-
Notifications
You must be signed in to change notification settings - Fork 331
/
paging.c
392 lines (331 loc) · 9.43 KB
/
paging.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
/*
* Jailhouse, a Linux-based partitioning hypervisor
*
* Copyright (c) Siemens AG, 2013
*
* Authors:
* Jan Kiszka <jan.kiszka@siemens.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*/
#include <jailhouse/paging.h>
#include <jailhouse/printk.h>
#include <jailhouse/string.h>
#include <jailhouse/control.h>
#include <asm/bitops.h>
#define BITS_PER_PAGE (PAGE_SIZE * 8)
#define PAGE_SCRUB_ON_FREE 0x1
extern u8 __start[], __page_pool[];
struct page_pool mem_pool;
struct page_pool remap_pool = {
.base_address = (void *)REMAP_BASE_ADDR,
.pages = BITS_PER_PAGE * NUM_REMAP_BITMAP_PAGES,
};
pgd_t *hv_page_table;
static void *page_alloc_one(struct page_pool *pool)
{
unsigned long word, page_nr;
for (word = 0; word < pool->pages / BITS_PER_LONG; word++)
if (pool->used_bitmap[word] != ~0UL) {
page_nr = ffz(pool->used_bitmap[word]) +
word * BITS_PER_LONG;
if (page_nr >= pool->pages)
break;
set_bit(page_nr, pool->used_bitmap);
pool->used_pages++;
return pool->base_address + page_nr * PAGE_SIZE;
}
return NULL;
}
void *page_alloc(struct page_pool *pool, unsigned int num)
{
void *start, *last, *next;
unsigned int allocated;
start = page_alloc_one(pool);
if (!start)
return NULL;
for (allocated = 1, last = start; allocated < num;
allocated++, last = next) {
next = page_alloc_one(pool);
if (next != last + PAGE_SIZE) {
page_free(pool, start, allocated);
return NULL;
}
}
return start;
}
void page_free(struct page_pool *pool, void *page, unsigned int num)
{
unsigned long page_nr;
if (!page)
return;
while (num-- > 0) {
if (pool->flags & PAGE_SCRUB_ON_FREE)
memset(page, 0, PAGE_SIZE);
page_nr = (page - pool->base_address) / PAGE_SIZE;
clear_bit(page_nr, pool->used_bitmap);
pool->used_pages--;
page += PAGE_SIZE;
}
}
unsigned long page_map_virt2phys(pgd_t *page_table,
unsigned long page_table_offset,
unsigned long virt)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
#if PAGE_DIR_LEVELS == 4
pgd = pgd_offset(page_table, virt);
if (!pgd_valid(pgd))
return INVALID_PHYS_ADDR;
pud = pud4l_offset(pgd, page_table_offset, virt);
#elif PAGE_DIR_LEVELS == 3
pud = pud3l_offset(pgd, page_table_offset, virt);
#else
# error Unsupported paging level
#endif
if (!pud_valid(pud))
return INVALID_PHYS_ADDR;
pmd = pmd_offset(pud, page_table_offset, virt);
if (!pmd_valid(pud))
return INVALID_PHYS_ADDR;
if (pmd_is_hugepage(pmd))
return phys_address_hugepage(pmd, virt);
pte = pte_offset(pmd, page_table_offset, virt);
if (!pte_valid(pte))
return INVALID_PHYS_ADDR;
return phys_address(pte, virt);
}
int page_map_create(pgd_t *page_table, unsigned long phys, unsigned long size,
unsigned long virt, unsigned long flags,
unsigned long table_flags, unsigned int levels)
{
unsigned long offs = hypervisor_header.page_offset;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
for (size = PAGE_ALIGN(size); size > 0;
phys += PAGE_SIZE, virt += PAGE_SIZE, size -= PAGE_SIZE) {
