* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
+#include "qapi/error.h"
#ifndef _WIN32
#include <sys/mman.h>
#endif
-#include "qemu-common.h"
+#include "qemu/cutils.h"
#include "cpu.h"
#include "tcg.h"
#include "hw/hw.h"
}
#ifdef __linux__
-
-#include <sys/vfs.h>
-
-#define HUGETLBFS_MAGIC 0x958458f6
-
-static long gethugepagesize(const char *path, Error **errp)
-{
- struct statfs fs;
- int ret;
-
- do {
- ret = statfs(path, &fs);
- } while (ret != 0 && errno == EINTR);
-
- if (ret != 0) {
- error_setg_errno(errp, errno, "failed to get page size of file %s",
- path);
- return 0;
- }
-
- return fs.f_bsize;
-}
-
static void *file_ram_alloc(RAMBlock *block,
ram_addr_t memory,
const char *path,
Error **errp)
{
- struct stat st;
+ bool unlink_on_error = false;
char *filename;
char *sanitized_name;
char *c;
void *area;
- int fd;
- uint64_t hpagesize;
- Error *local_err = NULL;
-
- hpagesize = gethugepagesize(path, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- goto error;
- }
- block->mr->align = hpagesize;
-
- if (memory < hpagesize) {
- error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to "
- "or larger than huge page size 0x%" PRIx64,
- memory, hpagesize);
- goto error;
- }
+ int fd = -1;
+ int64_t page_size;
if (kvm_enabled() && !kvm_has_sync_mmu()) {
error_setg(errp,
"host lacks kvm mmu notifiers, -mem-path unsupported");
- goto error;
+ return NULL;
}
- if (!stat(path, &st) && S_ISDIR(st.st_mode)) {
- /* Make name safe to use with mkstemp by replacing '/' with '_'. */
- sanitized_name = g_strdup(memory_region_name(block->mr));
- for (c = sanitized_name; *c != '\0'; c++) {
- if (*c == '/') {
- *c = '_';
- }
+ for (;;) {
+ fd = open(path, O_RDWR);
+ if (fd >= 0) {
+ /* @path names an existing file, use it */
+ break;
}
+ if (errno == ENOENT) {
+ /* @path names a file that doesn't exist, create it */
+ fd = open(path, O_RDWR | O_CREAT | O_EXCL, 0644);
+ if (fd >= 0) {
+ unlink_on_error = true;
+ break;
+ }
+ } else if (errno == EISDIR) {
+ /* @path names a directory, create a file there */
+ /* Make name safe to use with mkstemp by replacing '/' with '_'. */
+ sanitized_name = g_strdup(memory_region_name(block->mr));
+ for (c = sanitized_name; *c != '\0'; c++) {
+ if (*c == '/') {
+ *c = '_';
+ }
+ }
- filename = g_strdup_printf("%s/qemu_back_mem.%s.XXXXXX", path,
- sanitized_name);
- g_free(sanitized_name);
+ filename = g_strdup_printf("%s/qemu_back_mem.%s.XXXXXX", path,
+ sanitized_name);
+ g_free(sanitized_name);
- fd = mkstemp(filename);
- if (fd >= 0) {
- unlink(filename);
+ fd = mkstemp(filename);
+ if (fd >= 0) {
+ unlink(filename);
+ g_free(filename);
+ break;
+ }
+ g_free(filename);
}
- g_free(filename);
- } else {
- fd = open(path, O_RDWR | O_CREAT, 0644);
+ if (errno != EEXIST && errno != EINTR) {
+ error_setg_errno(errp, errno,
+ "can't open backing store %s for guest RAM",
+ path);
+ goto error;
+ }
+ /*
+ * Try again on EINTR and EEXIST. The latter happens when
+ * something else creates the file between our two open().
+ */
}
- if (fd < 0) {
- error_setg_errno(errp, errno,
- "unable to create backing store for hugepages");
+ page_size = qemu_fd_getpagesize(fd);
+ block->mr->align = page_size;
+
+ if (memory < page_size) {
+ error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to "
+ "or larger than page size 0x%" PRIx64,
+ memory, page_size);
goto error;
}
- memory = ROUND_UP(memory, hpagesize);
+ memory = ROUND_UP(memory, page_size);
/*
* ftruncate is not supported by hugetlbfs in older
perror("ftruncate");
}
- area = qemu_ram_mmap(fd, memory, hpagesize, block->flags & RAM_SHARED);
+ area = qemu_ram_mmap(fd, memory, page_size, block->flags & RAM_SHARED);
if (area == MAP_FAILED) {
error_setg_errno(errp, errno,
- "unable to map backing store for hugepages");
- close(fd);
+ "unable to map backing store for guest RAM");
goto error;
}
return area;
error:
+ if (unlink_on_error) {
+ unlink(path);
+ }
+ if (fd != -1) {
+ close(fd);
+ }
return NULL;
}
#endif
if (err) {
error_propagate(errp, err);
qemu_mutex_unlock_ramlist();
+ return;
}
} else {
new_block->host = phys_mem_alloc(new_block->max_length,
"cannot set up guest memory '%s'",
memory_region_name(new_block->mr));
qemu_mutex_unlock_ramlist();
+ return;
}
memory_try_enable_merging(new_block->host, new_block->max_length);
}
void qemu_ram_free(RAMBlock *block)
{
+ if (!block) {
+ return;
+ }
+
qemu_mutex_lock_ramlist();
QLIST_REMOVE_RCU(block, next);
ram_list.mru_block = NULL;
projects / qemu.git / blobdiff