* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
-#include <qemu/mmap-alloc.h>
-#include <sys/types.h>
-#include <sys/mman.h>
-#include <assert.h>
-void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
+#ifdef CONFIG_LINUX
+#include <linux/mman.h>
+#else /* !CONFIG_LINUX */
+#define MAP_SYNC 0x0
+#define MAP_SHARED_VALIDATE 0x0
+#endif /* CONFIG_LINUX */
+
+#include "qemu/osdep.h"
+#include "qemu/mmap-alloc.h"
+#include "qemu/host-utils.h"
+
+#define HUGETLBFS_MAGIC 0x958458f6
+
+#ifdef CONFIG_LINUX
+#include <sys/vfs.h>
+#endif
+
+size_t qemu_fd_getpagesize(int fd)
+{
+#ifdef CONFIG_LINUX
+ struct statfs fs;
+ int ret;
+
+ if (fd != -1) {
+ do {
+ ret = fstatfs(fd, &fs);
+ } while (ret != 0 && errno == EINTR);
+
+ if (ret == 0 && fs.f_type == HUGETLBFS_MAGIC) {
+ return fs.f_bsize;
+ }
+ }
+#ifdef __sparc__
+ /* SPARC Linux needs greater alignment than the pagesize */
+ return QEMU_VMALLOC_ALIGN;
+#endif
+#endif
+
+ return getpagesize();
+}
+
+size_t qemu_mempath_getpagesize(const char *mem_path)
{
+#ifdef CONFIG_LINUX
+ struct statfs fs;
+ int ret;
+
+ if (mem_path) {
+ do {
+ ret = statfs(mem_path, &fs);
+ } while (ret != 0 && errno == EINTR);
+
+ if (ret != 0) {
+ fprintf(stderr, "Couldn't statfs() memory path: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+
+ if (fs.f_type == HUGETLBFS_MAGIC) {
+ /* It's hugepage, return the huge page size */
+ return fs.f_bsize;
+ }
+ }
+#ifdef __sparc__
+ /* SPARC Linux needs greater alignment than the pagesize */
+ return QEMU_VMALLOC_ALIGN;
+#endif
+#endif
+
+ return getpagesize();
+}
+
+void *qemu_ram_mmap(int fd,
+ size_t size,
+ size_t align,
+ bool shared,
+ bool is_pmem)
+{
+ int flags;
+ int map_sync_flags = 0;
+ int guardfd;
+ size_t offset;
+ size_t pagesize;
+ size_t total;
+ void *guardptr;
+ void *ptr;
+
/*
* Note: this always allocates at least one extra page of virtual address
* space, even if size is already aligned.
*/
- size_t total = size + align;
- void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
- size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
- void *ptr1;
+ total = size + align;
- if (ptr == MAP_FAILED) {
- return NULL;
+#if defined(__powerpc64__) && defined(__linux__)
+ /* On ppc64 mappings in the same segment (aka slice) must share the same
+ * page size. Since we will be re-allocating part of this segment
+ * from the supplied fd, we should make sure to use the same page size, to
+ * this end we mmap the supplied fd. In this case, set MAP_NORESERVE to
+ * avoid allocating backing store memory.
+ * We do this unless we are using the system page size, in which case
+ * anonymous memory is OK.
+ */
+ flags = MAP_PRIVATE;
+ pagesize = qemu_fd_getpagesize(fd);
+ if (fd == -1 || pagesize == getpagesize()) {
+ guardfd = -1;
+ flags |= MAP_ANONYMOUS;
+ } else {
+ guardfd = fd;
+ flags |= MAP_NORESERVE;
}
+#else
+ guardfd = -1;
+ pagesize = getpagesize();
+ flags = MAP_PRIVATE | MAP_ANONYMOUS;
+#endif
+
+ guardptr = mmap(0, total, PROT_NONE, flags, guardfd, 0);
- /* Make sure align is a power of 2 */
- assert(!(align & (align - 1)));
+ if (guardptr == MAP_FAILED) {
+ return MAP_FAILED;
+ }
+
+ assert(is_power_of_2(align));
/* Always align to host page size */
- assert(align >= getpagesize());
-
- ptr1 = mmap(ptr + offset, size, PROT_READ | PROT_WRITE,
- MAP_FIXED |
- (fd == -1 ? MAP_ANONYMOUS : 0) |
- (shared ? MAP_SHARED : MAP_PRIVATE),
- fd, 0);
- if (ptr1 == MAP_FAILED) {
- munmap(ptr, total);
- return NULL;
+ assert(align >= pagesize);
+
+ flags = MAP_FIXED;
+ flags |= fd == -1 ? MAP_ANONYMOUS : 0;
+ flags |= shared ? MAP_SHARED : MAP_PRIVATE;
+ if (shared && is_pmem) {
+ map_sync_flags = MAP_SYNC | MAP_SHARED_VALIDATE;
}
- ptr += offset;
- total -= offset;
+ offset = QEMU_ALIGN_UP((uintptr_t)guardptr, align) - (uintptr_t)guardptr;
+
+ ptr = mmap(guardptr + offset, size, PROT_READ | PROT_WRITE,
+ flags | map_sync_flags, fd, 0);
+
+ if (ptr == MAP_FAILED && map_sync_flags) {
+ if (errno == ENOTSUP) {
+ char *proc_link, *file_name;
+ int len;
+ proc_link = g_strdup_printf("/proc/self/fd/%d", fd);
+ file_name = g_malloc0(PATH_MAX);
+ len = readlink(proc_link, file_name, PATH_MAX - 1);
+ if (len < 0) {
+ len = 0;
+ }
+ file_name[len] = '\0';
+ fprintf(stderr, "Warning: requesting persistence across crashes "
+ "for backend file %s failed. Proceeding without "
+ "persistence, data might become corrupted in case of host "
+ "crash.\n", file_name);
+ g_free(proc_link);
+ g_free(file_name);
+ }
+ /*
+ * if map failed with MAP_SHARED_VALIDATE | MAP_SYNC,
+ * we will remove these flags to handle compatibility.
+ */
+ ptr = mmap(guardptr + offset, size, PROT_READ | PROT_WRITE,
+ flags, fd, 0);
+ }
+
+ if (ptr == MAP_FAILED) {
+ munmap(guardptr, total);
+ return MAP_FAILED;
+ }
if (offset > 0) {
- munmap(ptr - offset, offset);
+ munmap(guardptr, offset);
}
/*
* Leave a single PROT_NONE page allocated after the RAM block, to serve as
* a guard page guarding against potential buffer overflows.
*/
- if (total > size + getpagesize()) {
- munmap(ptr + size + getpagesize(), total - size - getpagesize());
+ total -= offset;
+ if (total > size + pagesize) {
+ munmap(ptr + size + pagesize, total - size - pagesize);
}
return ptr;
}
-void qemu_ram_munmap(void *ptr, size_t size)
+void qemu_ram_munmap(int fd, void *ptr, size_t size)
{
+ size_t pagesize;
+
if (ptr) {
/* Unmap both the RAM block and the guard page */
- munmap(ptr, size + getpagesize());
+#if defined(__powerpc64__) && defined(__linux__)
+ pagesize = qemu_fd_getpagesize(fd);
+#else
+ pagesize = getpagesize();
+#endif
+ munmap(ptr, size + pagesize);
}
}
projects / qemu.git / blobdiff