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901d209a JG |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
7e0563de VK |
3 | /* |
4 | * Xen mmu operations | |
5 | * | |
6 | * This file contains the various mmu fetch and update operations. | |
7 | * The most important job they must perform is the mapping between the | |
8 | * domain's pfn and the overall machine mfns. | |
9 | * | |
10 | * Xen allows guests to directly update the pagetable, in a controlled | |
11 | * fashion. In other words, the guest modifies the same pagetable | |
12 | * that the CPU actually uses, which eliminates the overhead of having | |
13 | * a separate shadow pagetable. | |
14 | * | |
15 | * In order to allow this, it falls on the guest domain to map its | |
16 | * notion of a "physical" pfn - which is just a domain-local linear | |
17 | * address - into a real "machine address" which the CPU's MMU can | |
18 | * use. | |
19 | * | |
20 | * A pgd_t/pmd_t/pte_t will typically contain an mfn, and so can be | |
21 | * inserted directly into the pagetable. When creating a new | |
22 | * pte/pmd/pgd, it converts the passed pfn into an mfn. Conversely, | |
23 | * when reading the content back with __(pgd|pmd|pte)_val, it converts | |
24 | * the mfn back into a pfn. | |
25 | * | |
26 | * The other constraint is that all pages which make up a pagetable | |
27 | * must be mapped read-only in the guest. This prevents uncontrolled | |
28 | * guest updates to the pagetable. Xen strictly enforces this, and | |
29 | * will disallow any pagetable update which will end up mapping a | |
30 | * pagetable page RW, and will disallow using any writable page as a | |
31 | * pagetable. | |
32 | * | |
33 | * Naively, when loading %cr3 with the base of a new pagetable, Xen | |
34 | * would need to validate the whole pagetable before going on. | |
35 | * Naturally, this is quite slow. The solution is to "pin" a | |
36 | * pagetable, which enforces all the constraints on the pagetable even | |
37 | * when it is not actively in use. This menas that Xen can be assured | |
38 | * that it is still valid when you do load it into %cr3, and doesn't | |
39 | * need to revalidate it. | |
40 | * | |
41 | * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 | |
42 | */ | |
43 | #include <linux/sched/mm.h> | |
44 | #include <linux/highmem.h> | |
45 | #include <linux/debugfs.h> | |
46 | #include <linux/bug.h> | |
47 | #include <linux/vmalloc.h> | |
48 | #include <linux/export.h> | |
49 | #include <linux/init.h> | |
50 | #include <linux/gfp.h> | |
51 | #include <linux/memblock.h> | |
52 | #include <linux/seq_file.h> | |
53 | #include <linux/crash_dump.h> | |
65fddcfc | 54 | #include <linux/pgtable.h> |
29985b09 JG |
55 | #ifdef CONFIG_KEXEC_CORE |
56 | #include <linux/kexec.h> | |
57 | #endif | |
7e0563de VK |
58 | |
59 | #include <trace/events/xen.h> | |
60 | ||
7e0563de VK |
61 | #include <asm/tlbflush.h> |
62 | #include <asm/fixmap.h> | |
63 | #include <asm/mmu_context.h> | |
64 | #include <asm/setup.h> | |
65 | #include <asm/paravirt.h> | |
66 | #include <asm/e820/api.h> | |
67 | #include <asm/linkage.h> | |
68 | #include <asm/page.h> | |
69 | #include <asm/init.h> | |
eb243d1d | 70 | #include <asm/memtype.h> |
7e0563de | 71 | #include <asm/smp.h> |
48a8b97c | 72 | #include <asm/tlb.h> |
7e0563de VK |
73 | |
74 | #include <asm/xen/hypercall.h> | |
75 | #include <asm/xen/hypervisor.h> | |
76 | ||
77 | #include <xen/xen.h> | |
78 | #include <xen/page.h> | |
79 | #include <xen/interface/xen.h> | |
80 | #include <xen/interface/hvm/hvm_op.h> | |
81 | #include <xen/interface/version.h> | |
82 | #include <xen/interface/memory.h> | |
83 | #include <xen/hvc-console.h> | |
84 | ||
85 | #include "multicalls.h" | |
86 | #include "mmu.h" | |
87 | #include "debugfs.h" | |
88 | ||
7e0563de VK |
89 | /* l3 pud for userspace vsyscall mapping */ |
90 | static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss; | |
7e0563de | 91 | |
f030aade JG |
92 | /* |
93 | * Protects atomic reservation decrease/increase against concurrent increases. | |
94 | * Also protects non-atomic updates of current_pages and balloon lists. | |
95 | */ | |
4f2d7af7 | 96 | static DEFINE_SPINLOCK(xen_reservation_lock); |
f030aade | 97 | |
7e0563de VK |
98 | /* |
99 | * Note about cr3 (pagetable base) values: | |
100 | * | |
101 | * xen_cr3 contains the current logical cr3 value; it contains the | |
102 | * last set cr3. This may not be the current effective cr3, because | |
103 | * its update may be being lazily deferred. However, a vcpu looking | |
104 | * at its own cr3 can use this value knowing that it everything will | |
105 | * be self-consistent. | |
106 | * | |
107 | * xen_current_cr3 contains the actual vcpu cr3; it is set once the | |
108 | * hypercall to set the vcpu cr3 is complete (so it may be a little | |
109 | * out of date, but it will never be set early). If one vcpu is | |
110 | * looking at another vcpu's cr3 value, it should use this variable. | |
111 | */ | |
112 | DEFINE_PER_CPU(unsigned long, xen_cr3); /* cr3 stored as physaddr */ | |
113 | DEFINE_PER_CPU(unsigned long, xen_current_cr3); /* actual vcpu cr3 */ | |
114 | ||
115 | static phys_addr_t xen_pt_base, xen_pt_size __initdata; | |
116 | ||
6f84f8d1 PT |
117 | static DEFINE_STATIC_KEY_FALSE(xen_struct_pages_ready); |
118 | ||
7e0563de VK |
119 | /* |
120 | * Just beyond the highest usermode address. STACK_TOP_MAX has a | |
121 | * redzone above it, so round it up to a PGD boundary. | |
122 | */ | |
123 | #define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK) | |
124 | ||
125 | void make_lowmem_page_readonly(void *vaddr) | |
126 | { | |
127 | pte_t *pte, ptev; | |
128 | unsigned long address = (unsigned long)vaddr; | |
129 | unsigned int level; | |
130 | ||
131 | pte = lookup_address(address, &level); | |
132 | if (pte == NULL) | |
133 | return; /* vaddr missing */ | |
134 | ||
135 | ptev = pte_wrprotect(*pte); | |
136 | ||
137 | if (HYPERVISOR_update_va_mapping(address, ptev, 0)) | |
138 | BUG(); | |
139 | } | |
140 | ||
141 | void make_lowmem_page_readwrite(void *vaddr) | |
142 | { | |
143 | pte_t *pte, ptev; | |
144 | unsigned long address = (unsigned long)vaddr; | |
145 | unsigned int level; | |
146 | ||
147 | pte = lookup_address(address, &level); | |
148 | if (pte == NULL) | |
149 | return; /* vaddr missing */ | |
150 | ||
151 | ptev = pte_mkwrite(*pte); | |
152 | ||
153 | if (HYPERVISOR_update_va_mapping(address, ptev, 0)) | |
154 | BUG(); | |
155 | } | |
156 | ||
157 | ||
6f84f8d1 PT |
158 | /* |
159 | * During early boot all page table pages are pinned, but we do not have struct | |
160 | * pages, so return true until struct pages are ready. | |
161 | */ | |
7e0563de VK |
162 | static bool xen_page_pinned(void *ptr) |
163 | { | |
6f84f8d1 PT |
164 | if (static_branch_likely(&xen_struct_pages_ready)) { |
165 | struct page *page = virt_to_page(ptr); | |
7e0563de | 166 | |
6f84f8d1 PT |
167 | return PagePinned(page); |
168 | } | |
169 | return true; | |
7e0563de VK |
170 | } |
171 | ||
7e0563de VK |
172 | static void xen_extend_mmu_update(const struct mmu_update *update) |
173 | { | |
174 | struct multicall_space mcs; | |
175 | struct mmu_update *u; | |
176 | ||
177 | mcs = xen_mc_extend_args(__HYPERVISOR_mmu_update, sizeof(*u)); | |
178 | ||
179 | if (mcs.mc != NULL) { | |
180 | mcs.mc->args[1]++; | |
181 | } else { | |
182 | mcs = __xen_mc_entry(sizeof(*u)); | |
183 | MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_SELF); | |
184 | } | |
185 | ||
186 | u = mcs.args; | |
187 | *u = *update; | |
188 | } | |
189 | ||
190 | static void xen_extend_mmuext_op(const struct mmuext_op *op) | |
191 | { | |
192 | struct multicall_space mcs; | |
193 | struct mmuext_op *u; | |
194 | ||
195 | mcs = xen_mc_extend_args(__HYPERVISOR_mmuext_op, sizeof(*u)); | |
196 | ||
197 | if (mcs.mc != NULL) { | |
198 | mcs.mc->args[1]++; | |
199 | } else { | |
200 | mcs = __xen_mc_entry(sizeof(*u)); | |
201 | MULTI_mmuext_op(mcs.mc, mcs.args, 1, NULL, DOMID_SELF); | |
202 | } | |
203 | ||
204 | u = mcs.args; | |
205 | *u = *op; | |
206 | } | |
207 | ||
208 | static void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val) | |
209 | { | |
210 | struct mmu_update u; | |
211 | ||
212 | preempt_disable(); | |
213 | ||
214 | xen_mc_batch(); | |
215 | ||
216 | /* ptr may be ioremapped for 64-bit pagetable setup */ | |
217 | u.ptr = arbitrary_virt_to_machine(ptr).maddr; | |
218 | u.val = pmd_val_ma(val); | |
219 | xen_extend_mmu_update(&u); | |
220 | ||
221 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
222 | ||
223 | preempt_enable(); | |
224 | } | |
225 | ||
226 | static void xen_set_pmd(pmd_t *ptr, pmd_t val) | |
227 | { | |
228 | trace_xen_mmu_set_pmd(ptr, val); | |
229 | ||
230 | /* If page is not pinned, we can just update the entry | |
231 | directly */ | |
232 | if (!xen_page_pinned(ptr)) { | |
233 | *ptr = val; | |
234 | return; | |
235 | } | |
236 | ||
237 | xen_set_pmd_hyper(ptr, val); | |
238 | } | |
239 | ||
240 | /* | |
241 | * Associate a virtual page frame with a given physical page frame | |
242 | * and protection flags for that frame. | |
243 | */ | |
244 | void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags) | |
245 | { | |
246 | set_pte_vaddr(vaddr, mfn_pte(mfn, flags)); | |
247 | } | |
248 | ||
249 | static bool xen_batched_set_pte(pte_t *ptep, pte_t pteval) | |
250 | { | |
251 | struct mmu_update u; | |
252 | ||
253 | if (paravirt_get_lazy_mode() != PARAVIRT_LAZY_MMU) | |
254 | return false; | |
255 | ||
256 | xen_mc_batch(); | |
257 | ||
258 | u.ptr = virt_to_machine(ptep).maddr | MMU_NORMAL_PT_UPDATE; | |
259 | u.val = pte_val_ma(pteval); | |
260 | xen_extend_mmu_update(&u); | |
261 | ||
262 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
263 | ||
264 | return true; | |
265 | } | |
266 | ||
267 | static inline void __xen_set_pte(pte_t *ptep, pte_t pteval) | |
268 | { | |
269 | if (!xen_batched_set_pte(ptep, pteval)) { | |
270 | /* | |
271 | * Could call native_set_pte() here and trap and | |
a13f2ef1 | 272 | * emulate the PTE write, but a hypercall is much cheaper. |
7e0563de VK |
273 | */ |
274 | struct mmu_update u; | |
275 | ||
276 | u.ptr = virt_to_machine(ptep).maddr | MMU_NORMAL_PT_UPDATE; | |
277 | u.val = pte_val_ma(pteval); | |
278 | HYPERVISOR_mmu_update(&u, 1, NULL, DOMID_SELF); | |
279 | } | |
280 | } | |
281 | ||
282 | static void xen_set_pte(pte_t *ptep, pte_t pteval) | |
283 | { | |
284 | trace_xen_mmu_set_pte(ptep, pteval); | |
285 | __xen_set_pte(ptep, pteval); | |
286 | } | |
287 | ||
0cbe3e26 | 288 | pte_t xen_ptep_modify_prot_start(struct vm_area_struct *vma, |
7e0563de VK |
289 | unsigned long addr, pte_t *ptep) |
290 | { | |
291 | /* Just return the pte as-is. We preserve the bits on commit */ | |
0cbe3e26 | 292 | trace_xen_mmu_ptep_modify_prot_start(vma->vm_mm, addr, ptep, *ptep); |
7e0563de VK |
293 | return *ptep; |
294 | } | |
295 | ||
0cbe3e26 | 296 | void xen_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, |
7e0563de VK |
297 | pte_t *ptep, pte_t pte) |
298 | { | |
299 | struct mmu_update u; | |
300 | ||
0cbe3e26 | 301 | trace_xen_mmu_ptep_modify_prot_commit(vma->vm_mm, addr, ptep, pte); |
7e0563de VK |
302 | xen_mc_batch(); |
303 | ||
304 | u.ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD; | |
305 | u.val = pte_val_ma(pte); | |
306 | xen_extend_mmu_update(&u); | |
307 | ||
308 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
309 | } | |
310 | ||
