Commit | Line | Data |
---|---|---|
b5eafe92 JF |
1 | /* |
2 | * Xen leaves the responsibility for maintaining p2m mappings to the | |
3 | * guests themselves, but it must also access and update the p2m array | |
4 | * during suspend/resume when all the pages are reallocated. | |
5 | * | |
054954eb JG |
6 | * The logical flat p2m table is mapped to a linear kernel memory area. |
7 | * For accesses by Xen a three-level tree linked via mfns only is set up to | |
8 | * allow the address space to be sparse. | |
b5eafe92 | 9 | * |
054954eb JG |
10 | * Xen |
11 | * | | |
12 | * p2m_top_mfn | |
13 | * / \ | |
14 | * p2m_mid_mfn p2m_mid_mfn | |
15 | * / / | |
16 | * p2m p2m p2m ... | |
b5eafe92 JF |
17 | * |
18 | * The p2m_mid_mfn pages are mapped by p2m_top_mfn_p. | |
19 | * | |
054954eb JG |
20 | * The p2m_top_mfn level is limited to 1 page, so the maximum representable |
21 | * pseudo-physical address space is: | |
b5eafe92 JF |
22 | * P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages |
23 | * | |
24 | * P2M_PER_PAGE depends on the architecture, as a mfn is always | |
25 | * unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to | |
a3118beb | 26 | * 512 and 1024 entries respectively. |
f4cec35b KRW |
27 | * |
28 | * In short, these structures contain the Machine Frame Number (MFN) of the PFN. | |
29 | * | |
30 | * However not all entries are filled with MFNs. Specifically for all other | |
31 | * leaf entries, or for the top root, or middle one, for which there is a void | |
32 | * entry, we assume it is "missing". So (for example) | |
33 | * pfn_to_mfn(0x90909090)=INVALID_P2M_ENTRY. | |
054954eb JG |
34 | * We have a dedicated page p2m_missing with all entries being |
35 | * INVALID_P2M_ENTRY. This page may be referenced multiple times in the p2m | |
36 | * list/tree in case there are multiple areas with P2M_PER_PAGE invalid pfns. | |
f4cec35b KRW |
37 | * |
38 | * We also have the possibility of setting 1-1 mappings on certain regions, so | |
39 | * that: | |
40 | * pfn_to_mfn(0xc0000)=0xc0000 | |
41 | * | |
42 | * The benefit of this is, that we can assume for non-RAM regions (think | |
3cb83e46 | 43 | * PCI BARs, or ACPI spaces), we can create mappings easily because we |
f4cec35b KRW |
44 | * get the PFN value to match the MFN. |
45 | * | |
054954eb JG |
46 | * For this to work efficiently we have one new page p2m_identity. All entries |
47 | * in p2m_identity are set to INVALID_P2M_ENTRY type (Xen toolstack only | |
48 | * recognizes that and MFNs, no other fancy value). | |
f4cec35b KRW |
49 | * |
50 | * On lookup we spot that the entry points to p2m_identity and return the | |
51 | * identity value instead of dereferencing and returning INVALID_P2M_ENTRY. | |
52 | * If the entry points to an allocated page, we just proceed as before and | |
054954eb | 53 | * return the PFN. If the PFN has IDENTITY_FRAME_BIT set we unmask that in |
f4cec35b KRW |
54 | * appropriate functions (pfn_to_mfn). |
55 | * | |
56 | * The reason for having the IDENTITY_FRAME_BIT instead of just returning the | |
57 | * PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a | |
58 | * non-identity pfn. To protect ourselves against we elect to set (and get) the | |
59 | * IDENTITY_FRAME_BIT on all identity mapped PFNs. | |
b5eafe92 JF |
60 | */ |
61 | ||
62 | #include <linux/init.h> | |
63 | #include <linux/module.h> | |
448f2831 JF |
64 | #include <linux/list.h> |
65 | #include <linux/hash.h> | |
87f1d40a | 66 | #include <linux/sched.h> |
2222e71b | 67 | #include <linux/seq_file.h> |
2c185687 | 68 | #include <linux/bootmem.h> |
7108c9ce | 69 | #include <linux/slab.h> |
b5eafe92 JF |
70 | |
71 | #include <asm/cache.h> | |
72 | #include <asm/setup.h> | |
2e917175 | 73 | #include <asm/uaccess.h> |
b5eafe92 JF |
74 | |
75 | #include <asm/xen/page.h> | |
76 | #include <asm/xen/hypercall.h> | |
77 | #include <asm/xen/hypervisor.h> | |
ee072640 | 78 | #include <xen/balloon.h> |
0930bba6 | 79 | #include <xen/grant_table.h> |
b5eafe92 | 80 | |
4fbb67e3 | 81 | #include "p2m.h" |
0930bba6 | 82 | #include "multicalls.h" |
b5eafe92 JF |
83 | #include "xen-ops.h" |
84 | ||
054954eb JG |
85 | #define PMDS_PER_MID_PAGE (P2M_MID_PER_PAGE / PTRS_PER_PTE) |
86 | ||
448f2831 JF |
87 | static void __init m2p_override_init(void); |
88 | ||
5b8e7d80 JG |
89 | unsigned long *xen_p2m_addr __read_mostly; |
90 | EXPORT_SYMBOL_GPL(xen_p2m_addr); | |
91 | unsigned long xen_p2m_size __read_mostly; | |
92 | EXPORT_SYMBOL_GPL(xen_p2m_size); | |
b5eafe92 | 93 | unsigned long xen_max_p2m_pfn __read_mostly; |
5b8e7d80 | 94 | EXPORT_SYMBOL_GPL(xen_max_p2m_pfn); |
b5eafe92 | 95 | |
054954eb JG |
96 | static DEFINE_SPINLOCK(p2m_update_lock); |
97 | ||
2c185687 JG |
98 | static unsigned long *p2m_mid_missing_mfn; |
99 | static unsigned long *p2m_top_mfn; | |
100 | static unsigned long **p2m_top_mfn_p; | |
054954eb JG |
101 | static unsigned long *p2m_missing; |
102 | static unsigned long *p2m_identity; | |
103 | static pte_t *p2m_missing_pte; | |
