vhost: fix async copy on multi-page buffers
[dpdk.git] / lib / librte_vhost / virtio_net.c
index ca89288..bd9303c 100644 (file)
 #include <rte_udp.h>
 #include <rte_sctp.h>
 #include <rte_arp.h>
+#include <rte_spinlock.h>
+#include <rte_malloc.h>
+#include <rte_vhost_async.h>
 
 #include "iotlb.h"
 #include "vhost.h"
 
-#define MAX_PKT_BURST 32
-
 #define MAX_BATCH_LEN 256
 
+#define VHOST_ASYNC_BATCH_THRESHOLD 32
+
+static  __rte_always_inline bool
+rxvq_is_mergeable(struct virtio_net *dev)
+{
+       return dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF);
+}
+
+static  __rte_always_inline bool
+virtio_net_is_inorder(struct virtio_net *dev)
+{
+       return dev->features & (1ULL << VIRTIO_F_IN_ORDER);
+}
+
 static bool
 is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t nr_vring)
 {
        return (is_tx ^ (idx & 1)) == 0 && idx < nr_vring;
 }
 
+static inline void
+do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
+{
+       struct batch_copy_elem *elem = vq->batch_copy_elems;
+       uint16_t count = vq->batch_copy_nb_elems;
+       int i;
+
+       for (i = 0; i < count; i++) {
+               rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
+               vhost_log_cache_write_iova(dev, vq, elem[i].log_addr,
+                                          elem[i].len);
+               PRINT_PACKET(dev, (uintptr_t)elem[i].dst, elem[i].len, 0);
+       }
+
+       vq->batch_copy_nb_elems = 0;
+}
+
+static inline void
+do_data_copy_dequeue(struct vhost_virtqueue *vq)
+{
+       struct batch_copy_elem *elem = vq->batch_copy_elems;
+       uint16_t count = vq->batch_copy_nb_elems;
+       int i;
+
+       for (i = 0; i < count; i++)
+               rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
+
+       vq->batch_copy_nb_elems = 0;
+}
+
 static __rte_always_inline void
-do_flush_shadow_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
-                         uint16_t to, uint16_t from, uint16_t size)
+do_flush_shadow_used_ring_split(struct virtio_net *dev,
+                       struct vhost_virtqueue *vq,
+                       uint16_t to, uint16_t from, uint16_t size)
 {
        rte_memcpy(&vq->used->ring[to],
-                       &vq->shadow_used_ring[from],
+                       &vq->shadow_used_split[from],
                        size * sizeof(struct vring_used_elem));
-       vhost_log_used_vring(dev, vq,
+       vhost_log_cache_used_vring(dev, vq,
                        offsetof(struct vring_used, ring[to]),
                        size * sizeof(struct vring_used_elem));
 }
 
 static __rte_always_inline void
-flush_shadow_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq)
+flush_shadow_used_ring_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
 {
        uint16_t used_idx = vq->last_used_idx & (vq->size - 1);
 
        if (used_idx + vq->shadow_used_idx <= vq->size) {
-               do_flush_shadow_used_ring(dev, vq, used_idx, 0,
+               do_flush_shadow_used_ring_split(dev, vq, used_idx, 0,
                                          vq->shadow_used_idx);
        } else {
                uint16_t size;
 
                /* update used ring interval [used_idx, vq->size] */
                size = vq->size - used_idx;
-               do_flush_shadow_used_ring(dev, vq, used_idx, 0, size);
+               do_flush_shadow_used_ring_split(dev, vq, used_idx, 0, size);
 
                /* update the left half used ring interval [0, left_size] */
-               do_flush_shadow_used_ring(dev, vq, 0, size,
+               do_flush_shadow_used_ring_split(dev, vq, 0, size,
                                          vq->shadow_used_idx - size);
        }
        vq->last_used_idx += vq->shadow_used_idx;
 
-       rte_smp_wmb();
+       vhost_log_cache_sync(dev, vq);
 
-       *(volatile uint16_t *)&vq->used->idx += vq->shadow_used_idx;
+       __atomic_add_fetch(&vq->used->idx, vq->shadow_used_idx,
+                          __ATOMIC_RELEASE);
+       vq->shadow_used_idx = 0;
        vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
                sizeof(vq->used->idx));
 }
 
 static __rte_always_inline void
-update_shadow_used_ring(struct vhost_virtqueue *vq,
-                        uint16_t desc_idx, uint16_t len)
+async_flush_shadow_used_ring_split(struct virtio_net *dev,
+       struct vhost_virtqueue *vq)
+{
+       uint16_t used_idx = vq->last_used_idx & (vq->size - 1);
+
+       if (used_idx + vq->shadow_used_idx <= vq->size) {
+               do_flush_shadow_used_ring_split(dev, vq, used_idx, 0,
+                                         vq->shadow_used_idx);
+       } else {
+               uint16_t size;
+
+               /* update used ring interval [used_idx, vq->size] */
+               size = vq->size - used_idx;
+               do_flush_shadow_used_ring_split(dev, vq, used_idx, 0, size);
+
+               /* update the left half used ring interval [0, left_size] */
+               do_flush_shadow_used_ring_split(dev, vq, 0, size,
+                                         vq->shadow_used_idx - size);
+       }
+
+       vq->last_used_idx += vq->shadow_used_idx;
+       vq->shadow_used_idx = 0;
+}
+
+static __rte_always_inline void
+update_shadow_used_ring_split(struct vhost_virtqueue *vq,
+                        uint16_t desc_idx, uint32_t len)
 {
        uint16_t i = vq->shadow_used_idx++;
 
-       vq->shadow_used_ring[i].id  = desc_idx;
-       vq->shadow_used_ring[i].len = len;
+       vq->shadow_used_split[i].id  = desc_idx;
+       vq->shadow_used_split[i].len = len;
 }
 
-static inline void
-do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
+static __rte_always_inline void
+vhost_flush_enqueue_shadow_packed(struct virtio_net *dev,
+                                 struct vhost_virtqueue *vq)
 {
-       struct batch_copy_elem *elem = vq->batch_copy_elems;
-       uint16_t count = vq->batch_copy_nb_elems;
        int i;
+       uint16_t used_idx = vq->last_used_idx;
+       uint16_t head_idx = vq->last_used_idx;
+       uint16_t head_flags = 0;
+
+       /* Split loop in two to save memory barriers */
+       for (i = 0; i < vq->shadow_used_idx; i++) {
+               vq->desc_packed[used_idx].id = vq->shadow_used_packed[i].id;
+               vq->desc_packed[used_idx].len = vq->shadow_used_packed[i].len;
+
+               used_idx += vq->shadow_used_packed[i].count;
+               if (used_idx >= vq->size)
+                       used_idx -= vq->size;
+       }
 
-       for (i = 0; i < count; i++) {
-               rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
-               vhost_log_write(dev, elem[i].log_addr, elem[i].len);
-               PRINT_PACKET(dev, (uintptr_t)elem[i].dst, elem[i].len, 0);
+       rte_smp_wmb();
+
+       for (i = 0; i < vq->shadow_used_idx; i++) {
+               uint16_t flags;
+
+               if (vq->shadow_used_packed[i].len)
+                       flags = VRING_DESC_F_WRITE;
+               else
+                       flags = 0;
+
+               if (vq->used_wrap_counter) {
+                       flags |= VRING_DESC_F_USED;
+                       flags |= VRING_DESC_F_AVAIL;
+               } else {
+                       flags &= ~VRING_DESC_F_USED;
+                       flags &= ~VRING_DESC_F_AVAIL;
+               }
+
+               if (i > 0) {
+                       vq->desc_packed[vq->last_used_idx].flags = flags;
+
+                       vhost_log_cache_used_vring(dev, vq,
+                                       vq->last_used_idx *
+                                       sizeof(struct vring_packed_desc),
+                                       sizeof(struct vring_packed_desc));
+               } else {
+                       head_idx = vq->last_used_idx;
+                       head_flags = flags;
+               }
+
+               vq_inc_last_used_packed(vq, vq->shadow_used_packed[i].count);
        }
+
+       vq->desc_packed[head_idx].flags = head_flags;
+
+       vhost_log_cache_used_vring(dev, vq,
+                               head_idx *
+                               sizeof(struct vring_packed_desc),
+                               sizeof(struct vring_packed_desc));
+
+       vq->shadow_used_idx = 0;
+       vhost_log_cache_sync(dev, vq);
 }
 
-static inline void
-do_data_copy_dequeue(struct vhost_virtqueue *vq)
+static __rte_always_inline void
+vhost_flush_dequeue_shadow_packed(struct virtio_net *dev,
+                                 struct vhost_virtqueue *vq)
 {
-       struct batch_copy_elem *elem = vq->batch_copy_elems;
-       uint16_t count = vq->batch_copy_nb_elems;
-       int i;
+       struct vring_used_elem_packed *used_elem = &vq->shadow_used_packed[0];
 
-       for (i = 0; i < count; i++)
-               rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
+       vq->desc_packed[vq->shadow_last_used_idx].id = used_elem->id;
+       rte_smp_wmb();
+       vq->desc_packed[vq->shadow_last_used_idx].flags = used_elem->flags;
+
+       vhost_log_cache_used_vring(dev, vq, vq->shadow_last_used_idx *
+                                  sizeof(struct vring_packed_desc),
+                                  sizeof(struct vring_packed_desc));
+       vq->shadow_used_idx = 0;
+       vhost_log_cache_sync(dev, vq);
+}
+
+static __rte_always_inline void
+vhost_flush_enqueue_batch_packed(struct virtio_net *dev,
+                                struct vhost_virtqueue *vq,
+                                uint64_t *lens,
+                                uint16_t *ids)
+{
+       uint16_t i;
+       uint16_t flags;
+
+       if (vq->shadow_used_idx) {
+               do_data_copy_enqueue(dev, vq);
+               vhost_flush_enqueue_shadow_packed(dev, vq);
+       }
+
+       flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq->used_wrap_counter);
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               vq->desc_packed[vq->last_used_idx + i].id = ids[i];
+               vq->desc_packed[vq->last_used_idx + i].len = lens[i];
+       }
+
+       rte_smp_wmb();
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               vq->desc_packed[vq->last_used_idx + i].flags = flags;
+
+       vhost_log_cache_used_vring(dev, vq, vq->last_used_idx *
+                                  sizeof(struct vring_packed_desc),
+                                  sizeof(struct vring_packed_desc) *
+                                  PACKED_BATCH_SIZE);
+       vhost_log_cache_sync(dev, vq);
+
+       vq_inc_last_used_packed(vq, PACKED_BATCH_SIZE);
+}
+
+static __rte_always_inline void
+vhost_shadow_dequeue_batch_packed_inorder(struct vhost_virtqueue *vq,
+                                         uint16_t id)
+{
+       vq->shadow_used_packed[0].id = id;
+
+       if (!vq->shadow_used_idx) {
+               vq->shadow_last_used_idx = vq->last_used_idx;
+               vq->shadow_used_packed[0].flags =
+                       PACKED_DESC_DEQUEUE_USED_FLAG(vq->used_wrap_counter);
+               vq->shadow_used_packed[0].len = 0;
+               vq->shadow_used_packed[0].count = 1;
+               vq->shadow_used_idx++;
+       }
+
+       vq_inc_last_used_packed(vq, PACKED_BATCH_SIZE);
+}
+
+static __rte_always_inline void
+vhost_shadow_dequeue_batch_packed(struct virtio_net *dev,
+                                 struct vhost_virtqueue *vq,
+                                 uint16_t *ids)
+{
+       uint16_t flags;
+       uint16_t i;
+       uint16_t begin;
+
+       flags = PACKED_DESC_DEQUEUE_USED_FLAG(vq->used_wrap_counter);
+
+       if (!vq->shadow_used_idx) {
+               vq->shadow_last_used_idx = vq->last_used_idx;
+               vq->shadow_used_packed[0].id  = ids[0];
+               vq->shadow_used_packed[0].len = 0;
+               vq->shadow_used_packed[0].count = 1;
+               vq->shadow_used_packed[0].flags = flags;
+               vq->shadow_used_idx++;
+               begin = 1;
+       } else
+               begin = 0;
+
+       vhost_for_each_try_unroll(i, begin, PACKED_BATCH_SIZE) {
+               vq->desc_packed[vq->last_used_idx + i].id = ids[i];
+               vq->desc_packed[vq->last_used_idx + i].len = 0;
+       }
+
+       rte_smp_wmb();
+       vhost_for_each_try_unroll(i, begin, PACKED_BATCH_SIZE)
+               vq->desc_packed[vq->last_used_idx + i].flags = flags;
+
+       vhost_log_cache_used_vring(dev, vq, vq->last_used_idx *
+                                  sizeof(struct vring_packed_desc),
+                                  sizeof(struct vring_packed_desc) *
+                                  PACKED_BATCH_SIZE);
+       vhost_log_cache_sync(dev, vq);
+
+       vq_inc_last_used_packed(vq, PACKED_BATCH_SIZE);
+}
+
+static __rte_always_inline void
+vhost_shadow_dequeue_single_packed(struct vhost_virtqueue *vq,
+                                  uint16_t buf_id,
+                                  uint16_t count)
+{
+       uint16_t flags;
+
+       flags = vq->desc_packed[vq->last_used_idx].flags;
+       if (vq->used_wrap_counter) {
+               flags |= VRING_DESC_F_USED;
+               flags |= VRING_DESC_F_AVAIL;
+       } else {
+               flags &= ~VRING_DESC_F_USED;
+               flags &= ~VRING_DESC_F_AVAIL;
+       }
+
+       if (!vq->shadow_used_idx) {
+               vq->shadow_last_used_idx = vq->last_used_idx;
+
+               vq->shadow_used_packed[0].id  = buf_id;
+               vq->shadow_used_packed[0].len = 0;
+               vq->shadow_used_packed[0].flags = flags;
+               vq->shadow_used_idx++;
+       } else {
+               vq->desc_packed[vq->last_used_idx].id = buf_id;
+               vq->desc_packed[vq->last_used_idx].len = 0;
+               vq->desc_packed[vq->last_used_idx].flags = flags;
+       }
+
+       vq_inc_last_used_packed(vq, count);
+}
+
+static __rte_always_inline void
+vhost_shadow_dequeue_single_packed_inorder(struct vhost_virtqueue *vq,
+                                          uint16_t buf_id,
+                                          uint16_t count)
+{
+       uint16_t flags;
+
+       vq->shadow_used_packed[0].id = buf_id;
+
+       flags = vq->desc_packed[vq->last_used_idx].flags;
+       if (vq->used_wrap_counter) {
+               flags |= VRING_DESC_F_USED;
+               flags |= VRING_DESC_F_AVAIL;
+       } else {
+               flags &= ~VRING_DESC_F_USED;
+               flags &= ~VRING_DESC_F_AVAIL;
+       }
+
+       if (!vq->shadow_used_idx) {
+               vq->shadow_last_used_idx = vq->last_used_idx;
+               vq->shadow_used_packed[0].len = 0;
+               vq->shadow_used_packed[0].flags = flags;
+               vq->shadow_used_idx++;
+       }
+
+       vq_inc_last_used_packed(vq, count);
+}
+
+static __rte_always_inline void
+vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
+                                  struct vhost_virtqueue *vq,
+                                  uint32_t len[],
+                                  uint16_t id[],
+                                  uint16_t count[],
+                                  uint16_t num_buffers)
+{
+       uint16_t i;
+       for (i = 0; i < num_buffers; i++) {
+               /* enqueue shadow flush action aligned with batch num */
+               if (!vq->shadow_used_idx)
+                       vq->shadow_aligned_idx = vq->last_used_idx &
+                               PACKED_BATCH_MASK;
+               vq->shadow_used_packed[vq->shadow_used_idx].id  = id[i];
+               vq->shadow_used_packed[vq->shadow_used_idx].len = len[i];
+               vq->shadow_used_packed[vq->shadow_used_idx].count = count[i];
+               vq->shadow_aligned_idx += count[i];
+               vq->shadow_used_idx++;
+       }
+
+       if (vq->shadow_aligned_idx >= PACKED_BATCH_SIZE) {
+               do_data_copy_enqueue(dev, vq);
+               vhost_flush_enqueue_shadow_packed(dev, vq);
+       }
 }
 
 /* avoid write operation when necessary, to lessen cache issues */
@@ -110,7 +418,7 @@ do_data_copy_dequeue(struct vhost_virtqueue *vq)
                (var) = (val);                  \
 } while (0)
 