311 | /* Assume pteval_t is equivalent to all the other *val_t types. */ | |
312 | static pteval_t pte_mfn_to_pfn(pteval_t val) | |
313 | { | |
314 | if (val & _PAGE_PRESENT) { | |
6f0e8bf1 | 315 | unsigned long mfn = (val & XEN_PTE_MFN_MASK) >> PAGE_SHIFT; |
7e0563de VK |
316 | unsigned long pfn = mfn_to_pfn(mfn); |
317 | ||
318 | pteval_t flags = val & PTE_FLAGS_MASK; | |
319 | if (unlikely(pfn == ~0)) | |
320 | val = flags & ~_PAGE_PRESENT; | |
321 | else | |
322 | val = ((pteval_t)pfn << PAGE_SHIFT) | flags; | |
323 | } | |
324 | ||
325 | return val; | |
326 | } | |
327 | ||
328 | static pteval_t pte_pfn_to_mfn(pteval_t val) | |
329 | { | |
330 | if (val & _PAGE_PRESENT) { | |
331 | unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT; | |
332 | pteval_t flags = val & PTE_FLAGS_MASK; | |
333 | unsigned long mfn; | |
334 | ||
989513a7 JG |
335 | mfn = __pfn_to_mfn(pfn); |
336 | ||
7e0563de VK |
337 | /* |
338 | * If there's no mfn for the pfn, then just create an | |
339 | * empty non-present pte. Unfortunately this loses | |
340 | * information about the original pfn, so | |
341 | * pte_mfn_to_pfn is asymmetric. | |
342 | */ | |
343 | if (unlikely(mfn == INVALID_P2M_ENTRY)) { | |
344 | mfn = 0; | |
345 | flags = 0; | |
346 | } else | |
347 | mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); | |
348 | val = ((pteval_t)mfn << PAGE_SHIFT) | flags; | |
349 | } | |
350 | ||
351 | return val; | |
352 | } | |
353 | ||
354 | __visible pteval_t xen_pte_val(pte_t pte) | |
355 | { | |
356 | pteval_t pteval = pte.pte; | |
357 | ||
358 | return pte_mfn_to_pfn(pteval); | |
359 | } | |
360 | PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val); | |
361 | ||
362 | __visible pgdval_t xen_pgd_val(pgd_t pgd) | |
363 | { | |
364 | return pte_mfn_to_pfn(pgd.pgd); | |
365 | } | |
366 | PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val); | |
367 | ||
368 | __visible pte_t xen_make_pte(pteval_t pte) | |
369 | { | |
370 | pte = pte_pfn_to_mfn(pte); | |
371 | ||
372 | return native_make_pte(pte); | |
373 | } | |
374 | PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte); | |
375 | ||
376 | __visible pgd_t xen_make_pgd(pgdval_t pgd) | |
377 | { | |
378 | pgd = pte_pfn_to_mfn(pgd); | |
379 | return native_make_pgd(pgd); | |
380 | } | |
381 | PV_CALLEE_SAVE_REGS_THUNK(xen_make_pgd); | |
382 | ||
383 | __visible pmdval_t xen_pmd_val(pmd_t pmd) | |
384 | { | |
385 | return pte_mfn_to_pfn(pmd.pmd); | |
386 | } | |
387 | PV_CALLEE_SAVE_REGS_THUNK(xen_pmd_val); | |
388 | ||
389 | static void xen_set_pud_hyper(pud_t *ptr, pud_t val) | |
390 | { | |
391 | struct mmu_update u; | |
392 | ||
393 | preempt_disable(); | |
394 | ||
395 | xen_mc_batch(); | |
396 | ||
397 | /* ptr may be ioremapped for 64-bit pagetable setup */ | |
398 | u.ptr = arbitrary_virt_to_machine(ptr).maddr; | |
399 | u.val = pud_val_ma(val); | |
400 | xen_extend_mmu_update(&u); | |
401 | ||
402 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
403 | ||
404 | preempt_enable(); | |
405 | } | |
406 | ||
407 | static void xen_set_pud(pud_t *ptr, pud_t val) | |
408 | { | |
409 | trace_xen_mmu_set_pud(ptr, val); | |
410 | ||
411 | /* If page is not pinned, we can just update the entry | |
412 | directly */ | |
413 | if (!xen_page_pinned(ptr)) { | |
414 | *ptr = val; | |
415 | return; | |
416 | } | |
417 | ||
418 | xen_set_pud_hyper(ptr, val); | |
419 | } | |
420 | ||
7e0563de VK |
421 | __visible pmd_t xen_make_pmd(pmdval_t pmd) |
422 | { | |
423 | pmd = pte_pfn_to_mfn(pmd); | |
424 | return native_make_pmd(pmd); | |
425 | } | |
426 | PV_CALLEE_SAVE_REGS_THUNK(xen_make_pmd); | |
427 | ||
7e0563de VK |
428 | __visible pudval_t xen_pud_val(pud_t pud) |
429 | { | |
430 | return pte_mfn_to_pfn(pud.pud); | |
431 | } | |
432 | PV_CALLEE_SAVE_REGS_THUNK(xen_pud_val); | |
433 | ||
434 | __visible pud_t xen_make_pud(pudval_t pud) | |
435 | { | |
436 | pud = pte_pfn_to_mfn(pud); | |
437 | ||
438 | return native_make_pud(pud); | |
439 | } | |
440 | PV_CALLEE_SAVE_REGS_THUNK(xen_make_pud); | |
441 | ||
442 | static pgd_t *xen_get_user_pgd(pgd_t *pgd) | |
443 | { | |
444 | pgd_t *pgd_page = (pgd_t *)(((unsigned long)pgd) & PAGE_MASK); | |
445 | unsigned offset = pgd - pgd_page; | |
446 | pgd_t *user_ptr = NULL; | |
447 | ||
448 | if (offset < pgd_index(USER_LIMIT)) { | |
449 | struct page *page = virt_to_page(pgd_page); | |
450 | user_ptr = (pgd_t *)page->private; | |
451 | if (user_ptr) | |
452 | user_ptr += offset; | |
453 | } | |
454 | ||
455 | return user_ptr; | |
456 | } | |
457 | ||
458 | static void __xen_set_p4d_hyper(p4d_t *ptr, p4d_t val) | |
459 | { | |
460 | struct mmu_update u; | |
461 | ||
462 | u.ptr = virt_to_machine(ptr).maddr; | |
463 | u.val = p4d_val_ma(val); | |
464 | xen_extend_mmu_update(&u); | |
465 | } | |
466 | ||
467 | /* | |
468 | * Raw hypercall-based set_p4d, intended for in early boot before | |
469 | * there's a page structure. This implies: | |
470 | * 1. The only existing pagetable is the kernel's | |
471 | * 2. It is always pinned | |
472 | * 3. It has no user pagetable attached to it | |
473 | */ | |
474 | static void __init xen_set_p4d_hyper(p4d_t *ptr, p4d_t val) | |
475 | { | |
476 | preempt_disable(); | |
477 | ||
478 | xen_mc_batch(); | |
479 | ||
480 | __xen_set_p4d_hyper(ptr, val); | |
481 | ||
482 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
483 | ||
484 | preempt_enable(); | |
485 | } | |
486 | ||
487 | static void xen_set_p4d(p4d_t *ptr, p4d_t val) | |
488 | { | |
489 | pgd_t *user_ptr = xen_get_user_pgd((pgd_t *)ptr); | |
490 | pgd_t pgd_val; | |
491 | ||
492 | trace_xen_mmu_set_p4d(ptr, (p4d_t *)user_ptr, val); | |
493 | ||
494 | /* If page is not pinned, we can just update the entry | |
495 | directly */ | |
496 | if (!xen_page_pinned(ptr)) { | |
497 | *ptr = val; | |
498 | if (user_ptr) { | |
499 | WARN_ON(xen_page_pinned(user_ptr)); | |
500 | pgd_val.pgd = p4d_val_ma(val); | |
501 | *user_ptr = pgd_val; | |
502 | } | |
503 | return; | |
504 | } | |
505 | ||
506 | /* If it's pinned, then we can at least batch the kernel and | |
507 | user updates together. */ | |
508 | xen_mc_batch(); | |
509 | ||
510 | __xen_set_p4d_hyper(ptr, val); | |
511 | if (user_ptr) | |
512 | __xen_set_p4d_hyper((p4d_t *)user_ptr, val); | |
513 | ||
514 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
515 | } | |
b9952ec7 KS |
516 | |
517 | #if CONFIG_PGTABLE_LEVELS >= 5 | |
518 | __visible p4dval_t xen_p4d_val(p4d_t p4d) | |
519 | { | |
520 | return pte_mfn_to_pfn(p4d.p4d); | |
521 | } | |
522 | PV_CALLEE_SAVE_REGS_THUNK(xen_p4d_val); | |
523 | ||
524 | __visible p4d_t xen_make_p4d(p4dval_t p4d) | |
525 | { | |
526 | p4d = pte_pfn_to_mfn(p4d); | |
527 | ||
528 | return native_make_p4d(p4d); | |
529 | } | |
530 | PV_CALLEE_SAVE_REGS_THUNK(xen_make_p4d); | |
531 | #endif /* CONFIG_PGTABLE_LEVELS >= 5 */ | |
7e0563de | 532 | |
f2e39e8c JG |
533 | static void xen_pmd_walk(struct mm_struct *mm, pmd_t *pmd, |
534 | void (*func)(struct mm_struct *mm, struct page *, | |
535 | enum pt_level), | |
536 | bool last, unsigned long limit) | |
7e0563de | 537 | { |
f2e39e8c | 538 | int i, nr; |
7e0563de VK |
539 | |
540 | nr = last ? pmd_index(limit) + 1 : PTRS_PER_PMD; | |
541 | for (i = 0; i < nr; i++) { | |
542 | if (!pmd_none(pmd[i])) | |
f2e39e8c | 543 | (*func)(mm, pmd_page(pmd[i]), PT_PTE); |
7e0563de | 544 | } |
7e0563de VK |
545 | } |
546 | ||
f2e39e8c JG |
547 | static void xen_pud_walk(struct mm_struct *mm, pud_t *pud, |
548 | void (*func)(struct mm_struct *mm, struct page *, | |
549 | enum pt_level), | |
550 | bool last, unsigned long limit) | |
7e0563de | 551 | { |
f2e39e8c | 552 | int i, nr; |
7e0563de VK |
553 | |
554 | nr = last ? pud_index(limit) + 1 : PTRS_PER_PUD; | |
555 | for (i = 0; i < nr; i++) { | |
556 | pmd_t *pmd; | |
557 | ||
558 | if (pud_none(pud[i])) | |
559 | continue; | |
560 | ||
561 | pmd = pmd_offset(&pud[i], 0); | |
562 | if (PTRS_PER_PMD > 1) | |
f2e39e8c JG |
563 | (*func)(mm, virt_to_page(pmd), PT_PMD); |
564 | xen_pmd_walk(mm, pmd, func, last && i == nr - 1, limit); | |
7e0563de | 565 | } |
7e0563de VK |
566 | } |
567 | ||
f2e39e8c JG |
568 | static void xen_p4d_walk(struct mm_struct *mm, p4d_t *p4d, |
569 | void (*func)(struct mm_struct *mm, struct page *, | |
570 | enum pt_level), | |
571 | bool last, unsigned long limit) | |
7e0563de | 572 | { |
773dd2fc | 573 | pud_t *pud; |
7e0563de | 574 | |
7e0563de | 575 | |
773dd2fc | 576 | if (p4d_none(*p4d)) |
f2e39e8c | 577 | return; |
7e0563de | 578 | |
773dd2fc KS |
579 | pud = pud_offset(p4d, 0); |
580 | if (PTRS_PER_PUD > 1) | |
f2e39e8c JG |
581 | (*func)(mm, virt_to_page(pud), PT_PUD); |
582 | xen_pud_walk(mm, pud, func, last, limit); | |
7e0563de VK |
583 | } |
584 | ||
585 | /* | |
586 | * (Yet another) pagetable walker. This one is intended for pinning a | |
587 | * pagetable. This means that it walks a pagetable and calls the | |
588 | * callback function on each page it finds making up the page table, | |
589 | * at every level. It walks the entire pagetable, but it only bothers | |
590 | * pinning pte pages which are below limit. In the normal case this | |
591 | * will be STACK_TOP_MAX, but at boot we need to pin up to | |
592 | * FIXADDR_TOP. | |
593 | * | |
a13f2ef1 JG |
594 | * We must skip the Xen hole in the middle of the address space, just after |
595 | * the big x86-64 virtual hole. | |
7e0563de | 596 | */ |
f2e39e8c JG |
597 | static void __xen_pgd_walk(struct mm_struct *mm, pgd_t *pgd, |
598 | void (*func)(struct mm_struct *mm, struct page *, | |
599 | enum pt_level), | |
600 | unsigned long limit) | |
7e0563de | 601 | { |
f2e39e8c | 602 | int i, nr; |
16877a55 | 603 | unsigned hole_low = 0, hole_high = 0; |
7e0563de VK |
604 | |
605 | /* The limit is the last byte to be touched */ | |
606 | limit--; | |
607 | BUG_ON(limit >= FIXADDR_TOP); | |
608 | ||
7e0563de VK |
609 | /* |
610 | * 64-bit has a great big hole in the middle of the address | |
16877a55 | 611 | * space, which contains the Xen mappings. |
7e0563de | 612 | */ |
16877a55 KS |
613 | hole_low = pgd_index(GUARD_HOLE_BASE_ADDR); |
614 | hole_high = pgd_index(GUARD_HOLE_END_ADDR); | |
7e0563de VK |
615 | |
616 | nr = pgd_index(limit) + 1; | |
617 | for (i = 0; i < nr; i++) { | |
618 | p4d_t *p4d; | |
619 | ||
620 | if (i >= hole_low && i < hole_high) | |
621 | continue; | |
622 | ||
623 | if (pgd_none(pgd[i])) | |
624 | continue; | |
625 | ||
626 | p4d = p4d_offset(&pgd[i], 0); | |
f2e39e8c | 627 | xen_p4d_walk(mm, p4d, func, i == nr - 1, limit); |
7e0563de VK |
628 | } |
629 | ||
630 | /* Do the top level last, so that the callbacks can use it as | |
631 | a cue to do final things like tlb flushes. */ | |
f2e39e8c | 632 | (*func)(mm, virt_to_page(pgd), PT_PGD); |
7e0563de VK |
633 | } |
634 | ||
f2e39e8c JG |
635 | static void xen_pgd_walk(struct mm_struct *mm, |
636 | void (*func)(struct mm_struct *mm, struct page *, | |
637 | enum pt_level), | |
638 | unsigned long limit) | |
7e0563de | 639 | { |
f2e39e8c | 640 | __xen_pgd_walk(mm, mm->pgd, func, limit); |
7e0563de VK |
641 | } |
642 | ||
643 | /* If we're using split pte locks, then take the page's lock and | |
644 | return a pointer to it. Otherwise return NULL. */ | |
645 | static spinlock_t *xen_pte_lock(struct page *page, struct mm_struct *mm) | |
646 | { | |
647 | spinlock_t *ptl = NULL; | |
648 | ||
649 | #if USE_SPLIT_PTE_PTLOCKS | |
650 | ptl = ptlock_ptr(page); | |
651 | spin_lock_nest_lock(ptl, &mm->page_table_lock); | |
652 | #endif | |
