]> git.proxmox.com Git - mirror_qemu.git/blame - linux-user/mmap.c
added kqemu_set_notdirty()
[mirror_qemu.git] / linux-user / mmap.c
CommitLineData
54936004
FB
1/*
2 * mmap support for qemu
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20#include <stdlib.h>
21#include <stdio.h>
22#include <stdarg.h>
23#include <string.h>
24#include <unistd.h>
25#include <errno.h>
26#include <sys/mman.h>
27
28#include "qemu.h"
29
30//#define DEBUG_MMAP
31
32/* NOTE: all the constants are the HOST ones */
33int target_mprotect(unsigned long start, unsigned long len, int prot)
34{
35 unsigned long end, host_start, host_end, addr;
36 int prot1, ret;
37
38#ifdef DEBUG_MMAP
39 printf("mprotect: start=0x%lx len=0x%lx prot=%c%c%c\n", start, len,
40 prot & PROT_READ ? 'r' : '-',
41 prot & PROT_WRITE ? 'w' : '-',
42 prot & PROT_EXEC ? 'x' : '-');
43#endif
44
45 if ((start & ~TARGET_PAGE_MASK) != 0)
46 return -EINVAL;
47 len = TARGET_PAGE_ALIGN(len);
48 end = start + len;
49 if (end < start)
50 return -EINVAL;
51 if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC))
52 return -EINVAL;
53 if (len == 0)
54 return 0;
55
83fb7adf 56 host_start = start & qemu_host_page_mask;
54936004
FB
57 host_end = HOST_PAGE_ALIGN(end);
58 if (start > host_start) {
59 /* handle host page containing start */
60 prot1 = prot;
61 for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) {
62 prot1 |= page_get_flags(addr);
63 }
83fb7adf 64 if (host_end == host_start + qemu_host_page_size) {
d418c81e
FB
65 for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
66 prot1 |= page_get_flags(addr);
67 }
68 end = host_end;
69 }
83fb7adf 70 ret = mprotect((void *)host_start, qemu_host_page_size, prot1 & PAGE_BITS);
54936004
FB
71 if (ret != 0)
72 return ret;
83fb7adf 73 host_start += qemu_host_page_size;
54936004
FB
74 }
75 if (end < host_end) {
54936004
FB
76 prot1 = prot;
77 for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
78 prot1 |= page_get_flags(addr);
79 }
83fb7adf 80 ret = mprotect((void *)(host_end - qemu_host_page_size), qemu_host_page_size,
54936004
FB
81 prot1 & PAGE_BITS);
82 if (ret != 0)
83 return ret;
83fb7adf 84 host_end -= qemu_host_page_size;
54936004
FB
85 }
86
87 /* handle the pages in the middle */
88 if (host_start < host_end) {
89 ret = mprotect((void *)host_start, host_end - host_start, prot);
90 if (ret != 0)
91 return ret;
92 }
54936004
FB
93 page_set_flags(start, start + len, prot | PAGE_VALID);
94 return 0;
95}
96
97/* map an incomplete host page */
98int mmap_frag(unsigned long host_start,
99 unsigned long start, unsigned long end,
100 int prot, int flags, int fd, unsigned long offset)
101{
102 unsigned long host_end, ret, addr;
103 int prot1, prot_new;
104
83fb7adf 105 host_end = host_start + qemu_host_page_size;
54936004
FB
106
107 /* get the protection of the target pages outside the mapping */
108 prot1 = 0;
109 for(addr = host_start; addr < host_end; addr++) {
110 if (addr < start || addr >= end)
111 prot1 |= page_get_flags(addr);
112 }
113
114 if (prot1 == 0) {
115 /* no page was there, so we allocate one */
83fb7adf 116 ret = (long)mmap((void *)host_start, qemu_host_page_size, prot,
54936004
FB
117 flags | MAP_ANONYMOUS, -1, 0);
118 if (ret == -1)
119 return ret;
120 }
121 prot1 &= PAGE_BITS;
122
123 prot_new = prot | prot1;
124 if (!(flags & MAP_ANONYMOUS)) {
125 /* msync() won't work here, so we return an error if write is
126 possible while it is a shared mapping */
127 if ((flags & MAP_TYPE) == MAP_SHARED &&
128 (prot & PROT_WRITE))
129 return -EINVAL;
130
131 /* adjust protection to be able to read */
132 if (!(prot1 & PROT_WRITE))
83fb7adf 133 mprotect((void *)host_start, qemu_host_page_size, prot1 | PROT_WRITE);
54936004
FB
134
135 /* read the corresponding file data */
136 pread(fd, (void *)start, end - start, offset);
137
138 /* put final protection */
139 if (prot_new != (prot1 | PROT_WRITE))
83fb7adf 140 mprotect((void *)host_start, qemu_host_page_size, prot_new);
54936004
FB
141 } else {
142 /* just update the protection */
