diff -ur xen-2.0/linux-2.6.9-xen-sparse/drivers/xen/blkfront/blkfront.c xen-2.0-new/linux-2.6.9-xen-sparse/drivers/xen/blkfront/blkfront.c
--- xen-2.0/linux-2.6.9-xen-sparse/drivers/xen/blkfront/blkfront.c	2005-01-03 21:46:09.000000000 -0600
+++ xen-2.0-new/linux-2.6.9-xen-sparse/drivers/xen/blkfront/blkfront.c	2005-01-05 14:22:11.000000000 -0600
@@ -236,6 +236,7 @@
 int blkif_ioctl(struct inode *inode, struct file *filep,
                 unsigned command, unsigned long argument)
 {
+	int i;
     /*  struct gendisk *gd = inode->i_bdev->bd_disk; */
 
     DPRINTK_IOCTL("command: 0x%x, argument: 0x%lx, dev: 0x%04x\n",
@@ -247,6 +248,12 @@
         /* return ENOSYS to use defaults */
         return -ENOSYS;
 
+    case CDROMMULTISESSION:
+        DPRINTK("FIXME: support multisession CDs later\n");
+        for ( i = 0; i < sizeof(struct cdrom_multisession); i++ )
+            if ( put_user(0, (byte *)(argument + i)) ) return -EFAULT;
+        return 0;
+
     default:
         printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n",
                command);