653 | ||
654 | return ptl; | |
655 | } | |
656 | ||
657 | static void xen_pte_unlock(void *v) | |
658 | { | |
659 | spinlock_t *ptl = v; | |
660 | spin_unlock(ptl); | |
661 | } | |
662 | ||
663 | static void xen_do_pin(unsigned level, unsigned long pfn) | |
664 | { | |
665 | struct mmuext_op op; | |
666 | ||
667 | op.cmd = level; | |
668 | op.arg1.mfn = pfn_to_mfn(pfn); | |
669 | ||
670 | xen_extend_mmuext_op(&op); | |
671 | } | |
672 | ||
f2e39e8c JG |
673 | static void xen_pin_page(struct mm_struct *mm, struct page *page, |
674 | enum pt_level level) | |
7e0563de VK |
675 | { |
676 | unsigned pgfl = TestSetPagePinned(page); | |
f2e39e8c JG |
677 | |
678 | if (!pgfl) { | |
7e0563de VK |
679 | void *pt = lowmem_page_address(page); |
680 | unsigned long pfn = page_to_pfn(page); | |
681 | struct multicall_space mcs = __xen_mc_entry(0); | |
682 | spinlock_t *ptl; | |
683 | ||
7e0563de VK |
684 | /* |
685 | * We need to hold the pagetable lock between the time | |
686 | * we make the pagetable RO and when we actually pin | |
687 | * it. If we don't, then other users may come in and | |
688 | * attempt to update the pagetable by writing it, | |
689 | * which will fail because the memory is RO but not | |
690 | * pinned, so Xen won't do the trap'n'emulate. | |
691 | * | |
692 | * If we're using split pte locks, we can't hold the | |
693 | * entire pagetable's worth of locks during the | |
694 | * traverse, because we may wrap the preempt count (8 | |
695 | * bits). The solution is to mark RO and pin each PTE | |
696 | * page while holding the lock. This means the number | |
697 | * of locks we end up holding is never more than a | |
698 | * batch size (~32 entries, at present). | |
699 | * | |
700 | * If we're not using split pte locks, we needn't pin | |
701 | * the PTE pages independently, because we're | |
702 | * protected by the overall pagetable lock. | |
703 | */ | |
704 | ptl = NULL; | |
705 | if (level == PT_PTE) | |
706 | ptl = xen_pte_lock(page, mm); | |
707 | ||
708 | MULTI_update_va_mapping(mcs.mc, (unsigned long)pt, | |
709 | pfn_pte(pfn, PAGE_KERNEL_RO), | |
710 | level == PT_PGD ? UVMF_TLB_FLUSH : 0); | |
711 | ||
712 | if (ptl) { | |
713 | xen_do_pin(MMUEXT_PIN_L1_TABLE, pfn); | |
714 | ||
715 | /* Queue a deferred unlock for when this batch | |
716 | is completed. */ | |
717 | xen_mc_callback(xen_pte_unlock, ptl); | |
718 | } | |
719 | } | |
7e0563de VK |
720 | } |
721 | ||
722 | /* This is called just after a mm has been created, but it has not | |
723 | been used yet. We need to make sure that its pagetable is all | |
724 | read-only, and can be pinned. */ | |
725 | static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd) | |
726 | { | |
a13f2ef1 JG |
727 | pgd_t *user_pgd = xen_get_user_pgd(pgd); |
728 | ||
7e0563de VK |
729 | trace_xen_mmu_pgd_pin(mm, pgd); |
730 | ||
731 | xen_mc_batch(); | |
732 | ||
f2e39e8c | 733 | __xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT); |
7e0563de | 734 | |
a13f2ef1 | 735 | xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd))); |
7e0563de | 736 | |
a13f2ef1 JG |
737 | if (user_pgd) { |
738 | xen_pin_page(mm, virt_to_page(user_pgd), PT_PGD); | |
739 | xen_do_pin(MMUEXT_PIN_L4_TABLE, | |
740 | PFN_DOWN(__pa(user_pgd))); | |
7e0563de | 741 | } |
a13f2ef1 | 742 | |
7e0563de VK |
743 | xen_mc_issue(0); |
744 | } | |
745 | ||
746 | static void xen_pgd_pin(struct mm_struct *mm) | |
747 | { | |
748 | __xen_pgd_pin(mm, mm->pgd); | |
749 | } | |
750 | ||
751 | /* | |
752 | * On save, we need to pin all pagetables to make sure they get their | |
753 | * mfns turned into pfns. Search the list for any unpinned pgds and pin | |
754 | * them (unpinned pgds are not currently in use, probably because the | |
755 | * process is under construction or destruction). | |
756 | * | |
757 | * Expected to be called in stop_machine() ("equivalent to taking | |
758 | * every spinlock in the system"), so the locking doesn't really | |
759 | * matter all that much. | |
760 | */ | |
761 | void xen_mm_pin_all(void) | |
762 | { | |
763 | struct page *page; | |
764 | ||
765 | spin_lock(&pgd_lock); | |
766 | ||
767 | list_for_each_entry(page, &pgd_list, lru) { | |
768 | if (!PagePinned(page)) { | |
769 | __xen_pgd_pin(&init_mm, (pgd_t *)page_address(page)); | |
770 | SetPageSavePinned(page); | |
771 | } | |
772 | } | |
773 | ||
774 | spin_unlock(&pgd_lock); | |
775 | } | |
776 | ||
f2e39e8c JG |
777 | static void __init xen_mark_pinned(struct mm_struct *mm, struct page *page, |
778 | enum pt_level level) | |
7e0563de VK |
779 | { |
780 | SetPagePinned(page); | |
7e0563de VK |
781 | } |
782 | ||
6f84f8d1 PT |
783 | /* |
784 | * The init_mm pagetable is really pinned as soon as its created, but | |
785 | * that's before we have page structures to store the bits. So do all | |
786 | * the book-keeping now once struct pages for allocated pages are | |
c6ffc5ca | 787 | * initialized. This happens only after memblock_free_all() is called. |
6f84f8d1 PT |
788 | */ |
789 | static void __init xen_after_bootmem(void) | |
7e0563de | 790 | { |
6f84f8d1 | 791 | static_branch_enable(&xen_struct_pages_ready); |
6f84f8d1 | 792 | SetPagePinned(virt_to_page(level3_user_vsyscall)); |
7e0563de VK |
793 | xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP); |
794 | } | |
795 | ||
f2e39e8c JG |
796 | static void xen_unpin_page(struct mm_struct *mm, struct page *page, |
797 | enum pt_level level) | |
7e0563de VK |
798 | { |
799 | unsigned pgfl = TestClearPagePinned(page); | |
800 | ||
f2e39e8c | 801 | if (pgfl) { |
7e0563de VK |
802 | void *pt = lowmem_page_address(page); |
803 | unsigned long pfn = page_to_pfn(page); | |
804 | spinlock_t *ptl = NULL; | |
805 | struct multicall_space mcs; | |
806 | ||
807 | /* | |
808 | * Do the converse to pin_page. If we're using split | |
809 | * pte locks, we must be holding the lock for while | |
810 | * the pte page is unpinned but still RO to prevent | |
811 | * concurrent updates from seeing it in this | |
812 | * partially-pinned state. | |
813 | */ | |
814 | if (level == PT_PTE) { | |
815 | ptl = xen_pte_lock(page, mm); | |
816 | ||
817 | if (ptl) | |
818 | xen_do_pin(MMUEXT_UNPIN_TABLE, pfn); | |
819 | } | |
820 | ||
821 | mcs = __xen_mc_entry(0); | |
822 | ||
823 | MULTI_update_va_mapping(mcs.mc, (unsigned long)pt, | |
824 | pfn_pte(pfn, PAGE_KERNEL), | |
825 | level == PT_PGD ? UVMF_TLB_FLUSH : 0); | |
826 | ||
827 | if (ptl) { | |
828 | /* unlock when batch completed */ | |
829 | xen_mc_callback(xen_pte_unlock, ptl); | |
830 | } | |
831 | } | |
7e0563de VK |
832 | } |
833 | ||
834 | /* Release a pagetables pages back as normal RW */ | |
835 | static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd) | |
836 | { | |
a13f2ef1 JG |
837 | pgd_t *user_pgd = xen_get_user_pgd(pgd); |
838 | ||
7e0563de VK |
839 | trace_xen_mmu_pgd_unpin(mm, pgd); |
840 | ||
841 | xen_mc_batch(); | |
842 | ||
843 | xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd))); | |
844 | ||
a13f2ef1 JG |
845 | if (user_pgd) { |
846 | xen_do_pin(MMUEXT_UNPIN_TABLE, | |
847 | PFN_DOWN(__pa(user_pgd))); | |
848 | xen_unpin_page(mm, virt_to_page(user_pgd), PT_PGD); | |
7e0563de | 849 | } |
7e0563de VK |
850 | |
851 | __xen_pgd_walk(mm, pgd, xen_unpin_page, USER_LIMIT); | |
852 | ||
853 | xen_mc_issue(0); | |
854 | } | |
855 | ||
856 | static void xen_pgd_unpin(struct mm_struct *mm) | |
857 | { | |
858 | __xen_pgd_unpin(mm, mm->pgd); | |
859 | } | |
860 | ||
861 | /* | |
862 | * On resume, undo any pinning done at save, so that the rest of the | |
863 | * kernel doesn't see any unexpected pinned pagetables. | |
864 | */ | |
865 | void xen_mm_unpin_all(void) | |
866 | { | |
867 | struct page *page; | |
868 | ||
869 | spin_lock(&pgd_lock); | |
870 | ||
871 | list_for_each_entry(page, &pgd_list, lru) { | |
872 | if (PageSavePinned(page)) { | |
873 | BUG_ON(!PagePinned(page)); | |
874 | __xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page)); | |
875 | ClearPageSavePinned(page); | |
876 | } | |
877 | } | |
878 | ||
879 | spin_unlock(&pgd_lock); | |
880 | } | |
881 | ||
882 | static void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next) | |
883 | { | |
884 | spin_lock(&next->page_table_lock); | |
885 | xen_pgd_pin(next); | |
886 | spin_unlock(&next->page_table_lock); | |
887 | } | |
888 | ||
889 | static void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm) | |
890 | { | |
891 | spin_lock(&mm->page_table_lock); | |
892 | xen_pgd_pin(mm); | |
893 | spin_unlock(&mm->page_table_lock); | |
894 | } | |
895 | ||
3d28ebce | 896 | static void drop_mm_ref_this_cpu(void *info) |
7e0563de VK |
897 | { |
898 | struct mm_struct *mm = info; | |
7e0563de | 899 | |
3d28ebce | 900 | if (this_cpu_read(cpu_tlbstate.loaded_mm) == mm) |
7e0563de VK |
901 | leave_mm(smp_processor_id()); |
902 | ||
3d28ebce AL |
903 | /* |
904 | * If this cpu still has a stale cr3 reference, then make sure | |
905 | * it has been flushed. | |
906 | */ | |
7e0563de | 907 | if (this_cpu_read(xen_current_cr3) == __pa(mm->pgd)) |
3d28ebce | 908 | xen_mc_flush(); |
7e0563de VK |
909 | } |
910 | ||
3d28ebce AL |
911 | #ifdef CONFIG_SMP |
912 | /* | |
913 | * Another cpu may still have their %cr3 pointing at the pagetable, so | |
914 | * we need to repoint it somewhere else before we can unpin it. | |
915 | */ | |
7e0563de VK |
916 | static void xen_drop_mm_ref(struct mm_struct *mm) |
917 | { | |
918 | cpumask_var_t mask; | |
919 | unsigned cpu; | |
920 | ||
3d28ebce | 921 | drop_mm_ref_this_cpu(mm); |
7e0563de VK |
922 | |
923 | /* Get the "official" set of cpus referring to our pagetable. */ | |
924 | if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) { | |
925 | for_each_online_cpu(cpu) { | |
94b1b03b | 926 | if (per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd)) |
7e0563de | 927 | continue; |
3d28ebce | 928 | smp_call_function_single(cpu, drop_mm_ref_this_cpu, mm, 1); |
7e0563de VK |
929 | } |
930 | return; | |
931 | } | |
7e0563de | 932 | |
3d28ebce AL |
933 | /* |
934 | * It's possible that a vcpu may have a stale reference to our | |
935 | * cr3, because its in lazy mode, and it hasn't yet flushed | |
936 | * its set of pending hypercalls yet. In this case, we can | |
937 | * look at its actual current cr3 value, and force it to flush | |
938 | * if needed. | |
939 | */ | |
94b1b03b | 940 | cpumask_clear(mask); |
7e0563de VK |
941 | for_each_online_cpu(cpu) { |
942 | if (per_cpu(xen_current_cr3, cpu) == __pa(mm->pgd)) | |
943 | cpumask_set_cpu(cpu, mask); | |
944 | } | |
945 | ||
3d28ebce | 946 | smp_call_function_many(mask, drop_mm_ref_this_cpu, mm, 1); |
7e0563de VK |
947 | free_cpumask_var(mask); |
948 | } | |
949 | #else | |
950 | static void xen_drop_mm_ref(struct mm_struct *mm) | |
951 | { | |
3d28ebce | 952 | drop_mm_ref_this_cpu(mm); |
7e0563de VK |
953 | } |
954 | #endif | |
955 | ||
956 | /* | |
957 | * While a process runs, Xen pins its pagetables, which means that the | |
958 | * hypervisor forces it to be read-only, and it controls all updates | |
959 | * to it. This means that all pagetable updates have to go via the | |
960 | * hypervisor, which is moderately expensive. | |
961 | * | |
962 | * Since we're pulling the pagetable down, we switch to use init_mm, | |
963 | * unpin old process pagetable and mark it all read-write, which | |
964 | * allows further operations on it to be simple memory accesses. | |
965 | * | |
966 | * The only subtle point is that another CPU may be still using the | |
