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author | Stefan Hajnoczi <stefanha@redhat.com> | 2015-07-09 10:56:44 +0100 |
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committer | Timothy Pearson <tpearson@raptorengineering.com> | 2019-11-29 19:28:20 -0600 |
commit | aaeb3a609de0b3a8d7e8dc1ca3a1c6a5735a28a8 (patch) | |
tree | a332bd5906f878580df65521655f4efa3496da5d /block/io.c | |
parent | a6685041cc35ed9c5fb106db5f4498b7c5060979 (diff) | |
download | hqemu-aaeb3a609de0b3a8d7e8dc1ca3a1c6a5735a28a8.zip hqemu-aaeb3a609de0b3a8d7e8dc1ca3a1c6a5735a28a8.tar.gz |
block: add BlockLimits.max_iov field
The maximum number of struct iovec elements depends on the
BlockDriverState. The raw-posix and iSCSI protocols have a maximum of
IOV_MAX but others could have different values.
Cc: Peter Lieven <pl@kamp.de>
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/io.c')
-rw-r--r-- | block/io.c | 7 |
1 files changed, 7 insertions, 0 deletions
@@ -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 */ |