104 | static pte_t *p2m_identity_pte; | |
7108c9ce | 105 | |
b5eafe92 JF |
106 | static inline unsigned p2m_top_index(unsigned long pfn) |
107 | { | |
108 | BUG_ON(pfn >= MAX_P2M_PFN); | |
109 | return pfn / (P2M_MID_PER_PAGE * P2M_PER_PAGE); | |
110 | } | |
111 | ||
112 | static inline unsigned p2m_mid_index(unsigned long pfn) | |
113 | { | |
114 | return (pfn / P2M_PER_PAGE) % P2M_MID_PER_PAGE; | |
115 | } | |
116 | ||
117 | static inline unsigned p2m_index(unsigned long pfn) | |
118 | { | |
119 | return pfn % P2M_PER_PAGE; | |
120 | } | |
121 | ||
b5eafe92 JF |
122 | static void p2m_top_mfn_init(unsigned long *top) |
123 | { | |
124 | unsigned i; | |
125 | ||
126 | for (i = 0; i < P2M_TOP_PER_PAGE; i++) | |
127 | top[i] = virt_to_mfn(p2m_mid_missing_mfn); | |
128 | } | |
129 | ||
130 | static void p2m_top_mfn_p_init(unsigned long **top) | |
131 | { | |
132 | unsigned i; | |
133 | ||
134 | for (i = 0; i < P2M_TOP_PER_PAGE; i++) | |
135 | top[i] = p2m_mid_missing_mfn; | |
136 | } | |
137 | ||
054954eb | 138 | static void p2m_mid_mfn_init(unsigned long *mid, unsigned long *leaf) |
b5eafe92 JF |
139 | { |
140 | unsigned i; | |
141 | ||
142 | for (i = 0; i < P2M_MID_PER_PAGE; i++) | |
054954eb | 143 | mid[i] = virt_to_mfn(leaf); |
b5eafe92 JF |
144 | } |
145 | ||
054954eb | 146 | static void p2m_init(unsigned long *p2m) |
b5eafe92 JF |
147 | { |
148 | unsigned i; | |
149 | ||
054954eb JG |
150 | for (i = 0; i < P2M_PER_PAGE; i++) |
151 | p2m[i] = INVALID_P2M_ENTRY; | |
b5eafe92 JF |
152 | } |
153 | ||
054954eb | 154 | static void p2m_init_identity(unsigned long *p2m, unsigned long pfn) |
b5eafe92 JF |
155 | { |
156 | unsigned i; | |
157 | ||
054954eb JG |
158 | for (i = 0; i < P2M_PER_PAGE; i++) |
159 | p2m[i] = IDENTITY_FRAME(pfn + i); | |
b5eafe92 JF |
160 | } |
161 | ||
7108c9ce JG |
162 | static void * __ref alloc_p2m_page(void) |
163 | { | |
7108c9ce JG |
164 | if (unlikely(!slab_is_available())) |
165 | return alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE); | |
166 | ||
167 | return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT); | |
168 | } | |
169 | ||
701a261a | 170 | static void __ref free_p2m_page(void *p) |
7108c9ce | 171 | { |
701a261a BO |
172 | if (unlikely(!slab_is_available())) { |
173 | free_bootmem((unsigned long)p, PAGE_SIZE); | |
174 | return; | |
175 | } | |
176 | ||
7108c9ce JG |
177 | free_page((unsigned long)p); |
178 | } | |
179 | ||
b5eafe92 JF |
180 | /* |
181 | * Build the parallel p2m_top_mfn and p2m_mid_mfn structures | |
182 | * | |
183 | * This is called both at boot time, and after resuming from suspend: | |
2c185687 | 184 | * - At boot time we're called rather early, and must use alloc_bootmem*() |
b5eafe92 JF |
185 | * to allocate memory. |
186 | * | |
187 | * - After resume we're called from within stop_machine, but the mfn | |
2c185687 | 188 | * tree should already be completely allocated. |
b5eafe92 | 189 | */ |
44b46c3e | 190 | void __ref xen_build_mfn_list_list(void) |
b5eafe92 | 191 | { |
054954eb JG |
192 | unsigned long pfn, mfn; |
193 | pte_t *ptep; | |
194 | unsigned int level, topidx, mididx; | |
195 | unsigned long *mid_mfn_p; | |
b5eafe92 | 196 | |
696fd7c5 KRW |
197 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
198 | return; | |
199 | ||
b5eafe92 JF |
200 | /* Pre-initialize p2m_top_mfn to be completely missing */ |
201 | if (p2m_top_mfn == NULL) { | |
7108c9ce | 202 | p2m_mid_missing_mfn = alloc_p2m_page(); |
3cb83e46 | 203 | p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing); |
b5eafe92 | 204 | |
7108c9ce | 205 | p2m_top_mfn_p = alloc_p2m_page(); |
b5eafe92 JF |
206 | p2m_top_mfn_p_init(p2m_top_mfn_p); |
207 | ||
7108c9ce | 208 | p2m_top_mfn = alloc_p2m_page(); |
b5eafe92 JF |
209 | p2m_top_mfn_init(p2m_top_mfn); |
210 | } else { | |
211 | /* Reinitialise, mfn's all change after migration */ | |
3cb83e46 | 212 | p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing); |
b5eafe92 JF |
213 | } |
214 | ||
054954eb JG |
215 | for (pfn = 0; pfn < xen_max_p2m_pfn && pfn < MAX_P2M_PFN; |
216 | pfn += P2M_PER_PAGE) { | |
217 | topidx = p2m_top_index(pfn); | |
218 | mididx = p2m_mid_index(pfn); | |
b5eafe92 | 219 | |
b5eafe92 | 220 | mid_mfn_p = p2m_top_mfn_p[topidx]; |
054954eb JG |
221 | ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), |
222 | &level); | |
223 | BUG_ON(!ptep || level != PG_LEVEL_4K); | |
224 | mfn = pte_mfn(*ptep); | |
225 | ptep = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1)); | |
b5eafe92 JF |
226 | |
227 | /* Don't bother allocating any mfn mid levels if | |
228 | * they're just missing, just update the stored mfn, | |
229 | * since all could have changed over a migrate. | |
230 | */ | |
054954eb | 231 | if (ptep == p2m_missing_pte || ptep == p2m_identity_pte) { |
b5eafe92 JF |
232 | BUG_ON(mididx); |
233 | BUG_ON(mid_mfn_p != p2m_mid_missing_mfn); | |
234 | p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn); | |
235 | pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE; | |
