From 2647fab57d5d5e38b36f8dbda367d688045e6a2d Mon Sep 17 00:00:00 2001 From: Peter Lieven Date: Mon, 27 Oct 2014 10:18:44 +0100 Subject: [PATCH] BlockLimits: introduce max_transfer_length Signed-off-by: Peter Lieven Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi --- block.c | 4 ++++ include/block/block_int.h | 3 +++ 2 files changed, 7 insertions(+) diff --git a/block.c b/block.c index 88f6d9b236..76fcc1d6d3 100644 --- a/block.c +++ b/block.c @@ -519,6 +519,7 @@ 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; @@ -533,6 +534,9 @@ 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_NON_ZERO(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); diff --git a/include/block/block_int.h b/include/block/block_int.h index 8898c6c51b..a293e92852 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -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;