967 | * pagetable because of lazy tlb flushing. This means we need need to | |
968 | * switch all CPUs off this pagetable before we can unpin it. | |
969 | */ | |
970 | static void xen_exit_mmap(struct mm_struct *mm) | |
971 | { | |
972 | get_cpu(); /* make sure we don't move around */ | |
973 | xen_drop_mm_ref(mm); | |
974 | put_cpu(); | |
975 | ||
976 | spin_lock(&mm->page_table_lock); | |
977 | ||
978 | /* pgd may not be pinned in the error exit path of execve */ | |
979 | if (xen_page_pinned(mm->pgd)) | |
980 | xen_pgd_unpin(mm); | |
981 | ||
982 | spin_unlock(&mm->page_table_lock); | |
983 | } | |
984 | ||
985 | static void xen_post_allocator_init(void); | |
986 | ||
987 | static void __init pin_pagetable_pfn(unsigned cmd, unsigned long pfn) | |
988 | { | |
989 | struct mmuext_op op; | |
990 | ||
991 | op.cmd = cmd; | |
992 | op.arg1.mfn = pfn_to_mfn(pfn); | |
993 | if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF)) | |
994 | BUG(); | |
995 | } | |
996 | ||
7e0563de VK |
997 | static void __init xen_cleanhighmap(unsigned long vaddr, |
998 | unsigned long vaddr_end) | |
999 | { | |
1000 | unsigned long kernel_end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1; | |
1001 | pmd_t *pmd = level2_kernel_pgt + pmd_index(vaddr); | |
1002 | ||
1003 | /* NOTE: The loop is more greedy than the cleanup_highmap variant. | |
1004 | * We include the PMD passed in on _both_ boundaries. */ | |
1005 | for (; vaddr <= vaddr_end && (pmd < (level2_kernel_pgt + PTRS_PER_PMD)); | |
1006 | pmd++, vaddr += PMD_SIZE) { | |
1007 | if (pmd_none(*pmd)) | |
1008 | continue; | |
1009 | if (vaddr < (unsigned long) _text || vaddr > kernel_end) | |
1010 | set_pmd(pmd, __pmd(0)); | |
1011 | } | |
1012 | /* In case we did something silly, we should crash in this function | |
1013 | * instead of somewhere later and be confusing. */ | |
1014 | xen_mc_flush(); | |
1015 | } | |
1016 | ||
1017 | /* | |
1018 | * Make a page range writeable and free it. | |
1019 | */ | |
1020 | static void __init xen_free_ro_pages(unsigned long paddr, unsigned long size) | |
1021 | { | |
1022 | void *vaddr = __va(paddr); | |
1023 | void *vaddr_end = vaddr + size; | |
1024 | ||
1025 | for (; vaddr < vaddr_end; vaddr += PAGE_SIZE) | |
1026 | make_lowmem_page_readwrite(vaddr); | |
1027 | ||
1028 | memblock_free(paddr, size); | |
1029 | } | |
1030 | ||
1031 | static void __init xen_cleanmfnmap_free_pgtbl(void *pgtbl, bool unpin) | |
1032 | { | |
1033 | unsigned long pa = __pa(pgtbl) & PHYSICAL_PAGE_MASK; | |
1034 | ||
1035 | if (unpin) | |
1036 | pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(pa)); | |
1037 | ClearPagePinned(virt_to_page(__va(pa))); | |
1038 | xen_free_ro_pages(pa, PAGE_SIZE); | |
1039 | } | |
1040 | ||
1041 | static void __init xen_cleanmfnmap_pmd(pmd_t *pmd, bool unpin) | |
1042 | { | |
1043 | unsigned long pa; | |
1044 | pte_t *pte_tbl; | |
1045 | int i; | |
1046 | ||
1047 | if (pmd_large(*pmd)) { | |
1048 | pa = pmd_val(*pmd) & PHYSICAL_PAGE_MASK; | |
1049 | xen_free_ro_pages(pa, PMD_SIZE); | |
1050 | return; | |
1051 | } | |
1052 | ||
1053 | pte_tbl = pte_offset_kernel(pmd, 0); | |
1054 | for (i = 0; i < PTRS_PER_PTE; i++) { | |
1055 | if (pte_none(pte_tbl[i])) | |
1056 | continue; | |
1057 | pa = pte_pfn(pte_tbl[i]) << PAGE_SHIFT; | |
1058 | xen_free_ro_pages(pa, PAGE_SIZE); | |
1059 | } | |
1060 | set_pmd(pmd, __pmd(0)); | |
1061 | xen_cleanmfnmap_free_pgtbl(pte_tbl, unpin); | |
1062 | } | |
1063 | ||
1064 | static void __init xen_cleanmfnmap_pud(pud_t *pud, bool unpin) | |
1065 | { | |
1066 | unsigned long pa; | |
1067 | pmd_t *pmd_tbl; | |
1068 | int i; | |
1069 | ||
1070 | if (pud_large(*pud)) { | |
1071 | pa = pud_val(*pud) & PHYSICAL_PAGE_MASK; | |
1072 | xen_free_ro_pages(pa, PUD_SIZE); | |
1073 | return; | |
1074 | } | |
1075 | ||
1076 | pmd_tbl = pmd_offset(pud, 0); | |
1077 | for (i = 0; i < PTRS_PER_PMD; i++) { | |
1078 | if (pmd_none(pmd_tbl[i])) | |
1079 | continue; | |
1080 | xen_cleanmfnmap_pmd(pmd_tbl + i, unpin); | |
1081 | } | |
1082 | set_pud(pud, __pud(0)); | |
1083 | xen_cleanmfnmap_free_pgtbl(pmd_tbl, unpin); | |
1084 | } | |
1085 | ||
1086 | static void __init xen_cleanmfnmap_p4d(p4d_t *p4d, bool unpin) | |
1087 | { | |
1088 | unsigned long pa; | |
1089 | pud_t *pud_tbl; | |
1090 | int i; | |
1091 | ||
1092 | if (p4d_large(*p4d)) { | |
1093 | pa = p4d_val(*p4d) & PHYSICAL_PAGE_MASK; | |
1094 | xen_free_ro_pages(pa, P4D_SIZE); | |
1095 | return; | |
1096 | } | |
1097 | ||
1098 | pud_tbl = pud_offset(p4d, 0); | |
1099 | for (i = 0; i < PTRS_PER_PUD; i++) { | |
1100 | if (pud_none(pud_tbl[i])) | |
1101 | continue; | |
1102 | xen_cleanmfnmap_pud(pud_tbl + i, unpin); | |
1103 | } | |
1104 | set_p4d(p4d, __p4d(0)); | |
1105 | xen_cleanmfnmap_free_pgtbl(pud_tbl, unpin); | |
1106 | } | |
1107 | ||
1108 | /* | |
1109 | * Since it is well isolated we can (and since it is perhaps large we should) | |
1110 | * also free the page tables mapping the initial P->M table. | |
1111 | */ | |
1112 | static void __init xen_cleanmfnmap(unsigned long vaddr) | |
1113 | { | |
1114 | pgd_t *pgd; | |
1115 | p4d_t *p4d; | |
7e0563de VK |
1116 | bool unpin; |
1117 | ||
1118 | unpin = (vaddr == 2 * PGDIR_SIZE); | |
1119 | vaddr &= PMD_MASK; | |
1120 | pgd = pgd_offset_k(vaddr); | |
1121 | p4d = p4d_offset(pgd, 0); | |
773dd2fc KS |
1122 | if (!p4d_none(*p4d)) |
1123 | xen_cleanmfnmap_p4d(p4d, unpin); | |
7e0563de VK |
1124 | } |
1125 | ||
1126 | static void __init xen_pagetable_p2m_free(void) | |
1127 | { | |
1128 | unsigned long size; | |
1129 | unsigned long addr; | |
1130 | ||
1131 | size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long)); | |
1132 | ||
1133 | /* No memory or already called. */ | |
1134 | if ((unsigned long)xen_p2m_addr == xen_start_info->mfn_list) | |
1135 | return; | |
1136 | ||
1137 | /* using __ka address and sticking INVALID_P2M_ENTRY! */ | |
1138 | memset((void *)xen_start_info->mfn_list, 0xff, size); | |
1139 | ||
1140 | addr = xen_start_info->mfn_list; | |
1141 | /* | |
1142 | * We could be in __ka space. | |
1143 | * We roundup to the PMD, which means that if anybody at this stage is | |
1144 | * using the __ka address of xen_start_info or | |
32118f97 | 1145 | * xen_start_info->shared_info they are in going to crash. Fortunately |
7b25b9cb | 1146 | * we have already revectored in xen_setup_kernel_pagetable. |
7e0563de VK |
1147 | */ |
1148 | size = roundup(size, PMD_SIZE); | |
1149 | ||
1150 | if (addr >= __START_KERNEL_map) { | |
1151 | xen_cleanhighmap(addr, addr + size); | |
1152 | size = PAGE_ALIGN(xen_start_info->nr_pages * | |
1153 | sizeof(unsigned long)); | |
1154 | memblock_free(__pa(addr), size); | |
1155 | } else { | |
1156 | xen_cleanmfnmap(addr); | |
1157 | } | |
1158 | } | |
1159 | ||
1160 | static void __init xen_pagetable_cleanhighmap(void) | |
1161 | { | |
1162 | unsigned long size; | |
1163 | unsigned long addr; | |
1164 | ||
1165 | /* At this stage, cleanup_highmap has already cleaned __ka space | |
1166 | * from _brk_limit way up to the max_pfn_mapped (which is the end of | |
1167 | * the ramdisk). We continue on, erasing PMD entries that point to page | |
1168 | * tables - do note that they are accessible at this stage via __va. | |
0d805ee7 ZD |
1169 | * As Xen is aligning the memory end to a 4MB boundary, for good |
1170 | * measure we also round up to PMD_SIZE * 2 - which means that if | |
7e0563de VK |
1171 | * anybody is using __ka address to the initial boot-stack - and try |
1172 | * to use it - they are going to crash. The xen_start_info has been | |
1173 | * taken care of already in xen_setup_kernel_pagetable. */ | |
1174 | addr = xen_start_info->pt_base; | |
0d805ee7 | 1175 | size = xen_start_info->nr_pt_frames * PAGE_SIZE; |
7e0563de | 1176 | |
0d805ee7 | 1177 | xen_cleanhighmap(addr, roundup(addr + size, PMD_SIZE * 2)); |
7e0563de | 1178 | xen_start_info->pt_base = (unsigned long)__va(__pa(xen_start_info->pt_base)); |
7e0563de | 1179 | } |
7e0563de VK |
1180 | |
1181 | static void __init xen_pagetable_p2m_setup(void) | |
1182 | { | |
7e0563de VK |
1183 | xen_vmalloc_p2m_tree(); |
1184 | ||
7e0563de VK |
1185 | xen_pagetable_p2m_free(); |
1186 | ||
1187 | xen_pagetable_cleanhighmap(); | |
a13f2ef1 | 1188 | |
7e0563de VK |
1189 | /* And revector! Bye bye old array */ |
1190 | xen_start_info->mfn_list = (unsigned long)xen_p2m_addr; | |
1191 | } | |
1192 | ||
1193 | static void __init xen_pagetable_init(void) | |
1194 | { | |
1195 | paging_init(); | |
1196 | xen_post_allocator_init(); | |
1197 | ||
1198 | xen_pagetable_p2m_setup(); | |
1199 | ||
1200 | /* Allocate and initialize top and mid mfn levels for p2m structure */ | |
1201 | xen_build_mfn_list_list(); | |
1202 | ||
1203 | /* Remap memory freed due to conflicts with E820 map */ | |
989513a7 | 1204 | xen_remap_memory(); |
7b25b9cb | 1205 | xen_setup_mfn_list_list(); |
7e0563de VK |
1206 | } |
1207 | static void xen_write_cr2(unsigned long cr2) | |
1208 | { | |
1209 | this_cpu_read(xen_vcpu)->arch.cr2 = cr2; | |
1210 | } | |
1211 | ||
45dd9b06 | 1212 | static noinline void xen_flush_tlb(void) |
7e0563de VK |
1213 | { |
1214 | struct mmuext_op *op; | |
1215 | struct multicall_space mcs; | |
1216 | ||
7e0563de VK |
1217 | preempt_disable(); |
1218 | ||
1219 | mcs = xen_mc_entry(sizeof(*op)); | |
1220 | ||
1221 | op = mcs.args; | |
1222 | op->cmd = MMUEXT_TLB_FLUSH_LOCAL; | |
1223 | MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); | |
1224 | ||
1225 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
1226 | ||
1227 | preempt_enable(); | |
1228 | } | |
1229 | ||
1299ef1d | 1230 | static void xen_flush_tlb_one_user(unsigned long addr) |
7e0563de VK |
1231 | { |
1232 | struct mmuext_op *op; | |
1233 | struct multicall_space mcs; | |
1234 | ||
1299ef1d | 1235 | trace_xen_mmu_flush_tlb_one_user(addr); |
7e0563de VK |
1236 | |
1237 | preempt_disable(); | |
1238 | ||
1239 | mcs = xen_mc_entry(sizeof(*op)); | |
1240 | op = mcs.args; | |
1241 | op->cmd = MMUEXT_INVLPG_LOCAL; | |
1242 | op->arg1.linear_addr = addr & PAGE_MASK; | |
1243 | MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); | |
1244 | ||
1245 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
1246 | ||
1247 | preempt_enable(); | |
1248 | } | |
1249 | ||
4ce94eab NA |
1250 | static void xen_flush_tlb_multi(const struct cpumask *cpus, |
1251 | const struct flush_tlb_info *info) | |
7e0563de VK |
1252 | { |
1253 | struct { | |
1254 | struct mmuext_op op; | |
7e0563de | 1255 | DECLARE_BITMAP(mask, NR_CPUS); |
7e0563de VK |
1256 | } *args; |
1257 | struct multicall_space mcs; | |
66a640e7 ND |
1258 | const size_t mc_entry_size = sizeof(args->op) + |
1259 | sizeof(args->mask[0]) * BITS_TO_LONGS(num_possible_cpus()); | |
7e0563de | 1260 | |
4ce94eab | 1261 | trace_xen_mmu_flush_tlb_multi(cpus, info->mm, info->start, info->end); |
7e0563de VK |
1262 | |
1263 | if (cpumask_empty(cpus)) | |
1264 | return; /* nothing to do */ | |
1265 | ||
66a640e7 | 1266 | mcs = xen_mc_entry(mc_entry_size); |
7e0563de VK |
1267 | args = mcs.args; |
1268 | args->op.arg2.vcpumask = to_cpumask(args->mask); | |
1269 | ||
4ce94eab | 1270 | /* Remove any offline CPUs */ |
7e0563de | 1271 | cpumask_and(to_cpumask(args->mask), cpus, cpu_online_mask); |
7e0563de VK |
1272 | |
1273 | args->op.cmd = MMUEXT_TLB_FLUSH_MULTI; | |
a2055abe AL |
1274 | if (info->end != TLB_FLUSH_ALL && |
1275 | (info->end - info->start) <= PAGE_SIZE) { | |
7e0563de | 1276 | args->op.cmd = MMUEXT_INVLPG_MULTI; |
