virtio-scsi: Don't abort when media is ejected

[mirror_qemu.git] / util / mmap-alloc.c

diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index c37acbe58edebdd8f48923dbfb3a210f02ebcf68..5a85aa3c899b1d006ea91ba3f5dec7fd0bc4b97e 100644 (file)
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -9,10 +9,35 @@
  * 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>
+
+#include "qemu/osdep.h"
+#include "qemu/mmap-alloc.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 +46,21 @@ 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, 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.
+     */
+    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;