vdi: say why an image is bad

Instead of just putting it in debugging output, we can now put the
value in an Error.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/vdi.c

@@ -399,39 +399,46 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
         ret = -EINVAL;
         goto fail;
     } else if (header.version != VDI_VERSION_1_1) {
-        logout("unsupported version %u.%u\n",
-               header.version >> 16, header.version & 0xffff);
+        error_setg(errp, "unsupported VDI image (version %u.%u)",
+                   header.version >> 16, header.version & 0xffff);
         ret = -ENOTSUP;
         goto fail;
     } else if (header.offset_bmap % SECTOR_SIZE != 0) {
         /* We only support block maps which start on a sector boundary. */
-        logout("unsupported block map offset 0x%x B\n", header.offset_bmap);
+        error_setg(errp, "unsupported VDI image (unaligned block map offset "
+                   "0x%x)", header.offset_bmap);
         ret = -ENOTSUP;
         goto fail;
     } else if (header.offset_data % SECTOR_SIZE != 0) {
         /* We only support data blocks which start on a sector boundary. */
-        logout("unsupported data offset 0x%x B\n", header.offset_data);
+        error_setg(errp, "unsupported VDI image (unaligned data offset 0x%x)",
+                   header.offset_data);
         ret = -ENOTSUP;
         goto fail;
     } else if (header.sector_size != SECTOR_SIZE) {
-        logout("unsupported sector size %u B\n", header.sector_size);
+        error_setg(errp, "unsupported VDI image (sector size %u is not %u)",
+                   header.sector_size, SECTOR_SIZE);
         ret = -ENOTSUP;
         goto fail;
     } else if (header.block_size != 1 * MiB) {
-        logout("unsupported block size %u B\n", header.block_size);
+        error_setg(errp, "unsupported VDI image (sector size %u is not %u)",
+                   header.block_size, 1 * MiB);
         ret = -ENOTSUP;
         goto fail;
     } else if (header.disk_size >
                (uint64_t)header.blocks_in_image * header.block_size) {
-        logout("unsupported disk size %" PRIu64 " B\n", header.disk_size);
+        error_setg(errp, "unsupported VDI image (disk size %" PRIu64 ", "
+                   "image bitmap has room for %" PRIu64 ")",
+                   header.disk_size,
+                   (uint64_t)header.blocks_in_image * header.block_size);
         ret = -ENOTSUP;
         goto fail;
     } else if (!uuid_is_null(header.uuid_link)) {
-        logout("link uuid != 0, unsupported\n");
+        error_setg(errp, "unsupported VDI image (non-NULL link UUID)");
         ret = -ENOTSUP;
         goto fail;
     } else if (!uuid_is_null(header.uuid_parent)) {
-        logout("parent uuid != 0, unsupported\n");
+        error_setg(errp, "unsupported VDI image (non-NULL parent UUID)");
         ret = -ENOTSUP;
         goto fail;
     }