a2055abe | 1277 | args->op.arg1.linear_addr = info->start; |
7e0563de VK |
1278 | } |
1279 | ||
1280 | MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF); | |
1281 | ||
1282 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
1283 | } | |
1284 | ||
1285 | static unsigned long xen_read_cr3(void) | |
1286 | { | |
1287 | return this_cpu_read(xen_cr3); | |
1288 | } | |
1289 | ||
1290 | static void set_current_cr3(void *v) | |
1291 | { | |
1292 | this_cpu_write(xen_current_cr3, (unsigned long)v); | |
1293 | } | |
1294 | ||
1295 | static void __xen_write_cr3(bool kernel, unsigned long cr3) | |
1296 | { | |
1297 | struct mmuext_op op; | |
1298 | unsigned long mfn; | |
1299 | ||
1300 | trace_xen_mmu_write_cr3(kernel, cr3); | |
1301 | ||
1302 | if (cr3) | |
1303 | mfn = pfn_to_mfn(PFN_DOWN(cr3)); | |
1304 | else | |
1305 | mfn = 0; | |
1306 | ||
1307 | WARN_ON(mfn == 0 && kernel); | |
1308 | ||
1309 | op.cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR; | |
1310 | op.arg1.mfn = mfn; | |
1311 | ||
1312 | xen_extend_mmuext_op(&op); | |
1313 | ||
1314 | if (kernel) { | |
1315 | this_cpu_write(xen_cr3, cr3); | |
1316 | ||
1317 | /* Update xen_current_cr3 once the batch has actually | |
1318 | been submitted. */ | |
1319 | xen_mc_callback(set_current_cr3, (void *)cr3); | |
1320 | } | |
1321 | } | |
1322 | static void xen_write_cr3(unsigned long cr3) | |
1323 | { | |
a13f2ef1 JG |
1324 | pgd_t *user_pgd = xen_get_user_pgd(__va(cr3)); |
1325 | ||
7e0563de VK |
1326 | BUG_ON(preemptible()); |
1327 | ||
1328 | xen_mc_batch(); /* disables interrupts */ | |
1329 | ||
1330 | /* Update while interrupts are disabled, so its atomic with | |
1331 | respect to ipis */ | |
1332 | this_cpu_write(xen_cr3, cr3); | |
1333 | ||
1334 | __xen_write_cr3(true, cr3); | |
1335 | ||
a13f2ef1 JG |
1336 | if (user_pgd) |
1337 | __xen_write_cr3(false, __pa(user_pgd)); | |
1338 | else | |
1339 | __xen_write_cr3(false, 0); | |
7e0563de VK |
1340 | |
1341 | xen_mc_issue(PARAVIRT_LAZY_CPU); /* interrupts restored */ | |
1342 | } | |
1343 | ||
7e0563de VK |
1344 | /* |
1345 | * At the start of the day - when Xen launches a guest, it has already | |
1346 | * built pagetables for the guest. We diligently look over them | |
1347 | * in xen_setup_kernel_pagetable and graft as appropriate them in the | |
65ade2f8 KS |
1348 | * init_top_pgt and its friends. Then when we are happy we load |
1349 | * the new init_top_pgt - and continue on. | |
7e0563de VK |
1350 | * |
1351 | * The generic code starts (start_kernel) and 'init_mem_mapping' sets | |
1352 | * up the rest of the pagetables. When it has completed it loads the cr3. | |
1353 | * N.B. that baremetal would start at 'start_kernel' (and the early | |
1354 | * #PF handler would create bootstrap pagetables) - so we are running | |
1355 | * with the same assumptions as what to do when write_cr3 is executed | |
1356 | * at this point. | |
1357 | * | |
1358 | * Since there are no user-page tables at all, we have two variants | |
1359 | * of xen_write_cr3 - the early bootup (this one), and the late one | |
1360 | * (xen_write_cr3). The reason we have to do that is that in 64-bit | |
1361 | * the Linux kernel and user-space are both in ring 3 while the | |
1362 | * hypervisor is in ring 0. | |
1363 | */ | |
1364 | static void __init xen_write_cr3_init(unsigned long cr3) | |
1365 | { | |
1366 | BUG_ON(preemptible()); | |
1367 | ||
1368 | xen_mc_batch(); /* disables interrupts */ | |
1369 | ||
1370 | /* Update while interrupts are disabled, so its atomic with | |
1371 | respect to ipis */ | |
1372 | this_cpu_write(xen_cr3, cr3); | |
1373 | ||
1374 | __xen_write_cr3(true, cr3); | |
1375 | ||
1376 | xen_mc_issue(PARAVIRT_LAZY_CPU); /* interrupts restored */ | |
1377 | } | |
7e0563de VK |
1378 | |
1379 | static int xen_pgd_alloc(struct mm_struct *mm) | |
1380 | { | |
1381 | pgd_t *pgd = mm->pgd; | |
a13f2ef1 JG |
1382 | struct page *page = virt_to_page(pgd); |
1383 | pgd_t *user_pgd; | |
1384 | int ret = -ENOMEM; | |
7e0563de VK |
1385 | |
1386 | BUG_ON(PagePinned(virt_to_page(pgd))); | |
a13f2ef1 | 1387 | BUG_ON(page->private != 0); |
7e0563de | 1388 | |
a13f2ef1 JG |
1389 | user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); |
1390 | page->private = (unsigned long)user_pgd; | |
7e0563de | 1391 | |
a13f2ef1 | 1392 | if (user_pgd != NULL) { |
7e0563de | 1393 | #ifdef CONFIG_X86_VSYSCALL_EMULATION |
a13f2ef1 JG |
1394 | user_pgd[pgd_index(VSYSCALL_ADDR)] = |
1395 | __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE); | |
7e0563de | 1396 | #endif |
a13f2ef1 | 1397 | ret = 0; |
7e0563de | 1398 | } |
a13f2ef1 JG |
1399 | |
1400 | BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd)))); | |
1401 | ||
7e0563de VK |
1402 | return ret; |
1403 | } | |
1404 | ||
1405 | static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd) | |
1406 | { | |
7e0563de VK |
1407 | pgd_t *user_pgd = xen_get_user_pgd(pgd); |
1408 | ||
1409 | if (user_pgd) | |
1410 | free_page((unsigned long)user_pgd); | |
7e0563de VK |
1411 | } |
1412 | ||
1413 | /* | |
1414 | * Init-time set_pte while constructing initial pagetables, which | |
1415 | * doesn't allow RO page table pages to be remapped RW. | |
1416 | * | |
1417 | * If there is no MFN for this PFN then this page is initially | |
1418 | * ballooned out so clear the PTE (as in decrease_reservation() in | |
1419 | * drivers/xen/balloon.c). | |
1420 | * | |
1421 | * Many of these PTE updates are done on unpinned and writable pages | |
1422 | * and doing a hypercall for these is unnecessary and expensive. At | |
1423 | * this point it is not possible to tell if a page is pinned or not, | |
1424 | * so always write the PTE directly and rely on Xen trapping and | |
1425 | * emulating any updates as necessary. | |
1426 | */ | |
1427 | __visible pte_t xen_make_pte_init(pteval_t pte) | |
1428 | { | |
7e0563de VK |
1429 | unsigned long pfn; |
1430 | ||
1431 | /* | |
1432 | * Pages belonging to the initial p2m list mapped outside the default | |
1433 | * address range must be mapped read-only. This region contains the | |
1434 | * page tables for mapping the p2m list, too, and page tables MUST be | |
1435 | * mapped read-only. | |
1436 | */ | |
1437 | pfn = (pte & PTE_PFN_MASK) >> PAGE_SHIFT; | |
1438 | if (xen_start_info->mfn_list < __START_KERNEL_map && | |
1439 | pfn >= xen_start_info->first_p2m_pfn && | |
1440 | pfn < xen_start_info->first_p2m_pfn + xen_start_info->nr_p2m_frames) | |
1441 | pte &= ~_PAGE_RW; | |
a13f2ef1 | 1442 | |
7e0563de VK |
1443 | pte = pte_pfn_to_mfn(pte); |
1444 | return native_make_pte(pte); | |
1445 | } | |
1446 | PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_init); | |
1447 | ||
1448 | static void __init xen_set_pte_init(pte_t *ptep, pte_t pte) | |
1449 | { | |
f7c90c2a | 1450 | __xen_set_pte(ptep, pte); |
7e0563de VK |
1451 | } |
1452 | ||
1453 | /* Early in boot, while setting up the initial pagetable, assume | |
1454 | everything is pinned. */ | |
1455 | static void __init xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn) | |
1456 | { | |
1457 | #ifdef CONFIG_FLATMEM | |
1458 | BUG_ON(mem_map); /* should only be used early */ | |
1459 | #endif | |
1460 | make_lowmem_page_readonly(__va(PFN_PHYS(pfn))); | |
1461 | pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn); | |
1462 | } | |
1463 | ||
1464 | /* Used for pmd and pud */ | |
1465 | static void __init xen_alloc_pmd_init(struct mm_struct *mm, unsigned long pfn) | |
1466 | { | |
1467 | #ifdef CONFIG_FLATMEM | |
1468 | BUG_ON(mem_map); /* should only be used early */ | |
1469 | #endif | |
1470 | make_lowmem_page_readonly(__va(PFN_PHYS(pfn))); | |
1471 | } | |
1472 | ||
1473 | /* Early release_pte assumes that all pts are pinned, since there's | |
1474 | only init_mm and anything attached to that is pinned. */ | |
1475 | static void __init xen_release_pte_init(unsigned long pfn) | |
1476 | { | |
1477 | pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); | |
1478 | make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); | |
1479 | } | |
1480 | ||
1481 | static void __init xen_release_pmd_init(unsigned long pfn) | |
1482 | { | |
1483 | make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); | |
1484 | } | |
1485 | ||
1486 | static inline void __pin_pagetable_pfn(unsigned cmd, unsigned long pfn) | |
1487 | { | |
1488 | struct multicall_space mcs; | |
1489 | struct mmuext_op *op; | |
1490 | ||
1491 | mcs = __xen_mc_entry(sizeof(*op)); | |
1492 | op = mcs.args; | |
1493 | op->cmd = cmd; | |
1494 | op->arg1.mfn = pfn_to_mfn(pfn); | |
1495 | ||
1496 | MULTI_mmuext_op(mcs.mc, mcs.args, 1, NULL, DOMID_SELF); | |
1497 | } | |
1498 | ||
1499 | static inline void __set_pfn_prot(unsigned long pfn, pgprot_t prot) | |
1500 | { | |
1501 | struct multicall_space mcs; | |
1502 | unsigned long addr = (unsigned long)__va(pfn << PAGE_SHIFT); | |
1503 | ||
1504 | mcs = __xen_mc_entry(0); | |
1505 | MULTI_update_va_mapping(mcs.mc, (unsigned long)addr, | |
1506 | pfn_pte(pfn, prot), 0); | |
1507 | } | |
1508 | ||
1509 | /* This needs to make sure the new pte page is pinned iff its being | |
1510 | attached to a pinned pagetable. */ | |
1511 | static inline void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, | |
1512 | unsigned level) | |
1513 | { | |
6f84f8d1 | 1514 | bool pinned = xen_page_pinned(mm->pgd); |
7e0563de VK |
1515 | |
1516 | trace_xen_mmu_alloc_ptpage(mm, pfn, level, pinned); | |
1517 | ||
1518 | if (pinned) { | |
1519 | struct page *page = pfn_to_page(pfn); | |
1520 | ||
36c9b592 JG |
1521 | pinned = false; |
1522 | if (static_branch_likely(&xen_struct_pages_ready)) { | |
1523 | pinned = PagePinned(page); | |
6f84f8d1 | 1524 | SetPagePinned(page); |
36c9b592 | 1525 | } |
7e0563de | 1526 | |
f2e39e8c | 1527 | xen_mc_batch(); |
7e0563de | 1528 | |
f2e39e8c | 1529 | __set_pfn_prot(pfn, PAGE_KERNEL_RO); |
7e0563de | 1530 | |
36c9b592 | 1531 | if (level == PT_PTE && USE_SPLIT_PTE_PTLOCKS && !pinned) |
f2e39e8c | 1532 | __pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn); |
7e0563de | 1533 | |
f2e39e8c | 1534 | xen_mc_issue(PARAVIRT_LAZY_MMU); |
7e0563de VK |
1535 | } |
1536 | } | |
1537 | ||
1538 | static void xen_alloc_pte(struct mm_struct *mm, unsigned long pfn) | |
1539 | { | |
1540 | xen_alloc_ptpage(mm, pfn, PT_PTE); | |
1541 | } | |
1542 | ||
1543 | static void xen_alloc_pmd(struct mm_struct *mm, unsigned long pfn) | |
1544 | { | |
1545 | xen_alloc_ptpage(mm, pfn, PT_PMD); | |
1546 | } | |
1547 | ||
1548 | /* This should never happen until we're OK to use struct page */ | |
1549 | static inline void xen_release_ptpage(unsigned long pfn, unsigned level) | |
1550 | { | |
1551 | struct page *page = pfn_to_page(pfn); | |
1552 | bool pinned = PagePinned(page); | |
1553 | ||
1554 | trace_xen_mmu_release_ptpage(pfn, level, pinned); | |
1555 | ||
1556 | if (pinned) { | |
f2e39e8c | 1557 | xen_mc_batch(); |
7e0563de | 1558 | |
f2e39e8c JG |
1559 | if (level == PT_PTE && USE_SPLIT_PTE_PTLOCKS) |
1560 | __pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); | |
7e0563de | 1561 | |
f2e39e8c JG |
1562 | __set_pfn_prot(pfn, PAGE_KERNEL); |
1563 | ||
1564 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
7e0563de | 1565 | |
7e0563de VK |
1566 | ClearPagePinned(page); |
1567 | } | |
1568 | } | |
1569 | ||
1570 | static void xen_release_pte(unsigned long pfn) | |
1571 | { | |
1572 | xen_release_ptpage(pfn, PT_PTE); | |
1573 | } | |
1574 | ||
1575 | static void xen_release_pmd(unsigned long pfn) | |
