diff options
Diffstat (limited to 'src/seastar/dpdk/lib/librte_vhost/virtio_net.c')
| -rw-r--r-- | src/seastar/dpdk/lib/librte_vhost/virtio_net.c | 1638 |
1 files changed, 1638 insertions, 0 deletions
diff --git a/src/seastar/dpdk/lib/librte_vhost/virtio_net.c b/src/seastar/dpdk/lib/librte_vhost/virtio_net.c new file mode 100644 index 000000000..a6a33a101 --- /dev/null +++ b/src/seastar/dpdk/lib/librte_vhost/virtio_net.c @@ -0,0 +1,1638 @@ +/* SPDX-License-Identifier: BSD-3-Clause + * Copyright(c) 2010-2016 Intel Corporation + */ + +#include <stdint.h> +#include <stdbool.h> +#include <linux/virtio_net.h> + +#include <rte_mbuf.h> +#include <rte_memcpy.h> +#include <rte_ether.h> +#include <rte_ip.h> +#include <rte_vhost.h> +#include <rte_tcp.h> +#include <rte_udp.h> +#include <rte_sctp.h> +#include <rte_arp.h> +#include <rte_spinlock.h> +#include <rte_malloc.h> + +#include "iotlb.h" +#include "vhost.h" + +#define MAX_PKT_BURST 32 + +#define MAX_BATCH_LEN 256 + +static __rte_always_inline bool +rxvq_is_mergeable(struct virtio_net *dev) +{ + return dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF); +} + +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 __rte_always_inline void +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_split[from], + size * sizeof(struct vring_used_elem)); + 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_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; + + rte_smp_wmb(); + + vhost_log_cache_sync(dev, vq); + + *(volatile uint16_t *)&vq->used->idx += vq->shadow_used_idx; + 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_split(struct vhost_virtqueue *vq, + uint16_t desc_idx, uint32_t len) +{ + uint16_t i = vq->shadow_used_idx++; + + vq->shadow_used_split[i].id = desc_idx; + vq->shadow_used_split[i].len = len; +} + +static __rte_always_inline void +flush_shadow_used_ring_packed(struct virtio_net *dev, + struct vhost_virtqueue *vq) +{ + 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; + } + + 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->last_used_idx += vq->shadow_used_packed[i].count; + if (vq->last_used_idx >= vq->size) { + vq->used_wrap_counter ^= 1; + vq->last_used_idx -= vq->size; + } + } + + 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 __rte_always_inline void +update_shadow_used_ring_packed(struct vhost_virtqueue *vq, + uint16_t desc_idx, uint32_t len, uint16_t count) +{ + uint16_t i = vq->shadow_used_idx++; + + vq->shadow_used_packed[i].id = desc_idx; + vq->shadow_used_packed[i].len = len; + vq->shadow_used_packed[i].count = count; +} + +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(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; +} + +/* avoid write operation when necessary, to lessen cache issues */ +#define ASSIGN_UNLESS_EQUAL(var, val) do { \ + if ((var) != (val)) \ + (var) = (val); \ +} while (0) + +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; + + if (m_buf->ol_flags & PKT_TX_TCP_SEG) + csum_l4 |= PKT_TX_TCP_CKSUM; + + if (csum_l4) { + net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; + net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len; + + switch (csum_l4) { + case PKT_TX_TCP_CKSUM: + net_hdr->csum_offset = (offsetof(struct tcp_hdr, + cksum)); + break; + case PKT_TX_UDP_CKSUM: + net_hdr->csum_offset = (offsetof(struct udp_hdr, + dgram_cksum)); + break; + case PKT_TX_SCTP_CKSUM: + net_hdr->csum_offset = (offsetof(struct sctp_hdr, + cksum)); + break; + } + } else { + ASSIGN_UNLESS_EQUAL(net_hdr->csum_start, 0); + ASSIGN_UNLESS_EQUAL(net_hdr->csum_offset, 0); + ASSIGN_UNLESS_EQUAL(net_hdr->flags, 0); + } + + /* IP cksum verification cannot be bypassed, then calculate here */ + if (m_buf->ol_flags & PKT_TX_IP_CKSUM) { + struct ipv4_hdr *ipv4_hdr; + + ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct ipv4_hdr *, + m_buf->l2_len); + ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr); + } + + if (m_buf->ol_flags & PKT_TX_TCP_SEG) { + if (m_buf->ol_flags & PKT_TX_IPV4) + net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; + else + net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; + net_hdr->gso_size = m_buf->tso_segsz; + net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len + + m_buf->l4_len; + } else if (m_buf->ol_flags & PKT_TX_UDP_SEG) { + net_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP; + net_hdr->gso_size = m_buf->tso_segsz; + net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len + + m_buf->l4_len; + } else { + ASSIGN_UNLESS_EQUAL(net_hdr->gso_type, 0); + ASSIGN_UNLESS_EQUAL(net_hdr->gso_size, 0); + ASSIGN_UNLESS_EQUAL(net_hdr->hdr_len, 0); + } +} + +static __rte_always_inline int +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) +{ + uint16_t vec_id = *vec_idx; + + while (desc_len) { + uint64_t desc_addr; + uint64_t desc_chunck_len = desc_len; + + if (unlikely(vec_id >= BUF_VECTOR_MAX)) + return -1; + + desc_addr = vhost_iova_to_vva(dev, vq, + desc_iova, + &desc_chunck_len, + perm); + if (unlikely(!desc_addr)) + return -1; + + 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; + + desc_len -= desc_chunck_len; + desc_iova += desc_chunck_len; + vec_id++; + } + *vec_idx = vec_id; + + return 0; +} + +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; + + if (unlikely(idx >= vq->size)) + return -1; + + *desc_chain_head = idx; + + 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; + + 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; + + if (unlikely(dlen < vq->desc[idx].len)) { + /* + * The indirect desc table is not contiguous + * in process VA space, we have to copy it. + */ + idesc = alloc_copy_ind_table(dev, vq, + vq->desc[idx].addr, vq->desc[idx].len); + if (unlikely(!idesc)) + return -1; + + descs = idesc; + } + + idx = 0; + } + + while (1) { + if (unlikely(idx >= nr_descs || cnt++ >= nr_descs)) { + free_ind_table(idesc); + return -1; + } + + len += descs[idx].len; + + if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id, + descs[idx].addr, descs[idx].len, + perm))) { + free_ind_table(idesc); + return -1; + } + + if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0) + break; + + idx = descs[idx].next; + } + + *desc_chain_len = len; + *vec_idx = vec_id; + + if (unlikely(!!idesc)) + free_ind_table(idesc); + + return 0; +} + +/* + * 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; + + uint16_t head_idx = 0; + uint32_t len = 0; + + *num_buffers = 0; + cur_idx = vq->last_avail_idx; + + if (rxvq_is_mergeable(dev)) + max_tries = vq->size - 1; + else + max_tries = 1; + + 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; + + 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; + + cur_idx++; + *num_buffers += 1; + } + + *nr_vec = vec_idx; + + return 0; +} + +static __rte_always_inline int +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 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 = alloc_copy_ind_table(dev, vq, desc->addr, desc->len); + if (unlikely(!idescs)) + return -1; + + descs = idescs; + } + + nr_descs = desc->len / sizeof(struct vring_packed_desc); + if (unlikely(nr_descs >= vq->size)) { + free_ind_table(idescs); + return -1; + } + + for (i = 0; i < nr_descs; i++) { + if (unlikely(vec_id >= BUF_VECTOR_MAX)) { + free_ind_table(idescs); + return -1; + } + + *len += descs[i].len; + if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id, + descs[i].addr, descs[i].len, + perm))) + return -1; + } + *vec_idx = vec_id; + + if (unlikely(!!idescs)) + free_ind_table(idescs); + + return 0; +} + +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) +{ + bool wrap_counter = vq->avail_wrap_counter; + struct vring_packed_desc *descs = vq->desc_packed; + uint16_t vec_id = *vec_idx; + + if (avail_idx < vq->last_avail_idx) + wrap_counter ^= 1; + + if (unlikely(!desc_is_avail(&descs[avail_idx], wrap_counter))) + return -1; + + /* + * The ordering between desc flags and desc + * content reads need to be enforced. + */ + rte_smp_rmb(); + + *desc_count = 0; + *len = 0; + + while (1) { + if (unlikely(vec_id >= BUF_VECTOR_MAX)) + return -1; + + if (unlikely(*desc_count >= vq->size)) + return -1; + + *desc_count += 1; + *buf_id = descs[avail_idx].id; + + 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; +} + +/* + * Returns -1 on fail, 0 on success + */ +static inline int +reserve_avail_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, + uint32_t size, struct buf_vector *buf_vec, + uint16_t *nr_vec, uint16_t *num_buffers, + uint16_t *nr_descs) +{ + uint16_t avail_idx; + uint16_t vec_idx = 0; + uint16_t max_tries, tries = 0; + + uint16_t buf_id = 0; + uint32_t len = 0; + uint16_t desc_count; + + *num_buffers = 0; + avail_idx = vq->last_avail_idx; + + 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, &vec_idx, + &buf_id, &len, + VHOST_ACCESS_RW) < 0)) + return -1; + + len = RTE_MIN(len, size); + update_shadow_used_ring_packed(vq, buf_id, len, desc_count); + size -= len; + + avail_idx += desc_count; + if (avail_idx >= vq->size) + avail_idx -= vq->size; + + *nr_descs += desc_count; + *num_buffers += 1; + } + + *nr_vec = vec_idx; + + return 0; +} + +static __rte_always_inline int +copy_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) +{ + 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; + 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; + + if (unlikely(m == NULL)) { + error = -1; + 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; + + if (nr_vec > 1) + rte_prefetch0((void *)(uintptr_t)buf_vec[1].buf_addr); + + if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) { + error = -1; + goto out; + } + + 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; + + VHOST_LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n", + dev->vid, 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; + } + + mbuf_avail = rte_pktmbuf_data_len(m); + mbuf_offset = 0; + 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; + } + + buf_addr = buf_vec[vec_idx].buf_addr; + buf_iova = buf_vec[vec_idx].buf_iova; + buf_len = buf_vec[vec_idx].buf_len; + + /* Prefetch next buffer address. */ + if (vec_idx + 1 < nr_vec) + rte_prefetch0((void *)(uintptr_t) + buf_vec[vec_idx + 1].buf_addr); + buf_offset = 0; + buf_avail = buf_len; + } + + /* done with current mbuf, get the next one */ + if (mbuf_avail == 0) { + m = m->next; + + mbuf_offset = 0; + mbuf_avail = rte_pktmbuf_data_len(m); + } + + if (hdr_addr) { + virtio_enqueue_offload(hdr_mbuf, &hdr->hdr); + if (rxvq_is_mergeable(dev)) + ASSIGN_UNLESS_EQUAL(hdr->num_buffers, + num_buffers); + + if (unlikely(hdr == &tmp_hdr)) { + uint64_t len; + uint64_t remain = dev->vhost_hlen; + uint64_t src = (uint64_t)(uintptr_t)hdr, dst; + uint64_t iova = buf_vec[0].buf_iova; + uint16_t hdr_vec_idx = 0; + + while (remain) { + len = RTE_MIN(remain, + buf_vec[hdr_vec_idx].buf_len); + dst = buf_vec[hdr_vec_idx].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(dev, vq, + iova, len); + + remain -= len; + iova += len; + src += len; + hdr_vec_idx++; + } + } else { + PRINT_PACKET(dev, (uintptr_t)hdr_addr, + dev->vhost_hlen, 0); + vhost_log_cache_write(dev, vq, + buf_vec[0].buf_iova, + dev->vhost_hlen); + } + + hdr_addr = 0; + } + + cpy_len = RTE_MIN(buf_avail, mbuf_avail); + + 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_cache_write(dev, vq, buf_iova + buf_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: + + return error; +} + +static __rte_always_inline 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; + + avail_head = *((volatile uint16_t *)&vq->avail->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_DEBUG(VHOST_DATA, + "(%d) failed to get enough desc from vring\n", + dev->vid); + vq->shadow_used_idx -= num_buffers; + break; + } + + rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr); + + VHOST_LOG_DEBUG(VHOST_DATA, "(%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 uint32_t +virtio_dev_rx_packed(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]; + + 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; + uint16_t nr_descs = 0; + + if (unlikely(reserve_avail_buf_packed(dev, vq, + pkt_len, buf_vec, &nr_vec, + &num_buffers, &nr_descs) < 