Rather than only permitting SCSI_DISK0_MAJOR, permit all that blkfront
supports. However, as it is unclear to me what the meaning of major
is on non-Linux (it seems questionable whether non-Linux, if using a
similar major/minor concept, would happen to use major 8 as the first
SCSI disk one), do this extension on Linux only.

Also, is it intentional that the /dev/ prefix (accepted by xm) is not
accepted on the third argument by xl?

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

--- 2010-09-20.orig/tools/libxl/libxl_device.c	2010-09-13 08:54:25.000000000 +0200
+++ 2010-09-20/tools/libxl/libxl_device.c	2010-09-21 12:38:09.000000000 +0200
@@ -194,6 +194,18 @@ int libxl__device_disk_dev_number(char *
     char *ep;
     unsigned long ul;
     int chrused;
+    static const unsigned char scsi_majors[] = {
+#ifdef __linux__
+        SCSI_DISK0_MAJOR,  SCSI_DISK1_MAJOR,  SCSI_DISK2_MAJOR,
+        SCSI_DISK3_MAJOR,  SCSI_DISK4_MAJOR,  SCSI_DISK5_MAJOR,
+        SCSI_DISK6_MAJOR,  SCSI_DISK7_MAJOR,  SCSI_DISK8_MAJOR,
+        SCSI_DISK9_MAJOR,  SCSI_DISK10_MAJOR, SCSI_DISK11_MAJOR,
+        SCSI_DISK12_MAJOR, SCSI_DISK13_MAJOR, SCSI_DISK14_MAJOR,
+        SCSI_DISK15_MAJOR, SCSI_CDROM_MAJOR
+#else
+        8
+#endif
+    };
 
     chrused = -1;
     if ((sscanf(virtpath, "d%ip%i%n", &disk, &partition, &chrused)  >= 2
@@ -219,9 +231,9 @@ int libxl__device_disk_dev_number(char *
         return ((disk<2 ? 3 : 22) << 8) | ((disk & 1) << 6) | partition;
     }
     if (device_virtdisk_matches(virtpath, "sd",
-                                &disk, 15,
+                                &disk, ARRAY_SIZE(scsi_majors) * 16 - 1,
                                 &partition, 15)) {
-        return (8 << 8) | (disk << 4) | partition;
+        return (scsi_majors[disk >> 4] << 8) | ((disk & 0xf) << 4) | partition;
     }
     return -1;
 }
--- 2010-09-20.orig/tools/libxl/libxl_osdeps.h	2010-08-06 08:44:33.000000000 +0200
+++ 2010-09-20/tools/libxl/libxl_osdeps.h	2010-09-21 12:21:00.000000000 +0200
@@ -27,6 +27,7 @@
 #include <util.h>
 #elif defined(__linux__)
 #include <pty.h>
+#include <linux/major.h>
 #elif defined(__sun__)
 #include <stropts.h>
 #endif