1576 | { | |
1577 | xen_release_ptpage(pfn, PT_PMD); | |
1578 | } | |
1579 | ||
7e0563de VK |
1580 | static void xen_alloc_pud(struct mm_struct *mm, unsigned long pfn) |
1581 | { | |
1582 | xen_alloc_ptpage(mm, pfn, PT_PUD); | |
1583 | } | |
1584 | ||
1585 | static void xen_release_pud(unsigned long pfn) | |
1586 | { | |
1587 | xen_release_ptpage(pfn, PT_PUD); | |
1588 | } | |
7e0563de VK |
1589 | |
1590 | /* | |
1591 | * Like __va(), but returns address in the kernel mapping (which is | |
1592 | * all we have until the physical memory mapping has been set up. | |
1593 | */ | |
1594 | static void * __init __ka(phys_addr_t paddr) | |
1595 | { | |
7e0563de | 1596 | return (void *)(paddr + __START_KERNEL_map); |
7e0563de VK |
1597 | } |
1598 | ||
1599 | /* Convert a machine address to physical address */ | |
1600 | static unsigned long __init m2p(phys_addr_t maddr) | |
1601 | { | |
1602 | phys_addr_t paddr; | |
1603 | ||
6f0e8bf1 | 1604 | maddr &= XEN_PTE_MFN_MASK; |
7e0563de VK |
1605 | paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT; |
1606 | ||
1607 | return paddr; | |
1608 | } | |
1609 | ||
1610 | /* Convert a machine address to kernel virtual */ | |
1611 | static void * __init m2v(phys_addr_t maddr) | |
1612 | { | |
1613 | return __ka(m2p(maddr)); | |
1614 | } | |
1615 | ||
1616 | /* Set the page permissions on an identity-mapped pages */ | |
1617 | static void __init set_page_prot_flags(void *addr, pgprot_t prot, | |
1618 | unsigned long flags) | |
1619 | { | |
1620 | unsigned long pfn = __pa(addr) >> PAGE_SHIFT; | |
1621 | pte_t pte = pfn_pte(pfn, prot); | |
1622 | ||
1623 | if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, flags)) | |
1624 | BUG(); | |
1625 | } | |
1626 | static void __init set_page_prot(void *addr, pgprot_t prot) | |
1627 | { | |
1628 | return set_page_prot_flags(addr, prot, UVMF_NONE); | |
1629 | } | |
7e0563de | 1630 | |
7e0563de VK |
1631 | void __init xen_setup_machphys_mapping(void) |
1632 | { | |
1633 | struct xen_machphys_mapping mapping; | |
1634 | ||
1635 | if (HYPERVISOR_memory_op(XENMEM_machphys_mapping, &mapping) == 0) { | |
1636 | machine_to_phys_mapping = (unsigned long *)mapping.v_start; | |
1637 | machine_to_phys_nr = mapping.max_mfn + 1; | |
1638 | } else { | |
1639 | machine_to_phys_nr = MACH2PHYS_NR_ENTRIES; | |
1640 | } | |
7e0563de VK |
1641 | } |
1642 | ||
7e0563de VK |
1643 | static void __init convert_pfn_mfn(void *v) |
1644 | { | |
1645 | pte_t *pte = v; | |
1646 | int i; | |
1647 | ||
1648 | /* All levels are converted the same way, so just treat them | |
1649 | as ptes. */ | |
1650 | for (i = 0; i < PTRS_PER_PTE; i++) | |
1651 | pte[i] = xen_make_pte(pte[i].pte); | |
1652 | } | |
1653 | static void __init check_pt_base(unsigned long *pt_base, unsigned long *pt_end, | |
1654 | unsigned long addr) | |
1655 | { | |
1656 | if (*pt_base == PFN_DOWN(__pa(addr))) { | |
1657 | set_page_prot_flags((void *)addr, PAGE_KERNEL, UVMF_INVLPG); | |
1658 | clear_page((void *)addr); | |
1659 | (*pt_base)++; | |
1660 | } | |
1661 | if (*pt_end == PFN_DOWN(__pa(addr))) { | |
1662 | set_page_prot_flags((void *)addr, PAGE_KERNEL, UVMF_INVLPG); | |
1663 | clear_page((void *)addr); | |
1664 | (*pt_end)--; | |
1665 | } | |
1666 | } | |
1667 | /* | |
1668 | * Set up the initial kernel pagetable. | |
1669 | * | |
1670 | * We can construct this by grafting the Xen provided pagetable into | |
1671 | * head_64.S's preconstructed pagetables. We copy the Xen L2's into | |
1672 | * level2_ident_pgt, and level2_kernel_pgt. This means that only the | |
1673 | * kernel has a physical mapping to start with - but that's enough to | |
1674 | * get __va working. We need to fill in the rest of the physical | |
1675 | * mapping once some sort of allocator has been set up. | |
1676 | */ | |
1677 | void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) | |
1678 | { | |
1679 | pud_t *l3; | |
1680 | pmd_t *l2; | |
1681 | unsigned long addr[3]; | |
1682 | unsigned long pt_base, pt_end; | |
1683 | unsigned i; | |
1684 | ||
1685 | /* max_pfn_mapped is the last pfn mapped in the initial memory | |
1686 | * mappings. Considering that on Xen after the kernel mappings we | |
1687 | * have the mappings of some pages that don't exist in pfn space, we | |
1688 | * set max_pfn_mapped to the last real pfn mapped. */ | |
1689 | if (xen_start_info->mfn_list < __START_KERNEL_map) | |
1690 | max_pfn_mapped = xen_start_info->first_p2m_pfn; | |
1691 | else | |
1692 | max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->mfn_list)); | |
1693 | ||
1694 | pt_base = PFN_DOWN(__pa(xen_start_info->pt_base)); | |
1695 | pt_end = pt_base + xen_start_info->nr_pt_frames; | |
1696 | ||
1697 | /* Zap identity mapping */ | |
65ade2f8 | 1698 | init_top_pgt[0] = __pgd(0); |
7e0563de | 1699 | |
989513a7 | 1700 | /* Pre-constructed entries are in pfn, so convert to mfn */ |
d52888aa | 1701 | /* L4[273] -> level3_ident_pgt */ |
989513a7 | 1702 | /* L4[511] -> level3_kernel_pgt */ |
65ade2f8 | 1703 | convert_pfn_mfn(init_top_pgt); |
7e0563de | 1704 | |
989513a7 JG |
1705 | /* L3_i[0] -> level2_ident_pgt */ |
1706 | convert_pfn_mfn(level3_ident_pgt); | |
1707 | /* L3_k[510] -> level2_kernel_pgt */ | |
1708 | /* L3_k[511] -> level2_fixmap_pgt */ | |
1709 | convert_pfn_mfn(level3_kernel_pgt); | |
1710 | ||
05ab1d8a | 1711 | /* L3_k[511][508-FIXMAP_PMD_NUM ... 507] -> level1_fixmap_pgt */ |
989513a7 | 1712 | convert_pfn_mfn(level2_fixmap_pgt); |
7e0563de | 1713 | |
7e0563de VK |
1714 | /* We get [511][511] and have Xen's version of level2_kernel_pgt */ |
1715 | l3 = m2v(pgd[pgd_index(__START_KERNEL_map)].pgd); | |
1716 | l2 = m2v(l3[pud_index(__START_KERNEL_map)].pud); | |
1717 | ||
1718 | addr[0] = (unsigned long)pgd; | |
1719 | addr[1] = (unsigned long)l3; | |
1720 | addr[2] = (unsigned long)l2; | |
d52888aa KS |
1721 | /* Graft it onto L4[273][0]. Note that we creating an aliasing problem: |
1722 | * Both L4[273][0] and L4[511][510] have entries that point to the same | |
7e0563de VK |
1723 | * L2 (PMD) tables. Meaning that if you modify it in __va space |
1724 | * it will be also modified in the __ka space! (But if you just | |
1725 | * modify the PMD table to point to other PTE's or none, then you | |
1726 | * are OK - which is what cleanup_highmap does) */ | |
1727 | copy_page(level2_ident_pgt, l2); | |
1728 | /* Graft it onto L4[511][510] */ | |
1729 | copy_page(level2_kernel_pgt, l2); | |
1730 | ||
2cc42bac JB |
1731 | /* |
1732 | * Zap execute permission from the ident map. Due to the sharing of | |
1733 | * L1 entries we need to do this in the L2. | |
1734 | */ | |
1735 | if (__supported_pte_mask & _PAGE_NX) { | |
1736 | for (i = 0; i < PTRS_PER_PMD; ++i) { | |
1737 | if (pmd_none(level2_ident_pgt[i])) | |
1738 | continue; | |
1739 | level2_ident_pgt[i] = pmd_set_flags(level2_ident_pgt[i], _PAGE_NX); | |
1740 | } | |
1741 | } | |
1742 | ||
7e0563de VK |
1743 | /* Copy the initial P->M table mappings if necessary. */ |
1744 | i = pgd_index(xen_start_info->mfn_list); | |
1745 | if (i && i < pgd_index(__START_KERNEL_map)) | |
65ade2f8 | 1746 | init_top_pgt[i] = ((pgd_t *)xen_start_info->pt_base)[i]; |
7e0563de | 1747 | |
989513a7 | 1748 | /* Make pagetable pieces RO */ |
65ade2f8 | 1749 | set_page_prot(init_top_pgt, PAGE_KERNEL_RO); |
989513a7 JG |
1750 | set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO); |
1751 | set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO); | |
1752 | set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO); | |
1753 | set_page_prot(level2_ident_pgt, PAGE_KERNEL_RO); | |
1754 | set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO); | |
1755 | set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO); | |
05ab1d8a FT |
1756 | |
1757 | for (i = 0; i < FIXMAP_PMD_NUM; i++) { | |
1758 | set_page_prot(level1_fixmap_pgt + i * PTRS_PER_PTE, | |
1759 | PAGE_KERNEL_RO); | |
1760 | } | |
989513a7 JG |
1761 | |
1762 | /* Pin down new L4 */ | |
1763 | pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE, | |
65ade2f8 | 1764 | PFN_DOWN(__pa_symbol(init_top_pgt))); |
989513a7 JG |
1765 | |
1766 | /* Unpin Xen-provided one */ | |
1767 | pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd))); | |
7e0563de | 1768 | |
989513a7 JG |
1769 | /* |
1770 | * At this stage there can be no user pgd, and no page structure to | |
1771 | * attach it to, so make sure we just set kernel pgd. | |
1772 | */ | |
1773 | xen_mc_batch(); | |
65ade2f8 | 1774 | __xen_write_cr3(true, __pa(init_top_pgt)); |
989513a7 | 1775 | xen_mc_issue(PARAVIRT_LAZY_CPU); |
7e0563de VK |
1776 | |
1777 | /* We can't that easily rip out L3 and L2, as the Xen pagetables are | |
1778 | * set out this way: [L4], [L1], [L2], [L3], [L1], [L1] ... for | |
1779 | * the initial domain. For guests using the toolstack, they are in: | |
1780 | * [L4], [L3], [L2], [L1], [L1], order .. So for dom0 we can only | |
1781 | * rip out the [L4] (pgd), but for guests we shave off three pages. | |
1782 | */ | |
1783 | for (i = 0; i < ARRAY_SIZE(addr); i++) | |
1784 | check_pt_base(&pt_base, &pt_end, addr[i]); | |
1785 | ||
1786 | /* Our (by three pages) smaller Xen pagetable that we are using */ | |
1787 | xen_pt_base = PFN_PHYS(pt_base); | |
1788 | xen_pt_size = (pt_end - pt_base) * PAGE_SIZE; | |
1789 | memblock_reserve(xen_pt_base, xen_pt_size); | |
1790 | ||
1791 | /* Revector the xen_start_info */ | |
1792 | xen_start_info = (struct start_info *)__va(__pa(xen_start_info)); | |
1793 | } | |
1794 | ||
1795 | /* | |
1796 | * Read a value from a physical address. | |
1797 | */ | |
1798 | static unsigned long __init xen_read_phys_ulong(phys_addr_t addr) | |
1799 | { | |
1800 | unsigned long *vaddr; | |
1801 | unsigned long val; | |
1802 | ||
1803 | vaddr = early_memremap_ro(addr, sizeof(val)); | |
1804 | val = *vaddr; | |
1805 | early_memunmap(vaddr, sizeof(val)); | |
1806 | return val; | |
1807 | } | |
1808 | ||
1809 | /* | |
1810 | * Translate a virtual address to a physical one without relying on mapped | |
69861e0a JG |
1811 | * page tables. Don't rely on big pages being aligned in (guest) physical |
1812 | * space! | |
7e0563de VK |
1813 | */ |
1814 | static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr) | |
1815 | { | |
1816 | phys_addr_t pa; | |
1817 | pgd_t pgd; | |
1818 | pud_t pud; | |
1819 | pmd_t pmd; | |
1820 | pte_t pte; | |
1821 | ||
6c690ee1 | 1822 | pa = read_cr3_pa(); |
7e0563de VK |
1823 | pgd = native_make_pgd(xen_read_phys_ulong(pa + pgd_index(vaddr) * |
1824 | sizeof(pgd))); | |
1825 | if (!pgd_present(pgd)) | |
1826 | return 0; | |
1827 | ||
1828 | pa = pgd_val(pgd) & PTE_PFN_MASK; | |
1829 | pud = native_make_pud(xen_read_phys_ulong(pa + pud_index(vaddr) * | |
1830 | sizeof(pud))); | |
1831 | if (!pud_present(pud)) | |
1832 | return 0; | |
69861e0a | 1833 | pa = pud_val(pud) & PTE_PFN_MASK; |
7e0563de VK |
1834 | if (pud_large(pud)) |
1835 | return pa + (vaddr & ~PUD_MASK); | |
1836 | ||
1837 | pmd = native_make_pmd(xen_read_phys_ulong(pa + pmd_index(vaddr) * | |
1838 | sizeof(pmd))); | |
1839 | if (!pmd_present(pmd)) | |
1840 | return 0; | |
69861e0a | 1841 | pa = pmd_val(pmd) & PTE_PFN_MASK; |
7e0563de VK |
1842 | if (pmd_large(pmd)) |
1843 | return pa + (vaddr & ~PMD_MASK); | |
1844 | ||
1845 | pte = native_make_pte(xen_read_phys_ulong(pa + pte_index(vaddr) * | |
1846 | sizeof(pte))); | |
1847 | if (!pte_present(pte)) | |
1848 | return 0; | |
1849 | pa = pte_pfn(pte) << PAGE_SHIFT; | |
1850 | ||
1851 | return pa | (vaddr & ~PAGE_MASK); | |
