

static struct dentry *d_mmu_debug;

static int __init xen_mmu_debugfs(void)
{
	struct dentry *d_xen = xen_init_debugfs();

	if (d_xen == NULL)
		return -ENOMEM;

	d_mmu_debug = debugfs_create_dir("mmu", d_xen);

	debugfs_create_u8("zero_stats", 0644, d_mmu_debug, &zero_stats);

	debugfs_create_u32("pgd_update", 0444, d_mmu_debug, &mmu_stats.pgd_update);
	debugfs_create_u32("pgd_update_pinned", 0444, d_mmu_debug,
			   &mmu_stats.pgd_update_pinned);
	debugfs_create_u32("pgd_update_batched", 0444, d_mmu_debug,
			   &mmu_stats.pgd_update_pinned);

	debugfs_create_u32("pud_update", 0444, d_mmu_debug, &mmu_stats.pud_update);
	debugfs_create_u32("pud_update_pinned", 0444, d_mmu_debug,
			   &mmu_stats.pud_update_pinned);
	debugfs_create_u32("pud_update_batched", 0444, d_mmu_debug,
			   &mmu_stats.pud_update_pinned);

	debugfs_create_u32("pmd_update", 0444, d_mmu_debug, &mmu_stats.pmd_update);
	debugfs_create_u32("pmd_update_pinned", 0444, d_mmu_debug,
			   &mmu_stats.pmd_update_pinned);
	debugfs_create_u32("pmd_update_batched", 0444, d_mmu_debug,
			   &mmu_stats.pmd_update_pinned);

	debugfs_create_u32("pte_update", 0444, d_mmu_debug, &mmu_stats.pte_update);
//	debugfs_create_u32("pte_update_pinned", 0444, d_mmu_debug,
//			   &mmu_stats.pte_update_pinned);
	debugfs_create_u32("pte_update_batched", 0444, d_mmu_debug,
			   &mmu_stats.pte_update_pinned);

	debugfs_create_u32("mmu_update", 0444, d_mmu_debug, &mmu_stats.mmu_update);
	debugfs_create_u32("mmu_update_extended", 0444, d_mmu_debug,
			   &mmu_stats.mmu_update_extended);
	xen_debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug,
				     mmu_stats.mmu_update_histo, 20);

	debugfs_create_u32("set_pte_at", 0444, d_mmu_debug, &mmu_stats.set_pte_at);
	debugfs_create_u32("set_pte_at_batched", 0444, d_mmu_debug,
			   &mmu_stats.set_pte_at_batched);
	debugfs_create_u32("set_pte_at_current", 0444, d_mmu_debug,
			   &mmu_stats.set_pte_at_current);
	debugfs_create_u32("set_pte_at_kernel", 0444, d_mmu_debug,
			   &mmu_stats.set_pte_at_kernel);

	debugfs_create_u32("prot_commit", 0444, d_mmu_debug, &mmu_stats.prot_commit);
	debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
			   &mmu_stats.prot_commit_batched);

	return 0;
}
fs_initcall(xen_mmu_debugfs);

#endif	/* CONFIG_XEN_DEBUG_FS */