143 if (prot_new != prot1) {
83fb7adf 144 mprotect((void *)host_start, qemu_host_page_size, prot_new);
54936004
FB
145 }
146 }
147 return 0;
148}
149
150/* NOTE: all the constants are the HOST ones */
151long target_mmap(unsigned long start, unsigned long len, int prot,
152 int flags, int fd, unsigned long offset)
153{
154 unsigned long ret, end, host_start, host_end, retaddr, host_offset, host_len;
b8076a74
FB
155#if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) || \
156 defined(__ia64)
4f2ac237
FB
157 static unsigned long last_start = 0x40000000;
158#endif
54936004
FB
159
160#ifdef DEBUG_MMAP
161 {
162 printf("mmap: start=0x%lx len=0x%lx prot=%c%c%c flags=",
163 start, len,
164 prot & PROT_READ ? 'r' : '-',
165 prot & PROT_WRITE ? 'w' : '-',
166 prot & PROT_EXEC ? 'x' : '-');
167 if (flags & MAP_FIXED)
168 printf("MAP_FIXED ");
169 if (flags & MAP_ANONYMOUS)
170 printf("MAP_ANON ");
171 switch(flags & MAP_TYPE) {
172 case MAP_PRIVATE:
173 printf("MAP_PRIVATE ");
174 break;
175 case MAP_SHARED:
176 printf("MAP_SHARED ");
177 break;
178 default:
179 printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE);
180 break;
181 }
182 printf("fd=%d offset=%lx\n", fd, offset);
183 }
184#endif
185
186 if (offset & ~TARGET_PAGE_MASK)
187 return -EINVAL;
188
189 len = TARGET_PAGE_ALIGN(len);
190 if (len == 0)
191 return start;
83fb7adf 192 host_start = start & qemu_host_page_mask;
54936004
FB
193
194 if (!(flags & MAP_FIXED)) {
b8076a74
FB
195#if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) || \
196 defined(__ia64)
917f95fd 197 /* tell the kenel to search at the same place as i386 */
4f2ac237
FB
198 if (host_start == 0) {
199 host_start = last_start;
200 last_start += HOST_PAGE_ALIGN(len);
201 }
917f95fd 202#endif
83fb7adf 203 if (qemu_host_page_size != qemu_real_host_page_size) {
54936004
FB
204 /* NOTE: this code is only for debugging with '-p' option */
205 /* reserve a memory area */
83fb7adf 206 host_len = HOST_PAGE_ALIGN(len) + qemu_host_page_size - TARGET_PAGE_SIZE;
54936004
FB
207 host_start = (long)mmap((void *)host_start, host_len, PROT_NONE,
208 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
209 if (host_start == -1)
210 return host_start;
211 host_end = host_start + host_len;
212 start = HOST_PAGE_ALIGN(host_start);
213 end = start + HOST_PAGE_ALIGN(len);
214 if (start > host_start)
215 munmap((void *)host_start, start - host_start);
216 if (end < host_end)
217 munmap((void *)end, host_end - end);
218 /* use it as a fixed mapping */
219 flags |= MAP_FIXED;
220 } else {
221 /* if not fixed, no need to do anything */
83fb7adf 222 host_offset = offset & qemu_host_page_mask;
54936004
FB
223 host_len = len + offset - host_offset;
224 start = (long)mmap((void *)host_start, host_len,
225 prot, flags, fd, host_offset);
226 if (start == -1)
227 return start;
228 /* update start so that it points to the file position at 'offset' */
229 if (!(flags & MAP_ANONYMOUS))
230 start += offset - host_offset;
231 goto the_end1;
232 }
233 }
234
235 if (start & ~TARGET_PAGE_MASK)
236 return -EINVAL;
237 end = start + len;
238 host_end = HOST_PAGE_ALIGN(end);
239
240 /* worst case: we cannot map the file because the offset is not
241 aligned, so we read it */
242 if (!(flags & MAP_ANONYMOUS) &&
83fb7adf 243 (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
54936004
FB
244 /* msync() won't work here, so we return an error if write is
245 possible while it is a shared mapping */
246 if ((flags & MAP_TYPE) == MAP_SHARED &&
247 (prot & PROT_WRITE))
248 return -EINVAL;
249 retaddr = target_mmap(start, len, prot | PROT_WRITE,
250 MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
251 -1, 0);
252 if (retaddr == -1)
253 return retaddr;
254 pread(fd, (void *)start, len, offset);
255 if (!(prot & PROT_WRITE)) {
256 ret = target_mprotect(start, len, prot);
257 if (ret != 0)
258 return ret;
259 }
260 goto the_end;
261 }
262
263 /* handle the start of the mapping */
264 if (start > host_start) {
