From fea907b6897cb3e644dcee3c537ce6e64d7850ed Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Mon, 11 Jul 2016 05:33:35 +0200 Subject: [PATCH 2/7] BlockLimits: introduce max_transfer_length RH-Author: Fam Zheng Message-id: <1468215219-30793-3-git-send-email-famz@redhat.com> Patchwork-id: 71106 O-Subject: [RHEL-7.3 qemu-kvm PATCH 2/6] BlockLimits: introduce max_transfer_length Bugzilla: 1318199 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: John Snow RH-Acked-by: Paolo Bonzini From: Peter Lieven Signed-off-by: Peter Lieven Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi (cherry picked from commit 2647fab57d5d5e38b36f8dbda367d688045e6a2d) Signed-off-by: Fam Zheng Signed-off-by: Miroslav Rezanina --- block.c | 4 ++++ include/block/block_int.h | 3 +++ 2 files changed, 7 insertions(+) diff --git a/block.c b/block.c index ecb2b09..ae756aa 100644 --- a/block.c +++ b/block.c @@ -481,6 +481,7 @@ 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; @@ -495,6 +496,9 @@ 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 3f86649..28c34d8 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -240,6 +240,9 @@ 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; -- 1.8.3.1