1
2
3
4
5
6
7
8
9
10
11
12
13#include "qemu/osdep.h"
14#include "qemu/mmap-alloc.h"
15#include "qemu/host-utils.h"
16
17#define HUGETLBFS_MAGIC 0x958458f6
18
19#ifdef CONFIG_LINUX
20#include <sys/vfs.h>
21#endif
22
23size_t qemu_fd_getpagesize(int fd)
24{
25#ifdef CONFIG_LINUX
26 struct statfs fs;
27 int ret;
28
29 if (fd != -1) {
30 do {
31 ret = fstatfs(fd, &fs);
32 } while (ret != 0 && errno == EINTR);
33
34 if (ret == 0 && fs.f_type == HUGETLBFS_MAGIC) {
35 return fs.f_bsize;
36 }
37 }
38#endif
39
40 return getpagesize();
41}
42
43size_t qemu_mempath_getpagesize(const char *mem_path)
44{
45#ifdef CONFIG_LINUX
46 struct statfs fs;
47 int ret;
48
49 do {
50 ret = statfs(mem_path, &fs);
51 } while (ret != 0 && errno == EINTR);
52
53 if (ret != 0) {
54 fprintf(stderr, "Couldn't statfs() memory path: %s\n",
55 strerror(errno));
56 exit(1);
57 }
58
59 if (fs.f_type == HUGETLBFS_MAGIC) {
60
61 return fs.f_bsize;
62 }
63#endif
64
65 return getpagesize();
66}
67
68void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
69{
70
71
72
73
74 size_t total = size + align;
75#if defined(__powerpc64__) && defined(__linux__)
76
77
78
79
80
81
82
83
84 int anonfd = fd == -1 || qemu_fd_getpagesize(fd) == getpagesize() ? -1 : fd;
85 int flags = anonfd == -1 ? MAP_ANONYMOUS : MAP_NORESERVE;
86 void *ptr = mmap(0, total, PROT_NONE, flags | MAP_PRIVATE, anonfd, 0);
87#else
88 void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
89#endif
90 size_t offset;
91 void *ptr1;
92
93 if (ptr == MAP_FAILED) {
94 return MAP_FAILED;
95 }
96
97 assert(is_power_of_2(align));
98
99 assert(align >= getpagesize());
100
101 offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
102 ptr1 = mmap(ptr + offset, size, PROT_READ | PROT_WRITE,
103 MAP_FIXED |
104 (fd == -1 ? MAP_ANONYMOUS : 0) |
105 (shared ? MAP_SHARED : MAP_PRIVATE),
106 fd, 0);
107 if (ptr1 == MAP_FAILED) {
108 munmap(ptr, total);
109 return MAP_FAILED;
110 }
111
112 if (offset > 0) {
113 munmap(ptr, offset);
114 }
115
116
117
118
119
120 total -= offset;
121 if (total > size + getpagesize()) {
122 munmap(ptr1 + size + getpagesize(), total - size - getpagesize());
123 }
124
125 return ptr1;
126}
127
128void qemu_ram_munmap(void *ptr, size_t size)
129{
130 if (ptr) {
131
132 munmap(ptr, size + getpagesize());
133 }
134}
135