-static void
+static __rte_always_inline void
 virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 {
        uint64_t csum_l4 = m_buf->ol_flags & PKT_TX_L4_MASK;
@@ -124,15 +432,15 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 
                switch (csum_l4) {
                case PKT_TX_TCP_CKSUM:
-                       net_hdr->csum_offset = (offsetof(struct tcp_hdr,
+                       net_hdr->csum_offset = (offsetof(struct rte_tcp_hdr,
                                                cksum));
                        break;
                case PKT_TX_UDP_CKSUM:
-                       net_hdr->csum_offset = (offsetof(struct udp_hdr,
+                       net_hdr->csum_offset = (offsetof(struct rte_udp_hdr,
                                                dgram_cksum));
                        break;
                case PKT_TX_SCTP_CKSUM:
-                       net_hdr->csum_offset = (offsetof(struct sctp_hdr,
+                       net_hdr->csum_offset = (offsetof(struct rte_sctp_hdr,
                                                cksum));
                        break;
                }
@@ -144,10 +452,11 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 
        /* IP cksum verification cannot be bypassed, then calculate here */
        if (m_buf->ol_flags & PKT_TX_IP_CKSUM) {
-               struct ipv4_hdr *ipv4_hdr;
+               struct rte_ipv4_hdr *ipv4_hdr;
 
-               ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct ipv4_hdr *,
+               ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct rte_ipv4_hdr *,
                                                   m_buf->l2_len);
+               ipv4_hdr->hdr_checksum = 0;
                ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
        }
 
@@ -172,331 +481,338 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 }
 
 static __rte_always_inline int
-copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
-                 struct vring_desc *descs, struct rte_mbuf *m,
-                 uint16_t desc_idx, uint32_t size)
+map_one_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
+               struct buf_vector *buf_vec, uint16_t *vec_idx,
+               uint64_t desc_iova, uint64_t desc_len, uint8_t perm)
 {
-       uint32_t desc_avail, desc_offset;
-       uint32_t mbuf_avail, mbuf_offset;
-       uint32_t cpy_len;
-       struct vring_desc *desc;
-       uint64_t desc_addr;
-       /* A counter to avoid desc dead loop chain */
-       uint16_t nr_desc = 1;
-       struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
-       uint16_t copy_nb = vq->batch_copy_nb_elems;
-       int error = 0;
+       uint16_t vec_id = *vec_idx;
 
-       desc = &descs[desc_idx];
-       desc_addr = vhost_iova_to_vva(dev, vq, desc->addr,
-                                       desc->len, VHOST_ACCESS_RW);
-       /*
-        * Checking of 'desc_addr' placed outside of 'unlikely' macro to avoid
-        * performance issue with some versions of gcc (4.8.4 and 5.3.0) which
-        * otherwise stores offset on the stack instead of in a register.
-        */
-       if (unlikely(desc->len < dev->vhost_hlen) || !desc_addr) {
-               error = -1;
-               goto out;
-       }
+       while (desc_len) {
+               uint64_t desc_addr;
+               uint64_t desc_chunck_len = desc_len;
 
-       rte_prefetch0((void *)(uintptr_t)desc_addr);
+               if (unlikely(vec_id >= BUF_VECTOR_MAX))
+                       return -1;
 
-       virtio_enqueue_offload(m, (struct virtio_net_hdr *)(uintptr_t)desc_addr);
-       vhost_log_write(dev, desc->addr, dev->vhost_hlen);
-       PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
+               desc_addr = vhost_iova_to_vva(dev, vq,
+                               desc_iova,
+                               &desc_chunck_len,
+                               perm);
+               if (unlikely(!desc_addr))
+                       return -1;
 
-       desc_offset = dev->vhost_hlen;
-       desc_avail  = desc->len - dev->vhost_hlen;
+               rte_prefetch0((void *)(uintptr_t)desc_addr);
 
-       mbuf_avail  = rte_pktmbuf_data_len(m);
-       mbuf_offset = 0;
-       while (mbuf_avail != 0 || m->next != NULL) {
-               /* done with current mbuf, fetch next */
-               if (mbuf_avail == 0) {
-                       m = m->next;
+               buf_vec[vec_id].buf_iova = desc_iova;
+               buf_vec[vec_id].buf_addr = desc_addr;
+               buf_vec[vec_id].buf_len  = desc_chunck_len;
 
-                       mbuf_offset = 0;
-                       mbuf_avail  = rte_pktmbuf_data_len(m);
-               }
+               desc_len -= desc_chunck_len;
+               desc_iova += desc_chunck_len;
+               vec_id++;
+       }
+       *vec_idx = vec_id;
 
-               /* done with current desc buf, fetch next */
-               if (desc_avail == 0) {
-                       if ((desc->flags & VRING_DESC_F_NEXT) == 0) {
-                               /* Room in vring buffer is not enough */
-                               error = -1;
-                               goto out;
-                       }
-                       if (unlikely(desc->next >= size || ++nr_desc > size)) {
-                               error = -1;
-                               goto out;
-                       }
+       return 0;
+}
 
-                       desc = &descs[desc->next];
-                       desc_addr = vhost_iova_to_vva(dev, vq, desc->addr,
-                                                       desc->len,
-                                                       VHOST_ACCESS_RW);
-                       if (unlikely(!desc_addr)) {
-                               error = -1;
-                               goto out;
-                       }
+static __rte_always_inline int
+fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
+                        uint32_t avail_idx, uint16_t *vec_idx,
+                        struct buf_vector *buf_vec, uint16_t *desc_chain_head,
+                        uint32_t *desc_chain_len, uint8_t perm)
+{
+       uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
+       uint16_t vec_id = *vec_idx;
+       uint32_t len    = 0;
+       uint64_t dlen;
+       uint32_t nr_descs = vq->size;
+       uint32_t cnt    = 0;
+       struct vring_desc *descs = vq->desc;
+       struct vring_desc *idesc = NULL;
 
-                       desc_offset = 0;
-                       desc_avail  = desc->len;
-               }
+       if (unlikely(idx >= vq->size))
+               return -1;
 
-               cpy_len = RTE_MIN(desc_avail, mbuf_avail);
-               if (likely(cpy_len > MAX_BATCH_LEN || copy_nb >= vq->size)) {
-                       rte_memcpy((void *)((uintptr_t)(desc_addr +
-                                                       desc_offset)),
-                               rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
-                               cpy_len);
-                       vhost_log_write(dev, desc->addr + desc_offset, cpy_len);
-                       PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
-                                    cpy_len, 0);
-               } else {
-                       batch_copy[copy_nb].dst =
-                               (void *)((uintptr_t)(desc_addr + desc_offset));
-                       batch_copy[copy_nb].src =
-                               rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
-                       batch_copy[copy_nb].log_addr = desc->addr + desc_offset;
-                       batch_copy[copy_nb].len = cpy_len;
-                       copy_nb++;
-               }
+       *desc_chain_head = idx;
 
-               mbuf_avail  -= cpy_len;
-               mbuf_offset += cpy_len;
-               desc_avail  -= cpy_len;
-               desc_offset += cpy_len;
-       }
+       if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
+               dlen = vq->desc[idx].len;
+               nr_descs = dlen / sizeof(struct vring_desc);
+               if (unlikely(nr_descs > vq->size))
+                       return -1;
 
-out:
-       vq->batch_copy_nb_elems = copy_nb;
+               descs = (struct vring_desc *)(uintptr_t)
+                       vhost_iova_to_vva(dev, vq, vq->desc[idx].addr,
+                                               &dlen,
+                                               VHOST_ACCESS_RO);
+               if (unlikely(!descs))
+                       return -1;
 
-       return error;
-}
+               if (unlikely(dlen < vq->desc[idx].len)) {
+                       /*
+                        * The indirect desc table is not contiguous
+                        * in process VA space, we have to copy it.
+                        */
+                       idesc = vhost_alloc_copy_ind_table(dev, vq,
+                                       vq->desc[idx].addr, vq->desc[idx].len);
+                       if (unlikely(!idesc))
+                               return -1;
 
-/**
- * This function adds buffers to the virtio devices RX virtqueue. Buffers can
- * be received from the physical port or from another virtio device. A packet
- * count is returned to indicate the number of packets that are successfully
- * added to the RX queue. This function works when the mbuf is scattered, but
- * it doesn't support the mergeable feature.
- */
-static __rte_always_inline uint32_t
-virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
-             struct rte_mbuf **pkts, uint32_t count)
-{
-       struct vhost_virtqueue *vq;
-       uint16_t avail_idx, free_entries, start_idx;
-       uint16_t desc_indexes[MAX_PKT_BURST];
-       struct vring_desc *descs;
-       uint16_t used_idx;
-       uint32_t i, sz;
+                       descs = idesc;
+               }
 
-       LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
-       if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
-               RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
-                       dev->vid, __func__, queue_id);
-               return 0;
+               idx = 0;
        }
 
-       vq = dev->virtqueue[queue_id];
-       if (unlikely(vq->enabled == 0))
-               return 0;
-
-       if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
-               vhost_user_iotlb_rd_lock(vq);
-
-       if (unlikely(vq->access_ok == 0)) {
-               if (unlikely(vring_translate(dev, vq) < 0)) {
-                       count = 0;
-                       goto out;
+       while (1) {
+               if (unlikely(idx >= nr_descs || cnt++ >= nr_descs)) {
+                       free_ind_table(idesc);
+                       return -1;
                }
-       }
 
-       avail_idx = *((volatile uint16_t *)&vq->avail->idx);
-       start_idx = vq->last_used_idx;
-       free_entries = avail_idx - start_idx;
-       count = RTE_MIN(count, free_entries);
-       count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
-       if (count == 0)
-               goto out;
+               len += descs[idx].len;
 
-       LOG_DEBUG(VHOST_DATA, "(%d) start_idx %d | end_idx %d\n",
-               dev->vid, start_idx, start_idx + count);
+               if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
+                                               descs[idx].addr, descs[idx].len,
+                                               perm))) {
+                       free_ind_table(idesc);
+                       return -1;
+               }
 
-       vq->batch_copy_nb_elems = 0;
+               if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)
+                       break;
 
-       /* Retrieve all of the desc indexes first to avoid caching issues. */
-       rte_prefetch0(&vq->avail->ring[start_idx & (vq->size - 1)]);
-       for (i = 0; i < count; i++) {
-               used_idx = (start_idx + i) & (vq->size - 1);
-               desc_indexes[i] = vq->avail->ring[used_idx];
-               vq->used->ring[used_idx].id = desc_indexes[i];
-               vq->used->ring[used_idx].len = pkts[i]->pkt_len +
-                                              dev->vhost_hlen;
-               vhost_log_used_vring(dev, vq,
-                       offsetof(struct vring_used, ring[used_idx]),
-                       sizeof(vq->used->ring[used_idx]));
+               idx = descs[idx].next;
        }
 
-       rte_prefetch0(&vq->desc[desc_indexes[0]]);
-       for (i = 0; i < count; i++) {
-               uint16_t desc_idx = desc_indexes[i];
-               int err;
+       *desc_chain_len = len;
+       *vec_idx = vec_id;
 
-               if (vq->desc[desc_idx].flags & VRING_DESC_F_INDIRECT) {
-                       descs = (struct vring_desc *)(uintptr_t)
-                               vhost_iova_to_vva(dev,
-                                               vq, vq->desc[desc_idx].addr,
-                                               vq->desc[desc_idx].len,
-                                               VHOST_ACCESS_RO);
-                       if (unlikely(!descs)) {
-                               count = i;
-                               break;
-                       }
+       if (unlikely(!!idesc))
+               free_ind_table(idesc);
 
-                       desc_idx = 0;
-                       sz = vq->desc[desc_idx].len / sizeof(*descs);
-               } else {
-                       descs = vq->desc;
-                       sz = vq->size;
-               }
+       return 0;
+}
 
-               err = copy_mbuf_to_desc(dev, vq, descs, pkts[i], desc_idx, sz);
-               if (unlikely(err)) {
-                       count = i;
-                       break;
-               }
+/*
+ * Returns -1 on fail, 0 on success
+ */
+static inline int
+reserve_avail_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
+                               uint32_t size, struct buf_vector *buf_vec,
+                               uint16_t *num_buffers, uint16_t avail_head,
+                               uint16_t *nr_vec)
+{
+       uint16_t cur_idx;
+       uint16_t vec_idx = 0;
+       uint16_t max_tries, tries = 0;
 
-               if (i + 1 < count)
-                       rte_prefetch0(&vq->desc[desc_indexes[i+1]]);
-       }
+       uint16_t head_idx = 0;
+       uint32_t len = 0;
 
-       do_data_copy_enqueue(dev, vq);
+       *num_buffers = 0;
+       cur_idx  = vq->last_avail_idx;
 
-       rte_smp_wmb();
+       if (rxvq_is_mergeable(dev))
+               max_tries = vq->size - 1;
+       else
+               max_tries = 1;
 
-       *(volatile uint16_t *)&vq->used->idx += count;
-       vq->last_used_idx += count;
-       vhost_log_used_vring(dev, vq,
-               offsetof(struct vring_used, idx),
-               sizeof(vq->used->idx));
+       while (size > 0) {
+               if (unlikely(cur_idx == avail_head))
+                       return -1;
+               /*
+                * if we tried all available ring items, and still
+                * can't get enough buf, it means something abnormal
+                * happened.
+                */
+               if (unlikely(++tries > max_tries))
+                       return -1;
 
-       vhost_vring_call(dev, vq);
-out:
-       if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
-               vhost_user_iotlb_rd_unlock(vq);
+               if (unlikely(fill_vec_buf_split(dev, vq, cur_idx,
+                                               &vec_idx, buf_vec,
+                                               &head_idx, &len,
+                                               VHOST_ACCESS_RW) < 0))
+                       return -1;
+               len = RTE_MIN(len, size);
+               update_shadow_used_ring_split(vq, head_idx, len);
+               size -= len;
 
-       return count;
+               cur_idx++;
+               *num_buffers += 1;
+       }
+
+       *nr_vec = vec_idx;
+
+       return 0;
 }
 
 static __rte_always_inline int
-fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
-                        uint32_t avail_idx, uint32_t *vec_idx,
-                        struct buf_vector *buf_vec, uint16_t *desc_chain_head,
-                        uint16_t *desc_chain_len)
+fill_vec_buf_packed_indirect(struct virtio_net *dev,
+                       struct vhost_virtqueue *vq,
+                       struct vring_packed_desc *desc, uint16_t *vec_idx,
+                       struct buf_vector *buf_vec, uint32_t *len, uint8_t perm)
 {
-       uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
-       uint32_t vec_id = *vec_idx;
-       uint32_t len    = 0;
-       struct vring_desc *descs = vq->desc;
-
-       *desc_chain_head = idx;
-
-       if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
-               descs = (struct vring_desc *)(uintptr_t)
-                       vhost_iova_to_vva(dev, vq, vq->desc[idx].addr,
-                                               vq->desc[idx].len,
-                                               VHOST_ACCESS_RO);
-               if (unlikely(!descs))
+       uint16_t i;
+       uint32_t nr_descs;
+       uint16_t vec_id = *vec_idx;
+       uint64_t dlen;
+       struct vring_packed_desc *descs, *idescs = NULL;
+
+       dlen = desc->len;
+       descs = (struct vring_packed_desc *)(uintptr_t)
+               vhost_iova_to_vva(dev, vq, desc->addr, &dlen, VHOST_ACCESS_RO);
+       if (unlikely(!descs))
+               return -1;
+
+       if (unlikely(dlen < desc->len)) {
+               /*
+                * The indirect desc table is not contiguous
+                * in process VA space, we have to copy it.
+                */
+               idescs = vhost_alloc_copy_ind_table(dev,
+                               vq, desc->addr, desc->len);
+               if (unlikely(!idescs))
                        return -1;
 
-               idx = 0;
+               descs = idescs;
        }
 
-       while (1) {
-               if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
-                       return -1;
-
-               len += descs[idx].len;
-               buf_vec[vec_id].buf_addr = descs[idx].addr;
-               buf_vec[vec_id].buf_len  = descs[idx].len;
-               buf_vec[vec_id].desc_idx = idx;
-               vec_id++;
+       nr_descs =  desc->len / sizeof(struct vring_packed_desc);
+       if (unlikely(nr_descs >= vq->size)) {
+               free_ind_table(idescs);
+               return -1;
+       }
 
