X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=src%2Flaunch.c;h=7b3372c2bc85d43d596ff351eaf62cb15c9ace25;hb=ae45cee728039d7724fc73e5ffb2550c8054d268;hp=ce26e253c0ca300100ea1b61b42ae447553310ed;hpb=527079aa0db9b608ee4c25e7b3eccc4058685608;p=libguestfs.git

diff --git a/src/launch.c b/src/launch.c
index ce26e25..7b3372c 100644
--- a/src/launch.c
+++ b/src/launch.c
@@ -233,17 +233,21 @@ guestfs__config (guestfs_h *g,
  * O_DIRECT.  This fails on some filesystem types (notably tmpfs).
  * So we check if we can open the file with or without O_DIRECT,
  * and use cache=off (or not) accordingly.
+ *
+ * NB: This function is only called on the !readonly path.  We must
+ * try to open with O_RDWR to test that the file is readable and
+ * writable here.
  */
 static int
 test_cache_off (guestfs_h *g, const char *filename)
 {
-  int fd = open (filename, O_RDONLY|O_DIRECT);
+  int fd = open (filename, O_RDWR|O_DIRECT);
   if (fd >= 0) {
     close (fd);
     return 1;
   }
 
-  fd = open (filename, O_RDONLY);
+  fd = open (filename, O_RDWR);
   if (fd >= 0) {
     close (fd);
     return 0;
@@ -325,7 +329,7 @@ guestfs__add_drive_opts (guestfs_h *g, const char *filename,
   }
 
   if (readonly) {
-    if (access (filename, F_OK) == -1) {
+    if (access (filename, R_OK) == -1) {
       perrorf (g, "%s", filename);
       free (format);
       free (iface);
@@ -582,7 +586,19 @@ launch_appliance (guestfs_h *g)
      */
     if (qemu_supports (g, "-machine")) {
       add_cmdline (g, "-machine");
+#if QEMU_MACHINE_TYPE_IS_BROKEN
+      /* Workaround for qemu 0.15: We have to add the '[type=]pc'
+       * since there is no default.  This is not a permanent solution
+       * because this only works on PC-like hardware.  Other platforms
+       * like ppc would need a different machine type.
+       *
+       * This bug is fixed in qemu commit 2645c6dcaf6ea2a51a, and was
+       * not a problem in qemu < 0.15.
+       */
+      add_cmdline (g, "pc,accel=kvm:tcg");
+#else
       add_cmdline (g, "accel=kvm:tcg");
+#endif
     } else {
       /* qemu sometimes needs this option to enable hardware
        * virtualization, but some versions of 'qemu-kvm' will use KVM
@@ -853,6 +869,13 @@ launch_appliance (guestfs_h *g)
   if (r == -1)
     goto cleanup1;
 
+  /* NB: We reach here just because qemu has opened the socket.  It
+   * does not mean the daemon is up until we read the
+   * GUESTFS_LAUNCH_FLAG below.  Failures in qemu startup can still
+   * happen even if we reach here, even early failures like not being
+   * able to open a drive.
+   */
+
   close (g->sock); /* Close the listening socket. */
   g->sock = r; /* This is the accepted data socket. */