switch (levels) {
case 4:
pgd = pgd_offset(page_table, virt);
if (!pgd_valid(pgd)) {
pud = page_alloc(&mem_pool, 1);
if (!pud)
return -ENOMEM;
set_pgd(pgd, page_map_hvirt2phys(pud),
table_flags);
}
pud = pud4l_offset(pgd, offs, virt);
break;
case 3:
pud = pud3l_offset(page_table, virt);
break;
default:
return -EINVAL;
}
if (!pud_valid(pud)) {
pmd = page_alloc(&mem_pool, 1);
if (!pmd)
return -ENOMEM;
set_pud(pud, page_map_hvirt2phys(pmd), table_flags);
}
pmd = pmd_offset(pud, offs, virt);
if (!pmd_valid(pmd)) {
pte = page_alloc(&mem_pool, 1);
if (!pte)
return -ENOMEM;
set_pmd(pmd, page_map_hvirt2phys(pte), table_flags);
}
pte = pte_offset(pmd, offs, virt);
set_pte(pte, phys, flags);
}
flush_tlb();
return 0;
}
void page_map_destroy(pgd_t *page_table, unsigned long virt,
unsigned long size, unsigned int levels)
{
unsigned long offs = hypervisor_header.page_offset;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
for (size = PAGE_ALIGN(size); size > 0;
virt += PAGE_SIZE, size -= PAGE_SIZE) {
switch (levels) {
case 4:
pgd = pgd_offset(page_table, virt);
if (!pgd_valid(pgd))
continue;
pud = pud4l_offset(pgd, offs, virt);
break;
case 3:
pgd = 0; /* silence compiler warning */
pud = pud3l_offset(page_table, virt);
break;
default:
return;
}
if (!pud_valid(pud))
continue;
pmd = pmd_offset(pud, offs, virt);
if (!pmd_valid(pmd))
continue;
pte = pte_offset(pmd, offs, virt);
clear_pte(pte);
if (!pt_empty(pmd, offs))
continue;
page_free(&mem_pool, pte_offset(pmd, offs, 0), 1);
clear_pmd(pmd);
if (!pmd_empty(pud, offs))
continue;
page_free(&mem_pool, pmd_offset(pud, offs, 0), 1);
clear_pud(pud);
if (levels < 4 || !pud_empty(pgd, offs))
continue;
page_free(&mem_pool, pud4l_offset(pgd, offs, 0), 1);
clear_pgd(pgd);
}
flush_tlb();
}
void *page_map_get_foreign_page(unsigned int mapping_region,
unsigned long page_table_paddr,
unsigned long page_table_offset,
unsigned long virt, unsigned long flags)
{
unsigned long page_virt, pt_virt, phys;
#if PAGE_DIR_LEVELS == 4
pgd_t *pgd;
#endif
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
int err;
page_virt = FOREIGN_MAPPING_BASE +
mapping_region * PAGE_SIZE * NUM_FOREIGN_PAGES;
pt_virt = page_virt + PAGE_SIZE;
phys = page_table_paddr + page_table_offset;
err = page_map_create(hv_page_table, phys, PAGE_SIZE, pt_virt,
PAGE_READONLY_FLAGS, PAGE_DEFAULT_FLAGS,
PAGE_DIR_LEVELS);
if (err)
goto error_release;
#if PAGE_DIR_LEVELS == 4
pgd = pgd_offset((pgd_t *)pt_virt, virt);
if (!pgd_valid(pgd))
goto error_release;
pt_virt += PAGE_SIZE;
phys = (unsigned long)pud4l_offset(pgd, page_table_offset, 0);
err = page_map_create(hv_page_table, phys, PAGE_SIZE, pt_virt,
PAGE_READONLY_FLAGS, PAGE_DEFAULT_FLAGS,
PAGE_DIR_LEVELS);
if (err)
goto error_release;
pud = pud4l_offset((pgd_t *)&pt_virt, page_table_offset, virt);
#elif PAGE_DIR_LEVELS == 3
pud = pud3l_offset((pgd_t *)pt_virt, virt);
#else
# error Unsupported paging level
#endif
if (!pud_valid(pud))
goto error_release;
pt_virt += PAGE_SIZE;
phys = (unsigned long)pmd_offset(pud, page_table_offset, 0);
