This patch implements the vhost logic from scratch into a single function
designed for high performance and better maintainability.
Signed-off-by: Zhihong Wang <zhihong.wang at intel.com>
---
lib/librte_vhost/vhost_rxtx.c | 212 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 205 insertions(+), 7 deletions(-)
diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index 08a73fd..8e6d782 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -91,7 +91,7 @@ is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t
qp_nb)
return (is_tx ^ (idx & 1)) == 0 && idx < qp_nb * VIRTIO_QNUM;
}
-static void
+static inline void __attribute__((always_inline))
virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
{
if (m_buf->ol_flags & PKT_TX_L4_MASK) {
@@ -533,19 +533,217 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t
queue_id,
return pkt_idx;
}
+static inline uint32_t __attribute__((always_inline))
+loop_check(struct vhost_virtqueue *vq, uint16_t avail_idx, uint32_t pkt_left)
+{
+ if (pkt_left == 0 || avail_idx == vq->last_used_idx)
+ return 1;
+
+ return 0;
+}
+
+static inline uint32_t __attribute__((always_inline))
+enqueue_packet(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint16_t avail_idx, struct rte_mbuf *mbuf,
+ uint32_t is_mrg_rxbuf)
+{
+ struct virtio_net_hdr_mrg_rxbuf *virtio_hdr;
+ struct vring_desc *desc;
+ uint64_t desc_host_write_addr = 0;
+ uint32_t desc_chain_head = 0;
+ uint32_t desc_chain_len = 0;
+ uint32_t desc_current = 0;
+ uint32_t desc_write_offset = 0;
+ uint32_t mbuf_len = 0;
+ uint32_t mbuf_len_left = 0;
+ uint32_t copy_len = 0;
+ uint32_t extra_buffers = 0;
+ uint32_t used_idx_round = 0;
+
+ /* start with the first mbuf of the packet */
+ mbuf_len = rte_pktmbuf_data_len(mbuf);
+ mbuf_len_left = mbuf_len;
+
+ /* get the current desc */
+ desc_current = vq->avail->ring[(vq->last_used_idx) & (vq->size - 1)];
+ desc_chain_head = desc_current;
+ desc = &vq->desc[desc_current];
+ desc_host_write_addr = gpa_to_vva(dev, desc->addr);
+ if (unlikely(!desc_host_write_addr))
+ goto error;
+
+ /* handle virtio header */
+ virtio_hdr = (struct virtio_net_hdr_mrg_rxbuf *)
+ (uintptr_t)desc_host_write_addr;
+ memset((void *)(uintptr_t)&(virtio_hdr->hdr),
+ 0, dev->vhost_hlen);
+ virtio_enqueue_offload(mbuf, &(virtio_hdr->hdr));
+ vhost_log_write(dev, desc->addr, dev->vhost_hlen);
+ desc_write_offset = dev->vhost_hlen;
+ desc_chain_len = desc_write_offset;
+ desc_host_write_addr += desc_write_offset;
+ if (is_mrg_rxbuf)
+ virtio_hdr->num_buffers = 1;
+
+ /* start copy from mbuf to desc */
+ while (1) {
+ /* get the next mbuf if the current done */
+ if (!mbuf_len_left) {
+ if (mbuf->next) {
+ mbuf = mbuf->next;
+ mbuf_len = rte_pktmbuf_data_len(mbuf);
+ mbuf_len_left = mbuf_len;
+ } else
+ break;
+ }
+
+ /* get the next desc if the current done */
+ if (desc->len <= desc_write_offset) {
+ if (desc->flags & VRING_DESC_F_NEXT) {
+ /* go on with the current desc chain */
+ desc_write_offset = 0;
+ desc_current = desc->next;
+ desc = &vq->desc[desc_current];
+ desc_host_write_addr =
+ gpa_to_vva(dev, desc->addr);
+ if (unlikely(!desc_host_write_addr))
+ goto rollback;
+ } else if (is_mrg_rxbuf) {
+ /* start with the next desc chain */
+ used_idx_round = vq->last_used_idx