-               if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)
-                       break;
+       for (i = 0; i < nr_descs; i++) {
+               if (unlikely(vec_id >= BUF_VECTOR_MAX)) {
+                       free_ind_table(idescs);
+                       return -1;
+               }
 
-               idx = descs[idx].next;
+               *len += descs[i].len;
+               if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
+                                               descs[i].addr, descs[i].len,
+                                               perm)))
+                       return -1;
        }
-
-       *desc_chain_len = len;
        *vec_idx = vec_id;
 
+       if (unlikely(!!idescs))
+               free_ind_table(idescs);
+
        return 0;
 }
 
-/*
- * Returns -1 on fail, 0 on success
- */
-static inline int
-reserve_avail_buf_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
-                               uint32_t size, struct buf_vector *buf_vec,
-                               uint16_t *num_buffers, uint16_t avail_head)
+static __rte_always_inline int
+fill_vec_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
+                               uint16_t avail_idx, uint16_t *desc_count,
+                               struct buf_vector *buf_vec, uint16_t *vec_idx,
+                               uint16_t *buf_id, uint32_t *len, uint8_t perm)
 {
-       uint16_t cur_idx;
-       uint32_t vec_idx = 0;
-       uint16_t tries = 0;
+       bool wrap_counter = vq->avail_wrap_counter;
+       struct vring_packed_desc *descs = vq->desc_packed;
+       uint16_t vec_id = *vec_idx;
 
-       uint16_t head_idx = 0;
-       uint16_t len = 0;
+       if (avail_idx < vq->last_avail_idx)
+               wrap_counter ^= 1;
 
-       *num_buffers = 0;
-       cur_idx  = vq->last_avail_idx;
+       /*
+        * Perform a load-acquire barrier in desc_is_avail to
+        * enforce the ordering between desc flags and desc
+        * content.
+        */
+       if (unlikely(!desc_is_avail(&descs[avail_idx], wrap_counter)))
+               return -1;
 
-       while (size > 0) {
-               if (unlikely(cur_idx == avail_head))
+       *desc_count = 0;
+       *len = 0;
+
+       while (1) {
+               if (unlikely(vec_id >= BUF_VECTOR_MAX))
                        return -1;
 
-               if (unlikely(fill_vec_buf(dev, vq, cur_idx, &vec_idx, buf_vec,
-                                               &head_idx, &len) < 0))
+               if (unlikely(*desc_count >= vq->size))
                        return -1;
-               len = RTE_MIN(len, size);
-               update_shadow_used_ring(vq, head_idx, len);
-               size -= len;
 
-               cur_idx++;
-               tries++;
-               *num_buffers += 1;
+               *desc_count += 1;
+               *buf_id = descs[avail_idx].id;
 
-               /*
-                * if we tried all available ring items, and still
-                * can't get enough buf, it means something abnormal
-                * happened.
-                */
-               if (unlikely(tries >= vq->size))
-                       return -1;
+               if (descs[avail_idx].flags & VRING_DESC_F_INDIRECT) {
+                       if (unlikely(fill_vec_buf_packed_indirect(dev, vq,
+                                                       &descs[avail_idx],
+                                                       &vec_id, buf_vec,
+                                                       len, perm) < 0))
+                               return -1;
+               } else {
+                       *len += descs[avail_idx].len;
+
+                       if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
+                                                       descs[avail_idx].addr,
+                                                       descs[avail_idx].len,
+                                                       perm)))
+                               return -1;
+               }
+
+               if ((descs[avail_idx].flags & VRING_DESC_F_NEXT) == 0)
+                       break;
+
+               if (++avail_idx >= vq->size) {
+                       avail_idx -= vq->size;
+                       wrap_counter ^= 1;
+               }
        }
 
+       *vec_idx = vec_id;
+
        return 0;
 }
 
+static __rte_noinline void
+copy_vnet_hdr_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
+               struct buf_vector *buf_vec,
+               struct virtio_net_hdr_mrg_rxbuf *hdr)
+{
+       uint64_t len;
+       uint64_t remain = dev->vhost_hlen;
+       uint64_t src = (uint64_t)(uintptr_t)hdr, dst;
+       uint64_t iova = buf_vec->buf_iova;
+
+       while (remain) {
+               len = RTE_MIN(remain,
+                               buf_vec->buf_len);
+               dst = buf_vec->buf_addr;
+               rte_memcpy((void *)(uintptr_t)dst,
+                               (void *)(uintptr_t)src,
+                               len);
+
+               PRINT_PACKET(dev, (uintptr_t)dst,
+                               (uint32_t)len, 0);
+               vhost_log_cache_write_iova(dev, vq,
+                               iova, len);
+
+               remain -= len;
+               iova += len;
+               src += len;
+               buf_vec++;
+       }
+}
+
 static __rte_always_inline int
-copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
+copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
                            struct rte_mbuf *m, struct buf_vector *buf_vec,
-                           uint16_t num_buffers)
+                           uint16_t nr_vec, uint16_t num_buffers)
 {
        uint32_t vec_idx = 0;
-       uint64_t desc_addr;
        uint32_t mbuf_offset, mbuf_avail;
-       uint32_t desc_offset, desc_avail;
+       uint32_t buf_offset, buf_avail;
+       uint64_t buf_addr, buf_iova, buf_len;
        uint32_t cpy_len;
-       uint64_t hdr_addr, hdr_phys_addr;
+       uint64_t hdr_addr;
        struct rte_mbuf *hdr_mbuf;
        struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
-       uint16_t copy_nb = vq->batch_copy_nb_elems;
+       struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
        int error = 0;
 
        if (unlikely(m == NULL)) {
@@ -504,45 +820,54 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
                goto out;
        }
 
-       desc_addr = vhost_iova_to_vva(dev, vq, buf_vec[vec_idx].buf_addr,
-                                               buf_vec[vec_idx].buf_len,
-                                               VHOST_ACCESS_RW);
-       if (buf_vec[vec_idx].buf_len < dev->vhost_hlen || !desc_addr) {
+       buf_addr = buf_vec[vec_idx].buf_addr;
+       buf_iova = buf_vec[vec_idx].buf_iova;
+       buf_len = buf_vec[vec_idx].buf_len;
+
+       if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) {
                error = -1;
                goto out;
        }
 
        hdr_mbuf = m;
-       hdr_addr = desc_addr;
-       hdr_phys_addr = buf_vec[vec_idx].buf_addr;
-       rte_prefetch0((void *)(uintptr_t)hdr_addr);
+       hdr_addr = buf_addr;
+       if (unlikely(buf_len < dev->vhost_hlen))
+               hdr = &tmp_hdr;
+       else
+               hdr = (struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)hdr_addr;
 
-       LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
+       VHOST_LOG_DATA(DEBUG, "(%d) RX: num merge buffers %d\n",
                dev->vid, num_buffers);
 
-       desc_avail  = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
-       desc_offset = dev->vhost_hlen;
+       if (unlikely(buf_len < dev->vhost_hlen)) {
+               buf_offset = dev->vhost_hlen - buf_len;
+               vec_idx++;
+               buf_addr = buf_vec[vec_idx].buf_addr;
+               buf_iova = buf_vec[vec_idx].buf_iova;
+               buf_len = buf_vec[vec_idx].buf_len;
+               buf_avail = buf_len - buf_offset;
+       } else {
+               buf_offset = dev->vhost_hlen;
+               buf_avail = buf_len - dev->vhost_hlen;
+       }
 
        mbuf_avail  = rte_pktmbuf_data_len(m);
        mbuf_offset = 0;
        while (mbuf_avail != 0 || m->next != NULL) {
-               /* done with current desc buf, get the next one */
-               if (desc_avail == 0) {
+               /* done with current buf, get the next one */
+               if (buf_avail == 0) {
                        vec_idx++;
-                       desc_addr =
-                               vhost_iova_to_vva(dev, vq,
-                                       buf_vec[vec_idx].buf_addr,
-                                       buf_vec[vec_idx].buf_len,
-                                       VHOST_ACCESS_RW);
-                       if (unlikely(!desc_addr)) {
+                       if (unlikely(vec_idx >= nr_vec)) {
                                error = -1;
                                goto out;
                        }
 
-                       /* Prefetch buffer address. */
-                       rte_prefetch0((void *)(uintptr_t)desc_addr);
-                       desc_offset = 0;
-                       desc_avail  = buf_vec[vec_idx].buf_len;
+                       buf_addr = buf_vec[vec_idx].buf_addr;
+                       buf_iova = buf_vec[vec_idx].buf_iova;
+                       buf_len = buf_vec[vec_idx].buf_len;
+
+                       buf_offset = 0;
+                       buf_avail  = buf_len;
                }
 
                /* done with current mbuf, get the next one */
@@ -554,197 +879,981 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
                }
 
                if (hdr_addr) {
-                       struct virtio_net_hdr_mrg_rxbuf *hdr;
-
-                       hdr = (struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)
-                               hdr_addr;
                        virtio_enqueue_offload(hdr_mbuf, &hdr->hdr);
-                       ASSIGN_UNLESS_EQUAL(hdr->num_buffers, num_buffers);
+                       if (rxvq_is_mergeable(dev))
+                               ASSIGN_UNLESS_EQUAL(hdr->num_buffers,
+                                               num_buffers);
 
-                       vhost_log_write(dev, hdr_phys_addr, dev->vhost_hlen);
-                       PRINT_PACKET(dev, (uintptr_t)hdr_addr,
-                                    dev->vhost_hlen, 0);
+                       if (unlikely(hdr == &tmp_hdr)) {
+                               copy_vnet_hdr_to_desc(dev, vq, buf_vec, hdr);
+                       } else {
+                               PRINT_PACKET(dev, (uintptr_t)hdr_addr,
+                                               dev->vhost_hlen, 0);
+                               vhost_log_cache_write_iova(dev, vq,
+                                               buf_vec[0].buf_iova,
+                                               dev->vhost_hlen);
+                       }
 
                        hdr_addr = 0;
                }
 
-               cpy_len = RTE_MIN(desc_avail, mbuf_avail);
+               cpy_len = RTE_MIN(buf_avail, mbuf_avail);
 
-               if (likely(cpy_len > MAX_BATCH_LEN || copy_nb >= vq->size)) {
-                       rte_memcpy((void *)((uintptr_t)(desc_addr +
-                                                       desc_offset)),
+               if (likely(cpy_len > MAX_BATCH_LEN ||
+                                       vq->batch_copy_nb_elems >= vq->size)) {
+                       rte_memcpy((void *)((uintptr_t)(buf_addr + buf_offset)),
                                rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
                                cpy_len);
-                       vhost_log_write(dev,
-                               buf_vec[vec_idx].buf_addr + desc_offset,
-                               cpy_len);
-                       PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
+                       vhost_log_cache_write_iova(dev, vq,
+                                                  buf_iova + buf_offset,
+                                                  cpy_len);
+                       PRINT_PACKET(dev, (uintptr_t)(buf_addr + buf_offset),
                                cpy_len, 0);
                } else {
-                       batch_copy[copy_nb].dst =
-                               (void *)((uintptr_t)(desc_addr + desc_offset));
-                       batch_copy[copy_nb].src =
+                       batch_copy[vq->batch_copy_nb_elems].dst =
+                               (void *)((uintptr_t)(buf_addr + buf_offset));
+                       batch_copy[vq->batch_copy_nb_elems].src =
                                rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
-                       batch_copy[copy_nb].log_addr =
-                               buf_vec[vec_idx].buf_addr + desc_offset;
-                       batch_copy[copy_nb].len = cpy_len;
-                       copy_nb++;
+                       batch_copy[vq->batch_copy_nb_elems].log_addr =
+                               buf_iova + buf_offset;
+                       batch_copy[vq->batch_copy_nb_elems].len = cpy_len;
+                       vq->batch_copy_nb_elems++;
                }
 
                mbuf_avail  -= cpy_len;
                mbuf_offset += cpy_len;
-               desc_avail  -= cpy_len;
-               desc_offset += cpy_len;
+               buf_avail  -= cpy_len;
+               buf_offset += cpy_len;
        }
 
 out:
-       vq->batch_copy_nb_elems = copy_nb;
 
        return error;
 }
 
-static __rte_always_inline uint32_t
-virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
-       struct rte_mbuf **pkts, uint32_t count)
+static __rte_always_inline void
+async_fill_vec(struct iovec *v, void *base, size_t len)
 {
-       struct vhost_virtqueue *vq;
-       uint32_t pkt_idx = 0;
-       uint16_t num_buffers;
-       struct buf_vector buf_vec[BUF_VECTOR_MAX];
-       uint16_t avail_head;
+       v->iov_base = base;
+       v->iov_len = len;
+}
 
-       LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
-       if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
-               RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
-                       dev->vid, __func__, queue_id);
-               return 0;
+static __rte_always_inline void
+async_fill_iter(struct rte_vhost_iov_iter *it, size_t count,
+       struct iovec *vec, unsigned long nr_seg)
+{
+       it->offset = 0;
+       it->count = count;
+
+       if (count) {
+               it->iov = vec;
+               it->nr_segs = nr_seg;
+       } else {
+               it->iov = 0;
+               it->nr_segs = 0;
        }
+}
 
-       vq = dev->virtqueue[queue_id];
-       if (unlikely(vq->enabled == 0))
-               return 0;
+static __rte_always_inline void
+async_fill_desc(struct rte_vhost_async_desc *desc,
+       struct rte_vhost_iov_iter *src, struct rte_vhost_iov_iter *dst)
+{
+       desc->src = src;
+       desc->dst = dst;
+}
 
-       if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
-               vhost_user_iotlb_rd_lock(vq);
+static __rte_always_inline int
+async_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
+                       struct rte_mbuf *m, struct buf_vector *buf_vec,
+                       uint16_t nr_vec, uint16_t num_buffers,
+                       struct iovec *src_iovec, struct iovec *dst_iovec,
+                       struct rte_vhost_iov_iter *src_it,
+                       struct rte_vhost_iov_iter *dst_it)
+{
+       uint32_t vec_idx = 0;
+       uint32_t mbuf_offset, mbuf_avail;
+       uint32_t buf_offset, buf_avail;
+       uint64_t buf_addr, buf_iova, buf_len;
+       uint32_t cpy_len, cpy_threshold;
+       uint64_t hdr_addr;
+       struct rte_mbuf *hdr_mbuf;
+       struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
+       struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
+       int error = 0;
+       uint64_t mapped_len;
 
-       if (unlikely(vq->access_ok == 0))
-               if (unlikely(vring_translate(dev, vq) < 0))
-                       goto out;
+       uint32_t tlen = 0;
+       int tvec_idx = 0;
+       void *hpa;
 
-       count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
-       if (count == 0)
+       if (unlikely(m == NULL)) {
+               error = -1;
                goto out;
+       }
 
-       vq->batch_copy_nb_elems = 0;
-
-       rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
+       cpy_threshold = vq->async_threshold;
 
-       vq->shadow_used_idx = 0;
-       avail_head = *((volatile uint16_t *)&vq->avail->idx);
-       for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
-               uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
+       buf_addr = buf_vec[vec_idx].buf_addr;
+       buf_iova = buf_vec[vec_idx].buf_iova;
+       buf_len = buf_vec[vec_idx].buf_len;
 
-               if (unlikely(reserve_avail_buf_mergeable(dev, vq,
-                                               pkt_len, buf_vec, &num_buffers,
-                                               avail_head) < 0)) {
-                       LOG_DEBUG(VHOST_DATA,
-                               "(%d) failed to get enough desc from vring\n",
-                               dev->vid);
-                       vq->shadow_used_idx -= num_buffers;
-                       break;
-               }
+       if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) {
+               error = -1;
+               goto out;
+       }
 
-               LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
-                       dev->vid, vq->last_avail_idx,
-                       vq->last_avail_idx + num_buffers);
+       hdr_mbuf = m;
+       hdr_addr = buf_addr;
+       if (unlikely(buf_len < dev->vhost_hlen))
+               hdr = &tmp_hdr;
+       else
+               hdr = (struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)hdr_addr;
 
-               if (copy_mbuf_to_desc_mergeable(dev, vq, pkts[pkt_idx],
-                                               buf_vec, num_buffers) < 0) {
-                       vq->shadow_used_idx -= num_buffers;
-                       break;
-               }
+       VHOST_LOG_DATA(DEBUG, "(%d) RX: num merge buffers %d\n",
+               dev->vid, num_buffers);
 