err = page_map_create(hv_page_table, phys, PAGE_SIZE, pt_virt,
PAGE_READONLY_FLAGS, PAGE_DEFAULT_FLAGS,
PAGE_DIR_LEVELS);
if (err)
goto error_release;
pmd = pmd_offset((pud_t *)&pt_virt, page_table_offset, virt);
if (!pmd_valid(pmd))
goto error_release;
if (pmd_is_hugepage(pmd))
phys = phys_address_hugepage(pmd, virt);
else {
pt_virt += PAGE_SIZE;
phys = (unsigned long)pte_offset(pmd, page_table_offset, 0);
err = page_map_create(hv_page_table, phys, PAGE_SIZE, pt_virt,
PAGE_READONLY_FLAGS,
PAGE_DEFAULT_FLAGS, PAGE_DIR_LEVELS);
if (err)
goto error_release;
pte = pte_offset((pmd_t *)&pt_virt, page_table_offset, virt);
if (!pte_valid(pte))
goto error_release;
phys = phys_address(pte, 0) + page_table_offset;
}
err = page_map_create(hv_page_table, phys, PAGE_SIZE, page_virt,
flags, PAGE_DEFAULT_FLAGS, PAGE_DIR_LEVELS);
if (err)
goto error_release;
return (void *)page_virt;
error_release:
page_map_release_foreign_page(mapping_region);
return NULL;
}
void page_map_release_foreign_page(unsigned int mapping_region)
{
page_map_destroy(hv_page_table,
FOREIGN_MAPPING_BASE +
mapping_region * PAGE_SIZE * NUM_FOREIGN_PAGES,
NUM_FOREIGN_PAGES * PAGE_SIZE, PAGE_DIR_LEVELS);
}
int paging_init(void)
{
unsigned long per_cpu_pages, config_pages, bitmap_pages;
unsigned long n;
u8 *addr;
int err;
mem_pool.pages =
(hypervisor_header.size - (__page_pool - __start)) / PAGE_SIZE;
per_cpu_pages = hypervisor_header.possible_cpus *
sizeof(struct per_cpu) / PAGE_SIZE;
bitmap_pages = (mem_pool.pages + BITS_PER_PAGE - 1) / BITS_PER_PAGE;
system_config = (struct jailhouse_system *)
(__page_pool + per_cpu_pages * PAGE_SIZE);
config_pages = (jailhouse_system_config_size(system_config) +
PAGE_SIZE - 1) / PAGE_SIZE;
if (mem_pool.pages <= per_cpu_pages + config_pages + bitmap_pages)
goto error_nomem;
mem_pool.base_address = __page_pool;
mem_pool.used_bitmap =
(unsigned long *)(__page_pool + per_cpu_pages * PAGE_SIZE +
config_pages * PAGE_SIZE);
mem_pool.used_pages = per_cpu_pages + config_pages + bitmap_pages;
for (n = 0; n < mem_pool.used_pages; n++)
set_bit(n, mem_pool.used_bitmap);
mem_pool.flags = PAGE_SCRUB_ON_FREE;
remap_pool.used_bitmap = page_alloc(&mem_pool, NUM_REMAP_BITMAP_PAGES);
remap_pool.used_pages =
hypervisor_header.possible_cpus * NUM_FOREIGN_PAGES;
for (n = 0; n < remap_pool.used_pages; n++)
set_bit(n, remap_pool.used_bitmap);
hv_page_table = page_alloc(&mem_pool, 1);
if (!hv_page_table)
goto error_nomem;
/* Replicate hypervisor mapping of Linux */
for (addr = __start; addr < __start + hypervisor_header.size;
addr += PAGE_SIZE) {
err = page_map_create(hv_page_table, page_map_hvirt2phys(addr),
PAGE_SIZE, (unsigned long)addr,
PAGE_DEFAULT_FLAGS, PAGE_DEFAULT_FLAGS,
PAGE_DIR_LEVELS);
if (err)
goto error_nomem;
}
return 0;
error_nomem:
printk("FATAL: page pool much too small\n");
return -ENOMEM;
}
void page_map_dump_stats(const char *when)
{
printk("Page pool usage %s: mem %d/%d, remap %d/%d\n", when,
mem_pool.used_pages, mem_pool.pages,
remap_pool.used_pages, remap_pool.pages);
}