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| author | Eric Blake <eblake@redhat.com> | 2016-06-23 16:37:19 -0600 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2016-07-05 16:46:25 +0200 |
| commit | 5def6b80e1eca696c1fc6099e7f4d36729686402 (patch) | |
| tree | 5948b16242a3b57bb1dffa6c650ef05e9154f59e /hw/block | |
| parent | 79ba8c986adb9ca07f52abd0b3d33c3aee8e6ff9 (diff) | |
| download | qemu-5def6b80e1eca696c1fc6099e7f4d36729686402.zip qemu-5def6b80e1eca696c1fc6099e7f4d36729686402.tar.gz qemu-5def6b80e1eca696c1fc6099e7f4d36729686402.tar.bz2 | |
block: Switch transfer length bounds to byte-based
Sector-based limits are awkward to think about; in our on-going
quest to move to byte-based interfaces, convert max_transfer_length
and opt_transfer_length. Rename them (dropping the _length suffix)
so that the compiler will help us catch the change in semantics
across any rebased code, and improve the documentation. Use unsigned
values, so that we don't have to worry about negative values and
so that bit-twiddling is easier; however, we are still constrained
by 2^31 of signed int in most APIs.
When a value comes from an external source (iscsi and raw-posix),
sanitize the results to ensure that opt_transfer is a power of 2.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'hw/block')
| -rw-r--r-- | hw/block/virtio-blk.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index dd94cd4..ae86e94 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -384,7 +384,7 @@ static int multireq_compare(const void *a, const void *b) void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb) { int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0; - int max_xfer_len; + uint32_t max_transfer; int64_t sector_num = 0; if (mrb->num_reqs == 1) { @@ -393,7 +393,7 @@ void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb) return; } - max_xfer_len = blk_get_max_transfer_length(mrb->reqs[0]->dev->blk); + max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk); qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs), &multireq_compare); @@ -409,8 +409,9 @@ void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb) */ if (sector_num + nb_sectors != req->sector_num || niov > blk_get_max_iov(blk) - req->qiov.niov || - req->qiov.size / BDRV_SECTOR_SIZE > max_xfer_len || - nb_sectors > max_xfer_len - req->qiov.size / BDRV_SECTOR_SIZE) { + req->qiov.size > max_transfer || + nb_sectors > (max_transfer - + req->qiov.size) / BDRV_SECTOR_SIZE) { submit_requests(blk, mrb, start, num_reqs, niov); num_reqs = 0; } |