236 | continue; | |
237 | } | |
238 | ||
239 | if (mid_mfn_p == p2m_mid_missing_mfn) { | |
7108c9ce | 240 | mid_mfn_p = alloc_p2m_page(); |
3cb83e46 | 241 | p2m_mid_mfn_init(mid_mfn_p, p2m_missing); |
b5eafe92 JF |
242 | |
243 | p2m_top_mfn_p[topidx] = mid_mfn_p; | |
244 | } | |
245 | ||
246 | p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p); | |
054954eb | 247 | mid_mfn_p[mididx] = mfn; |
b5eafe92 JF |
248 | } |
249 | } | |
250 | ||
251 | void xen_setup_mfn_list_list(void) | |
252 | { | |
4dd322bc MR |
253 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
254 | return; | |
255 | ||
b5eafe92 JF |
256 | BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); |
257 | ||
258 | HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = | |
259 | virt_to_mfn(p2m_top_mfn); | |
260 | HYPERVISOR_shared_info->arch.max_pfn = xen_max_p2m_pfn; | |
261 | } | |
262 | ||
263 | /* Set up p2m_top to point to the domain-builder provided p2m pages */ | |
264 | void __init xen_build_dynamic_phys_to_machine(void) | |
265 | { | |
b5eafe92 JF |
266 | unsigned long pfn; |
267 | ||
696fd7c5 KRW |
268 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
269 | return; | |
270 | ||
5b8e7d80 | 271 | xen_p2m_addr = (unsigned long *)xen_start_info->mfn_list; |
054954eb | 272 | xen_p2m_size = ALIGN(xen_start_info->nr_pages, P2M_PER_PAGE); |
b5eafe92 | 273 | |
054954eb JG |
274 | for (pfn = xen_start_info->nr_pages; pfn < xen_p2m_size; pfn++) |
275 | xen_p2m_addr[pfn] = INVALID_P2M_ENTRY; | |
b5eafe92 | 276 | |
054954eb JG |
277 | xen_max_p2m_pfn = xen_p2m_size; |
278 | } | |
b5eafe92 | 279 | |
054954eb JG |
280 | #define P2M_TYPE_IDENTITY 0 |
281 | #define P2M_TYPE_MISSING 1 | |
282 | #define P2M_TYPE_PFN 2 | |
283 | #define P2M_TYPE_UNKNOWN 3 | |
b5eafe92 | 284 | |
054954eb JG |
285 | static int xen_p2m_elem_type(unsigned long pfn) |
286 | { | |
287 | unsigned long mfn; | |
b5eafe92 | 288 | |
054954eb JG |
289 | if (pfn >= xen_p2m_size) |
290 | return P2M_TYPE_IDENTITY; | |
b5eafe92 | 291 | |
054954eb | 292 | mfn = xen_p2m_addr[pfn]; |
b5eafe92 | 293 | |
054954eb JG |
294 | if (mfn == INVALID_P2M_ENTRY) |
295 | return P2M_TYPE_MISSING; | |
cf04d120 | 296 | |
054954eb JG |
297 | if (mfn & IDENTITY_FRAME_BIT) |
298 | return P2M_TYPE_IDENTITY; | |
299 | ||
300 | return P2M_TYPE_PFN; | |
b5eafe92 | 301 | } |
054954eb JG |
302 | |
303 | static void __init xen_rebuild_p2m_list(unsigned long *p2m) | |
357a3cfb | 304 | { |
054954eb | 305 | unsigned int i, chunk; |
357a3cfb | 306 | unsigned long pfn; |
054954eb JG |
307 | unsigned long *mfns; |
308 | pte_t *ptep; | |
309 | pmd_t *pmdp; | |
310 | int type; | |
357a3cfb | 311 | |
054954eb JG |
312 | p2m_missing = alloc_p2m_page(); |
313 | p2m_init(p2m_missing); | |
314 | p2m_identity = alloc_p2m_page(); | |
315 | p2m_init(p2m_identity); | |
b5eafe92 | 316 | |
054954eb JG |
317 | p2m_missing_pte = alloc_p2m_page(); |
318 | paravirt_alloc_pte(&init_mm, __pa(p2m_missing_pte) >> PAGE_SHIFT); | |
319 | p2m_identity_pte = alloc_p2m_page(); | |
320 | paravirt_alloc_pte(&init_mm, __pa(p2m_identity_pte) >> PAGE_SHIFT); | |
321 | for (i = 0; i < PTRS_PER_PTE; i++) { | |
322 | set_pte(p2m_missing_pte + i, | |
2e917175 | 323 | pfn_pte(PFN_DOWN(__pa(p2m_missing)), PAGE_KERNEL_RO)); |
054954eb | 324 | set_pte(p2m_identity_pte + i, |
2e917175 | 325 | pfn_pte(PFN_DOWN(__pa(p2m_identity)), PAGE_KERNEL_RO)); |
054954eb | 326 | } |
357a3cfb | 327 | |
054954eb JG |
328 | for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += chunk) { |
329 | /* | |
330 | * Try to map missing/identity PMDs or p2m-pages if possible. | |
331 | * We have to respect the structure of the mfn_list_list | |
332 | * which will be built just afterwards. | |
333 | * Chunk size to test is one p2m page if we are in the middle | |
334 | * of a mfn_list_list mid page and the complete mid page area | |
335 | * if we are at index 0 of the mid page. Please note that a | |
336 | * mid page might cover more than one PMD, e.g. on 32 bit PAE | |
337 | * kernels. | |
338 | */ | |
339 | chunk = (pfn & (P2M_PER_PAGE * P2M_MID_PER_PAGE - 1)) ? | |
340 | P2M_PER_PAGE : P2M_PER_PAGE * P2M_MID_PER_PAGE; | |
341 | ||
342 | type = xen_p2m_elem_type(pfn); | |
343 | i = 0; | |
344 | if (type != P2M_TYPE_PFN) | |
345 | for (i = 1; i < chunk; i++) | |
346 | if (xen_p2m_elem_type(pfn + i) != type) | |
347 | break; | |
348 | if (i < chunk) | |
349 | /* Reset to minimal chunk size. */ | |
350 | chunk = P2M_PER_PAGE; | |
351 | ||
352 | if (type == P2M_TYPE_PFN || i < chunk) { | |
353 | /* Use initial p2m page contents. */ | |
354 | #ifdef CONFIG_X86_64 | |
355 | mfns = alloc_p2m_page(); | |
356 | copy_page(mfns, xen_p2m_addr + pfn); | |
357 | #else | |
358 | mfns = xen_p2m_addr + pfn; | |
359 | #endif | |
360 | ptep = populate_extra_pte((unsigned long)(p2m + pfn)); | |
361 | set_pte(ptep, | |
362 | pfn_pte(PFN_DOWN(__pa(mfns)), PAGE_KERNEL)); | |
357a3cfb | 363 | continue; |
054954eb | 364 | } |
b5eafe92 | 365 | |
054954eb JG |
