[PATCH] tools: libxl: translate xvd[a-d] to hd[a-d] for new qemu

[Ian Campbell <ian.campbell@citrix.com>]

# HG changeset patch
# User Ian Campbell <ian.campbell@citrix.com>
# Date 1301571089 -3600
# Node ID d0dd569bfcb0f5f8e2d903c8b6f9999ff1290e96
# Parent  7b5c5a365f2a0a57e83479f69e5b56beb07752c1
tools: libxl: translate xvd[a-d] to hd[a-d] for new qemu

xvde+ are ignored.

Old qemu did this itself internally. Fixes "qemu: -xvda: invalid
option" and allows PVHVM to work with new qemu.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>

diff -r 7b5c5a365f2a -r d0dd569bfcb0 tools/libxl/libxl_dm.c
--- a/tools/libxl/libxl_dm.c	Thu Mar 31 11:57:29 2011 +0100
+++ b/tools/libxl/libxl_dm.c	Thu Mar 31 12:31:29 2011 +0100
@@ -175,6 +175,7 @@ static char ** libxl__build_device_model
                                                   libxl_device_nic *vifs,
                                                   int num_vifs)
 {
+    libxl_ctx *ctx = libxl__gc_owner(gc);
     flexarray_t *dm_args;
     libxl_device_disk *disks;
     int nb, i;
@@ -318,8 +319,25 @@ static char ** libxl__build_device_model
                 flexarray_append(dm_args, "-cdrom");
                 flexarray_append(dm_args, libxl__strdup(gc, disks[i].pdev_path));
             } else {
-                flexarray_append(dm_args, libxl__sprintf(gc, "-%s", disks[i].vdev));
-                flexarray_append(dm_args, libxl__strdup(gc, disks[i].pdev_path));
+                char hd_dev[] = "hdX";
+                const char *vdev = NULL;
+
+                if (strncmp(disks[i].vdev, "xvd", 3) == 0) {
+                    if (disks[i].vdev[3] >= 'a' && disks[i].vdev[3] <= 'd') {
+                        hd_dev[2] = disks[i].vdev[3];
+                        vdev = &hd_dev[0];
+                        LIBXL__LOG(ctx, LIBXL__LOG_INFO, "translated disk device %s to %s", disks[i].vdev, vdev);
+                    } else {
+                        LIBXL__LOG(ctx, LIBXL__LOG_INFO, "ignored disk device %s", disks[i].vdev);
+                    }
+                } else {
+                    vdev = disks[i].vdev;
+                }
+
+                if (vdev) {
+                    flexarray_append(dm_args, libxl__sprintf(gc, "-%s", vdev));
+                    flexarray_append(dm_args, libxl__strdup(gc, disks[i].pdev_path));
+                }
             }
             libxl_device_disk_destroy(&disks[i]);
         }