@@ -541,6 +541,7 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
return;
}
bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length;
+ bs->bl.max_transfer_length = bs->file->bl.max_transfer_length;
bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment;
} else {
bs->bl.opt_mem_alignment = 512;
@@ -555,6 +556,9 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
bs->bl.opt_transfer_length =
MAX(bs->bl.opt_transfer_length,
bs->backing_hd->bl.opt_transfer_length);
+ bs->bl.max_transfer_length =
+ MIN(bs->bl.max_transfer_length,
+ bs->backing_hd->bl.max_transfer_length);
bs->bl.opt_mem_alignment =
MAX(bs->bl.opt_mem_alignment,
bs->backing_hd->bl.opt_mem_alignment);
@@ -289,6 +289,9 @@ typedef struct BlockLimits {
/* optimal transfer length in sectors */
int opt_transfer_length;
+ /* maximal transfer length in sectors */
+ int max_transfer_length;
+
/* memory alignment so that no bounce buffer is needed */
size_t opt_mem_alignment;
} BlockLimits;