-               vq->last_avail_idx += num_buffers;
+       if (unlikely(buf_len < dev->vhost_hlen)) {
+               buf_offset = dev->vhost_hlen - buf_len;
+               vec_idx++;
+               buf_addr = buf_vec[vec_idx].buf_addr;
+               buf_iova = buf_vec[vec_idx].buf_iova;
+               buf_len = buf_vec[vec_idx].buf_len;
+               buf_avail = buf_len - buf_offset;
+       } else {
+               buf_offset = dev->vhost_hlen;
+               buf_avail = buf_len - dev->vhost_hlen;
        }
 
-       do_data_copy_enqueue(dev, vq);
+       mbuf_avail  = rte_pktmbuf_data_len(m);
+       mbuf_offset = 0;
 
-       if (likely(vq->shadow_used_idx)) {
-               flush_shadow_used_ring(dev, vq);
-               vhost_vring_call(dev, vq);
-       }
+       while (mbuf_avail != 0 || m->next != NULL) {
+               /* done with current buf, get the next one */
+               if (buf_avail == 0) {
+                       vec_idx++;
+                       if (unlikely(vec_idx >= nr_vec)) {
+                               error = -1;
+                               goto out;
+                       }
 
-out:
-       if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
-               vhost_user_iotlb_rd_unlock(vq);
+                       buf_addr = buf_vec[vec_idx].buf_addr;
+                       buf_iova = buf_vec[vec_idx].buf_iova;
+                       buf_len = buf_vec[vec_idx].buf_len;
 
-       return pkt_idx;
-}
+                       buf_offset = 0;
+                       buf_avail  = buf_len;
+               }
 
-uint16_t
-rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
-       struct rte_mbuf **pkts, uint16_t count)
-{
-       struct virtio_net *dev = get_device(vid);
+               /* done with current mbuf, get the next one */
+               if (mbuf_avail == 0) {
+                       m = m->next;
 
-       if (!dev)
-               return 0;
+                       mbuf_offset = 0;
+                       mbuf_avail  = rte_pktmbuf_data_len(m);
+               }
 
-       if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
-               return virtio_dev_merge_rx(dev, queue_id, pkts, count);
-       else
-               return virtio_dev_rx(dev, queue_id, pkts, count);
-}
+               if (hdr_addr) {
+                       virtio_enqueue_offload(hdr_mbuf, &hdr->hdr);
+                       if (rxvq_is_mergeable(dev))
+                               ASSIGN_UNLESS_EQUAL(hdr->num_buffers,
+                                               num_buffers);
 
-static inline bool
-virtio_net_with_host_offload(struct virtio_net *dev)
-{
-       if (dev->features &
-                       ((1ULL << VIRTIO_NET_F_CSUM) |
-                        (1ULL << VIRTIO_NET_F_HOST_ECN) |
-                        (1ULL << VIRTIO_NET_F_HOST_TSO4) |
-                        (1ULL << VIRTIO_NET_F_HOST_TSO6) |
-                        (1ULL << VIRTIO_NET_F_HOST_UFO)))
-               return true;
+                       if (unlikely(hdr == &tmp_hdr)) {
+                               copy_vnet_hdr_to_desc(dev, vq, buf_vec, hdr);
+                       } else {
+                               PRINT_PACKET(dev, (uintptr_t)hdr_addr,
+                                               dev->vhost_hlen, 0);
+                               vhost_log_cache_write_iova(dev, vq,
+                                               buf_vec[0].buf_iova,
+                                               dev->vhost_hlen);
+                       }
 
-       return false;
-}
+                       hdr_addr = 0;
+               }
 
-static void
-parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
-{
-       struct ipv4_hdr *ipv4_hdr;
-       struct ipv6_hdr *ipv6_hdr;
-       void *l3_hdr = NULL;
-       struct ether_hdr *eth_hdr;
-       uint16_t ethertype;
+               cpy_len = RTE_MIN(buf_avail, mbuf_avail);
 
-       eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
+               while (unlikely(cpy_len && cpy_len >= cpy_threshold)) {
+                       hpa = (void *)(uintptr_t)gpa_to_first_hpa(dev,
+                                       buf_iova + buf_offset,
+                                       cpy_len, &mapped_len);
 
-       m->l2_len = sizeof(struct ether_hdr);
-       ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
+                       if (unlikely(!hpa || mapped_len < cpy_threshold))
+                               break;
 
-       if (ethertype == ETHER_TYPE_VLAN) {
-               struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
+                       async_fill_vec(src_iovec + tvec_idx,
+                               (void *)(uintptr_t)rte_pktmbuf_iova_offset(m,
+                               mbuf_offset), (size_t)mapped_len);
 
-               m->l2_len += sizeof(struct vlan_hdr);
-               ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
-       }
+                       async_fill_vec(dst_iovec + tvec_idx,
+                                       hpa, (size_t)mapped_len);
 
-       l3_hdr = (char *)eth_hdr + m->l2_len;
+                       tlen += (uint32_t)mapped_len;
+                       cpy_len -= (uint32_t)mapped_len;
+                       mbuf_avail  -= (uint32_t)mapped_len;
+                       mbuf_offset += (uint32_t)mapped_len;
+                       buf_avail  -= (uint32_t)mapped_len;
+                       buf_offset += (uint32_t)mapped_len;
+                       tvec_idx++;
+               }
 
-       switch (ethertype) {
-       case ETHER_TYPE_IPv4:
+               if (likely(cpy_len)) {
+                       if (unlikely(vq->batch_copy_nb_elems >= vq->size)) {
+                               rte_memcpy(
+                               (void *)((uintptr_t)(buf_addr + buf_offset)),
+                               rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
+                               cpy_len);
+
+                               PRINT_PACKET(dev,
+                                       (uintptr_t)(buf_addr + buf_offset),
+                                       cpy_len, 0);
+                       } else {
+                               batch_copy[vq->batch_copy_nb_elems].dst =
+                               (void *)((uintptr_t)(buf_addr + buf_offset));
+                               batch_copy[vq->batch_copy_nb_elems].src =
+                               rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
+                               batch_copy[vq->batch_copy_nb_elems].log_addr =
+                                       buf_iova + buf_offset;
+                               batch_copy[vq->batch_copy_nb_elems].len =
+                                       cpy_len;
+                               vq->batch_copy_nb_elems++;
+                       }
+
+                       mbuf_avail  -= cpy_len;
+                       mbuf_offset += cpy_len;
+                       buf_avail  -= cpy_len;
+                       buf_offset += cpy_len;
+               }
+
+       }
+
+out:
+       async_fill_iter(src_it, tlen, src_iovec, tvec_idx);
+       async_fill_iter(dst_it, tlen, dst_iovec, tvec_idx);
+
+       return error;
+}
+
+static __rte_always_inline int
+vhost_enqueue_single_packed(struct virtio_net *dev,
+                           struct vhost_virtqueue *vq,
+                           struct rte_mbuf *pkt,
+                           struct buf_vector *buf_vec,
+                           uint16_t *nr_descs)
+{
+       uint16_t nr_vec = 0;
+       uint16_t avail_idx = vq->last_avail_idx;
+       uint16_t max_tries, tries = 0;
+       uint16_t buf_id = 0;
+       uint32_t len = 0;
+       uint16_t desc_count;
+       uint32_t size = pkt->pkt_len + dev->vhost_hlen;
+       uint16_t num_buffers = 0;
+       uint32_t buffer_len[vq->size];
+       uint16_t buffer_buf_id[vq->size];
+       uint16_t buffer_desc_count[vq->size];
+
+       if (rxvq_is_mergeable(dev))
+               max_tries = vq->size - 1;
+       else
+               max_tries = 1;
+
+       while (size > 0) {
+               /*
+                * if we tried all available ring items, and still
+                * can't get enough buf, it means something abnormal
+                * happened.
+                */
+               if (unlikely(++tries > max_tries))
+                       return -1;
+
+               if (unlikely(fill_vec_buf_packed(dev, vq,
+                                               avail_idx, &desc_count,
+                                               buf_vec, &nr_vec,
+                                               &buf_id, &len,
+                                               VHOST_ACCESS_RW) < 0))
+                       return -1;
+
+               len = RTE_MIN(len, size);
+               size -= len;
+
+               buffer_len[num_buffers] = len;
+               buffer_buf_id[num_buffers] = buf_id;
+               buffer_desc_count[num_buffers] = desc_count;
+               num_buffers += 1;
+
+               *nr_descs += desc_count;
+               avail_idx += desc_count;
+               if (avail_idx >= vq->size)
+                       avail_idx -= vq->size;
+       }
+
+       if (copy_mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, num_buffers) < 0)
+               return -1;
+
+       vhost_shadow_enqueue_single_packed(dev, vq, buffer_len, buffer_buf_id,
+                                          buffer_desc_count, num_buffers);
+
+       return 0;
+}
+
+static __rte_noinline uint32_t
+virtio_dev_rx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
+       struct rte_mbuf **pkts, uint32_t count)
+{
+       uint32_t pkt_idx = 0;
+       uint16_t num_buffers;
+       struct buf_vector buf_vec[BUF_VECTOR_MAX];
+       uint16_t avail_head;
+
+       /*
+        * The ordering between avail index and
+        * desc reads needs to be enforced.
+        */
+       avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE);
+
+       rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
+
+       for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
+               uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
+               uint16_t nr_vec = 0;
+
+               if (unlikely(reserve_avail_buf_split(dev, vq,
+                                               pkt_len, buf_vec, &num_buffers,
+                                               avail_head, &nr_vec) < 0)) {
+                       VHOST_LOG_DATA(DEBUG,
+                               "(%d) failed to get enough desc from vring\n",
+                               dev->vid);
+                       vq->shadow_used_idx -= num_buffers;
+                       break;
+               }
+
+               VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end index %d\n",
+                       dev->vid, vq->last_avail_idx,
+                       vq->last_avail_idx + num_buffers);
+
+               if (copy_mbuf_to_desc(dev, vq, pkts[pkt_idx],
+                                               buf_vec, nr_vec,
+                                               num_buffers) < 0) {
+                       vq->shadow_used_idx -= num_buffers;
+                       break;
+               }
+
+               vq->last_avail_idx += num_buffers;
+       }
+
+       do_data_copy_enqueue(dev, vq);
+
+       if (likely(vq->shadow_used_idx)) {
+               flush_shadow_used_ring_split(dev, vq);
+               vhost_vring_call_split(dev, vq);
+       }
+
+       return pkt_idx;
+}
+
+static __rte_always_inline int
+virtio_dev_rx_batch_packed(struct virtio_net *dev,
+                          struct vhost_virtqueue *vq,
+                          struct rte_mbuf **pkts)
+{
+       bool wrap_counter = vq->avail_wrap_counter;
+       struct vring_packed_desc *descs = vq->desc_packed;
+       uint16_t avail_idx = vq->last_avail_idx;
+       uint64_t desc_addrs[PACKED_BATCH_SIZE];
+       struct virtio_net_hdr_mrg_rxbuf *hdrs[PACKED_BATCH_SIZE];
+       uint32_t buf_offset = dev->vhost_hlen;
+       uint64_t lens[PACKED_BATCH_SIZE];
+       uint16_t ids[PACKED_BATCH_SIZE];
+       uint16_t i;
+
+       if (unlikely(avail_idx & PACKED_BATCH_MASK))
+               return -1;
+
+       if (unlikely((avail_idx + PACKED_BATCH_SIZE) > vq->size))
+               return -1;
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               if (unlikely(pkts[i]->next != NULL))
+                       return -1;
+               if (unlikely(!desc_is_avail(&descs[avail_idx + i],
+                                           wrap_counter)))
+                       return -1;
+       }
+
+       rte_smp_rmb();
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               lens[i] = descs[avail_idx + i].len;
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               if (unlikely(pkts[i]->pkt_len > (lens[i] - buf_offset)))
+                       return -1;
+       }
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               desc_addrs[i] = vhost_iova_to_vva(dev, vq,
+                                                 descs[avail_idx + i].addr,
+                                                 &lens[i],
+                                                 VHOST_ACCESS_RW);
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               if (unlikely(!desc_addrs[i]))
+                       return -1;
+               if (unlikely(lens[i] != descs[avail_idx + i].len))
+                       return -1;
+       }
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               rte_prefetch0((void *)(uintptr_t)desc_addrs[i]);
+               hdrs[i] = (struct virtio_net_hdr_mrg_rxbuf *)
+                                       (uintptr_t)desc_addrs[i];
+               lens[i] = pkts[i]->pkt_len + dev->vhost_hlen;
+       }
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               virtio_enqueue_offload(pkts[i], &hdrs[i]->hdr);
+
+       vq_inc_last_avail_packed(vq, PACKED_BATCH_SIZE);
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               rte_memcpy((void *)(uintptr_t)(desc_addrs[i] + buf_offset),
+                          rte_pktmbuf_mtod_offset(pkts[i], void *, 0),
+                          pkts[i]->pkt_len);
+       }
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               vhost_log_cache_write_iova(dev, vq, descs[avail_idx + i].addr,
+                                          lens[i]);
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               ids[i] = descs[avail_idx + i].id;
+
+       vhost_flush_enqueue_batch_packed(dev, vq, lens, ids);
+
+       return 0;
+}
+
+static __rte_always_inline int16_t
+virtio_dev_rx_single_packed(struct virtio_net *dev,
+                           struct vhost_virtqueue *vq,
+                           struct rte_mbuf *pkt)
+{
+       struct buf_vector buf_vec[BUF_VECTOR_MAX];
+       uint16_t nr_descs = 0;
+
+       rte_smp_rmb();
+       if (unlikely(vhost_enqueue_single_packed(dev, vq, pkt, buf_vec,
+                                                &nr_descs) < 0)) {
+               VHOST_LOG_DATA(DEBUG,
+                               "(%d) failed to get enough desc from vring\n",
+                               dev->vid);
+               return -1;
+       }
+
+       VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end index %d\n",
+                       dev->vid, vq->last_avail_idx,
+                       vq->last_avail_idx + nr_descs);
+
+       vq_inc_last_avail_packed(vq, nr_descs);
+
+       return 0;
+}
+
+static __rte_noinline uint32_t
+virtio_dev_rx_packed(struct virtio_net *dev,
+                    struct vhost_virtqueue *__rte_restrict vq,
+                    struct rte_mbuf **__rte_restrict pkts,
+                    uint32_t count)
+{
+       uint32_t pkt_idx = 0;
+       uint32_t remained = count;
+
+       do {
+               rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
+
+               if (remained >= PACKED_BATCH_SIZE) {
+                       if (!virtio_dev_rx_batch_packed(dev, vq,
+                                                       &pkts[pkt_idx])) {
+                               pkt_idx += PACKED_BATCH_SIZE;
+                               remained -= PACKED_BATCH_SIZE;
+                               continue;
+                       }
+               }
+
+               if (virtio_dev_rx_single_packed(dev, vq, pkts[pkt_idx]))
+                       break;
+               pkt_idx++;
+               remained--;
+
+       } while (pkt_idx < count);
+
+       if (vq->shadow_used_idx) {
+               do_data_copy_enqueue(dev, vq);
+               vhost_flush_enqueue_shadow_packed(dev, vq);
+       }
+
+       if (pkt_idx)
+               vhost_vring_call_packed(dev, vq);
+
+       return pkt_idx;
+}
+
+static __rte_always_inline uint32_t
+virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
+       struct rte_mbuf **pkts, uint32_t count)
+{
+       struct vhost_virtqueue *vq;
+       uint32_t nb_tx = 0;
+
+       VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
+       if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
+               VHOST_LOG_DATA(ERR, "(%d) %s: invalid virtqueue idx %d.\n",
+                       dev->vid, __func__, queue_id);
+               return 0;
+       }
+
+       vq = dev->virtqueue[queue_id];
+
+       rte_spinlock_lock(&vq->access_lock);
+
+       if (unlikely(vq->enabled == 0))
+               goto out_access_unlock;
+
+       if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+               vhost_user_iotlb_rd_lock(vq);
+
+       if (unlikely(vq->access_ok == 0))
+               if (unlikely(vring_translate(dev, vq) < 0))
+                       goto out;
+
+       count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
+       if (count == 0)
+               goto out;
+
+       if (vq_is_packed(dev))
+               nb_tx = virtio_dev_rx_packed(dev, vq, pkts, count);
+       else
+               nb_tx = virtio_dev_rx_split(dev, vq, pkts, count);
+
+out:
+       if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+               vhost_user_iotlb_rd_unlock(vq);
+
+out_access_unlock:
+       rte_spinlock_unlock(&vq->access_lock);
+
+       return nb_tx;
+}
+
+uint16_t
+rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
+       struct rte_mbuf **__rte_restrict pkts, uint16_t count)
+{
+       struct virtio_net *dev = get_device(vid);
+
+       if (!dev)
+               return 0;
+
+       if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
+               VHOST_LOG_DATA(ERR,
+                       "(%d) %s: built-in vhost net backend is disabled.\n",
+                       dev->vid, __func__);
+               return 0;
+       }
+
+       return virtio_dev_rx(dev, queue_id, pkts, count);
+}
+
+static __rte_always_inline uint16_t
+virtio_dev_rx_async_get_info_idx(uint16_t pkts_idx,
+       uint16_t vq_size, uint16_t n_inflight)
+{
+       return pkts_idx > n_inflight ? (pkts_idx - n_inflight) :
+               (vq_size - n_inflight + pkts_idx) & (vq_size - 1);
+}
+
+static __rte_always_inline void
+virtio_dev_rx_async_submit_split_err(struct virtio_net *dev,
+       struct vhost_virtqueue *vq, uint16_t queue_id,
+       uint16_t last_idx, uint16_t shadow_idx)
+{
+       uint16_t start_idx, pkts_idx, vq_size;
+       uint64_t *async_pending_info;
+
+       pkts_idx = vq->async_pkts_idx;
+       async_pending_info = vq->async_pending_info;
+       vq_size = vq->size;
+       start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
+               vq_size, vq->async_pkts_inflight_n);
+
+       while (likely((start_idx & (vq_size - 1)) != pkts_idx)) {
+               uint64_t n_seg =
+                       async_pending_info[(start_idx) & (vq_size - 1)] >>
+                       ASYNC_PENDING_INFO_N_SFT;
+
+               while (n_seg)
+                       n_seg -= vq->async_ops.check_completed_copies(dev->vid,
+                               queue_id, 0, 1);
+       }
+
+       vq->async_pkts_inflight_n = 0;
+       vq->batch_copy_nb_elems = 0;
+
+       vq->shadow_used_idx = shadow_idx;
+       vq->last_avail_idx = last_idx;
+}
+
+static __rte_noinline uint32_t
+virtio_dev_rx_async_submit_split(struct virtio_net *dev,
+       struct vhost_virtqueue *vq, uint16_t queue_id,
+       struct rte_mbuf **pkts, uint32_t count)
+{
+       uint32_t pkt_idx = 0, pkt_burst_idx = 0;
+       uint16_t num_buffers;
+       struct buf_vector buf_vec[BUF_VECTOR_MAX];
+       uint16_t avail_head, last_idx, shadow_idx;
+
+       struct rte_vhost_iov_iter *it_pool = vq->it_pool;
+       struct iovec *vec_pool = vq->vec_pool;
+       struct rte_vhost_async_desc tdes[MAX_PKT_BURST];
+       struct iovec *src_iovec = vec_pool;
+       struct iovec *dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1);
+       struct rte_vhost_iov_iter *src_it = it_pool;
+       struct rte_vhost_iov_iter *dst_it = it_pool + 1;
+       uint16_t n_free_slot, slot_idx;
+       int n_pkts = 0;
+
+       avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE);
+       last_idx = vq->last_avail_idx;
+       shadow_idx = vq->shadow_used_idx;
+
+       /*
+        * The ordering between avail index and
+        * desc reads needs to be enforced.
+        */
+       rte_smp_rmb();
+
+       rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
+
+       for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
+               uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
+               uint16_t nr_vec = 0;
+
+               if (unlikely(reserve_avail_buf_split(dev, vq,
+                                               pkt_len, buf_vec, &num_buffers,
+                                               avail_head, &nr_vec) < 0)) {
+                       VHOST_LOG_DATA(DEBUG,
+                               "(%d) failed to get enough desc from vring\n",
+                               dev->vid);
+                       vq->shadow_used_idx -= num_buffers;
+                       break;
+               }
+
+               VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end index %d\n",
+                       dev->vid, vq->last_avail_idx,
+                       vq->last_avail_idx + num_buffers);
+
+               if (async_mbuf_to_desc(dev, vq, pkts[pkt_idx],
+                               buf_vec, nr_vec, num_buffers,
+                               src_iovec, dst_iovec, src_it, dst_it) < 0) {
+                       vq->shadow_used_idx -= num_buffers;
+                       break;
+               }
+
+               slot_idx = (vq->async_pkts_idx + pkt_idx) & (vq->size - 1);
+               if (src_it->count) {
+                       async_fill_desc(&tdes[pkt_burst_idx], src_it, dst_it);
+                       pkt_burst_idx++;
+                       vq->async_pending_info[slot_idx] =
+                               num_buffers | (src_it->nr_segs << 16);
+                       src_iovec += src_it->nr_segs;
+                       dst_iovec += dst_it->nr_segs;
+                       src_it += 2;
+                       dst_it += 2;
+               } else {
+                       vq->async_pending_info[slot_idx] = num_buffers;
+                       vq->async_pkts_inflight_n++;
+               }
+
+               vq->last_avail_idx += num_buffers;
+
+               if (pkt_burst_idx >= VHOST_ASYNC_BATCH_THRESHOLD ||
+                               (pkt_idx == count - 1 && pkt_burst_idx)) {
+                       n_pkts = vq->async_ops.transfer_data(dev->vid,
+                                       queue_id, tdes, 0, pkt_burst_idx);
+                       src_iovec = vec_pool;
+                       dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1);
+                       src_it = it_pool;
+                       dst_it = it_pool + 1;
+
+                       if (unlikely(n_pkts < (int)pkt_burst_idx)) {
+                               vq->async_pkts_inflight_n +=
+                                       n_pkts > 0 ? n_pkts : 0;
+                               virtio_dev_rx_async_submit_split_err(dev,
+                                       vq, queue_id, last_idx, shadow_idx);
+                               return 0;
+                       }
+
+                       pkt_burst_idx = 0;
+                       vq->async_pkts_inflight_n += n_pkts;
+               }
+       }
+
+       if (pkt_burst_idx) {
+               n_pkts = vq->async_ops.transfer_data(dev->vid,
+                               queue_id, tdes, 0, pkt_burst_idx);
+               if (unlikely(n_pkts < (int)pkt_burst_idx)) {
+                       vq->async_pkts_inflight_n += n_pkts > 0 ? n_pkts : 0;
+                       virtio_dev_rx_async_submit_split_err(dev, vq, queue_id,
+                               last_idx, shadow_idx);
+                       return 0;
+               }
+
+               vq->async_pkts_inflight_n += n_pkts;
+       }
+
+       do_data_copy_enqueue(dev, vq);
+
+       n_free_slot = vq->size - vq->async_pkts_idx;
+       if (n_free_slot > pkt_idx) {
+               rte_memcpy(&vq->async_pkts_pending[vq->async_pkts_idx],
+                       pkts, pkt_idx * sizeof(uintptr_t));
+               vq->async_pkts_idx += pkt_idx;
+       } else {
+               rte_memcpy(&vq->async_pkts_pending[vq->async_pkts_idx],
+                       pkts, n_free_slot * sizeof(uintptr_t));
+               rte_memcpy(&vq->async_pkts_pending[0],
+                       &pkts[n_free_slot],
+                       (pkt_idx - n_free_slot) * sizeof(uintptr_t));
+               vq->async_pkts_idx = pkt_idx - n_free_slot;
+       }
+
+       if (likely(vq->shadow_used_idx))
+               async_flush_shadow_used_ring_split(dev, vq);
+
+       return pkt_idx;
+}
+
+uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
+               struct rte_mbuf **pkts, uint16_t count)
+{
+       struct virtio_net *dev = get_device(vid);
+       struct vhost_virtqueue *vq;
+       uint16_t n_segs_cpl, n_pkts_put = 0, n_descs = 0;
+       uint16_t start_idx, pkts_idx, vq_size;
+       uint16_t n_inflight;
+       uint64_t *async_pending_info;
+
+       if (!dev)
+               return 0;
+
+       VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
+       if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
+               VHOST_LOG_DATA(ERR, "(%d) %s: invalid virtqueue idx %d.\n",
+                       dev->vid, __func__, queue_id);
+               return 0;
+       }
+
+       vq = dev->virtqueue[queue_id];
+
+       rte_spinlock_lock(&vq->access_lock);
+
+       n_inflight = vq->async_pkts_inflight_n;
+       pkts_idx = vq->async_pkts_idx;
+       async_pending_info = vq->async_pending_info;
+       vq_size = vq->size;
+       start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
+               vq_size, vq->async_pkts_inflight_n);
+
+       n_segs_cpl = vq->async_ops.check_completed_copies(vid, queue_id,
+               0, ASYNC_MAX_POLL_SEG - vq->async_last_seg_n) +
+               vq->async_last_seg_n;
+
+       rte_smp_wmb();
+
+       while (likely((n_pkts_put < count) && n_inflight)) {
+               uint64_t info = async_pending_info[
+                       (start_idx + n_pkts_put) & (vq_size - 1)];
+               uint64_t n_segs;
+               n_pkts_put++;
+               n_inflight--;
+               n_descs += info & ASYNC_PENDING_INFO_N_MSK;
+               n_segs = info >> ASYNC_PENDING_INFO_N_SFT;
+
+               if (n_segs) {
+                       if (unlikely(n_segs_cpl < n_segs)) {
+                               n_pkts_put--;
+                               n_inflight++;
+                               n_descs -= info & ASYNC_PENDING_INFO_N_MSK;
+                               if (n_segs_cpl) {
+                                       async_pending_info[
+                                               (start_idx + n_pkts_put) &
+                                               (vq_size - 1)] =
+                                       ((n_segs - n_segs_cpl) <<
+                                        ASYNC_PENDING_INFO_N_SFT) |
+                                       (info & ASYNC_PENDING_INFO_N_MSK);
+                                       n_segs_cpl = 0;
+                               }
+                               break;
+                       }
+                       n_segs_cpl -= n_segs;
+               }
+       }
+
+       vq->async_last_seg_n = n_segs_cpl;
+
+       if (n_pkts_put) {
+               vq->async_pkts_inflight_n = n_inflight;
+               if (likely(vq->enabled && vq->access_ok)) {
+                       __atomic_add_fetch(&vq->used->idx,
+                                       n_descs, __ATOMIC_RELEASE);
+                       vhost_vring_call_split(dev, vq);
+               }
+       }
+
+       if (start_idx + n_pkts_put <= vq_size) {
+               rte_memcpy(pkts, &vq->async_pkts_pending[start_idx],
+                       n_pkts_put * sizeof(uintptr_t));
+       } else {
+               rte_memcpy(pkts, &vq->async_pkts_pending[start_idx],
+                       (vq_size - start_idx) * sizeof(uintptr_t));
+               rte_memcpy(&pkts[vq_size - start_idx], vq->async_pkts_pending,
+                       (n_pkts_put - vq_size + start_idx) * sizeof(uintptr_t));
+       }
+
+       rte_spinlock_unlock(&vq->access_lock);
+
+       return n_pkts_put;
+}
+
+static __rte_always_inline uint32_t
+virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
+       struct rte_mbuf **pkts, uint32_t count)
+{
+       struct vhost_virtqueue *vq;
+       uint32_t nb_tx = 0;
+       bool drawback = false;
+
+       VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
+       if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
+               VHOST_LOG_DATA(ERR, "(%d) %s: invalid virtqueue idx %d.\n",
+                       dev->vid, __func__, queue_id);
+               return 0;
+       }
+
+       vq = dev->virtqueue[queue_id];
+
+       rte_spinlock_lock(&vq->access_lock);
+
+       if (unlikely(vq->enabled == 0))
+               goto out_access_unlock;
+
+       if (unlikely(!vq->async_registered)) {
+               drawback = true;
+               goto out_access_unlock;
+       }
+
+       if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+               vhost_user_iotlb_rd_lock(vq);
+
+       if (unlikely(vq->access_ok == 0))
+               if (unlikely(vring_translate(dev, vq) < 0))
+                       goto out;
+
+       count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
+       if (count == 0)
+               goto out;
+
+       /* TODO: packed queue not implemented */
+       if (vq_is_packed(dev))
+               nb_tx = 0;
+       else
+               nb_tx = virtio_dev_rx_async_submit_split(dev,
+                               vq, queue_id, pkts, count);
+
+out:
+       if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+               vhost_user_iotlb_rd_unlock(vq);
+
+out_access_unlock:
+       rte_spinlock_unlock(&vq->access_lock);
+
+       if (drawback)
+               return rte_vhost_enqueue_burst(dev->vid, queue_id, pkts, count);
+
+       return nb_tx;
+}
+
+uint16_t
+rte_vhost_submit_enqueue_burst(int vid, uint16_t queue_id,
+               struct rte_mbuf **pkts, uint16_t count)
+{
+       struct virtio_net *dev = get_device(vid);
+
+       if (!dev)
+               return 0;
+
+       if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
+               VHOST_LOG_DATA(ERR,
+                       "(%d) %s: built-in vhost net backend is disabled.\n",
+                       dev->vid, __func__);
+               return 0;
+       }
+
+       return virtio_dev_rx_async_submit(dev, queue_id, pkts, count);
+}
+
+static inline bool
+virtio_net_with_host_offload(struct virtio_net *dev)
+{
+       if (dev->features &
+                       ((1ULL << VIRTIO_NET_F_CSUM) |
+                        (1ULL << VIRTIO_NET_F_HOST_ECN) |
+                        (1ULL << VIRTIO_NET_F_HOST_TSO4) |
+                        (1ULL << VIRTIO_NET_F_HOST_TSO6) |
+                        (1ULL << VIRTIO_NET_F_HOST_UFO)))
+               return true;
+
+       return false;
+}
+
+static void
+parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
+{
+       struct rte_ipv4_hdr *ipv4_hdr;
+       struct rte_ipv6_hdr *ipv6_hdr;
+       void *l3_hdr = NULL;
+       struct rte_ether_hdr *eth_hdr;
+       uint16_t ethertype;
+
+       eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+
+       m->l2_len = sizeof(struct rte_ether_hdr);
+       ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
+
+       if (ethertype == RTE_ETHER_TYPE_VLAN) {
+               struct rte_vlan_hdr *vlan_hdr =
+                       (struct rte_vlan_hdr *)(eth_hdr + 1);
+
+               m->l2_len += sizeof(struct rte_vlan_hdr);
+               ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
+       }
+
+       l3_hdr = (char *)eth_hdr + m->l2_len;
+
+       switch (ethertype) {
+       case RTE_ETHER_TYPE_IPV4:
                ipv4_hdr = l3_hdr;
                *l4_proto = ipv4_hdr->next_proto_id;
                m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
                *l4_hdr = (char *)l3_hdr + m->l3_len;
                m->ol_flags |= PKT_TX_IPV4;
                break;
-       case ETHER_TYPE_IPv6:
+       case RTE_ETHER_TYPE_IPV6:
                ipv6_hdr = l3_hdr;
                *l4_proto = ipv6_hdr->proto;
-               m->l3_len = sizeof(struct ipv6_hdr);
+               m->l3_len = sizeof(struct rte_ipv6_hdr);
                *l4_hdr = (char *)l3_hdr + m->l3_len;
                m->ol_flags |= PKT_TX_IPV6;
                break;
@@ -756,330 +1865,905 @@ parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
        }
 }
 