366 | if (chunk == P2M_PER_PAGE) { |
367 | /* Map complete missing or identity p2m-page. */ | |
368 | mfns = (type == P2M_TYPE_MISSING) ? | |
369 | p2m_missing : p2m_identity; | |
370 | ptep = populate_extra_pte((unsigned long)(p2m + pfn)); | |
371 | set_pte(ptep, | |
2e917175 | 372 | pfn_pte(PFN_DOWN(__pa(mfns)), PAGE_KERNEL_RO)); |
357a3cfb | 373 | continue; |
054954eb | 374 | } |
357a3cfb | 375 | |
054954eb JG |
376 | /* Complete missing or identity PMD(s) can be mapped. */ |
377 | ptep = (type == P2M_TYPE_MISSING) ? | |
378 | p2m_missing_pte : p2m_identity_pte; | |
379 | for (i = 0; i < PMDS_PER_MID_PAGE; i++) { | |
380 | pmdp = populate_extra_pmd( | |
381 | (unsigned long)(p2m + pfn + i * PTRS_PER_PTE)); | |
382 | set_pmd(pmdp, __pmd(__pa(ptep) | _KERNPG_TABLE)); | |
383 | } | |
384 | } | |
385 | } | |
357a3cfb | 386 | |
054954eb JG |
387 | void __init xen_vmalloc_p2m_tree(void) |
388 | { | |
389 | static struct vm_struct vm; | |
357a3cfb | 390 | |
054954eb JG |
391 | vm.flags = VM_ALLOC; |
392 | vm.size = ALIGN(sizeof(unsigned long) * xen_max_p2m_pfn, | |
393 | PMD_SIZE * PMDS_PER_MID_PAGE); | |
394 | vm_area_register_early(&vm, PMD_SIZE * PMDS_PER_MID_PAGE); | |
395 | pr_notice("p2m virtual area at %p, size is %lx\n", vm.addr, vm.size); | |
3fc509fc | 396 | |
054954eb | 397 | xen_max_p2m_pfn = vm.size / sizeof(unsigned long); |
357a3cfb | 398 | |
054954eb | 399 | xen_rebuild_p2m_list(vm.addr); |
357a3cfb | 400 | |
054954eb | 401 | xen_p2m_addr = vm.addr; |
5b8e7d80 | 402 | xen_p2m_size = xen_max_p2m_pfn; |
5b8e7d80 JG |
403 | |
404 | xen_inv_extra_mem(); | |
405 | ||
97f4533a | 406 | m2p_override_init(); |
357a3cfb | 407 | } |
054954eb | 408 | |
b5eafe92 JF |
409 | unsigned long get_phys_to_machine(unsigned long pfn) |
410 | { | |
054954eb JG |
411 | pte_t *ptep; |
412 | unsigned int level; | |
b5eafe92 | 413 | |
5b8e7d80 JG |
414 | if (unlikely(pfn >= xen_p2m_size)) { |
415 | if (pfn < xen_max_p2m_pfn) | |
416 | return xen_chk_extra_mem(pfn); | |
417 | ||
25b884a8 | 418 | return IDENTITY_FRAME(pfn); |
5b8e7d80 | 419 | } |
b5eafe92 | 420 | |
054954eb JG |
421 | ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), &level); |
422 | BUG_ON(!ptep || level != PG_LEVEL_4K); | |
b5eafe92 | 423 | |
f4cec35b KRW |
424 | /* |
425 | * The INVALID_P2M_ENTRY is filled in both p2m_*identity | |
426 | * and in p2m_*missing, so returning the INVALID_P2M_ENTRY | |
427 | * would be wrong. | |
428 | */ | |
054954eb | 429 | if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_identity))) |
f4cec35b KRW |
430 | return IDENTITY_FRAME(pfn); |
431 | ||
054954eb | 432 | return xen_p2m_addr[pfn]; |
b5eafe92 JF |
433 | } |
434 | EXPORT_SYMBOL_GPL(get_phys_to_machine); | |
435 | ||
054954eb JG |
436 | /* |
437 | * Allocate new pmd(s). It is checked whether the old pmd is still in place. | |
438 | * If not, nothing is changed. This is okay as the only reason for allocating | |
439 | * a new pmd is to replace p2m_missing_pte or p2m_identity_pte by a individual | |
440 | * pmd. In case of PAE/x86-32 there are multiple pmds to allocate! | |
441 | */ | |
442 | static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *ptep, pte_t *pte_pg) | |
443 | { | |
444 | pte_t *ptechk; | |
445 | pte_t *pteret = ptep; | |
446 | pte_t *pte_newpg[PMDS_PER_MID_PAGE]; | |
447 | pmd_t *pmdp; | |
448 | unsigned int level; | |
449 | unsigned long flags; | |
450 | unsigned long vaddr; | |
451 | int i; | |
452 | ||
453 | /* Do all allocations first to bail out in error case. */ | |
454 | for (i = 0; i < PMDS_PER_MID_PAGE; i++) { | |
455 | pte_newpg[i] = alloc_p2m_page(); | |
456 | if (!pte_newpg[i]) { | |
457 | for (i--; i >= 0; i--) | |
458 | free_p2m_page(pte_newpg[i]); | |
459 | ||
460 | return NULL; | |
461 | } | |
462 | } | |
463 | ||
464 | vaddr = addr & ~(PMD_SIZE * PMDS_PER_MID_PAGE - 1); | |
465 | ||
466 | for (i = 0; i < PMDS_PER_MID_PAGE; i++) { | |
467 | copy_page(pte_newpg[i], pte_pg); | |
468 | paravirt_alloc_pte(&init_mm, __pa(pte_newpg[i]) >> PAGE_SHIFT); | |
469 | ||
470 | pmdp = lookup_pmd_address(vaddr); | |
471 | BUG_ON(!pmdp); | |
472 | ||
473 | spin_lock_irqsave(&p2m_update_lock, flags); | |
474 | ||
475 | ptechk = lookup_address(vaddr, &level); | |
476 | if (ptechk == pte_pg) { | |
477 | set_pmd(pmdp, | |
478 | __pmd(__pa(pte_newpg[i]) | _KERNPG_TABLE)); | |
479 | if (vaddr == (addr & ~(PMD_SIZE - 1))) | |
480 | pteret = pte_offset_kernel(pmdp, addr); | |
481 | pte_newpg[i] = NULL; | |
482 | } | |
483 | ||
484 | spin_unlock_irqrestore(&p2m_update_lock, flags); | |
485 | ||
486 | if (pte_newpg[i]) { | |
487 | paravirt_release_pte(__pa(pte_newpg[i]) >> PAGE_SHIFT); | |
488 | free_p2m_page(pte_newpg[i]); | |
489 | } | |
490 | ||
491 | vaddr += PMD_SIZE; | |
492 | } | |
493 | ||
494 | return pteret; | |
495 | } | |
496 | ||
a3118beb | 497 | /* |
b5eafe92 JF |
498 | * Fully allocate the p2m structure for a given pfn. We need to check |
499 | * that both the top and mid levels are allocated, and make sure the | |