1852 | } | |
1853 | ||
1854 | /* | |
1855 | * Find a new area for the hypervisor supplied p2m list and relocate the p2m to | |
1856 | * this area. | |
1857 | */ | |
1858 | void __init xen_relocate_p2m(void) | |
1859 | { | |
773dd2fc | 1860 | phys_addr_t size, new_area, pt_phys, pmd_phys, pud_phys; |
7e0563de | 1861 | unsigned long p2m_pfn, p2m_pfn_end, n_frames, pfn, pfn_end; |
773dd2fc | 1862 | int n_pte, n_pt, n_pmd, n_pud, idx_pte, idx_pt, idx_pmd, idx_pud; |
7e0563de VK |
1863 | pte_t *pt; |
1864 | pmd_t *pmd; | |
1865 | pud_t *pud; | |
7e0563de VK |
1866 | pgd_t *pgd; |
1867 | unsigned long *new_p2m; | |
7e0563de VK |
1868 | |
1869 | size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long)); | |
1870 | n_pte = roundup(size, PAGE_SIZE) >> PAGE_SHIFT; | |
1871 | n_pt = roundup(size, PMD_SIZE) >> PMD_SHIFT; | |
1872 | n_pmd = roundup(size, PUD_SIZE) >> PUD_SHIFT; | |
1873 | n_pud = roundup(size, P4D_SIZE) >> P4D_SHIFT; | |
773dd2fc | 1874 | n_frames = n_pte + n_pt + n_pmd + n_pud; |
7e0563de VK |
1875 | |
1876 | new_area = xen_find_free_area(PFN_PHYS(n_frames)); | |
1877 | if (!new_area) { | |
1878 | xen_raw_console_write("Can't find new memory area for p2m needed due to E820 map conflict\n"); | |
1879 | BUG(); | |
1880 | } | |
1881 | ||
1882 | /* | |
1883 | * Setup the page tables for addressing the new p2m list. | |
1884 | * We have asked the hypervisor to map the p2m list at the user address | |
1885 | * PUD_SIZE. It may have done so, or it may have used a kernel space | |
1886 | * address depending on the Xen version. | |
1887 | * To avoid any possible virtual address collision, just use | |
1888 | * 2 * PUD_SIZE for the new area. | |
1889 | */ | |
773dd2fc | 1890 | pud_phys = new_area; |
7e0563de VK |
1891 | pmd_phys = pud_phys + PFN_PHYS(n_pud); |
1892 | pt_phys = pmd_phys + PFN_PHYS(n_pmd); | |
1893 | p2m_pfn = PFN_DOWN(pt_phys) + n_pt; | |
1894 | ||
6c690ee1 | 1895 | pgd = __va(read_cr3_pa()); |
7e0563de | 1896 | new_p2m = (unsigned long *)(2 * PGDIR_SIZE); |
773dd2fc KS |
1897 | for (idx_pud = 0; idx_pud < n_pud; idx_pud++) { |
1898 | pud = early_memremap(pud_phys, PAGE_SIZE); | |
1899 | clear_page(pud); | |
1900 | for (idx_pmd = 0; idx_pmd < min(n_pmd, PTRS_PER_PUD); | |
1901 | idx_pmd++) { | |
1902 | pmd = early_memremap(pmd_phys, PAGE_SIZE); | |
1903 | clear_page(pmd); | |
1904 | for (idx_pt = 0; idx_pt < min(n_pt, PTRS_PER_PMD); | |
1905 | idx_pt++) { | |
1906 | pt = early_memremap(pt_phys, PAGE_SIZE); | |
1907 | clear_page(pt); | |
1908 | for (idx_pte = 0; | |
01bd2ac2 JG |
1909 | idx_pte < min(n_pte, PTRS_PER_PTE); |
1910 | idx_pte++) { | |
1911 | pt[idx_pte] = pfn_pte(p2m_pfn, | |
1912 | PAGE_KERNEL); | |
773dd2fc | 1913 | p2m_pfn++; |
7e0563de | 1914 | } |
773dd2fc KS |
1915 | n_pte -= PTRS_PER_PTE; |
1916 | early_memunmap(pt, PAGE_SIZE); | |
1917 | make_lowmem_page_readonly(__va(pt_phys)); | |
1918 | pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, | |
1919 | PFN_DOWN(pt_phys)); | |
01bd2ac2 | 1920 | pmd[idx_pt] = __pmd(_PAGE_TABLE | pt_phys); |
773dd2fc | 1921 | pt_phys += PAGE_SIZE; |
7e0563de | 1922 | } |
773dd2fc KS |
1923 | n_pt -= PTRS_PER_PMD; |
1924 | early_memunmap(pmd, PAGE_SIZE); | |
1925 | make_lowmem_page_readonly(__va(pmd_phys)); | |
1926 | pin_pagetable_pfn(MMUEXT_PIN_L2_TABLE, | |
1927 | PFN_DOWN(pmd_phys)); | |
01bd2ac2 | 1928 | pud[idx_pmd] = __pud(_PAGE_TABLE | pmd_phys); |
773dd2fc | 1929 | pmd_phys += PAGE_SIZE; |
7e0563de | 1930 | } |
773dd2fc KS |
1931 | n_pmd -= PTRS_PER_PUD; |
1932 | early_memunmap(pud, PAGE_SIZE); | |
1933 | make_lowmem_page_readonly(__va(pud_phys)); | |
1934 | pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(pud_phys)); | |
1935 | set_pgd(pgd + 2 + idx_pud, __pgd(_PAGE_TABLE | pud_phys)); | |
1936 | pud_phys += PAGE_SIZE; | |
1937 | } | |
7e0563de VK |
1938 | |
1939 | /* Now copy the old p2m info to the new area. */ | |
1940 | memcpy(new_p2m, xen_p2m_addr, size); | |
1941 | xen_p2m_addr = new_p2m; | |
1942 | ||
1943 | /* Release the old p2m list and set new list info. */ | |
1944 | p2m_pfn = PFN_DOWN(xen_early_virt_to_phys(xen_start_info->mfn_list)); | |
1945 | BUG_ON(!p2m_pfn); | |
1946 | p2m_pfn_end = p2m_pfn + PFN_DOWN(size); | |
1947 | ||
1948 | if (xen_start_info->mfn_list < __START_KERNEL_map) { | |
1949 | pfn = xen_start_info->first_p2m_pfn; | |
1950 | pfn_end = xen_start_info->first_p2m_pfn + | |
1951 | xen_start_info->nr_p2m_frames; | |
1952 | set_pgd(pgd + 1, __pgd(0)); | |
1953 | } else { | |
1954 | pfn = p2m_pfn; | |
1955 | pfn_end = p2m_pfn_end; | |
1956 | } | |
1957 | ||
1958 | memblock_free(PFN_PHYS(pfn), PAGE_SIZE * (pfn_end - pfn)); | |
1959 | while (pfn < pfn_end) { | |
1960 | if (pfn == p2m_pfn) { | |
1961 | pfn = p2m_pfn_end; | |
1962 | continue; | |
1963 | } | |
1964 | make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); | |
1965 | pfn++; | |
1966 | } | |
1967 | ||
1968 | xen_start_info->mfn_list = (unsigned long)xen_p2m_addr; | |
1969 | xen_start_info->first_p2m_pfn = PFN_DOWN(new_area); | |
1970 | xen_start_info->nr_p2m_frames = n_frames; | |
1971 | } | |
1972 | ||
7e0563de VK |
1973 | void __init xen_reserve_special_pages(void) |
1974 | { | |
1975 | phys_addr_t paddr; | |
1976 | ||
1977 | memblock_reserve(__pa(xen_start_info), PAGE_SIZE); | |
1978 | if (xen_start_info->store_mfn) { | |
1979 | paddr = PFN_PHYS(mfn_to_pfn(xen_start_info->store_mfn)); | |
1980 | memblock_reserve(paddr, PAGE_SIZE); | |
1981 | } | |
1982 | if (!xen_initial_domain()) { | |
1983 | paddr = PFN_PHYS(mfn_to_pfn(xen_start_info->console.domU.mfn)); | |
1984 | memblock_reserve(paddr, PAGE_SIZE); | |
1985 | } | |
1986 | } | |
1987 | ||
1988 | void __init xen_pt_check_e820(void) | |
1989 | { | |
1990 | if (xen_is_e820_reserved(xen_pt_base, xen_pt_size)) { | |
1991 | xen_raw_console_write("Xen hypervisor allocated page table memory conflicts with E820 map\n"); | |
1992 | BUG(); | |
1993 | } | |
1994 | } | |
1995 | ||
1996 | static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss; | |
1997 | ||
1998 | static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) | |
1999 | { | |
2000 | pte_t pte; | |
2001 | ||
2002 | phys >>= PAGE_SHIFT; | |
2003 | ||
2004 | switch (idx) { | |
2005 | case FIX_BTMAP_END ... FIX_BTMAP_BEGIN: | |
a13f2ef1 | 2006 | #ifdef CONFIG_X86_VSYSCALL_EMULATION |
7e0563de VK |
2007 | case VSYSCALL_PAGE: |
2008 | #endif | |
7e0563de VK |
2009 | /* All local page mappings */ |
2010 | pte = pfn_pte(phys, prot); | |
2011 | break; | |
2012 | ||
2013 | #ifdef CONFIG_X86_LOCAL_APIC | |
2014 | case FIX_APIC_BASE: /* maps dummy local APIC */ | |
2015 | pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL); | |
2016 | break; | |
2017 | #endif | |
2018 | ||
2019 | #ifdef CONFIG_X86_IO_APIC | |
2020 | case FIX_IO_APIC_BASE_0 ... FIX_IO_APIC_BASE_END: | |
2021 | /* | |
2022 | * We just don't map the IO APIC - all access is via | |
2023 | * hypercalls. Keep the address in the pte for reference. | |
2024 | */ | |
2025 | pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL); | |
2026 | break; | |
2027 | #endif | |
2028 | ||
2029 | case FIX_PARAVIRT_BOOTMAP: | |
2030 | /* This is an MFN, but it isn't an IO mapping from the | |
2031 | IO domain */ | |
2032 | pte = mfn_pte(phys, prot); | |
2033 | break; | |
2034 | ||
2035 | default: | |
2036 | /* By default, set_fixmap is used for hardware mappings */ | |
2037 | pte = mfn_pte(phys, prot); | |
2038 | break; | |
2039 | } | |
2040 | ||
2041 | __native_set_fixmap(idx, pte); | |
2042 | ||
2043 | #ifdef CONFIG_X86_VSYSCALL_EMULATION | |
2044 | /* Replicate changes to map the vsyscall page into the user | |
2045 | pagetable vsyscall mapping. */ | |
2046 | if (idx == VSYSCALL_PAGE) { | |
2047 | unsigned long vaddr = __fix_to_virt(idx); | |
2048 | set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte); | |
2049 | } | |
2050 | #endif | |
2051 | } | |
2052 | ||
2053 | static void __init xen_post_allocator_init(void) | |
2054 | { | |
5c83511b JG |
2055 | pv_ops.mmu.set_pte = xen_set_pte; |
2056 | pv_ops.mmu.set_pmd = xen_set_pmd; | |
2057 | pv_ops.mmu.set_pud = xen_set_pud; | |
5c83511b | 2058 | pv_ops.mmu.set_p4d = xen_set_p4d; |
7e0563de VK |
2059 | |
2060 | /* This will work as long as patching hasn't happened yet | |
2061 | (which it hasn't) */ | |
5c83511b JG |
2062 | pv_ops.mmu.alloc_pte = xen_alloc_pte; |
2063 | pv_ops.mmu.alloc_pmd = xen_alloc_pmd; | |
2064 | pv_ops.mmu.release_pte = xen_release_pte; | |
2065 | pv_ops.mmu.release_pmd = xen_release_pmd; | |
5c83511b JG |
2066 | pv_ops.mmu.alloc_pud = xen_alloc_pud; |
2067 | pv_ops.mmu.release_pud = xen_release_pud; | |
5c83511b | 2068 | pv_ops.mmu.make_pte = PV_CALLEE_SAVE(xen_make_pte); |
7e0563de | 2069 | |
5c83511b | 2070 | pv_ops.mmu.write_cr3 = &xen_write_cr3; |
7e0563de VK |
2071 | } |
2072 | ||
2073 | static void xen_leave_lazy_mmu(void) | |
2074 | { | |
2075 | preempt_disable(); | |
2076 | xen_mc_flush(); | |
2077 | paravirt_leave_lazy_mmu(); | |
2078 | preempt_enable(); | |
2079 | } | |
2080 | ||
2081 | static const struct pv_mmu_ops xen_mmu_ops __initconst = { | |
55aedddb | 2082 | .read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2), |
7e0563de VK |
2083 | .write_cr2 = xen_write_cr2, |
2084 | ||
2085 | .read_cr3 = xen_read_cr3, | |
2086 | .write_cr3 = xen_write_cr3_init, | |
2087 | ||
2088 | .flush_tlb_user = xen_flush_tlb, | |
2089 | .flush_tlb_kernel = xen_flush_tlb, | |
1299ef1d | 2090 | .flush_tlb_one_user = xen_flush_tlb_one_user, |
4ce94eab | 2091 | .flush_tlb_multi = xen_flush_tlb_multi, |
48a8b97c | 2092 | .tlb_remove_table = tlb_remove_table, |
7e0563de | 2093 | |
7e0563de VK |
2094 | .pgd_alloc = xen_pgd_alloc, |
2095 | .pgd_free = xen_pgd_free, | |
2096 | ||
2097 | .alloc_pte = xen_alloc_pte_init, | |
2098 | .release_pte = xen_release_pte_init, | |
2099 | .alloc_pmd = xen_alloc_pmd_init, | |
2100 | .release_pmd = xen_release_pmd_init, | |
2101 | ||
2102 | .set_pte = xen_set_pte_init, | |
7e0563de VK |
2103 | .set_pmd = xen_set_pmd_hyper, |
2104 | ||
2526cff7 JG |
2105 | .ptep_modify_prot_start = xen_ptep_modify_prot_start, |
2106 | .ptep_modify_prot_commit = xen_ptep_modify_prot_commit, | |
7e0563de VK |
2107 | |
2108 | .pte_val = PV_CALLEE_SAVE(xen_pte_val), | |
2109 | .pgd_val = PV_CALLEE_SAVE(xen_pgd_val), | |
2110 | ||
2111 | .make_pte = PV_CALLEE_SAVE(xen_make_pte_init), | |
2112 | .make_pgd = PV_CALLEE_SAVE(xen_make_pgd), | |
2113 | ||
7e0563de VK |
2114 | .set_pud = xen_set_pud_hyper, |
2115 | ||
2116 | .make_pmd = PV_CALLEE_SAVE(xen_make_pmd), | |
2117 | .pmd_val = PV_CALLEE_SAVE(xen_pmd_val), | |
2118 | ||
7e0563de VK |
2119 | .pud_val = PV_CALLEE_SAVE(xen_pud_val), |
2120 | .make_pud = PV_CALLEE_SAVE(xen_make_pud), | |
2121 | .set_p4d = xen_set_p4d_hyper, | |
2122 | ||
2123 | .alloc_pud = xen_alloc_pmd_init, | |
2124 | .release_pud = xen_release_pmd_init, | |
b9952ec7 KS |
2125 | |
2126 | #if CONFIG_PGTABLE_LEVELS >= 5 | |
2127 | .p4d_val = PV_CALLEE_SAVE(xen_p4d_val), | |
2128 | .make_p4d = PV_CALLEE_SAVE(xen_make_p4d), | |
2129 | #endif | |
7e0563de VK |
2130 | |
2131 | .activate_mm = xen_activate_mm, | |
2132 | .dup_mmap = xen_dup_mmap, | |
2133 | .exit_mmap = xen_exit_mmap, | |
2134 | ||
2135 | .lazy_mode = { | |
2136 | .enter = paravirt_enter_lazy_mmu, | |
2137 | .leave = xen_leave_lazy_mmu, | |
2138 | .flush = paravirt_flush_lazy_mmu, | |
2139 | }, | |
2140 | ||
2141 | .set_fixmap = xen_set_fixmap, | |
2142 | }; | |
2143 | ||
2144 | void __init xen_init_mmu_ops(void) | |