83fb7adf 265 if (host_end == host_start + qemu_host_page_size) {
54936004
FB
266 /* one single host page */
267 ret = mmap_frag(host_start, start, end,
268 prot, flags, fd, offset);
269 if (ret == -1)
270 return ret;
271 goto the_end1;
272 }
83fb7adf 273 ret = mmap_frag(host_start, start, host_start + qemu_host_page_size,
54936004
FB
274 prot, flags, fd, offset);
275 if (ret == -1)
276 return ret;
83fb7adf 277 host_start += qemu_host_page_size;
54936004
FB
278 }
279 /* handle the end of the mapping */
280 if (end < host_end) {
83fb7adf
FB
281 ret = mmap_frag(host_end - qemu_host_page_size,
282 host_end - qemu_host_page_size, host_end,
54936004 283 prot, flags, fd,
83fb7adf 284 offset + host_end - qemu_host_page_size - start);
54936004
FB
285 if (ret == -1)
286 return ret;
83fb7adf 287 host_end -= qemu_host_page_size;
54936004
FB
288 }
289
290 /* map the middle (easier) */
291 if (host_start < host_end) {
4a585ccb
FB
292 unsigned long offset1;
293 if (flags & MAP_ANONYMOUS)
294 offset1 = 0;
295 else
296 offset1 = offset + host_start - start;
54936004 297 ret = (long)mmap((void *)host_start, host_end - host_start,
4a585ccb 298 prot, flags, fd, offset1);
54936004
FB
299 if (ret == -1)
300 return ret;
301 }
302 the_end1:
303 page_set_flags(start, start + len, prot | PAGE_VALID);
304 the_end:
305#ifdef DEBUG_MMAP
917f95fd 306 printf("ret=0x%lx\n", (long)start);
54936004
FB
307 page_dump(stdout);
308 printf("\n");
309#endif
310 return start;
311}
312
313int target_munmap(unsigned long start, unsigned long len)
314{
315 unsigned long end, host_start, host_end, addr;
316 int prot, ret;
317
318#ifdef DEBUG_MMAP
319 printf("munmap: start=0x%lx len=0x%lx\n", start, len);
320#endif
321 if (start & ~TARGET_PAGE_MASK)
322 return -EINVAL;
323 len = TARGET_PAGE_ALIGN(len);
324 if (len == 0)
325 return -EINVAL;
326 end = start + len;
83fb7adf 327 host_start = start & qemu_host_page_mask;
54936004
FB
328 host_end = HOST_PAGE_ALIGN(end);
329
330 if (start > host_start) {
331 /* handle host page containing start */
332 prot = 0;
333 for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) {
334 prot |= page_get_flags(addr);
335 }
83fb7adf 336 if (host_end == host_start + qemu_host_page_size) {
d418c81e
FB
337 for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
338 prot |= page_get_flags(addr);
339 }
340 end = host_end;
341 }
54936004 342 if (prot != 0)
83fb7adf 343 host_start += qemu_host_page_size;
54936004
FB
344 }
345 if (end < host_end) {
54936004
FB
346 prot = 0;
347 for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
348 prot |= page_get_flags(addr);
349 }
350 if (prot != 0)
83fb7adf 351 host_end -= qemu_host_page_size;
54936004
FB
352 }
353
354 /* unmap what we can */
355 if (host_start < host_end) {
356 ret = munmap((void *)host_start, host_end - host_start);
357 if (ret != 0)
358 return ret;
359 }
360
361 page_set_flags(start, start + len, 0);
362 return 0;
363}
364
365/* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED
366 blocks which have been allocated starting on a host page */
367long target_mremap(unsigned long old_addr, unsigned long old_size,
368 unsigned long new_size, unsigned long flags,
369 unsigned long new_addr)
370{
371 int prot;
372
373 /* XXX: use 5 args syscall */
374 new_addr = (long)mremap((void *)old_addr, old_size, new_size, flags);
375 if (new_addr == -1)
376 return new_addr;
377 prot = page_get_flags(old_addr);
378 page_set_flags(old_addr, old_addr + old_size, 0);
379 page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID);
380 return new_addr;
381}
382
383int target_msync(unsigned long start, unsigned long len, int flags)
384{
385 unsigned long end;
386
387 if (start & ~TARGET_PAGE_MASK)
388 return -EINVAL;
389 len = TARGET_PAGE_ALIGN(len);
54936004 390 end = start + len;
d418c81e
FB
391 if (end < start)
392 return -EINVAL;
393 if (end == start)
394 return 0;
54936004 395
83fb7adf 396 start &= qemu_host_page_mask;
d418c81e 397 return msync((void *)start, end - start, flags);
54936004
FB
398}
399