0)) { + VHOST_LOG_DEBUG(VHOST_DATA, + "(%d) failed to get enough desc from vring\n", + dev->vid); + vq->shadow_used_idx -= num_buffers; + break; + } + + rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr); + + VHOST_LOG_DEBUG(VHOST_DATA, "(%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 += nr_descs; + if (vq->last_avail_idx >= vq->size) { + vq->last_avail_idx -= vq->size; + vq->avail_wrap_counter ^= 1; + } + } + + do_data_copy_enqueue(dev, vq); + + if (likely(vq->shadow_used_idx)) { + flush_shadow_used_ring_packed(dev, vq); + 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_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; + } + + 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 **pkts, uint16_t count) +{ + struct virtio_net *dev = get_device(vid); + + if (!dev) + return 0; + + if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) { + RTE_LOG(ERR, VHOST_DATA, + "(%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 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 ipv4_hdr *ipv4_hdr; + struct ipv6_hdr *ipv6_hdr; + void *l3_hdr = NULL; + struct ether_hdr *eth_hdr; + uint16_t ethertype; + + eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *); + + m->l2_len = sizeof(struct ether_hdr); + ethertype = rte_be_to_cpu_16(eth_hdr->ether_type); + + if (ethertype == ETHER_TYPE_VLAN) { + struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1); + + m->l2_len += sizeof(struct vlan_hdr); + ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto); + } + + l3_hdr = (char *)eth_hdr + m->l2_len; + + switch (ethertype) { + case 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: + ipv6_hdr = l3_hdr; + *l4_proto = ipv6_hdr->proto; + m->l3_len = sizeof(struct ipv6_hdr); + *l4_hdr = (char *)l3_hdr + m->l3_len; + m->ol_flags |= PKT_TX_IPV6; + break; + default: + m->l3_len = 0; + *l4_proto = 0; + *l4_hdr = NULL; + break; + } +} + +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 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 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; + } + } + } + + 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 udp_hdr); + break; + default: + RTE_LOG(WARNING, VHOST_DATA, + "unsupported gso type %u.\n", hdr->gso_type); + break; + } + } +} + +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 (likely(nr_vec > 1)) + rte_prefetch0((void *)(uintptr_t)buf_vec[1].buf_addr); + + if (virtio_net_with_host_offload(dev)) { + if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) { + uint64_t len; + uint64_t remain = sizeof(struct virtio_net_hdr); + uint64_t src; + uint64_t dst = (uint64_t)(uintptr_t)&tmp_hdr; + uint16_t hdr_vec_idx = 0; + + /* + * No luck, the virtio-net header doesn't fit + * in a contiguous virtual area. + */ + while (remain) { + len = RTE_MIN(remain, + buf_vec[hdr_vec_idx].buf_len); + src = buf_vec[hdr_vec_idx].buf_addr; + rte_memcpy((void *)(uintptr_t)dst, + (void *)(uintptr_t)src, len); + + remain -= len; + dst += len; + hdr_vec_idx++; + } + + hdr = &tmp_hdr; + } else { + hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr); + rte_prefetch0(hdr); + } + } + + /* + * 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; + } + + rte_prefetch0((void *)(uintptr_t) + (buf_addr + buf_offset)); + + 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; + + /* + * Prefecth desc n + 1 buffer while + * desc n buffer is processed. + */ + if (vec_idx + 1 < nr_vec) + rte_prefetch0((void *)(uintptr_t) + buf_vec[vec_idx + 1].buf_addr); + + 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)) { + RTE_LOG(ERR, VHOST_DATA, "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 i; + uint16_t last; + int tries = 0; + + /* search [last_zmbuf_idx, zmbuf_size) */ + i = vq->last_zmbuf_idx; + last = vq->zmbuf_size; + +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 __rte_always_inline 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; + + 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); + } + } + + free_entries = *((volatile uint16_t *)&vq->avail->idx) - + vq->last_avail_idx; + if (free_entries == 0) + return 0; + + /* + * 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)]); + + VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__); + + count = RTE_MIN(count, MAX_PKT_BURST); + count = RTE_MIN(count, free_entries); + VHOST_LOG_DEBUG(VHOST_DATA, "(%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 dummy_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, &dummy_len, + VHOST_ACCESS_RO) < 0)) + break; + + if (likely(dev->dequeue_zero_copy == 0)) + update_shadow_used_ring_split(vq, head_idx, 0); + + rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr); + + 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, buf_vec, nr_vec, pkts[i], + 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 = 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; +} + +static __rte_always_inline uint16_t +virtio_dev_tx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count) +{ + uint16_t i; + + 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_packed(vq, + zmbuf->desc_idx, + 0, + 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; + } + } + + if (likely(vq->shadow_used_idx)) { + flush_shadow_used_ring_packed(dev, vq); + vhost_vring_call_packed(dev, vq); + } + } + + VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__); + + count = RTE_MIN(count, MAX_PKT_BURST); + VHOST_LOG_DEBUG(VHOST_DATA, "(%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 buf_id; + uint32_t dummy_len; + uint16_t desc_count, nr_vec = 0; + int err; + + if (unlikely(fill_vec_buf_packed(dev, vq, + vq->last_avail_idx, &desc_count, + buf_vec, &nr_vec, + &buf_id, &dummy_len, + VHOST_ACCESS_RO) < 0)) + break; + + if (likely(dev->dequeue_zero_copy == 0)) + update_shadow_used_ring_packed(vq, buf_id, 0, + desc_count); + + rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr); + + 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, buf_vec, nr_vec, pkts[i], + 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 = buf_id; + zmbuf->desc_count = desc_count; + + /* + * 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 += desc_count; + if (vq->last_avail_idx >= vq->size) { + vq->last_avail_idx -= vq->size; + vq->avail_wrap_counter ^= 1; + } + } + + 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_packed(dev, vq); + vhost_vring_call_packed(dev, vq); + } + } + + return i; +} + +uint16_t +rte_vhost_dequeue_burst(int vid, uint16_t queue_id, + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count) +{ + struct virtio_net *dev; + struct rte_mbuf *rarp_mbuf = NULL; + struct vhost_virtqueue *vq; + + dev = get_device(vid); + if (!dev) + return 0; + + if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) { + RTE_LOG(ERR, VHOST_DATA, + "(%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", + dev->vid, __func__, queue_id); + return 0; + } + + vq = dev->virtqueue[queue_id]; + + if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0)) + return 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)) { + count = 0; + goto out; + } + + /* + * Construct a RARP broadcast packet, and inject it to the "pkts" + * array, to looks like that guest actually send such packet. + * + * Check user_send_rarp() for more information. + * + * 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. + * + * Prevent unnecessary false sharing by reading broadcast_rarp first + * and only performing cmpset if the read indicates it is likely to + * be set. + */ + if (unlikely(rte_atomic16_read(&dev->broadcast_rarp) && + rte_atomic16_cmpset((volatile uint16_t *) + &dev->broadcast_rarp.cnt, 1, 0))) { + + rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac); + if (rarp_mbuf == NULL) { + RTE_LOG(ERR, VHOST_DATA, + "Failed to make RARP packet.\n"); + count = 0; + goto out; + } + count -= 1; + } + + if (vq_is_packed(dev)) + 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, count * sizeof(struct rte_mbuf *)); + pkts[0] = rarp_mbuf; + count += 1; + } + + return count; +} |