500 | * parallel mfn tree is kept in sync. We may race with other cpus, so | |
501 | * the new pages are installed with cmpxchg; if we lose the race then | |
502 | * simply free the page we allocated and use the one that's there. | |
503 | */ | |
504 | static bool alloc_p2m(unsigned long pfn) | |
505 | { | |
506 | unsigned topidx, mididx; | |
b5eafe92 | 507 | unsigned long *top_mfn_p, *mid_mfn; |
054954eb JG |
508 | pte_t *ptep, *pte_pg; |
509 | unsigned int level; | |
510 | unsigned long flags; | |
511 | unsigned long addr = (unsigned long)(xen_p2m_addr + pfn); | |
512 | unsigned long p2m_pfn; | |
b5eafe92 JF |
513 | |
514 | topidx = p2m_top_index(pfn); | |
515 | mididx = p2m_mid_index(pfn); | |
516 | ||
054954eb JG |
517 | ptep = lookup_address(addr, &level); |
518 | BUG_ON(!ptep || level != PG_LEVEL_4K); | |
519 | pte_pg = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1)); | |
b5eafe92 | 520 | |
054954eb JG |
521 | if (pte_pg == p2m_missing_pte || pte_pg == p2m_identity_pte) { |
522 | /* PMD level is missing, allocate a new one */ | |
523 | ptep = alloc_p2m_pmd(addr, ptep, pte_pg); | |
524 | if (!ptep) | |
b5eafe92 | 525 | return false; |
b5eafe92 JF |
526 | } |
527 | ||
054954eb JG |
528 | if (p2m_top_mfn) { |
529 | top_mfn_p = &p2m_top_mfn[topidx]; | |
530 | mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]); | |
b5eafe92 | 531 | |
054954eb | 532 | BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p); |
b5eafe92 | 533 | |
054954eb JG |
534 | if (mid_mfn == p2m_mid_missing_mfn) { |
535 | /* Separately check the mid mfn level */ | |
536 | unsigned long missing_mfn; | |
537 | unsigned long mid_mfn_mfn; | |
538 | unsigned long old_mfn; | |
b5eafe92 | 539 | |
054954eb JG |
540 | mid_mfn = alloc_p2m_page(); |
541 | if (!mid_mfn) | |
542 | return false; | |
b5eafe92 | 543 | |
054954eb | 544 | p2m_mid_mfn_init(mid_mfn, p2m_missing); |
b5eafe92 | 545 | |
054954eb JG |
546 | missing_mfn = virt_to_mfn(p2m_mid_missing_mfn); |
547 | mid_mfn_mfn = virt_to_mfn(mid_mfn); | |
548 | old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn); | |
549 | if (old_mfn != missing_mfn) { | |
550 | free_p2m_page(mid_mfn); | |
551 | mid_mfn = mfn_to_virt(old_mfn); | |
552 | } else { | |
553 | p2m_top_mfn_p[topidx] = mid_mfn; | |
554 | } | |
239af7c7 | 555 | } |
054954eb JG |
556 | } else { |
557 | mid_mfn = NULL; | |
b5eafe92 JF |
558 | } |
559 | ||
054954eb JG |
560 | p2m_pfn = pte_pfn(ACCESS_ONCE(*ptep)); |
561 | if (p2m_pfn == PFN_DOWN(__pa(p2m_identity)) || | |
562 | p2m_pfn == PFN_DOWN(__pa(p2m_missing))) { | |
b5eafe92 JF |
563 | /* p2m leaf page is missing */ |
564 | unsigned long *p2m; | |
565 | ||
566 | p2m = alloc_p2m_page(); | |
567 | if (!p2m) | |
568 | return false; | |
569 | ||
054954eb JG |
570 | if (p2m_pfn == PFN_DOWN(__pa(p2m_missing))) |
571 | p2m_init(p2m); | |
572 | else | |
573 | p2m_init_identity(p2m, pfn); | |
574 | ||
575 | spin_lock_irqsave(&p2m_update_lock, flags); | |
576 | ||
577 | if (pte_pfn(*ptep) == p2m_pfn) { | |
578 | set_pte(ptep, | |
579 | pfn_pte(PFN_DOWN(__pa(p2m)), PAGE_KERNEL)); | |
580 | if (mid_mfn) | |
581 | mid_mfn[mididx] = virt_to_mfn(p2m); | |
582 | p2m = NULL; | |
583 | } | |
584 | ||
585 | spin_unlock_irqrestore(&p2m_update_lock, flags); | |
b5eafe92 | 586 | |
054954eb | 587 | if (p2m) |
b5eafe92 | 588 | free_p2m_page(p2m); |
b5eafe92 JF |
589 | } |
590 | ||
591 | return true; | |
592 | } | |
593 | ||
b83c6e55 | 594 | unsigned long __init set_phys_range_identity(unsigned long pfn_s, |
f4cec35b KRW |
595 | unsigned long pfn_e) |
596 | { | |
597 | unsigned long pfn; | |
598 | ||
5b8e7d80 | 599 | if (unlikely(pfn_s >= xen_p2m_size)) |
f4cec35b KRW |
600 | return 0; |
601 | ||
602 | if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) | |
603 | return pfn_e - pfn_s; | |
604 | ||
605 | if (pfn_s > pfn_e) | |
606 | return 0; | |
607 | ||
5b8e7d80 JG |
608 | if (pfn_e > xen_p2m_size) |
609 | pfn_e = xen_p2m_size; | |
f4cec35b | 610 | |
5b8e7d80 JG |
611 | for (pfn = pfn_s; pfn < pfn_e; pfn++) |
612 | xen_p2m_addr[pfn] = IDENTITY_FRAME(pfn); | |
f4cec35b KRW |
613 | |
614 | return pfn - pfn_s; | |
615 | } | |
616 | ||
b5eafe92 JF |
617 | bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) |
618 | { | |
054954eb JG |
619 | pte_t *ptep; |
620 | unsigned int level; | |
b5eafe92 | 621 | |
2f558d40 SS |
622 | /* don't track P2M changes in autotranslate guests */ |
623 | if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) | |
6eaa412f | 624 | return true; |
2f558d40 | 625 | |
5b8e7d80 | 626 | if (unlikely(pfn >= xen_p2m_size)) { |
b5eafe92 JF |
627 | BUG_ON(mfn != INVALID_P2M_ENTRY); |
628 | return true; | |
629 | } | |
630 | ||
90fff3ea | 631 | if (likely(!xen_safe_write_ulong(xen_p2m_addr + pfn, mfn))) |
2e917175 JG |
632 | return true; |
633 | ||
054954eb JG |
634 | ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), &level); |
635 | BUG_ON(!ptep || level != PG_LEVEL_4K); | |
f4cec35b | 636 | |
054954eb | 637 | if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_missing))) |
