On 02/04/2015 17:16, Fam Zheng wrote:
>>>> > >> After qemu_iovec_destroy, the QEMUIOVector's size is zeroed and
>>>> > >> the zero size ultimately is used to compute virtqueue_push's len
>>>> > >> argument. Therefore, reads from virtio-blk devices did not
>>>> > >> migrate their results correctly. (Writes were okay).
>>> > >
>>> > > Can't we move qemu_iovec_destroy to virtio_blk_free_request?
>> >
>> > You would still have to add more code to differentiate reads and
>> > writes---I think.
> Yeah, but the extra field will not be needed.
Can you post an alternative patch? One small complication is that
is_write is in mrb but not in mrb->reqs[x]. virtio_blk_rw_complete is
already doing
int p = virtio_ldl_p(VIRTIO_DEVICE(req->dev), &req->out.type);
bool is_read = !(p & VIRTIO_BLK_T_OUT);
but only in a slow path.
Paolo
