From: Marvin Liu Date: Thu, 24 Oct 2019 16:08:26 +0000 (+0800) Subject: vhost: flush enqueue updates by cacheline X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=33d4a554f9e7df9cb1d7da5df503e4c1c8717f8a;p=dpdk.git vhost: flush enqueue updates by cacheline Buffer vhost packed ring enqueue updates, flush ring descs if buffered content filled up one cacheline. Thus virtio can receive packets at a faster frequency. Signed-off-by: Marvin Liu Reviewed-by: Maxime Coquelin --- diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index 67724c3423..d594464423 100644 --- a/lib/librte_vhost/vhost.h +++ b/lib/librte_vhost/vhost.h @@ -174,6 +174,8 @@ struct vhost_virtqueue { struct vring_used_elem_packed *shadow_used_packed; }; uint16_t shadow_used_idx; + /* Record packed ring enqueue latest desc cache aligned index */ + uint16_t shadow_aligned_idx; struct vhost_vring_addr ring_addrs; struct batch_copy_elem *batch_copy_elems; diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index 76435204f9..25bffdd524 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -91,6 +91,69 @@ update_shadow_used_ring_split(struct vhost_virtqueue *vq, vq->shadow_used_split[i].len = len; } +static __rte_always_inline void +vhost_flush_enqueue_shadow_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_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 __rte_always_inline void flush_shadow_used_ring_packed(struct virtio_net *dev, struct vhost_virtqueue *vq) @@ -194,6 +257,33 @@ do_data_copy_dequeue(struct vhost_virtqueue *vq) vq->batch_copy_nb_elems = 0; } +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 */ #define ASSIGN_UNLESS_EQUAL(var, val) do { \ if ((var) != (val)) \ @@ -785,6 +875,9 @@ vhost_enqueue_single_packed(struct virtio_net *dev, 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; @@ -810,6 +903,9 @@ vhost_enqueue_single_packed(struct virtio_net *dev, 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; @@ -821,6 +917,9 @@ vhost_enqueue_single_packed(struct virtio_net *dev, 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; } @@ -1017,7 +1116,7 @@ virtio_dev_rx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, do_data_copy_enqueue(dev, vq); if (likely(vq->shadow_used_idx)) { - flush_shadow_used_ring_packed(dev, vq); + vhost_flush_enqueue_shadow_packed(dev, vq); vhost_vring_call_packed(dev, vq); }