b5eafe92 JF |
638 | return mfn == INVALID_P2M_ENTRY; |
639 | ||
054954eb JG |
640 | if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_identity))) |
641 | return mfn == IDENTITY_FRAME(pfn); | |
642 | ||
2e917175 | 643 | return false; |
b5eafe92 JF |
644 | } |
645 | ||
646 | bool set_phys_to_machine(unsigned long pfn, unsigned long mfn) | |
647 | { | |
054954eb | 648 | if (unlikely(!__set_phys_to_machine(pfn, mfn))) { |
b5eafe92 JF |
649 | if (!alloc_p2m(pfn)) |
650 | return false; | |
651 | ||
054954eb | 652 | return __set_phys_to_machine(pfn, mfn); |
b5eafe92 JF |
653 | } |
654 | ||
655 | return true; | |
656 | } | |
448f2831 JF |
657 | |
658 | #define M2P_OVERRIDE_HASH_SHIFT 10 | |
659 | #define M2P_OVERRIDE_HASH (1 << M2P_OVERRIDE_HASH_SHIFT) | |
660 | ||
97f4533a | 661 | static struct list_head *m2p_overrides; |
448f2831 JF |
662 | static DEFINE_SPINLOCK(m2p_override_lock); |
663 | ||
664 | static void __init m2p_override_init(void) | |
665 | { | |
666 | unsigned i; | |
667 | ||
97f4533a JG |
668 | m2p_overrides = alloc_bootmem_align( |
669 | sizeof(*m2p_overrides) * M2P_OVERRIDE_HASH, | |
670 | sizeof(unsigned long)); | |
448f2831 JF |
671 | |
672 | for (i = 0; i < M2P_OVERRIDE_HASH; i++) | |
673 | INIT_LIST_HEAD(&m2p_overrides[i]); | |
674 | } | |
675 | ||
676 | static unsigned long mfn_hash(unsigned long mfn) | |
677 | { | |
678 | return hash_long(mfn, M2P_OVERRIDE_HASH_SHIFT); | |
679 | } | |
680 | ||
681 | /* Add an MFN override for a particular page */ | |
820c4db2 JG |
682 | static int m2p_add_override(unsigned long mfn, struct page *page, |
683 | struct gnttab_map_grant_ref *kmap_op) | |
448f2831 JF |
684 | { |
685 | unsigned long flags; | |
87f1d40a | 686 | unsigned long pfn; |
6b08cfeb | 687 | unsigned long uninitialized_var(address); |
87f1d40a JF |
688 | unsigned level; |
689 | pte_t *ptep = NULL; | |
690 | ||
691 | pfn = page_to_pfn(page); | |
692 | if (!PageHighMem(page)) { | |
693 | address = (unsigned long)__va(pfn << PAGE_SHIFT); | |
694 | ptep = lookup_address(address, &level); | |
87f1d40a | 695 | if (WARN(ptep == NULL || level != PG_LEVEL_4K, |
6f58d89e | 696 | "m2p_add_override: pfn %lx not mapped", pfn)) |
87f1d40a JF |
697 | return -EINVAL; |
698 | } | |
b254244d | 699 | |
0930bba6 SS |
700 | if (kmap_op != NULL) { |
701 | if (!PageHighMem(page)) { | |
702 | struct multicall_space mcs = | |
703 | xen_mc_entry(sizeof(*kmap_op)); | |
704 | ||
705 | MULTI_grant_table_op(mcs.mc, | |
706 | GNTTABOP_map_grant_ref, kmap_op, 1); | |
707 | ||
708 | xen_mc_issue(PARAVIRT_LAZY_MMU); | |
709 | } | |
0930bba6 | 710 | } |
448f2831 JF |
711 | spin_lock_irqsave(&m2p_override_lock, flags); |
712 | list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]); | |
713 | spin_unlock_irqrestore(&m2p_override_lock, flags); | |
87f1d40a | 714 | |
b9e0d95c SS |
715 | /* p2m(m2p(mfn)) == mfn: the mfn is already present somewhere in |
716 | * this domain. Set the FOREIGN_FRAME_BIT in the p2m for the other | |
717 | * pfn so that the following mfn_to_pfn(mfn) calls will return the | |
718 | * pfn from the m2p_override (the backend pfn) instead. | |
719 | * We need to do this because the pages shared by the frontend | |
720 | * (xen-blkfront) can be already locked (lock_page, called by | |
721 | * do_read_cache_page); when the userspace backend tries to use them | |
722 | * with direct_IO, mfn_to_pfn returns the pfn of the frontend, so | |
723 | * do_blockdev_direct_IO is going to try to lock the same pages | |
724 | * again resulting in a deadlock. | |
725 | * As a side effect get_user_pages_fast might not be safe on the | |
726 | * frontend pages while they are being shared with the backend, | |
727 | * because mfn_to_pfn (that ends up being called by GUPF) will | |
728 | * return the backend pfn rather than the frontend pfn. */ | |
0160676b | 729 | pfn = mfn_to_pfn_no_overrides(mfn); |
0aad5689 | 730 | if (__pfn_to_mfn(pfn) == mfn) |
b9e0d95c SS |
731 | set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)); |
732 | ||
87f1d40a | 733 | return 0; |
448f2831 | 734 | } |
1429d46d | 735 | |
820c4db2 JG |
736 | int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, |
737 | struct gnttab_map_grant_ref *kmap_ops, | |
738 | struct page **pages, unsigned int count) | |
1429d46d ZK |
739 | { |
740 | int i, ret = 0; | |
741 | bool lazy = false; | |
820c4db2 | 742 | pte_t *pte; |
1429d46d ZK |
743 | |
744 | if (xen_feature(XENFEAT_auto_translated_physmap)) | |
745 | return 0; | |
746 | ||
747 | if (kmap_ops && | |
748 | !in_interrupt() && | |
749 | paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { | |
750 | arch_enter_lazy_mmu_mode(); | |
751 | lazy = true; | |
752 | } | |
753 | ||
754 | for (i = 0; i < count; i++) { | |
820c4db2 | 755 | unsigned long mfn, pfn; |
1429d46d | 756 | |
820c4db2 JG |
757 | /* Do not add to override if the map failed. */ |
758 | if (map_ops[i].status) | |
759 | continue; | |
760 | ||
761 | if (map_ops[i].flags & GNTMAP_contains_pte) { | |