2145 | { | |
2146 | x86_init.paging.pagetable_init = xen_pagetable_init; | |
6f84f8d1 | 2147 | x86_init.hyper.init_after_bootmem = xen_after_bootmem; |
7e0563de | 2148 | |
5c83511b | 2149 | pv_ops.mmu = xen_mmu_ops; |
7e0563de VK |
2150 | |
2151 | memset(dummy_mapping, 0xff, PAGE_SIZE); | |
2152 | } | |
2153 | ||
2154 | /* Protected by xen_reservation_lock. */ | |
2155 | #define MAX_CONTIG_ORDER 9 /* 2MB */ | |
2156 | static unsigned long discontig_frames[1<<MAX_CONTIG_ORDER]; | |
2157 | ||
2158 | #define VOID_PTE (mfn_pte(0, __pgprot(0))) | |
2159 | static void xen_zap_pfn_range(unsigned long vaddr, unsigned int order, | |
2160 | unsigned long *in_frames, | |
2161 | unsigned long *out_frames) | |
2162 | { | |
2163 | int i; | |
2164 | struct multicall_space mcs; | |
2165 | ||
2166 | xen_mc_batch(); | |
2167 | for (i = 0; i < (1UL<<order); i++, vaddr += PAGE_SIZE) { | |
2168 | mcs = __xen_mc_entry(0); | |
2169 | ||
2170 | if (in_frames) | |
2171 | in_frames[i] = virt_to_mfn(vaddr); | |
2172 | ||
2173 | MULTI_update_va_mapping(mcs.mc, vaddr, VOID_PTE, 0); | |
2174 | __set_phys_to_machine(virt_to_pfn(vaddr), INVALID_P2M_ENTRY); | |
2175 | ||
2176 | if (out_frames) | |
2177 | out_frames[i] = virt_to_pfn(vaddr); | |
2178 | } | |
2179 | xen_mc_issue(0); | |
2180 | } | |
2181 | ||
2182 | /* | |
2183 | * Update the pfn-to-mfn mappings for a virtual address range, either to | |
2184 | * point to an array of mfns, or contiguously from a single starting | |
2185 | * mfn. | |
2186 | */ | |
2187 | static void xen_remap_exchanged_ptes(unsigned long vaddr, int order, | |
2188 | unsigned long *mfns, | |
2189 | unsigned long first_mfn) | |
2190 | { | |
2191 | unsigned i, limit; | |
2192 | unsigned long mfn; | |
2193 | ||
2194 | xen_mc_batch(); | |
2195 | ||
2196 | limit = 1u << order; | |
2197 | for (i = 0; i < limit; i++, vaddr += PAGE_SIZE) { | |
2198 | struct multicall_space mcs; | |
2199 | unsigned flags; | |
2200 | ||
2201 | mcs = __xen_mc_entry(0); | |
2202 | if (mfns) | |
2203 | mfn = mfns[i]; | |
2204 | else | |
2205 | mfn = first_mfn + i; | |
2206 | ||
2207 | if (i < (limit - 1)) | |
2208 | flags = 0; | |
2209 | else { | |
2210 | if (order == 0) | |
2211 | flags = UVMF_INVLPG | UVMF_ALL; | |
2212 | else | |
2213 | flags = UVMF_TLB_FLUSH | UVMF_ALL; | |
2214 | } | |
2215 | ||
2216 | MULTI_update_va_mapping(mcs.mc, vaddr, | |
2217 | mfn_pte(mfn, PAGE_KERNEL), flags); | |
2218 | ||
2219 | set_phys_to_machine(virt_to_pfn(vaddr), mfn); | |
2220 | } | |
2221 | ||
2222 | xen_mc_issue(0); | |
2223 | } | |
2224 | ||
2225 | /* | |
2226 | * Perform the hypercall to exchange a region of our pfns to point to | |
2227 | * memory with the required contiguous alignment. Takes the pfns as | |
2228 | * input, and populates mfns as output. | |
2229 | * | |
2230 | * Returns a success code indicating whether the hypervisor was able to | |
2231 | * satisfy the request or not. | |
2232 | */ | |
2233 | static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in, | |
2234 | unsigned long *pfns_in, | |
2235 | unsigned long extents_out, | |
2236 | unsigned int order_out, | |
2237 | unsigned long *mfns_out, | |
2238 | unsigned int address_bits) | |
2239 | { | |
2240 | long rc; | |
2241 | int success; | |
2242 | ||
2243 | struct xen_memory_exchange exchange = { | |
2244 | .in = { | |
2245 | .nr_extents = extents_in, | |
2246 | .extent_order = order_in, | |
2247 | .extent_start = pfns_in, | |
2248 | .domid = DOMID_SELF | |
2249 | }, | |
2250 | .out = { | |
2251 | .nr_extents = extents_out, | |
2252 | .extent_order = order_out, | |
2253 | .extent_start = mfns_out, | |
2254 | .address_bits = address_bits, | |
2255 | .domid = DOMID_SELF | |
2256 | } | |
2257 | }; | |
2258 | ||
2259 | BUG_ON(extents_in << order_in != extents_out << order_out); | |
2260 | ||
2261 | rc = HYPERVISOR_memory_op(XENMEM_exchange, &exchange); | |
2262 | success = (exchange.nr_exchanged == extents_in); | |
2263 | ||
2264 | BUG_ON(!success && ((exchange.nr_exchanged != 0) || (rc == 0))); | |
2265 | BUG_ON(success && (rc != 0)); | |
2266 | ||
2267 | return success; | |
2268 | } | |
2269 | ||
2270 | int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, | |
2271 | unsigned int address_bits, | |
2272 | dma_addr_t *dma_handle) | |
2273 | { | |
2274 | unsigned long *in_frames = discontig_frames, out_frame; | |
2275 | unsigned long flags; | |
2276 | int success; | |
2277 | unsigned long vstart = (unsigned long)phys_to_virt(pstart); | |
2278 | ||
2279 | /* | |
2280 | * Currently an auto-translated guest will not perform I/O, nor will | |
2281 | * it require PAE page directories below 4GB. Therefore any calls to | |
2282 | * this function are redundant and can be ignored. | |
2283 | */ | |
2284 | ||
7e0563de VK |
2285 | if (unlikely(order > MAX_CONTIG_ORDER)) |
2286 | return -ENOMEM; | |
2287 | ||
2288 | memset((void *) vstart, 0, PAGE_SIZE << order); | |
2289 | ||
2290 | spin_lock_irqsave(&xen_reservation_lock, flags); | |
2291 | ||
2292 | /* 1. Zap current PTEs, remembering MFNs. */ | |
2293 | xen_zap_pfn_range(vstart, order, in_frames, NULL); | |
2294 | ||
2295 | /* 2. Get a new contiguous memory extent. */ | |
2296 | out_frame = virt_to_pfn(vstart); | |
2297 | success = xen_exchange_memory(1UL << order, 0, in_frames, | |
2298 | 1, order, &out_frame, | |
2299 | address_bits); | |
2300 | ||
2301 | /* 3. Map the new extent in place of old pages. */ | |
2302 | if (success) | |
2303 | xen_remap_exchanged_ptes(vstart, order, NULL, out_frame); | |
2304 | else | |
2305 | xen_remap_exchanged_ptes(vstart, order, in_frames, 0); | |
2306 | ||
2307 | spin_unlock_irqrestore(&xen_reservation_lock, flags); | |
2308 | ||
2309 | *dma_handle = virt_to_machine(vstart).maddr; | |
2310 | return success ? 0 : -ENOMEM; | |
2311 | } | |
7e0563de VK |
2312 | |
2313 | void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) | |
2314 | { | |
2315 | unsigned long *out_frames = discontig_frames, in_frame; | |
2316 | unsigned long flags; | |
2317 | int success; | |
2318 | unsigned long vstart; | |
2319 | ||
7e0563de VK |
2320 | if (unlikely(order > MAX_CONTIG_ORDER)) |
2321 | return; | |
2322 | ||
2323 | vstart = (unsigned long)phys_to_virt(pstart); | |
2324 | memset((void *) vstart, 0, PAGE_SIZE << order); | |
2325 | ||
2326 | spin_lock_irqsave(&xen_reservation_lock, flags); | |
2327 | ||
2328 | /* 1. Find start MFN of contiguous extent. */ | |
2329 | in_frame = virt_to_mfn(vstart); | |
2330 | ||
2331 | /* 2. Zap current PTEs. */ | |
2332 | xen_zap_pfn_range(vstart, order, NULL, out_frames); | |
2333 | ||
2334 | /* 3. Do the exchange for non-contiguous MFNs. */ | |
2335 | success = xen_exchange_memory(1, order, &in_frame, 1UL << order, | |
2336 | 0, out_frames, 0); | |
2337 | ||
2338 | /* 4. Map new pages in place of old pages. */ | |
2339 | if (success) | |
2340 | xen_remap_exchanged_ptes(vstart, order, out_frames, 0); | |
2341 | else | |
2342 | xen_remap_exchanged_ptes(vstart, order, NULL, in_frame); | |
2343 | ||
2344 | spin_unlock_irqrestore(&xen_reservation_lock, flags); | |
2345 | } | |
29985b09 | 2346 | |
f030aade JG |
2347 | static noinline void xen_flush_tlb_all(void) |
2348 | { | |
2349 | struct mmuext_op *op; | |
2350 | struct multicall_space mcs; | |
2351 | ||
2352 | preempt_disable(); | |
2353 | ||
2354 | mcs = xen_mc_entry(sizeof(*op)); | |
2355 | ||
2356 | op = mcs.args; | |
2357 | op->cmd = MMUEXT_TLB_FLUSH_ALL; | |
2358 | MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF); | |
2359 | ||
2360 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
2361 | ||
2362 | preempt_enable(); | |
2363 | } | |
2364 | ||
2365 | #define REMAP_BATCH_SIZE 16 | |
2366 | ||
2367 | struct remap_data { | |
2368 | xen_pfn_t *pfn; | |
2369 | bool contiguous; | |
2370 | bool no_translate; | |
2371 | pgprot_t prot; | |
2372 | struct mmu_update *mmu_update; | |
2373 | }; | |
2374 | ||
8b1e0f81 | 2375 | static int remap_area_pfn_pte_fn(pte_t *ptep, unsigned long addr, void *data) |
f030aade JG |
2376 | { |
2377 | struct remap_data *rmd = data; | |
2378 | pte_t pte = pte_mkspecial(mfn_pte(*rmd->pfn, rmd->prot)); | |
2379 | ||
2380 | /* | |
2381 | * If we have a contiguous range, just update the pfn itself, | |
2382 | * else update pointer to be "next pfn". | |
2383 | */ | |
2384 | if (rmd->contiguous) | |
2385 | (*rmd->pfn)++; | |
2386 | else | |
2387 | rmd->pfn++; | |
2388 | ||
2389 | rmd->mmu_update->ptr = virt_to_machine(ptep).maddr; | |
2390 | rmd->mmu_update->ptr |= rmd->no_translate ? | |
2391 | MMU_PT_UPDATE_NO_TRANSLATE : | |
2392 | MMU_NORMAL_PT_UPDATE; | |
2393 | rmd->mmu_update->val = pte_val_ma(pte); | |
2394 | rmd->mmu_update++; | |
2395 | ||
2396 | return 0; | |
2397 | } | |
2398 | ||
2399 | int xen_remap_pfn(struct vm_area_struct *vma, unsigned long addr, | |
2400 | xen_pfn_t *pfn, int nr, int *err_ptr, pgprot_t prot, | |
97315723 | 2401 | unsigned int domid, bool no_translate) |
f030aade JG |
2402 | { |
2403 | int err = 0; | |
2404 | struct remap_data rmd; | |
2405 | struct mmu_update mmu_update[REMAP_BATCH_SIZE]; | |
2406 | unsigned long range; | |
2407 | int mapped = 0; | |
2408 | ||
2409 | BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO))); | |
2410 | ||
2411 | rmd.pfn = pfn; | |
2412 | rmd.prot = prot; | |
2413 | /* | |
2414 | * We use the err_ptr to indicate if there we are doing a contiguous | |
163b0991 | 2415 | * mapping or a discontiguous mapping. |
f030aade JG |
2416 | */ |
2417 | rmd.contiguous = !err_ptr; | |
2418 | rmd.no_translate = no_translate; | |
2419 | ||
2420 | while (nr) { | |
2421 | int index = 0; | |
2422 | int done = 0; | |
2423 | int batch = min(REMAP_BATCH_SIZE, nr); | |
2424 | int batch_left = batch; | |
2425 | ||
2426 | range = (unsigned long)batch << PAGE_SHIFT; | |
2427 | ||
2428 | rmd.mmu_update = mmu_update; | |
2429 | err = apply_to_page_range(vma->vm_mm, addr, range, | |
2430 | remap_area_pfn_pte_fn, &rmd); | |
2431 | if (err) | |
2432 | goto out; | |
2433 | ||
2434 | /* | |
2435 | * We record the error for each page that gives an error, but | |
2436 | * continue mapping until the whole set is done | |
2437 | */ | |
2438 | do { | |
2439 | int i; | |
2440 | ||
2441 | err = HYPERVISOR_mmu_update(&mmu_update[index], | |
2442 | batch_left, &done, domid); | |
2443 | ||
2444 | /* | |
2445 | * @err_ptr may be the same buffer as @gfn, so | |
2446 | * only clear it after each chunk of @gfn is | |
2447 | * used. | |
2448 | */ | |
2449 | if (err_ptr) { | |
2450 | for (i = index; i < index + done; i++) | |
2451 | err_ptr[i] = 0; | |
2452 | } | |
2453 | if (err < 0) { | |
2454 | if (!err_ptr) | |
2455 | goto out; | |
2456 | err_ptr[i] = err; | |
2457 | done++; /* Skip failed frame. */ | |
2458 | } else | |
2459 | mapped += done; | |
2460 | batch_left -= done; | |
2461 | index += done; | |
2462 | } while (batch_left); | |
2463 | ||
2464 | nr -= batch; | |
2465 | addr += range; | |
2466 | if (err_ptr) | |
2467 | err_ptr += batch; | |
2468 | cond_resched(); | |
2469 | } | |
2470 | out: | |
2471 | ||
2472 | xen_flush_tlb_all(); | |
2473 | ||
2474 | return err < 0 ? err : mapped; | |
2475 | } | |
2476 | EXPORT_SYMBOL_GPL(xen_remap_pfn); | |
2477 | ||
29985b09 JG |
2478 | #ifdef CONFIG_KEXEC_CORE |
2479 | phys_addr_t paddr_vmcoreinfo_note(void) | |
2480 | { | |
2481 | if (xen_pv_domain()) | |
203e9e41 | 2482 | return virt_to_machine(vmcoreinfo_note).maddr; |
29985b09 | 2483 | else |
203e9e41 | 2484 | return __pa(vmcoreinfo_note); |
29985b09 JG |
2485 | } |
2486 | #endif /* CONFIG_KEXEC_CORE */ |