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).
Save the size in virtio_blk_handle_request, and use it when the request
is completed.
Based on a patch by Wen Congyang.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Message-id: 1427997044-392-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>