From 04b36384e91cf0e6242be9daa1d06d269cb9cf3d Mon Sep 17 00:00:00 2001
From: Olaf Hering <olaf@aepfle.de>
Date: Mon, 3 Sep 2012 19:50:44 +0200
Subject: [PATCH] force virtio_blk in old guest kernel

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
 src/launch-appliance.c | 24 ++++++++++++++++++++++++
 test-tool/test-tool.c  | 15 ++++++++++-----
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/src/launch-appliance.c b/src/launch-appliance.c
index e353e05..f037d15 100644
--- a/src/launch-appliance.c
+++ b/src/launch-appliance.c
@@ -869,6 +869,28 @@ is_openable (guestfs_h *g, const char *path, int flags)
   return 1;
 }
 
+/*
+ * Currently virtio_scsi is forced if qemu in the host supports this
+ * feature. This test does however not take the capabilities of the started
+ * guest into account. As a result no disks will be found if the guest
+ * kernel is older than 3.4.
+ */
+static void qemu_force_virtio_blk(guestfs_h *g)
+{
+#ifdef GUESTFS_QEMU_NO_VIRTIO_BLK
+	static const char env_string[] = "GUESTFS_QEMU_NO_VIRTIO_BLK";
+	char *p = getenv(env_string);
+	if (p) {
+		if (g->verbose)
+			guestfs___print_timestamped_message (g, "SuSE: %s in environment, preserving virtio-scsi setting.", env_string);
+	} else {
+		if (g->verbose)
+			guestfs___print_timestamped_message (g, "SuSE: %s not in environment, preventing virtio-scsi usage in old guest kernel.", env_string);
+		g->app.virtio_scsi = 2;
+	}
+#endif
+}
+
 /* Returns 1 = use virtio-scsi, or 0 = use virtio-blk. */
 static int
 qemu_supports_virtio_scsi (guestfs_h *g)
@@ -891,6 +913,8 @@ qemu_supports_virtio_scsi (guestfs_h *g)
       g->app.virtio_scsi = 3;
   }
 
+  qemu_force_virtio_blk(g);
+
   return g->app.virtio_scsi == 1;
 }
 
diff --git a/test-tool/test-tool.c b/test-tool/test-tool.c
index 4b764ee..2ba9977 100644
--- a/test-tool/test-tool.c
+++ b/test-tool/test-tool.c
@@ -35,6 +35,11 @@
 
 #include <guestfs.h>
 
+#ifdef GUESTFS_QEMU_NO_VIRTIO_BLK
+#define VDISK_KERNEL_NAME "vda"
+#else
+#define VDISK_KERNEL_NAME "sda"
+#endif
 #define _(str) dgettext(PACKAGE, (str))
 //#define N_(str) dgettext(PACKAGE, (str))
 
@@ -55,7 +60,7 @@
 #define DEFAULT_TIMEOUT 600
 
 static int timeout = DEFAULT_TIMEOUT;
-static char tmpf[] = P_tmpdir "/libguestfs-test-tool-sda-XXXXXX";
+static char tmpf[] = P_tmpdir "/libguestfs-test-tool-" VDISK_KERNEL_NAME "-XXXXXX";
 static guestfs_h *g;
 
 static void make_files (void);
@@ -240,21 +245,21 @@ main (int argc, char *argv[])
   fflush (stdout);
 
   /* Create the filesystem and mount everything. */
-  if (guestfs_part_disk (g, "/dev/sda", "mbr") == -1) {
+  if (guestfs_part_disk (g, "/dev/" VDISK_KERNEL_NAME "", "mbr") == -1) {
     fprintf (stderr,
              _("libguestfs-test-tool: failed to run part-disk\n"));
     exit (EXIT_FAILURE);
   }
 
-  if (guestfs_mkfs (g, "ext2", "/dev/sda1") == -1) {
+  if (guestfs_mkfs (g, "ext2", "/dev/" VDISK_KERNEL_NAME "1") == -1) {
     fprintf (stderr,
              _("libguestfs-test-tool: failed to mkfs.ext2\n"));
     exit (EXIT_FAILURE);
   }
 
-  if (guestfs_mount (g, "/dev/sda1", "/") == -1) {
+  if (guestfs_mount (g, "/dev/" VDISK_KERNEL_NAME "1", "/") == -1) {
     fprintf (stderr,
-             _("libguestfs-test-tool: failed to mount /dev/sda1 on /\n"));
+             _("libguestfs-test-tool: failed to mount /dev/" VDISK_KERNEL_NAME "1 on /\n"));
     exit (EXIT_FAILURE);
   }
 
-- 
1.7.12