+ & (vq->size - 1);
+ vq->used->ring[used_idx_round].id =
+ desc_chain_head;
+ vq->used->ring[used_idx_round].len =
+ desc_chain_len;
+ vhost_log_used_vring(dev, vq,
+ offsetof(struct vring_used,
+ ring[used_idx_round]),
+ sizeof(vq->used->ring[
+ used_idx_round]));
+ vq->last_used_idx++;
+ extra_buffers++;
+ virtio_hdr->num_buffers++;
+ if (avail_idx == vq->last_used_idx)
+ goto rollback;
+
+ desc_current =
+ vq->avail->ring[(vq->last_used_idx) &
+ (vq->size - 1)];
+ desc_chain_head = desc_current;
+ desc = &vq->desc[desc_current];
+ desc_host_write_addr =
+ gpa_to_vva(dev, desc->addr);
+ if (unlikely(!desc_host_write_addr))
+ goto rollback;
+
+ desc_chain_len = 0;
+ desc_write_offset = 0;
+ } else
+ goto rollback;
+ }
+
+ /* copy mbuf data */
+ copy_len = RTE_MIN(desc->len - desc_write_offset,
+ mbuf_len_left);
+ rte_memcpy((void *)(uintptr_t)desc_host_write_addr,
+ rte_pktmbuf_mtod_offset(mbuf, void *,
+ mbuf_len - mbuf_len_left),
+ copy_len);
+ vhost_log_write(dev, desc->addr + desc_write_offset,
+ copy_len);
+ mbuf_len_left -= copy_len;
+ desc_write_offset += copy_len;
+ desc_host_write_addr += copy_len;
+ desc_chain_len += copy_len;
+ }
+
+ used_idx_round = vq->last_used_idx & (vq->size - 1);
+ vq->used->ring[used_idx_round].id = desc_chain_head;
+ vq->used->ring[used_idx_round].len = desc_chain_len;
+ vhost_log_used_vring(dev, vq,
+ offsetof(struct vring_used, ring[used_idx_round]),
+ sizeof(vq->used->ring[used_idx_round]));
+ vq->last_used_idx++;
+
+ return 0;
+
+rollback:
+ /* rollback on any error if last_used_idx update on-the-fly */
+ if (is_mrg_rxbuf)
+ vq->last_used_idx -= extra_buffers;
+
+error:
+ return 1;
+}
+
+static inline void __attribute__((always_inline))
+notify_guest(struct virtio_net *dev, struct vhost_virtqueue *vq)
+{
+ rte_smp_wmb();
+ vq->used->idx = vq->last_used_idx;
+ vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
+ sizeof(vq->used->idx));
+ rte_mb();
+ if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+ && (vq->callfd >= 0))
+ eventfd_write(vq->callfd, (eventfd_t)1);
+}
+
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);
+ struct vhost_virtqueue *vq;
+ struct virtio_net *dev;
+ uint32_t pkt_idx = 0;
+ uint32_t pkt_left = 0;
+ uint32_t pkt_sent = 0;
+ uint32_t is_mrg_rxbuf = 0;
+ uint16_t avail_idx = 0;
+
+ /* precheck */
+ if (unlikely(count == 0))
+ return 0;
- if (!dev)
+ count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
+
+ dev = get_device(vid);
+ if (unlikely(!dev))
return 0;
- 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 (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb)))
+ return 0;
+
+ vq = dev->virtqueue[queue_id];
+ if (unlikely(!vq->enabled))
+ return 0;
+
+ if (dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF))
+ is_mrg_rxbuf = 1;
+
+ /* start enqueuing packets 1 by 1 */
+ pkt_idx = 0;
+ pkt_left = count;
+ avail_idx = *((volatile uint16_t *)&vq->avail->idx);
+ while (1) {
+ if (loop_check(vq, avail_idx, pkt_left))
+ break;
+
+ if (enqueue_packet(dev, vq, avail_idx, pkts[pkt_idx],
+ is_mrg_rxbuf))
+ break;
+
+ pkt_idx++;
+ pkt_sent++;
+ pkt_left--;
+ }
+
+ /* update used idx and kick the guest if necessary */
+ if (pkt_sent)
+ notify_guest(dev, vq);
+
+ return pkt_sent;
}
static void
--
2.7.4
