From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhihong Wang Subject: [PATCH v3 4/5] vhost: batch update used ring Date: Fri, 19 Aug 2016 01:43:49 -0400 Message-ID: <1471585430-125925-5-git-send-email-zhihong.wang@intel.com> References: <1471319402-112998-1-git-send-email-zhihong.wang@intel.com> <1471585430-125925-1-git-send-email-zhihong.wang@intel.com> Cc: maxime.coquelin@redhat.com, yuanhan.liu@linux.intel.com, Zhihong Wang To: dev@dpdk.org Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 923036AE0 for ; Fri, 19 Aug 2016 14:51:59 +0200 (CEST) In-Reply-To: <1471585430-125925-1-git-send-email-zhihong.wang@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" This patch enables batch update of the used ring for better efficiency. Signed-off-by: Zhihong Wang --- lib/librte_vhost/vhost-net.h | 4 +++ lib/librte_vhost/vhost_rxtx.c | 68 +++++++++++++++++++++++++++++++++---------- lib/librte_vhost/virtio-net.c | 15 ++++++++-- 3 files changed, 68 insertions(+), 19 deletions(-) diff --git a/lib/librte_vhost/vhost-net.h b/lib/librte_vhost/vhost-net.h index 51fdf3d..a15182c 100644 --- a/lib/librte_vhost/vhost-net.h +++ b/lib/librte_vhost/vhost-net.h @@ -85,6 +85,10 @@ struct vhost_virtqueue { /* Physical address of used ring, for logging */ uint64_t log_guest_addr; + + /* Shadow used ring for performance */ + struct vring_used_elem *shadow_used_ring; + uint32_t shadow_used_idx; } __rte_cache_aligned; /* Old kernels have no such macro defined */ diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c index 7523b2d..c4abaf1 100644 --- a/lib/librte_vhost/vhost_rxtx.c +++ b/lib/librte_vhost/vhost_rxtx.c @@ -155,7 +155,6 @@ enqueue_packet(struct virtio_net *dev, struct vhost_virtqueue *vq, uint32_t mbuf_avail = 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); @@ -203,17 +202,11 @@ enqueue_packet(struct virtio_net *dev, struct vhost_virtqueue *vq, 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 = + vq->shadow_used_ring[vq->shadow_used_idx].id = desc_chain_head; - vq->used->ring[used_idx_round].len = + vq->shadow_used_ring[vq->shadow_used_idx].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->shadow_used_idx++; vq->last_used_idx++; extra_buffers++; virtio_hdr->num_buffers++; @@ -248,12 +241,9 @@ enqueue_packet(struct virtio_net *dev, struct vhost_virtqueue *vq, 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->shadow_used_ring[vq->shadow_used_idx].id = desc_chain_head; + vq->shadow_used_ring[vq->shadow_used_idx].len = desc_chain_len; + vq->shadow_used_idx++; vq->last_used_idx++; return 0; @@ -268,6 +258,45 @@ error: } static inline void __attribute__((always_inline)) +update_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq, + uint32_t used_idx_start) +{ + if (used_idx_start + vq->shadow_used_idx < vq->size) { + rte_memcpy(&vq->used->ring[used_idx_start], + &vq->shadow_used_ring[0], + vq->shadow_used_idx * + sizeof(struct vring_used_elem)); + vhost_log_used_vring(dev, vq, + offsetof(struct vring_used, + ring[used_idx_start]), + vq->shadow_used_idx * + sizeof(struct vring_used_elem)); + } else { + uint32_t part_1 = vq->size - used_idx_start; + uint32_t part_2 = vq->shadow_used_idx - part_1; + + rte_memcpy(&vq->used->ring[used_idx_start], + &vq->shadow_used_ring[0], + part_1 * + sizeof(struct vring_used_elem)); + vhost_log_used_vring(dev, vq, + offsetof(struct vring_used, + ring[used_idx_start]), + part_1 * + sizeof(struct vring_used_elem)); + rte_memcpy(&vq->used->ring[0], + &vq->shadow_used_ring[part_1], + part_2 * + sizeof(struct vring_used_elem)); + vhost_log_used_vring(dev, vq, + offsetof(struct vring_used, + ring[0]), + part_2 * + sizeof(struct vring_used_elem)); + } +} + +static inline void __attribute__((always_inline)) notify_guest(struct virtio_net *dev, struct vhost_virtqueue *vq) { rte_smp_wmb(); @@ -286,6 +315,7 @@ rte_vhost_enqueue_burst(int vid, uint16_t queue_id, { struct vhost_virtqueue *vq; struct virtio_net *dev; + uint32_t used_idx_start = 0; uint32_t pkt_idx = 0; uint32_t pkt_left = 0; uint32_t pkt_sent = 0; @@ -315,6 +345,8 @@ rte_vhost_enqueue_burst(int vid, uint16_t queue_id, /* start enqueuing packets 1 by 1 */ pkt_idx = 0; pkt_left = count; + vq->shadow_used_idx = 0; + used_idx_start = vq->last_used_idx & (vq->size - 1); avail_idx = *((volatile uint16_t *)&vq->avail->idx); while (1) { if (loop_check(vq, avail_idx, pkt_left)) @@ -329,6 +361,10 @@ rte_vhost_enqueue_burst(int vid, uint16_t queue_id, pkt_left--; } + /* batch update used ring for better performance */ + if (likely(vq->shadow_used_idx > 0)) + update_used_ring(dev, vq, used_idx_start); + /* update used idx and kick the guest if necessary */ if (pkt_sent) notify_guest(dev, vq); diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c index 1785695..87d09fa 100644 --- a/lib/librte_vhost/virtio-net.c +++ b/lib/librte_vhost/virtio-net.c @@ -152,10 +152,14 @@ cleanup_device(struct virtio_net *dev, int destroy) static void free_device(struct virtio_net *dev) { + struct vhost_virtqueue *vq; uint32_t i; - for (i = 0; i < dev->virt_qp_nb; i++) - rte_free(dev->virtqueue[i * VIRTIO_QNUM]); + for (i = 0; i < dev->virt_qp_nb; i++) { + vq = dev->virtqueue[i * VIRTIO_QNUM]; + rte_free(vq->shadow_used_ring); + rte_free(vq); + } rte_free(dev); } @@ -418,13 +422,18 @@ int vhost_set_vring_num(int vid, struct vhost_vring_state *state) { struct virtio_net *dev; + struct vhost_virtqueue *vq; dev = get_device(vid); if (dev == NULL) return -1; /* State->index refers to the queue index. The txq is 1, rxq is 0. */ - dev->virtqueue[state->index]->size = state->num; + vq = dev->virtqueue[state->index]; + vq->size = state->num; + vq->shadow_used_ring = rte_malloc("", + vq->size * sizeof(struct vring_used_elem), + RTE_CACHE_LINE_SIZE); return 0; } -- 2.7.4