-static __rte_always_inline void
-vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
+static __rte_always_inline void
+vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
+{
+       uint16_t l4_proto = 0;
+       void *l4_hdr = NULL;
+       struct rte_tcp_hdr *tcp_hdr = NULL;
+
+       if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
+               return;
+
+       parse_ethernet(m, &l4_proto, &l4_hdr);
+       if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
+               if (hdr->csum_start == (m->l2_len + m->l3_len)) {
+                       switch (hdr->csum_offset) {
+                       case (offsetof(struct rte_tcp_hdr, cksum)):
+                               if (l4_proto == IPPROTO_TCP)
+                                       m->ol_flags |= PKT_TX_TCP_CKSUM;
+                               break;
+                       case (offsetof(struct rte_udp_hdr, dgram_cksum)):
+                               if (l4_proto == IPPROTO_UDP)
+                                       m->ol_flags |= PKT_TX_UDP_CKSUM;
+                               break;
+                       case (offsetof(struct rte_sctp_hdr, cksum)):
+                               if (l4_proto == IPPROTO_SCTP)
+                                       m->ol_flags |= PKT_TX_SCTP_CKSUM;
+                               break;
+                       default:
+                               break;
+                       }
+               }
+       }
+
+       if (l4_hdr && hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
+               switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
+               case VIRTIO_NET_HDR_GSO_TCPV4:
+               case VIRTIO_NET_HDR_GSO_TCPV6:
+                       tcp_hdr = l4_hdr;
+                       m->ol_flags |= PKT_TX_TCP_SEG;
+                       m->tso_segsz = hdr->gso_size;
+                       m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
+                       break;
+               case VIRTIO_NET_HDR_GSO_UDP:
+                       m->ol_flags |= PKT_TX_UDP_SEG;
+                       m->tso_segsz = hdr->gso_size;
+                       m->l4_len = sizeof(struct rte_udp_hdr);
+                       break;
+               default:
+                       VHOST_LOG_DATA(WARNING,
+                               "unsupported gso type %u.\n", hdr->gso_type);
+                       break;
+               }
+       }
+}
+
+static __rte_noinline void
+copy_vnet_hdr_from_desc(struct virtio_net_hdr *hdr,
+               struct buf_vector *buf_vec)
+{
+       uint64_t len;
+       uint64_t remain = sizeof(struct virtio_net_hdr);
+       uint64_t src;
+       uint64_t dst = (uint64_t)(uintptr_t)hdr;
+
+       while (remain) {
+               len = RTE_MIN(remain, buf_vec->buf_len);
+               src = buf_vec->buf_addr;
+               rte_memcpy((void *)(uintptr_t)dst,
+                               (void *)(uintptr_t)src, len);
+
+               remain -= len;
+               dst += len;
+               buf_vec++;
+       }
+}
+
+static __rte_always_inline int
+copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
+                 struct buf_vector *buf_vec, uint16_t nr_vec,
+                 struct rte_mbuf *m, struct rte_mempool *mbuf_pool)
+{
+       uint32_t buf_avail, buf_offset;
+       uint64_t buf_addr, buf_iova, buf_len;
+       uint32_t mbuf_avail, mbuf_offset;
+       uint32_t cpy_len;
+       struct rte_mbuf *cur = m, *prev = m;
+       struct virtio_net_hdr tmp_hdr;
+       struct virtio_net_hdr *hdr = NULL;
+       /* A counter to avoid desc dead loop chain */
+       uint16_t vec_idx = 0;
+       struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
+       int error = 0;
+
+       buf_addr = buf_vec[vec_idx].buf_addr;
+       buf_iova = buf_vec[vec_idx].buf_iova;
+       buf_len = buf_vec[vec_idx].buf_len;
+
+       if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) {
+               error = -1;
+               goto out;
+       }
+
+       if (virtio_net_with_host_offload(dev)) {
+               if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
+                       /*
+                        * No luck, the virtio-net header doesn't fit
+                        * in a contiguous virtual area.
+                        */
+                       copy_vnet_hdr_from_desc(&tmp_hdr, buf_vec);
+                       hdr = &tmp_hdr;
+               } else {
+                       hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
+               }
+       }
+
+       /*
+        * A virtio driver normally uses at least 2 desc buffers
+        * for Tx: the first for storing the header, and others
+        * for storing the data.
+        */
+       if (unlikely(buf_len < dev->vhost_hlen)) {
+               buf_offset = dev->vhost_hlen - buf_len;
+               vec_idx++;
+               buf_addr = buf_vec[vec_idx].buf_addr;
+               buf_iova = buf_vec[vec_idx].buf_iova;
+               buf_len = buf_vec[vec_idx].buf_len;
+               buf_avail  = buf_len - buf_offset;
+       } else if (buf_len == dev->vhost_hlen) {
+               if (unlikely(++vec_idx >= nr_vec))
+                       goto out;
+               buf_addr = buf_vec[vec_idx].buf_addr;
+               buf_iova = buf_vec[vec_idx].buf_iova;
+               buf_len = buf_vec[vec_idx].buf_len;
+
+               buf_offset = 0;
+               buf_avail = buf_len;
+       } else {
+               buf_offset = dev->vhost_hlen;
+               buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
+       }
+
+       PRINT_PACKET(dev,
+                       (uintptr_t)(buf_addr + buf_offset),
+                       (uint32_t)buf_avail, 0);
+
+       mbuf_offset = 0;
+       mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
+       while (1) {
+               uint64_t hpa;
+
+               cpy_len = RTE_MIN(buf_avail, mbuf_avail);
+
+               /*
+                * A desc buf might across two host physical pages that are
+                * not continuous. In such case (gpa_to_hpa returns 0), data
+                * will be copied even though zero copy is enabled.
+                */
+               if (unlikely(dev->dequeue_zero_copy && (hpa = gpa_to_hpa(dev,
+                                       buf_iova + buf_offset, cpy_len)))) {
+                       cur->data_len = cpy_len;
+                       cur->data_off = 0;
+                       cur->buf_addr =
+                               (void *)(uintptr_t)(buf_addr + buf_offset);
+                       cur->buf_iova = hpa;
+
+                       /*
+                        * In zero copy mode, one mbuf can only reference data
+                        * for one or partial of one desc buff.
+                        */
+                       mbuf_avail = cpy_len;
+               } else {
+                       if (likely(cpy_len > MAX_BATCH_LEN ||
+                                  vq->batch_copy_nb_elems >= vq->size ||
+                                  (hdr && cur == m))) {
+                               rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
+                                                                  mbuf_offset),
+                                          (void *)((uintptr_t)(buf_addr +
+                                                          buf_offset)),
+                                          cpy_len);
+                       } else {
+                               batch_copy[vq->batch_copy_nb_elems].dst =
+                                       rte_pktmbuf_mtod_offset(cur, void *,
+                                                               mbuf_offset);
+                               batch_copy[vq->batch_copy_nb_elems].src =
+                                       (void *)((uintptr_t)(buf_addr +
+                                                               buf_offset));
+                               batch_copy[vq->batch_copy_nb_elems].len =
+                                       cpy_len;
+                               vq->batch_copy_nb_elems++;
+                       }
+               }
+
+               mbuf_avail  -= cpy_len;
+               mbuf_offset += cpy_len;
+               buf_avail -= cpy_len;
+               buf_offset += cpy_len;
+
+               /* This buf reaches to its end, get the next one */
+               if (buf_avail == 0) {
+                       if (++vec_idx >= nr_vec)
+                               break;
+
+                       buf_addr = buf_vec[vec_idx].buf_addr;
+                       buf_iova = buf_vec[vec_idx].buf_iova;
+                       buf_len = buf_vec[vec_idx].buf_len;
+
+                       buf_offset = 0;
+                       buf_avail  = buf_len;
+
+                       PRINT_PACKET(dev, (uintptr_t)buf_addr,
+                                       (uint32_t)buf_avail, 0);
+               }
+
+               /*
+                * This mbuf reaches to its end, get a new one
+                * to hold more data.
+                */
+               if (mbuf_avail == 0) {
+                       cur = rte_pktmbuf_alloc(mbuf_pool);
+                       if (unlikely(cur == NULL)) {
+                               VHOST_LOG_DATA(ERR, "Failed to "
+                                       "allocate memory for mbuf.\n");
+                               error = -1;
+                               goto out;
+                       }
+                       if (unlikely(dev->dequeue_zero_copy))
+                               rte_mbuf_refcnt_update(cur, 1);
+
+                       prev->next = cur;
+                       prev->data_len = mbuf_offset;
+                       m->nb_segs += 1;
+                       m->pkt_len += mbuf_offset;
+                       prev = cur;
+
+                       mbuf_offset = 0;
+                       mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+               }
+       }
+
+       prev->data_len = mbuf_offset;
+       m->pkt_len    += mbuf_offset;
+
+       if (hdr)
+               vhost_dequeue_offload(hdr, m);
+
+out:
+
+       return error;
+}
+
+static __rte_always_inline struct zcopy_mbuf *
+get_zmbuf(struct vhost_virtqueue *vq)
 {
-       uint16_t l4_proto = 0;
-       void *l4_hdr = NULL;
-       struct tcp_hdr *tcp_hdr = NULL;
+       uint16_t i;
+       uint16_t last;
+       int tries = 0;
 
-       if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
-               return;
+       /* search [last_zmbuf_idx, zmbuf_size) */
+       i = vq->last_zmbuf_idx;
+       last = vq->zmbuf_size;
 
-       parse_ethernet(m, &l4_proto, &l4_hdr);
-       if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
-               if (hdr->csum_start == (m->l2_len + m->l3_len)) {
-                       switch (hdr->csum_offset) {
-                       case (offsetof(struct tcp_hdr, cksum)):
-                               if (l4_proto == IPPROTO_TCP)
-                                       m->ol_flags |= PKT_TX_TCP_CKSUM;
-                               break;
-                       case (offsetof(struct udp_hdr, dgram_cksum)):
-                               if (l4_proto == IPPROTO_UDP)
-                                       m->ol_flags |= PKT_TX_UDP_CKSUM;
-                               break;
-                       case (offsetof(struct sctp_hdr, cksum)):
-                               if (l4_proto == IPPROTO_SCTP)
-                                       m->ol_flags |= PKT_TX_SCTP_CKSUM;
-                               break;
-                       default:
-                               break;
+again:
+       for (; i < last; i++) {
+               if (vq->zmbufs[i].in_use == 0) {
+                       vq->last_zmbuf_idx = i + 1;
+                       vq->zmbufs[i].in_use = 1;
+                       return &vq->zmbufs[i];
+               }
+       }
+
+       tries++;
+       if (tries == 1) {
+               /* search [0, last_zmbuf_idx) */
+               i = 0;
+               last = vq->last_zmbuf_idx;
+               goto again;
+       }
+
+       return NULL;
+}
+
+static void
+virtio_dev_extbuf_free(void *addr __rte_unused, void *opaque)
+{
+       rte_free(opaque);
+}
+
+static int
+virtio_dev_extbuf_alloc(struct rte_mbuf *pkt, uint32_t size)
+{
+       struct rte_mbuf_ext_shared_info *shinfo = NULL;
+       uint32_t total_len = RTE_PKTMBUF_HEADROOM + size;
+       uint16_t buf_len;
+       rte_iova_t iova;
+       void *buf;
+
+       /* Try to use pkt buffer to store shinfo to reduce the amount of memory
+        * required, otherwise store shinfo in the new buffer.
+        */
+       if (rte_pktmbuf_tailroom(pkt) >= sizeof(*shinfo))
+               shinfo = rte_pktmbuf_mtod(pkt,
+                                         struct rte_mbuf_ext_shared_info *);
+       else {
+               total_len += sizeof(*shinfo) + sizeof(uintptr_t);
+               total_len = RTE_ALIGN_CEIL(total_len, sizeof(uintptr_t));
+       }
+
+       if (unlikely(total_len > UINT16_MAX))
+               return -ENOSPC;
+
+       buf_len = total_len;
+       buf = rte_malloc(NULL, buf_len, RTE_CACHE_LINE_SIZE);
+       if (unlikely(buf == NULL))
+               return -ENOMEM;
+
+       /* Initialize shinfo */
+       if (shinfo) {
+               shinfo->free_cb = virtio_dev_extbuf_free;
+               shinfo->fcb_opaque = buf;
+               rte_mbuf_ext_refcnt_set(shinfo, 1);
+       } else {
+               shinfo = rte_pktmbuf_ext_shinfo_init_helper(buf, &buf_len,
+                                             virtio_dev_extbuf_free, buf);
+               if (unlikely(shinfo == NULL)) {
+                       rte_free(buf);
+                       VHOST_LOG_DATA(ERR, "Failed to init shinfo\n");
+                       return -1;
+               }
+       }
+
+       iova = rte_malloc_virt2iova(buf);
+       rte_pktmbuf_attach_extbuf(pkt, buf, iova, buf_len, shinfo);
+       rte_pktmbuf_reset_headroom(pkt);
+
+       return 0;
+}
+
+/*
+ * Allocate a host supported pktmbuf.
+ */
+static __rte_always_inline struct rte_mbuf *
+virtio_dev_pktmbuf_alloc(struct virtio_net *dev, struct rte_mempool *mp,
+                        uint32_t data_len)
+{
+       struct rte_mbuf *pkt = rte_pktmbuf_alloc(mp);
+
+       if (unlikely(pkt == NULL)) {
+               VHOST_LOG_DATA(ERR,
+                       "Failed to allocate memory for mbuf.\n");
+               return NULL;
+       }
+
+       if (rte_pktmbuf_tailroom(pkt) >= data_len)
+               return pkt;
+
+       /* attach an external buffer if supported */
+       if (dev->extbuf && !virtio_dev_extbuf_alloc(pkt, data_len))
+               return pkt;
+
+       /* check if chained buffers are allowed */
+       if (!dev->linearbuf)
+               return pkt;
+
+       /* Data doesn't fit into the buffer and the host supports
+        * only linear buffers
+        */
+       rte_pktmbuf_free(pkt);
+
+       return NULL;
+}
+
+static __rte_noinline uint16_t
+virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
+       struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
+{
+       uint16_t i;
+       uint16_t free_entries;
+       uint16_t dropped = 0;
+       static bool allocerr_warned;
+
+       if (unlikely(dev->dequeue_zero_copy)) {
+               struct zcopy_mbuf *zmbuf, *next;
+
+               for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
+                    zmbuf != NULL; zmbuf = next) {
+                       next = TAILQ_NEXT(zmbuf, next);
+
+                       if (mbuf_is_consumed(zmbuf->mbuf)) {
+                               update_shadow_used_ring_split(vq,
+                                               zmbuf->desc_idx, 0);
+                               TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
+                               restore_mbuf(zmbuf->mbuf);
+                               rte_pktmbuf_free(zmbuf->mbuf);
+                               put_zmbuf(zmbuf);
+                               vq->nr_zmbuf -= 1;
                        }
                }
+
+               if (likely(vq->shadow_used_idx)) {
+                       flush_shadow_used_ring_split(dev, vq);
+                       vhost_vring_call_split(dev, vq);
+               }
        }
 
