> -----Original Message-----
> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Junjie Chen
> Sent: Wednesday, January 17, 2018 6:42 PM
> To: y...@fridaylinux.org; maxime.coque...@redhat.com
> Cc: dev@dpdk.org; Chen, Junjie J
> Subject: [dpdk-dev] [PATCH] vhost: dequeue zero copy should restore mbuf
> before return to pool
>
> dequeue zero copy change buf_addr and buf_iova of mbuf, and return
> to mbuf pool without restore them, it breaks vm memory if others allocate
> mbuf from same pool since mbuf reset doesn't reset buf_addr and buf_iova.
>
> Signed-off-by: Junjie Chen <junjie.j.c...@intel.com>
> ---
> lib/librte_vhost/virtio_net.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 568ad0e..e9aaf6d 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -1158,6 +1158,26 @@ mbuf_is_consumed(struct rte_mbuf *m)
> return true;
> }
>
> +
> +static __rte_always_inline void
> +restore_mbuf(struct rte_mbuf *m)
> +{
> + uint32_t mbuf_size, priv_size;
> +
> + while (m) {
> + priv_size = rte_pktmbuf_priv_size(m->pool);
> + mbuf_size = sizeof(struct rte_mbuf) + priv_size;
> + /* start of buffer is after mbuf structure and priv data */
> + m->priv_size = priv_size;
I don't think we need to restore priv_size. Refer to its definition in rte_mbuf:
"Size of the application private data. In case of an indirect mbuf, it
stores the direct mbuf private data size."
Thanks,
Jianfeng
> +
> + m->buf_addr = (char *)m + mbuf_size;
> + m->buf_iova = rte_mempool_virt2iova(m) + mbuf_size;
> + m->data_off = RTE_MIN(RTE_PKTMBUF_HEADROOM,
> + (uint16_t)m->buf_len);
> + m = m->next;
> + }
> +}
> +
> uint16_t
> rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
> struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t
> count)
> @@ -1209,6 +1229,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t
> queue_id,
> nr_updated += 1;
>
> TAILQ_REMOVE(&vq->zmbuf_list, zmbuf,
> next);
> + restore_mbuf(zmbuf->mbuf);
> rte_pktmbuf_free(zmbuf->mbuf);
> put_zmbuf(zmbuf);
> vq->nr_zmbuf -= 1;
> --
> 2.0.1