762 | pte = (pte_t *)(mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) + | |
763 | (map_ops[i].host_addr & ~PAGE_MASK)); | |
764 | mfn = pte_mfn(*pte); | |
765 | } else { | |
766 | mfn = PFN_DOWN(map_ops[i].dev_bus_addr); | |
1429d46d | 767 | } |
820c4db2 | 768 | pfn = page_to_pfn(pages[i]); |
1429d46d | 769 | |
820c4db2 JG |
770 | WARN_ON(PagePrivate(pages[i])); |
771 | SetPagePrivate(pages[i]); | |
772 | set_page_private(pages[i], mfn); | |
773 | pages[i]->index = pfn_to_mfn(pfn); | |
1429d46d | 774 | |
820c4db2 JG |
775 | if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) { |
776 | ret = -ENOMEM; | |
1429d46d | 777 | goto out; |
820c4db2 JG |
778 | } |
779 | ||
780 | if (kmap_ops) { | |
781 | ret = m2p_add_override(mfn, pages[i], &kmap_ops[i]); | |
782 | if (ret) | |
783 | goto out; | |
784 | } | |
1429d46d ZK |
785 | } |
786 | ||
787 | out: | |
788 | if (lazy) | |
789 | arch_leave_lazy_mmu_mode(); | |
820c4db2 | 790 | |
1429d46d ZK |
791 | return ret; |
792 | } | |
820c4db2 | 793 | EXPORT_SYMBOL_GPL(set_foreign_p2m_mapping); |
1429d46d | 794 | |
820c4db2 JG |
795 | static struct page *m2p_find_override(unsigned long mfn) |
796 | { | |
797 | unsigned long flags; | |
97f4533a | 798 | struct list_head *bucket; |
820c4db2 JG |
799 | struct page *p, *ret; |
800 | ||
97f4533a JG |
801 | if (unlikely(!m2p_overrides)) |
802 | return NULL; | |
803 | ||
820c4db2 | 804 | ret = NULL; |
97f4533a | 805 | bucket = &m2p_overrides[mfn_hash(mfn)]; |
820c4db2 JG |
806 | |
807 | spin_lock_irqsave(&m2p_override_lock, flags); | |
808 | ||
809 | list_for_each_entry(p, bucket, lru) { | |
810 | if (page_private(p) == mfn) { | |
811 | ret = p; | |
812 | break; | |
813 | } | |
814 | } | |
815 | ||
816 | spin_unlock_irqrestore(&m2p_override_lock, flags); | |
817 | ||
818 | return ret; | |
819 | } | |
820 | ||
821 | static int m2p_remove_override(struct page *page, | |
822 | struct gnttab_map_grant_ref *kmap_op, | |
823 | unsigned long mfn) | |
448f2831 JF |
824 | { |
825 | unsigned long flags; | |
9b705f0e | 826 | unsigned long pfn; |
6b08cfeb | 827 | unsigned long uninitialized_var(address); |
87f1d40a JF |
828 | unsigned level; |
829 | pte_t *ptep = NULL; | |
9b705f0e SS |
830 | |
831 | pfn = page_to_pfn(page); | |
87f1d40a JF |
832 | |
833 | if (!PageHighMem(page)) { | |
834 | address = (unsigned long)__va(pfn << PAGE_SHIFT); | |
835 | ptep = lookup_address(address, &level); | |
836 | ||
837 | if (WARN(ptep == NULL || level != PG_LEVEL_4K, | |
6f58d89e | 838 | "m2p_remove_override: pfn %lx not mapped", pfn)) |
87f1d40a JF |
839 | return -EINVAL; |
840 | } | |
9b705f0e | 841 | |
448f2831 JF |
842 | spin_lock_irqsave(&m2p_override_lock, flags); |
843 | list_del(&page->lru); | |
844 | spin_unlock_irqrestore(&m2p_override_lock, flags); | |
87f1d40a | 845 | |
2fc136ee | 846 | if (kmap_op != NULL) { |
0930bba6 SS |
847 | if (!PageHighMem(page)) { |
848 | struct multicall_space mcs; | |
ee072640 SS |
849 | struct gnttab_unmap_and_replace *unmap_op; |
850 | struct page *scratch_page = get_balloon_scratch_page(); | |
851 | unsigned long scratch_page_address = (unsigned long) | |
852 | __va(page_to_pfn(scratch_page) << PAGE_SHIFT); | |
0930bba6 SS |
853 | |
854 | /* | |
855 | * It might be that we queued all the m2p grant table | |
856 | * hypercalls in a multicall, then m2p_remove_override | |
857 | * get called before the multicall has actually been | |
858 | * issued. In this case handle is going to -1 because | |
859 | * it hasn't been modified yet. | |
860 | */ | |
2fc136ee | 861 | if (kmap_op->handle == -1) |
0930bba6 SS |
862 | xen_mc_flush(); |
863 | /* | |
2fc136ee | 864 | * Now if kmap_op->handle is negative it means that the |
0930bba6 SS |
865 | * hypercall actually returned an error. |
866 | */ | |
2fc136ee | 867 | if (kmap_op->handle == GNTST_general_error) { |
6f58d89e JG |
868 | pr_warn("m2p_remove_override: pfn %lx mfn %lx, failed to modify kernel mappings", |
869 | pfn, mfn); | |
d7f8f48d | 870 | put_balloon_scratch_page(); |
0930bba6 SS |
871 | return -1; |
872 | } | |
873 | ||
d7f8f48d BO |
874 | xen_mc_batch(); |
875 | ||
876 | mcs = __xen_mc_entry( | |
6f58d89e | 877 | sizeof(struct gnttab_unmap_and_replace)); |
0930bba6 | 878 | unmap_op = mcs.args; |
2fc136ee | 879 | unmap_op->host_addr = kmap_op->host_addr; |
ee072640 | 880 | unmap_op->new_addr = scratch_page_address; |
2fc136ee | 881 | unmap_op->handle = kmap_op->handle; |
0930bba6 SS |
882 | |
883 | MULTI_grant_table_op(mcs.mc, | |
6f58d89e | 884 | GNTTABOP_unmap_and_replace, unmap_op, 1); |
0930bba6 | 885 | |
ee072640 SS |
886 | mcs = __xen_mc_entry(0); |
887 | MULTI_update_va_mapping(mcs.mc, scratch_page_address, | |
d7f8f48d | 888 | pfn_pte(page_to_pfn(scratch_page), |
ee072640 | 889 | PAGE_KERNEL_RO), 0); |
d7f8f48d | 890 | |
ee072640 SS |
891 | xen_mc_issue(PARAVIRT_LAZY_MMU); |
892 | ||
2fc136ee | 893 | kmap_op->host_addr = 0; |
ee072640 | 894 | put_balloon_scratch_page(); |
0930bba6 | 895 | } |
2fc136ee | 896 | } |
