diff options
| -rw-r--r-- | block/io.c | 7 | ||||
| -rw-r--r-- | include/block/block_int.h | 3 |
2 files changed, 10 insertions, 0 deletions
diff --git a/block/io.c b/block/io.c index 841f5b503f..42050a0598 100644 --- a/block/io.c +++ b/block/io.c @@ -166,9 +166,13 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) bs->bl.max_transfer_length = bs->file->bs->bl.max_transfer_length; bs->bl.min_mem_alignment = bs->file->bs->bl.min_mem_alignment; bs->bl.opt_mem_alignment = bs->file->bs->bl.opt_mem_alignment; + bs->bl.max_iov = bs->file->bs->bl.max_iov; } else { bs->bl.min_mem_alignment = 512; bs->bl.opt_mem_alignment = getpagesize(); + + /* Safe default since most protocols use readv()/writev()/etc */ + bs->bl.max_iov = IOV_MAX; } if (bs->backing) { @@ -189,6 +193,9 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) bs->bl.min_mem_alignment = MAX(bs->bl.min_mem_alignment, bs->backing->bs->bl.min_mem_alignment); + bs->bl.max_iov = + MIN(bs->bl.max_iov, + bs->backing->bs->bl.max_iov); } /* Then let the driver override it */ diff --git a/include/block/block_int.h b/include/block/block_int.h index 9a1c466c84..256609dd3d 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -330,6 +330,9 @@ typedef struct BlockLimits { /* memory alignment for bounce buffer */ size_t opt_mem_alignment; + + /* maximum number of iovec elements */ + int max_iov; } BlockLimits; typedef struct BdrvOpBlocker BdrvOpBlocker; |