-       if (l4_hdr && hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
-               switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
-               case VIRTIO_NET_HDR_GSO_TCPV4:
-               case VIRTIO_NET_HDR_GSO_TCPV6:
-                       tcp_hdr = l4_hdr;
-                       m->ol_flags |= PKT_TX_TCP_SEG;
-                       m->tso_segsz = hdr->gso_size;
-                       m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
+       /*
+        * The ordering between avail index and
+        * desc reads needs to be enforced.
+        */
+       free_entries = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE) -
+                       vq->last_avail_idx;
+       if (free_entries == 0)
+               return 0;
+
+       rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
+
+       VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
+
+       count = RTE_MIN(count, MAX_PKT_BURST);
+       count = RTE_MIN(count, free_entries);
+       VHOST_LOG_DATA(DEBUG, "(%d) about to dequeue %u buffers\n",
+                       dev->vid, count);
+
+       for (i = 0; i < count; i++) {
+               struct buf_vector buf_vec[BUF_VECTOR_MAX];
+               uint16_t head_idx;
+               uint32_t buf_len;
+               uint16_t nr_vec = 0;
+               int err;
+
+               if (unlikely(fill_vec_buf_split(dev, vq,
+                                               vq->last_avail_idx + i,
+                                               &nr_vec, buf_vec,
+                                               &head_idx, &buf_len,
+                                               VHOST_ACCESS_RO) < 0))
                        break;
-               case VIRTIO_NET_HDR_GSO_UDP:
-                       m->ol_flags |= PKT_TX_UDP_SEG;
-                       m->tso_segsz = hdr->gso_size;
-                       m->l4_len = sizeof(struct udp_hdr);
+
+               if (likely(dev->dequeue_zero_copy == 0))
+                       update_shadow_used_ring_split(vq, head_idx, 0);
+
+               pkts[i] = virtio_dev_pktmbuf_alloc(dev, mbuf_pool, buf_len);
+               if (unlikely(pkts[i] == NULL)) {
+                       /*
+                        * mbuf allocation fails for jumbo packets when external
+                        * buffer allocation is not allowed and linear buffer
+                        * is required. Drop this packet.
+                        */
+                       if (!allocerr_warned) {
+                               VHOST_LOG_DATA(ERR,
+                                       "Failed mbuf alloc of size %d from %s on %s.\n",
+                                       buf_len, mbuf_pool->name, dev->ifname);
+                               allocerr_warned = true;
+                       }
+                       dropped += 1;
+                       i++;
                        break;
-               default:
-                       RTE_LOG(WARNING, VHOST_DATA,
-                               "unsupported gso type %u.\n", hdr->gso_type);
+               }
+
+               err = copy_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkts[i],
+                               mbuf_pool);
+               if (unlikely(err)) {
+                       rte_pktmbuf_free(pkts[i]);
+                       if (!allocerr_warned) {
+                               VHOST_LOG_DATA(ERR,
+                                       "Failed to copy desc to mbuf on %s.\n",
+                                       dev->ifname);
+                               allocerr_warned = true;
+                       }
+                       dropped += 1;
+                       i++;
                        break;
                }
+
+               if (unlikely(dev->dequeue_zero_copy)) {
+                       struct zcopy_mbuf *zmbuf;
+
+                       zmbuf = get_zmbuf(vq);
+                       if (!zmbuf) {
+                               rte_pktmbuf_free(pkts[i]);
+                               dropped += 1;
+                               i++;
+                               break;
+                       }
+                       zmbuf->mbuf = pkts[i];
+                       zmbuf->desc_idx = head_idx;
+
+                       /*
+                        * Pin lock the mbuf; we will check later to see
+                        * whether the mbuf is freed (when we are the last
+                        * user) or not. If that's the case, we then could
+                        * update the used ring safely.
+                        */
+                       rte_mbuf_refcnt_update(pkts[i], 1);
+
+                       vq->nr_zmbuf += 1;
+                       TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next);
+               }
+       }
+       vq->last_avail_idx += i;
+
+       if (likely(dev->dequeue_zero_copy == 0)) {
+               do_data_copy_dequeue(vq);
+               if (unlikely(i < count))
+                       vq->shadow_used_idx = i;
+               if (likely(vq->shadow_used_idx)) {
+                       flush_shadow_used_ring_split(dev, vq);
+                       vhost_vring_call_split(dev, vq);
+               }
+       }
+
+       return (i - dropped);
+}
+
+static __rte_always_inline int
+vhost_reserve_avail_batch_packed(struct virtio_net *dev,
+                                struct vhost_virtqueue *vq,
+                                struct rte_mempool *mbuf_pool,
+                                struct rte_mbuf **pkts,
+                                uint16_t avail_idx,
+                                uintptr_t *desc_addrs,
+                                uint16_t *ids)
+{
+       bool wrap = vq->avail_wrap_counter;
+       struct vring_packed_desc *descs = vq->desc_packed;
+       struct virtio_net_hdr *hdr;
+       uint64_t lens[PACKED_BATCH_SIZE];
+       uint64_t buf_lens[PACKED_BATCH_SIZE];
+       uint32_t buf_offset = dev->vhost_hlen;
+       uint16_t flags, i;
+
+       if (unlikely(avail_idx & PACKED_BATCH_MASK))
+               return -1;
+       if (unlikely((avail_idx + PACKED_BATCH_SIZE) > vq->size))
+               return -1;
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               flags = descs[avail_idx + i].flags;
+               if (unlikely((wrap != !!(flags & VRING_DESC_F_AVAIL)) ||
+                            (wrap == !!(flags & VRING_DESC_F_USED))  ||
+                            (flags & PACKED_DESC_SINGLE_DEQUEUE_FLAG)))
+                       return -1;
+       }
+
+       rte_smp_rmb();
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               lens[i] = descs[avail_idx + i].len;
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               desc_addrs[i] = vhost_iova_to_vva(dev, vq,
+                                                 descs[avail_idx + i].addr,
+                                                 &lens[i], VHOST_ACCESS_RW);
+       }
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               if (unlikely(!desc_addrs[i]))
+                       return -1;
+               if (unlikely((lens[i] != descs[avail_idx + i].len)))
+                       return -1;
+       }
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               pkts[i] = virtio_dev_pktmbuf_alloc(dev, mbuf_pool, lens[i]);
+               if (!pkts[i])
+                       goto free_buf;
+       }
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               buf_lens[i] = pkts[i]->buf_len - pkts[i]->data_off;
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               if (unlikely(buf_lens[i] < (lens[i] - buf_offset)))
+                       goto free_buf;
+       }
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               pkts[i]->pkt_len = descs[avail_idx + i].len - buf_offset;
+               pkts[i]->data_len = pkts[i]->pkt_len;
+               ids[i] = descs[avail_idx + i].id;
+       }
+
+       if (virtio_net_with_host_offload(dev)) {
+               vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+                       hdr = (struct virtio_net_hdr *)(desc_addrs[i]);
+                       vhost_dequeue_offload(hdr, pkts[i]);
+               }
        }
+
+       return 0;
+
+free_buf:
+       for (i = 0; i < PACKED_BATCH_SIZE; i++)
+               rte_pktmbuf_free(pkts[i]);
+
+       return -1;
 }
 
-static __rte_always_inline void
-put_zmbuf(struct zcopy_mbuf *zmbuf)
+static __rte_always_inline int
+virtio_dev_tx_batch_packed(struct virtio_net *dev,
+                          struct vhost_virtqueue *vq,
+                          struct rte_mempool *mbuf_pool,
+                          struct rte_mbuf **pkts)
 {
-       zmbuf->in_use = 0;
+       uint16_t avail_idx = vq->last_avail_idx;
+       uint32_t buf_offset = dev->vhost_hlen;
+       uintptr_t desc_addrs[PACKED_BATCH_SIZE];
+       uint16_t ids[PACKED_BATCH_SIZE];
+       uint16_t i;
+
+       if (vhost_reserve_avail_batch_packed(dev, vq, mbuf_pool, pkts,
+                                            avail_idx, desc_addrs, ids))
+               return -1;
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               rte_prefetch0((void *)(uintptr_t)desc_addrs[i]);
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               rte_memcpy(rte_pktmbuf_mtod_offset(pkts[i], void *, 0),
+                          (void *)(uintptr_t)(desc_addrs[i] + buf_offset),
+                          pkts[i]->pkt_len);
+
+       if (virtio_net_is_inorder(dev))
+               vhost_shadow_dequeue_batch_packed_inorder(vq,
+                       ids[PACKED_BATCH_SIZE - 1]);
+       else
+               vhost_shadow_dequeue_batch_packed(dev, vq, ids);
+
+       vq_inc_last_avail_packed(vq, PACKED_BATCH_SIZE);
+
+       return 0;
+}
+
+static __rte_always_inline int
+vhost_dequeue_single_packed(struct virtio_net *dev,
+                           struct vhost_virtqueue *vq,
+                           struct rte_mempool *mbuf_pool,
+                           struct rte_mbuf **pkts,
+                           uint16_t *buf_id,
+                           uint16_t *desc_count)
+{
+       struct buf_vector buf_vec[BUF_VECTOR_MAX];
+       uint32_t buf_len;
+       uint16_t nr_vec = 0;
+       int err;
+       static bool allocerr_warned;
+
+       if (unlikely(fill_vec_buf_packed(dev, vq,
+                                        vq->last_avail_idx, desc_count,
+                                        buf_vec, &nr_vec,
+                                        buf_id, &buf_len,
+                                        VHOST_ACCESS_RO) < 0))
+               return -1;
+
+       *pkts = virtio_dev_pktmbuf_alloc(dev, mbuf_pool, buf_len);
+       if (unlikely(*pkts == NULL)) {
+               if (!allocerr_warned) {
+                       VHOST_LOG_DATA(ERR,
+                               "Failed mbuf alloc of size %d from %s on %s.\n",
+                               buf_len, mbuf_pool->name, dev->ifname);
+                       allocerr_warned = true;
+               }
+               return -1;
+       }
+
+       err = copy_desc_to_mbuf(dev, vq, buf_vec, nr_vec, *pkts,
+                               mbuf_pool);
+       if (unlikely(err)) {
+               if (!allocerr_warned) {
+                       VHOST_LOG_DATA(ERR,
+                               "Failed to copy desc to mbuf on %s.\n",
+                               dev->ifname);
+                       allocerr_warned = true;
+               }
+               rte_pktmbuf_free(*pkts);
+               return -1;
+       }
+
+       return 0;
+}
+
+static __rte_always_inline int
+virtio_dev_tx_single_packed(struct virtio_net *dev,
+                           struct vhost_virtqueue *vq,
+                           struct rte_mempool *mbuf_pool,
+                           struct rte_mbuf **pkts)
+{
+
+       uint16_t buf_id, desc_count = 0;
+       int ret;
+
+       ret = vhost_dequeue_single_packed(dev, vq, mbuf_pool, pkts, &buf_id,
+                                       &desc_count);
+
+       if (likely(desc_count > 0)) {
+               if (virtio_net_is_inorder(dev))
+                       vhost_shadow_dequeue_single_packed_inorder(vq, buf_id,
+                                                                  desc_count);
+               else
+                       vhost_shadow_dequeue_single_packed(vq, buf_id,
+                                       desc_count);
+
+               vq_inc_last_avail_packed(vq, desc_count);
+       }
+
+       return ret;
 }
 
 static __rte_always_inline int
-copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
-                 struct vring_desc *descs, uint16_t max_desc,
-                 struct rte_mbuf *m, uint16_t desc_idx,
-                 struct rte_mempool *mbuf_pool)
+virtio_dev_tx_batch_packed_zmbuf(struct virtio_net *dev,
+                                struct vhost_virtqueue *vq,
+                                struct rte_mempool *mbuf_pool,
+                                struct rte_mbuf **pkts)
 {
-       struct vring_desc *desc;
-       uint64_t desc_addr;
-       uint32_t desc_avail, desc_offset;
-       uint32_t mbuf_avail, mbuf_offset;
-       uint32_t cpy_len;
-       struct rte_mbuf *cur = m, *prev = m;
-       struct virtio_net_hdr *hdr = NULL;
-       /* A counter to avoid desc dead loop chain */
-       uint32_t nr_desc = 1;
-       struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
-       uint16_t copy_nb = vq->batch_copy_nb_elems;
-       int error = 0;
+       struct zcopy_mbuf *zmbufs[PACKED_BATCH_SIZE];
+       uintptr_t desc_addrs[PACKED_BATCH_SIZE];
+       uint16_t ids[PACKED_BATCH_SIZE];
+       uint16_t i;
 
-       desc = &descs[desc_idx];
-       if (unlikely((desc->len < dev->vhost_hlen)) ||
-                       (desc->flags & VRING_DESC_F_INDIRECT)) {
-               error = -1;
-               goto out;
-       }
+       uint16_t avail_idx = vq->last_avail_idx;
 
-       desc_addr = vhost_iova_to_vva(dev,
-                                       vq, desc->addr,
-                                       desc->len,
-                                       VHOST_ACCESS_RO);
-       if (unlikely(!desc_addr)) {
-               error = -1;
-               goto out;
-       }
+       if (vhost_reserve_avail_batch_packed(dev, vq, mbuf_pool, pkts,
+                                            avail_idx, desc_addrs, ids))
+               return -1;
 
-       if (virtio_net_with_host_offload(dev)) {
-               hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr);
-               rte_prefetch0(hdr);
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               zmbufs[i] = get_zmbuf(vq);
+
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               if (!zmbufs[i])
+                       goto free_pkt;
        }
 
-       /*
-        * A virtio driver normally uses at least 2 desc buffers
-        * for Tx: the first for storing the header, and others
-        * for storing the data.
-        */
-       if (likely((desc->len == dev->vhost_hlen) &&
-                  (desc->flags & VRING_DESC_F_NEXT) != 0)) {
-               desc = &descs[desc->next];
-               if (unlikely(desc->flags & VRING_DESC_F_INDIRECT)) {
-                       error = -1;
-                       goto out;
-               }
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
+               zmbufs[i]->mbuf = pkts[i];
+               zmbufs[i]->desc_idx = ids[i];
+               zmbufs[i]->desc_count = 1;
+       }
 
-               desc_addr = vhost_iova_to_vva(dev,
-                                                       vq, desc->addr,
-                                                       desc->len,
-                                                       VHOST_ACCESS_RO);
-               if (unlikely(!desc_addr)) {
-                       error = -1;
-                       goto out;
-               }
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               rte_mbuf_refcnt_update(pkts[i], 1);
 
-               desc_offset = 0;
-               desc_avail  = desc->len;
-               nr_desc    += 1;
-       } else {
-               desc_avail  = desc->len - dev->vhost_hlen;
-               desc_offset = dev->vhost_hlen;
-       }
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbufs[i], next);
 
-       rte_prefetch0((void *)(uintptr_t)(desc_addr + desc_offset));
+       vq->nr_zmbuf += PACKED_BATCH_SIZE;
+       vq_inc_last_avail_packed(vq, PACKED_BATCH_SIZE);
 
-       PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset), desc_avail, 0);
+       return 0;
 
-       mbuf_offset = 0;
-       mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
-       while (1) {
-               uint64_t hpa;
+free_pkt:
+       vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
+               rte_pktmbuf_free(pkts[i]);
 
-               cpy_len = RTE_MIN(desc_avail, mbuf_avail);
+       return -1;
+}
 
-               /*
-                * A desc buf might across two host physical pages that are
-                * not continuous. In such case (gpa_to_hpa returns 0), data
-                * will be copied even though zero copy is enabled.
-                */
-               if (unlikely(dev->dequeue_zero_copy && (hpa = gpa_to_hpa(dev,
-                                       desc->addr + desc_offset, cpy_len)))) {
-                       cur->data_len = cpy_len;
-                       cur->data_off = 0;
-                       cur->buf_addr = (void *)(uintptr_t)(desc_addr
-                               + desc_offset);
-                       cur->buf_iova = hpa;
+static __rte_always_inline int
+virtio_dev_tx_single_packed_zmbuf(struct virtio_net *dev,
+                                 struct vhost_virtqueue *vq,
+                                 struct rte_mempool *mbuf_pool,
+                                 struct rte_mbuf **pkts)
+{
+       uint16_t buf_id, desc_count;
+       struct zcopy_mbuf *zmbuf;
 
-                       /*
-                        * In zero copy mode, one mbuf can only reference data
-                        * for one or partial of one desc buff.
-                        */
-                       mbuf_avail = cpy_len;
-               } else {
-                       if (likely(cpy_len > MAX_BATCH_LEN ||
-                                  copy_nb >= vq->size ||
-                                  (hdr && cur == m))) {
-                               rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
-                                                                  mbuf_offset),
-                                          (void *)((uintptr_t)(desc_addr +
-                                                               desc_offset)),
-                                          cpy_len);
-                       } else {
-                               batch_copy[copy_nb].dst =
-                                       rte_pktmbuf_mtod_offset(cur, void *,
-                                                               mbuf_offset);
-                               batch_copy[copy_nb].src =
-                                       (void *)((uintptr_t)(desc_addr +
-                                                            desc_offset));
-                               batch_copy[copy_nb].len = cpy_len;
-                               copy_nb++;
-                       }
-               }
+       if (vhost_dequeue_single_packed(dev, vq, mbuf_pool, pkts, &buf_id,
+                                       &desc_count))
+               return -1;
 
-               mbuf_avail  -= cpy_len;
-               mbuf_offset += cpy_len;
-               desc_avail  -= cpy_len;
-               desc_offset += cpy_len;
+       zmbuf = get_zmbuf(vq);
+       if (!zmbuf) {
+               rte_pktmbuf_free(*pkts);
+               return -1;
+       }
+       zmbuf->mbuf = *pkts;
+       zmbuf->desc_idx = buf_id;
+       zmbuf->desc_count = desc_count;
 
-               /* This desc reaches to its end, get the next one */
-               if (desc_avail == 0) {
-                       if ((desc->flags & VRING_DESC_F_NEXT) == 0)
-                               break;
+       rte_mbuf_refcnt_update(*pkts, 1);
 
-                       if (unlikely(desc->next >= max_desc ||
-                                    ++nr_desc > max_desc)) {
-                               error = -1;
-                               goto out;
-                       }
-                       desc = &descs[desc->next];
-                       if (unlikely(desc->flags & VRING_DESC_F_INDIRECT)) {
-                               error = -1;
-                               goto out;
-                       }
+       vq->nr_zmbuf += 1;
+       TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next);
 
