For an O_DIRECT request to succeed, it's not only necessary that all base addresses in the qiov are aligned, but also that each length in it is aligned.
Signed-off-by: Kevin Wolf <kw...@redhat.com> Reviewed-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com> --- block.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block.c b/block.c index 8eae359..62c5a75 100644 --- a/block.c +++ b/block.c @@ -4561,6 +4561,9 @@ bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) if ((uintptr_t) qiov->iov[i].iov_base % bs->buffer_alignment) { return false; } + if (qiov->iov[i].iov_len % bs->buffer_alignment) { + return false; + } } return true; -- 1.8.1.4