87f1d40a | 897 | |
b9e0d95c SS |
898 | /* p2m(m2p(mfn)) == FOREIGN_FRAME(mfn): the mfn is already present |
899 | * somewhere in this domain, even before being added to the | |
900 | * m2p_override (see comment above in m2p_add_override). | |
901 | * If there are no other entries in the m2p_override corresponding | |
902 | * to this mfn, then remove the FOREIGN_FRAME_BIT from the p2m for | |
903 | * the original pfn (the one shared by the frontend): the backend | |
904 | * cannot do any IO on this page anymore because it has been | |
905 | * unshared. Removing the FOREIGN_FRAME_BIT from the p2m entry of | |
906 | * the original pfn causes mfn_to_pfn(mfn) to return the frontend | |
907 | * pfn again. */ | |
908 | mfn &= ~FOREIGN_FRAME_BIT; | |
0160676b | 909 | pfn = mfn_to_pfn_no_overrides(mfn); |
0aad5689 | 910 | if (__pfn_to_mfn(pfn) == FOREIGN_FRAME(mfn) && |
b9e0d95c SS |
911 | m2p_find_override(mfn) == NULL) |
912 | set_phys_to_machine(pfn, mfn); | |
913 | ||
87f1d40a | 914 | return 0; |
448f2831 JF |
915 | } |
916 | ||
820c4db2 JG |
917 | int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, |
918 | struct gnttab_map_grant_ref *kmap_ops, | |
919 | struct page **pages, unsigned int count) | |
448f2831 | 920 | { |
820c4db2 JG |
921 | int i, ret = 0; |
922 | bool lazy = false; | |
448f2831 | 923 | |
820c4db2 JG |
924 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
925 | return 0; | |
448f2831 | 926 | |
820c4db2 JG |
927 | if (kmap_ops && |
928 | !in_interrupt() && | |
929 | paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { | |
930 | arch_enter_lazy_mmu_mode(); | |
931 | lazy = true; | |
932 | } | |
448f2831 | 933 | |
820c4db2 | 934 | for (i = 0; i < count; i++) { |
0aad5689 | 935 | unsigned long mfn = __pfn_to_mfn(page_to_pfn(pages[i])); |
820c4db2 JG |
936 | unsigned long pfn = page_to_pfn(pages[i]); |
937 | ||
938 | if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) { | |
939 | ret = -EINVAL; | |
940 | goto out; | |
448f2831 | 941 | } |
448f2831 | 942 | |
820c4db2 JG |
943 | set_page_private(pages[i], INVALID_P2M_ENTRY); |
944 | WARN_ON(!PagePrivate(pages[i])); | |
945 | ClearPagePrivate(pages[i]); | |
946 | set_phys_to_machine(pfn, pages[i]->index); | |
448f2831 | 947 | |
820c4db2 JG |
948 | if (kmap_ops) |
949 | ret = m2p_remove_override(pages[i], &kmap_ops[i], mfn); | |
950 | if (ret) | |
951 | goto out; | |
952 | } | |
953 | ||
954 | out: | |
955 | if (lazy) | |
956 | arch_leave_lazy_mmu_mode(); | |
448f2831 JF |
957 | return ret; |
958 | } | |
820c4db2 | 959 | EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping); |
448f2831 JF |
960 | |
961 | unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn) | |
962 | { | |
963 | struct page *p = m2p_find_override(mfn); | |
964 | unsigned long ret = pfn; | |
965 | ||
966 | if (p) | |
967 | ret = page_to_pfn(p); | |
968 | ||
969 | return ret; | |
970 | } | |
e1b478e4 | 971 | EXPORT_SYMBOL_GPL(m2p_find_override_pfn); |
2222e71b KRW |
972 | |
973 | #ifdef CONFIG_XEN_DEBUG_FS | |
a867db10 KRW |
974 | #include <linux/debugfs.h> |
975 | #include "debugfs.h" | |
976 | static int p2m_dump_show(struct seq_file *m, void *v) | |
2222e71b | 977 | { |
a491dbef | 978 | static const char * const type_name[] = { |
054954eb JG |
979 | [P2M_TYPE_IDENTITY] = "identity", |
980 | [P2M_TYPE_MISSING] = "missing", | |
981 | [P2M_TYPE_PFN] = "pfn", | |
982 | [P2M_TYPE_UNKNOWN] = "abnormal"}; | |
983 | unsigned long pfn, first_pfn; | |
984 | int type, prev_type; | |
985 | ||
986 | prev_type = xen_p2m_elem_type(0); | |
987 | first_pfn = 0; | |
988 | ||
989 | for (pfn = 0; pfn < xen_p2m_size; pfn++) { | |
990 | type = xen_p2m_elem_type(pfn); | |
991 | if (type != prev_type) { | |
992 | seq_printf(m, " [0x%lx->0x%lx] %s\n", first_pfn, pfn, | |
993 | type_name[prev_type]); | |
2222e71b | 994 | prev_type = type; |
054954eb | 995 | first_pfn = pfn; |
2222e71b KRW |
996 | } |
997 | } | |
054954eb JG |
998 | seq_printf(m, " [0x%lx->0x%lx] %s\n", first_pfn, pfn, |
999 | type_name[prev_type]); | |
2222e71b | 1000 | return 0; |
2222e71b | 1001 | } |
a867db10 KRW |
1002 | |
1003 | static int p2m_dump_open(struct inode *inode, struct file *filp) | |
1004 | { | |
1005 | return single_open(filp, p2m_dump_show, NULL); | |
1006 | } | |
1007 | ||
1008 | static const struct file_operations p2m_dump_fops = { | |
1009 | .open = p2m_dump_open, | |
1010 | .read = seq_read, | |
1011 | .llseek = seq_lseek, | |
1012 | .release = single_release, | |
1013 | }; | |
1014 | ||
1015 | static struct dentry *d_mmu_debug; | |
1016 | ||
1017 | static int __init xen_p2m_debugfs(void) | |
1018 | { | |
1019 | struct dentry *d_xen = xen_init_debugfs(); | |
1020 | ||
1021 | if (d_xen == NULL) | |
1022 | return -ENOMEM; | |
1023 | ||
1024 | d_mmu_debug = debugfs_create_dir("mmu", d_xen); | |
1025 | ||
1026 | debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops); | |
1027 | return 0; | |
1028 | } | |
1029 | fs_initcall(xen_p2m_debugfs); | |
1030 | #endif /* CONFIG_XEN_DEBUG_FS */ |