-                       desc_addr = vhost_iova_to_vva(dev,
-                                                       vq, desc->addr,
-                                                       desc->len,
-                                                       VHOST_ACCESS_RO);
-                       if (unlikely(!desc_addr)) {
-                               error = -1;
-                               goto out;
-                       }
+       vq_inc_last_avail_packed(vq, desc_count);
+       return 0;
+}
 
-                       rte_prefetch0((void *)(uintptr_t)desc_addr);
+static __rte_always_inline void
+free_zmbuf(struct vhost_virtqueue *vq)
+{
+       struct zcopy_mbuf *next = NULL;
+       struct zcopy_mbuf *zmbuf;
 
-                       desc_offset = 0;
-                       desc_avail  = desc->len;
+       for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
+            zmbuf != NULL; zmbuf = next) {
+               next = TAILQ_NEXT(zmbuf, next);
 
-                       PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0);
-               }
+               uint16_t last_used_idx = vq->last_used_idx;
 
-               /*
-                * This mbuf reaches to its end, get a new one
-                * to hold more data.
-                */
-               if (mbuf_avail == 0) {
-                       cur = rte_pktmbuf_alloc(mbuf_pool);
-                       if (unlikely(cur == NULL)) {
-                               RTE_LOG(ERR, VHOST_DATA, "Failed to "
-                                       "allocate memory for mbuf.\n");
-                               error = -1;
-                               goto out;
+               if (mbuf_is_consumed(zmbuf->mbuf)) {
+                       uint16_t flags;
+                       flags = vq->desc_packed[last_used_idx].flags;
+                       if (vq->used_wrap_counter) {
+                               flags |= VRING_DESC_F_USED;
+                               flags |= VRING_DESC_F_AVAIL;
+                       } else {
+                               flags &= ~VRING_DESC_F_USED;
+                               flags &= ~VRING_DESC_F_AVAIL;
                        }
-                       if (unlikely(dev->dequeue_zero_copy))
-                               rte_mbuf_refcnt_update(cur, 1);
 
-                       prev->next = cur;
-                       prev->data_len = mbuf_offset;
-                       m->nb_segs += 1;
-                       m->pkt_len += mbuf_offset;
-                       prev = cur;
+                       vq->desc_packed[last_used_idx].id = zmbuf->desc_idx;
+                       vq->desc_packed[last_used_idx].len = 0;
 
-                       mbuf_offset = 0;
-                       mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+                       rte_smp_wmb();
+                       vq->desc_packed[last_used_idx].flags = flags;
+
+                       vq_inc_last_used_packed(vq, zmbuf->desc_count);
+
+                       TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
+                       restore_mbuf(zmbuf->mbuf);
+                       rte_pktmbuf_free(zmbuf->mbuf);
+                       put_zmbuf(zmbuf);
+                       vq->nr_zmbuf -= 1;
                }
        }
+}
 
-       prev->data_len = mbuf_offset;
-       m->pkt_len    += mbuf_offset;
-
-       if (hdr)
-               vhost_dequeue_offload(hdr, m);
+static __rte_noinline uint16_t
+virtio_dev_tx_packed_zmbuf(struct virtio_net *dev,
+                          struct vhost_virtqueue *__rte_restrict vq,
+                          struct rte_mempool *mbuf_pool,
+                          struct rte_mbuf **__rte_restrict pkts,
+                          uint32_t count)
+{
+       uint32_t pkt_idx = 0;
+       uint32_t remained = count;
 
-out:
-       vq->batch_copy_nb_elems = copy_nb;
+       free_zmbuf(vq);
 
-       return error;
-}
+       do {
+               if (remained >= PACKED_BATCH_SIZE) {
+                       if (!virtio_dev_tx_batch_packed_zmbuf(dev, vq,
+                               mbuf_pool, &pkts[pkt_idx])) {
+                               pkt_idx += PACKED_BATCH_SIZE;
+                               remained -= PACKED_BATCH_SIZE;
+                               continue;
+                       }
+               }
 
-static __rte_always_inline void
-update_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
-                uint32_t used_idx, uint32_t desc_idx)
-{
-       vq->used->ring[used_idx].id  = desc_idx;
-       vq->used->ring[used_idx].len = 0;
-       vhost_log_used_vring(dev, vq,
-                       offsetof(struct vring_used, ring[used_idx]),
-                       sizeof(vq->used->ring[used_idx]));
-}
+               if (virtio_dev_tx_single_packed_zmbuf(dev, vq, mbuf_pool,
+                                                     &pkts[pkt_idx]))
+                       break;
+               pkt_idx++;
+               remained--;
 
-static __rte_always_inline void
-update_used_idx(struct virtio_net *dev, struct vhost_virtqueue *vq,
-               uint32_t count)
-{
-       if (unlikely(count == 0))
-               return;
+       } while (remained);
 
-       rte_smp_wmb();
-       rte_smp_rmb();
+       if (pkt_idx)
+               vhost_vring_call_packed(dev, vq);
 
-       vq->used->idx += count;
-       vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
-                       sizeof(vq->used->idx));
-       vhost_vring_call(dev, vq);
+       return pkt_idx;
 }
 
-static __rte_always_inline struct zcopy_mbuf *
-get_zmbuf(struct vhost_virtqueue *vq)
+static __rte_noinline uint16_t
+virtio_dev_tx_packed(struct virtio_net *dev,
+                    struct vhost_virtqueue *__rte_restrict vq,
+                    struct rte_mempool *mbuf_pool,
+                    struct rte_mbuf **__rte_restrict pkts,
+                    uint32_t count)
 {
-       uint16_t i;
-       uint16_t last;
-       int tries = 0;
+       uint32_t pkt_idx = 0;
+       uint32_t remained = count;
 
-       /* search [last_zmbuf_idx, zmbuf_size) */
-       i = vq->last_zmbuf_idx;
-       last = vq->zmbuf_size;
+       do {
+               rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
 
-again:
-       for (; i < last; i++) {
-               if (vq->zmbufs[i].in_use == 0) {
-                       vq->last_zmbuf_idx = i + 1;
-                       vq->zmbufs[i].in_use = 1;
-                       return &vq->zmbufs[i];
+               if (remained >= PACKED_BATCH_SIZE) {
+                       if (!virtio_dev_tx_batch_packed(dev, vq, mbuf_pool,
+                                                       &pkts[pkt_idx])) {
+                               pkt_idx += PACKED_BATCH_SIZE;
+                               remained -= PACKED_BATCH_SIZE;
+                               continue;
+                       }
                }
-       }
 
-       tries++;
-       if (tries == 1) {
-               /* search [0, last_zmbuf_idx) */
-               i = 0;
-               last = vq->last_zmbuf_idx;
-               goto again;
-       }
+               if (virtio_dev_tx_single_packed(dev, vq, mbuf_pool,
+                                               &pkts[pkt_idx]))
+                       break;
+               pkt_idx++;
+               remained--;
 
-       return NULL;
-}
+       } while (remained);
 
-static __rte_always_inline bool
-mbuf_is_consumed(struct rte_mbuf *m)
-{
-       while (m) {
-               if (rte_mbuf_refcnt_read(m) > 1)
-                       return false;
-               m = m->next;
+       if (vq->shadow_used_idx) {
+               do_data_copy_dequeue(vq);
+
+               vhost_flush_dequeue_shadow_packed(dev, vq);
+               vhost_vring_call_packed(dev, vq);
        }
 
-       return true;
+       return pkt_idx;
 }
 
 uint16_t
@@ -1089,59 +2773,45 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
        struct virtio_net *dev;
        struct rte_mbuf *rarp_mbuf = NULL;
        struct vhost_virtqueue *vq;
-       uint32_t desc_indexes[MAX_PKT_BURST];
-       uint32_t used_idx;
-       uint32_t i = 0;
-       uint16_t free_entries;
-       uint16_t avail_idx;
+       int16_t success = 1;
 
        dev = get_device(vid);
        if (!dev)
                return 0;
 
+       if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
+               VHOST_LOG_DATA(ERR,
+                       "(%d) %s: built-in vhost net backend is disabled.\n",
+                       dev->vid, __func__);
+               return 0;
+       }
+
        if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
-               RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
+               VHOST_LOG_DATA(ERR,
+                       "(%d) %s: invalid virtqueue idx %d.\n",
                        dev->vid, __func__, queue_id);
                return 0;
        }
 
        vq = dev->virtqueue[queue_id];
-       if (unlikely(vq->enabled == 0))
+
+       if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
                return 0;
 
-       vq->batch_copy_nb_elems = 0;
+       if (unlikely(vq->enabled == 0)) {
+               count = 0;
+               goto out_access_unlock;
+       }
 
        if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
                vhost_user_iotlb_rd_lock(vq);
 
        if (unlikely(vq->access_ok == 0))
-               if (unlikely(vring_translate(dev, vq) < 0))
+               if (unlikely(vring_translate(dev, vq) < 0)) {
+                       count = 0;
                        goto out;
-
-       if (unlikely(dev->dequeue_zero_copy)) {
-               struct zcopy_mbuf *zmbuf, *next;
-               int nr_updated = 0;
-
-               for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
-                    zmbuf != NULL; zmbuf = next) {
-                       next = TAILQ_NEXT(zmbuf, next);
-
-                       if (mbuf_is_consumed(zmbuf->mbuf)) {
-                               used_idx = vq->last_used_idx++ & (vq->size - 1);
-                               update_used_ring(dev, vq, used_idx,
-                                                zmbuf->desc_idx);
-                               nr_updated += 1;
-
-                               TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
-                               rte_pktmbuf_free(zmbuf->mbuf);
-                               put_zmbuf(zmbuf);
-                               vq->nr_zmbuf -= 1;
-                       }
                }
 
-               update_used_idx(dev, vq, nr_updated);
-       }
-
        /*
         * Construct a RARP broadcast packet, and inject it to the "pkts"
         * array, to looks like that guest actually send such packet.
@@ -1150,147 +2820,53 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
         *
         * broadcast_rarp shares a cacheline in the virtio_net structure
         * with some fields that are accessed during enqueue and
-        * rte_atomic16_cmpset() causes a write if using cmpxchg. This could
-        * result in false sharing between enqueue and dequeue.
+        * __atomic_compare_exchange_n causes a write if performed compare
+        * and exchange. This could result in false sharing between enqueue
+        * and dequeue.
         *
         * Prevent unnecessary false sharing by reading broadcast_rarp first
-        * and only performing cmpset if the read indicates it is likely to
-        * be set.
+        * and only performing compare and exchange if the read indicates it
+        * is likely to be set.
         */
+       if (unlikely(__atomic_load_n(&dev->broadcast_rarp, __ATOMIC_ACQUIRE) &&
+                       __atomic_compare_exchange_n(&dev->broadcast_rarp,
+                       &success, 0, 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED))) {
 
-       if (unlikely(rte_atomic16_read(&dev->broadcast_rarp) &&
-                       rte_atomic16_cmpset((volatile uint16_t *)
-                               &dev->broadcast_rarp.cnt, 1, 0))) {
-
-               rarp_mbuf = rte_pktmbuf_alloc(mbuf_pool);
+               rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
                if (rarp_mbuf == NULL) {
-                       RTE_LOG(ERR, VHOST_DATA,
-                               "Failed to allocate memory for mbuf.\n");
-                       return 0;
-               }
-
-               if (rte_net_make_rarp_packet(rarp_mbuf, &dev->mac) < 0) {
-                       rte_pktmbuf_free(rarp_mbuf);
-                       rarp_mbuf = NULL;
-               } else {
-                       count -= 1;
-               }
-       }
-
-       free_entries = *((volatile uint16_t *)&vq->avail->idx) -
-                       vq->last_avail_idx;
-       if (free_entries == 0)
-               goto out;
-
-       LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
-
-       /* Prefetch available and used ring */
-       avail_idx = vq->last_avail_idx & (vq->size - 1);
-       used_idx  = vq->last_used_idx  & (vq->size - 1);
-       rte_prefetch0(&vq->avail->ring[avail_idx]);
-       rte_prefetch0(&vq->used->ring[used_idx]);
-
-       count = RTE_MIN(count, MAX_PKT_BURST);
-       count = RTE_MIN(count, free_entries);
-       LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n",
-                       dev->vid, count);
-
-       /* Retrieve all of the head indexes first to avoid caching issues. */
-       for (i = 0; i < count; i++) {
-               avail_idx = (vq->last_avail_idx + i) & (vq->size - 1);
-               used_idx  = (vq->last_used_idx  + i) & (vq->size - 1);
-               desc_indexes[i] = vq->avail->ring[avail_idx];
-
-               if (likely(dev->dequeue_zero_copy == 0))
-                       update_used_ring(dev, vq, used_idx, desc_indexes[i]);
-       }
-
-       /* Prefetch descriptor index. */
-       rte_prefetch0(&vq->desc[desc_indexes[0]]);
-       for (i = 0; i < count; i++) {
-               struct vring_desc *desc;
-               uint16_t sz, idx;
-               int err;
-
-               if (likely(i + 1 < count))
-                       rte_prefetch0(&vq->desc[desc_indexes[i + 1]]);
-
-               if (vq->desc[desc_indexes[i]].flags & VRING_DESC_F_INDIRECT) {
-                       desc = (struct vring_desc *)(uintptr_t)
-                               vhost_iova_to_vva(dev, vq,
-                                               vq->desc[desc_indexes[i]].addr,
-                                               sizeof(*desc),
-                                               VHOST_ACCESS_RO);
-                       if (unlikely(!desc))
-                               break;
-
-                       rte_prefetch0(desc);
-                       sz = vq->desc[desc_indexes[i]].len / sizeof(*desc);
-                       idx = 0;
-               } else {
-                       desc = vq->desc;
-                       sz = vq->size;
-                       idx = desc_indexes[i];
-               }
-
-               pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
-               if (unlikely(pkts[i] == NULL)) {
-                       RTE_LOG(ERR, VHOST_DATA,
-                               "Failed to allocate memory for mbuf.\n");
-                       break;
-               }
-
-               err = copy_desc_to_mbuf(dev, vq, desc, sz, pkts[i], idx,
-                                       mbuf_pool);
-               if (unlikely(err)) {
-                       rte_pktmbuf_free(pkts[i]);
-                       break;
-               }
-
-               if (unlikely(dev->dequeue_zero_copy)) {
-                       struct zcopy_mbuf *zmbuf;
-
-                       zmbuf = get_zmbuf(vq);
-                       if (!zmbuf) {
-                               rte_pktmbuf_free(pkts[i]);
-                               break;
-                       }
-                       zmbuf->mbuf = pkts[i];
-                       zmbuf->desc_idx = desc_indexes[i];
-
-                       /*
-                        * Pin lock the mbuf; we will check later to see
-                        * whether the mbuf is freed (when we are the last
-                        * user) or not. If that's the case, we then could
-                        * update the used ring safely.
-                        */
-                       rte_mbuf_refcnt_update(pkts[i], 1);
-
-                       vq->nr_zmbuf += 1;
-                       TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next);
+                       VHOST_LOG_DATA(ERR, "Failed to make RARP packet.\n");
+                       count = 0;
+                       goto out;
                }
+               count -= 1;
        }
-       vq->last_avail_idx += i;
 
-       if (likely(dev->dequeue_zero_copy == 0)) {
-               do_data_copy_dequeue(vq);
-               vq->last_used_idx += i;
-               update_used_idx(dev, vq, i);
-       }
+       if (vq_is_packed(dev)) {
+               if (unlikely(dev->dequeue_zero_copy))
+                       count = virtio_dev_tx_packed_zmbuf(dev, vq, mbuf_pool,
+                                                          pkts, count);
+               else
+                       count = virtio_dev_tx_packed(dev, vq, mbuf_pool, pkts,
+                                                    count);
+       } else
+               count = virtio_dev_tx_split(dev, vq, mbuf_pool, pkts, count);
 
 out:
        if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
                vhost_user_iotlb_rd_unlock(vq);
 
+out_access_unlock:
+       rte_spinlock_unlock(&vq->access_lock);
+
        if (unlikely(rarp_mbuf != NULL)) {
                /*
                 * Inject it to the head of "pkts" array, so that switch's mac
                 * learning table will get updated first.
                 */
-               memmove(&pkts[1], pkts, i * sizeof(struct rte_mbuf *));
+               memmove(&pkts[1], pkts, count * sizeof(struct rte_mbuf *));
                pkts[0] = rarp_mbuf;
-               i += 1;
+               count += 1;
        }
 
-       return i;
+       return count;
 }