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-rw-r--r--util/mmap-alloc.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index c37acbe58..54793a5dc 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -14,6 +14,32 @@
#include <sys/mman.h>
#include <assert.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;
+ }
+ }
+#endif
+
+ return getpagesize();
+}
+
void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
{
/*
@@ -21,7 +47,20 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
* space, even if size is already aligned.
*/
size_t total = size + align;
+#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,
+ * unless we are using the system page size, in which case anonymous memory
+ * is OK. Use align as a hint for the page size.
+ * In this case, set MAP_NORESERVE to avoid allocating backing store memory.
+ */
+ int anonfd = fd == -1 || qemu_fd_getpagesize(fd) == getpagesize() ? -1 : fd;
+ int flags = anonfd == -1 ? MAP_ANONYMOUS : MAP_NORESERVE;
+ void *ptr = mmap(0, total, PROT_NONE, flags | MAP_PRIVATE, anonfd, 0);
+#else
void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+#endif
size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
void *ptr1;