vhost: fix mbuf free

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.

Fixes: b0a985d1f340 ("vhost: add dequeue zero copy")
Cc: stable@dpdk.org
Signed-off-by: Junjie Chen <junjie.j.chen@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Yuanhan Liu <yliu@fridaylinux.org>

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index a1d8026071319d36bcd0d25a71c31b59a6d2a590..8ef71ccca7b4c68ac7f841f5ae5a9494213eb91c 100644 (file)
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1082,6 +1082,22 @@ 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->buf_addr = (char *)m + mbuf_size;
+               m->buf_iova = rte_mempool_virt2iova(m) + mbuf_size;
+               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)
@@ -1133,6 +1149,7 @@ 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;