Add 'append', LIBGUESTFS_APPEND to set additional kernel options.

3 files changed, 48 insertions, 2 deletions

diff --git a/src/generator.ml b/src/generator.ml
index b3388f6e..fdd4ae63 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -342,6 +342,31 @@ Return the current search path.
 This is always non-NULL.  If it wasn't set already, then this will
 return the default path.");
 
+  ("set_append", (RErr, [String "append"]), -1, [FishAlias "append"],
+   [],
+   "add options to kernel command line",
+   "\
+This function is used to add additional options to the
+guest kernel command line.
+
+The default is C<NULL> unless overridden by setting
+C<LIBGUESTFS_APPEND> environment variable.
+
+The string C<append> is stashed in the libguestfs handle, so the caller
+must make sure it remains valid for the lifetime of the handle.
+
+Setting C<append> to C<NULL> means I<no> additional options
+are passed (libguestfs always adds a few of its own).");
+
+  ("get_append", (RConstString "append", []), -1, [],
+   [],
+   "get the additional kernel options",
+   "\
+Return the additional kernel options which are added to the
+guest kernel command line.
+
+If C<NULL> then no options are added.");
+
   ("set_autosync", (RErr, [Bool "autosync"]), -1, [FishAlias "autosync"],
    [],
    "set autosync mode",
diff --git a/src/guestfs-actions.h b/src/guestfs-actions.h
index bad72718..92c1a932 100644
--- a/src/guestfs-actions.h
+++ b/src/guestfs-actions.h
@@ -29,6 +29,8 @@ extern int guestfs_set_qemu (guestfs_h *handle, const char *qemu);
 extern const char *guestfs_get_qemu (guestfs_h *handle);
 extern int guestfs_set_path (guestfs_h *handle, const char *path);
 extern const char *guestfs_get_path (guestfs_h *handle);
+extern int guestfs_set_append (guestfs_h *handle, const char *append);
+extern const char *guestfs_get_append (guestfs_h *handle);
 extern int guestfs_set_autosync (guestfs_h *handle, int autosync);
 extern int guestfs_get_autosync (guestfs_h *handle);
 extern int guestfs_set_verbose (guestfs_h *handle, int verbose);
diff --git a/src/guestfs.c b/src/guestfs.c
index 43571af7..646be772 100644
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -161,6 +161,8 @@ struct guestfs_h
   const char *path;
   const char *qemu;
 
+  const char *append;		/* Append to kernel command line. */
+
   char *last_error;
 
   /* Callbacks. */
@@ -225,6 +227,9 @@ guestfs_create (void)
   str = getenv ("LIBGUESTFS_QEMU");
   g->qemu = str != NULL ? str : QEMU;
 
+  str = getenv ("LIBGUESTFS_APPEND");
+  g->append = str;
+
   g->main_loop = guestfs_get_default_main_loop ();
 
   /* Start with large serial numbers so they are easy to spot
@@ -540,6 +545,19 @@ guestfs_get_qemu (guestfs_h *g)
   return g->qemu;
 }
 
+int
+guestfs_set_append (guestfs_h *g, const char *append)
+{
+  g->append = append;
+  return 0;
+}
+
+const char *
+guestfs_get_append (guestfs_h *g)
+{
+  return g->append;
+}
+
 /* Add a string to the current command line. */
 static void
 incr_cmdline_size (guestfs_h *g)
@@ -764,9 +782,10 @@ guestfs_launch (guestfs_h *g)
 
     /* Linux kernel command line. */
     snprintf (append, sizeof append,
-	      "panic=1 console=ttyS0 guestfs=%s:%d%s",
+	      "panic=1 console=ttyS0 guestfs=%s:%d%s%s%s",
 	      VMCHANNEL_ADDR, VMCHANNEL_PORT,
-	      g->verbose ? " guestfs_verbose=1" : "");
+	      g->verbose ? " guestfs_verbose=1" : "",
+	      g->append ? " " : "", g->append ? g->append : "");
 
     snprintf (memsize_str, sizeof memsize_str, "%d", memsize);