[Xen-devel] [PATCH 4 of 5] libxl: specify disks using supported command line syntax for new qemu

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

# HG changeset patch
# User Ian Campbell <ian.campbell@xxxxxxxxxx>
# Date 1301923169 -3600
# Node ID 4243987a85117cb2fe417e5290a0e894f035f85d
# Parent  8abca96d78c1368cee94c3ac5984a92aebbb2711
libxl: specify disks using supported command line syntax for new qemu

The -hdX syntax is only retained for compatibility reasons and the
-sdX syntax doesn't even exist.

Additionally convert the first four non-SCSI disks to hd[a-d] and
ignore any further non-SCSI disks (since qemu only supports 4 IDE
devices).

SCSI disks are passed through as is. qemu-xen was limited to 7 SCSI
devices but upstream qemu supports 256, therefore do not limit the
number of disks on the libxl side.

qemu-xen did all this itself internally.

Fixes "qemu: -xvda: invalid option" and allows PVHVM to work with
upstream qemu.

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

diff -r 8abca96d78c1 -r 4243987a8511 tools/libxl/libxl_dm.c
--- a/tools/libxl/libxl_dm.c    Mon Apr 04 14:19:29 2011 +0100
+++ b/tools/libxl/libxl_dm.c    Mon Apr 04 14:19:29 2011 +0100
@@ -175,6 +175,7 @@ static char ** libxl__build_device_model
                                                   libxl_device_disk *disks, 
int num_disks,
                                                   libxl_device_nic *vifs, int 
num_vifs)
 {
+    libxl_ctx *ctx = libxl__gc_owner(gc);
     flexarray_t *dm_args;
     int i;
 
@@ -312,13 +313,43 @@ static char ** libxl__build_device_model
 
     if (info->type == XENFV) {
         for (i; i < num_disks; i++) {
+            int disk, part;
+            int dev_number = libxl__device_disk_dev_number(disks[i].vdev, 
&disk, &part);
+            char *drive;
+
+            if (dev_number == -1) {
+                LIBXL__LOG(ctx, LIBXL__LOG_WARNING, "unable to determine disk 
number for %s", disks[i].vdev);
+                continue;
+            }
+
             if (disks[i].is_cdrom) {
-                flexarray_append(dm_args, "-cdrom");
-                flexarray_append(dm_args, libxl__strdup(gc, 
disks[i].pdev_path));
+                if (disks[i].format == DISK_FORMAT_EMPTY)
+                    drive = libxl__sprintf(gc, "if=ide,index=%d,media=cdrom", 
disk);
+                else
+                    drive = libxl__sprintf(gc, 
"file=%s,if=ide,index=%d,media=cdrom",
+                                           disks[i].pdev_path, disk);
             } else {
-                flexarray_append(dm_args, libxl__sprintf(gc, "-%s", 
disks[i].vdev));
-                flexarray_append(dm_args, libxl__strdup(gc, 
disks[i].pdev_path));
+                if (disks[i].format == DISK_FORMAT_EMPTY)
+                    continue;
+
+                /*
+                 * Explicit sd disks are passed through as is.
+                 *
+                 * For other disks we translate devices 0..3 into
+                 * hd[a-d] and ignore the rest.
+                 */
+                if (strncmp(disks[i].vdev, "sd", 2) == 0)
+                    drive = libxl__sprintf(gc, "file=%s,if=scsi,bus=0,unit=%d",
+                                           disks[i].pdev_path, disk);
+                else if (disk < 4)
+                    drive = libxl__sprintf(gc, 
"file=%s,if=ide,index=%d,media=disk",
+                                           disks[i].pdev_path, disk);
+                else
+                    continue; /* Do not emulate this disk */
             }
+
+            flexarray_append(dm_args, "-drive");
+            flexarray_append(dm_args, drive);
         }
     }
     flexarray_append(dm_args, NULL);

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel