--- kvm-69/qemu/hw/ide.c        2008-05-12 04:30:43.000000000 -0700
+++ kvm-69/qemu/hw/ide.c        2008-05-25 01:44:27.000000000 -0700
@@ -1716,6 +1716,7 @@
     case GPCMD_GET_CONFIGURATION:
         {
             uint32_t len;
+            uint8_t index = 0;
 
             /* only feature 0 is supported */
             if (packet[2] != 0 || packet[3] != 0) {
@@ -1726,41 +1727,40 @@
 
             /* XXX: could result in alignment problems in some architectures */
             max_len = ube16_to_cpu(packet + 7);
-            /*
-             * XXX: avoid overflow for io_buffer if max_len is bigger than the
-             *      size of that buffer (dimensioned to max number of sectors
-             *      to transfer at once)
-             *
-             *      Only a problem if the feature/profiles grow exponentially.
-             */
-            if (max_len > 512) /* XXX: assume 1 sector */
-                max_len = 512;
-
-            memset(buf, 0, max_len);
-            /* 
-             * the number of sectors from the media tells us which profile
-             * to use as current.  0 means there is no media
-             *
-             * XXX: fails to detect correctly DVDs with less data burned
-             *      than what a CD can hold
-             */
-            if ((s -> nb_sectors)) {
-                if ((s -> nb_sectors > CD_MAX_SECTORS))
-                    cpu_to_ube16(buf + 6, MMC_PROFILE_DVD_ROM);
-                else
-                    cpu_to_ube16(buf + 6, MMC_PROFILE_CD_ROM);
-            }
 
-            len = 8; /* header completed */
-            if (max_len > len) {
-                uint8_t index = 0;
-
-                buf[10] = 0x02 | 0x01; /* persistent and current */
-                len += 4; /* header */
-                len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_DVD_ROM);
-                len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_CD_ROM);
-            }
-            cpu_to_ube32(buf, len - 4); /* data length */
+            if (max_len > 0) {
+                /*
+                 * XXX: avoid overflow for io_buffer if max_len is bigger than
+                 *      the size of that buffer (dimensioned to max number of
+                 *      sectors to transfer at once)
+                 *
+                 *      Only a problem if the feature/profiles grow 
+                 */
+                if (max_len > 512) /* XXX: assume 1 sector */
+                    max_len = 512;
+
+                memset(buf, 0, max_len);
+                /* 
+                 * the number of sectors from the media tells us which profile
+                 * to use as current.  0 means there is no media
+                 *
+                 * XXX: fails to detect correctly DVDs with less data burned
+                 *      than what a CD can hold
+                 */
+                if (s -> nb_sectors) {
+                    if (s -> nb_sectors > CD_MAX_SECTORS)
+                        cpu_to_ube16(buf + 6, MMC_PROFILE_DVD_ROM);
+                    else
+                        cpu_to_ube16(buf + 6, MMC_PROFILE_CD_ROM);
+                }
+
+                buf[10] = 0x02 | 0x01; /* persistent and current */
+                len = 12; /* headers: 8 + 4 */
+                len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_DVD_ROM);
+                len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_CD_ROM);
+                cpu_to_ube32(buf, len - 4); /* data length */
+            } else
+                len = 0;
 
             ide_atapi_cmd_reply(s, len, max_len);
             break;