[dpdk-dev] [PATCH v2 18/19] vhost: per device virtio net header len

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

Virtio net header length is set per device, but not per queue. So, there
is no reason to store it in vhost_virtqueue struct, instead, we should
store it in virtio_net struct, to make one copy only.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
---
 lib/librte_vhost/vhost-net.h  |  2 +-
 lib/librte_vhost/vhost_rxtx.c | 40 ++++++++++++++++++++--------------------
 lib/librte_vhost/virtio-net.c | 13 ++-----------
 3 files changed, 23 insertions(+), 32 deletions(-)

diff --git a/lib/librte_vhost/vhost-net.h b/lib/librte_vhost/vhost-net.h
index dbd2d62..590a039 100644
--- a/lib/librte_vhost/vhost-net.h
+++ b/lib/librte_vhost/vhost-net.h
@@ -69,7 +69,6 @@ struct vhost_virtqueue {
 	struct vring_avail	*avail;
 	struct vring_used	*used;
 	uint32_t		size;
-	uint16_t		vhost_hlen;
 
 	/* Last index used on the available ring */
 	volatile uint16_t	last_used_idx;
@@ -129,6 +128,7 @@ struct virtio_net {
 	uint64_t		protocol_features;
 	int			vid;
 	uint32_t		flags;
+	uint16_t		vhost_hlen;
 #define IF_NAME_SZ (PATH_MAX > IFNAMSIZ ? PATH_MAX : IFNAMSIZ)
 	char			ifname[IF_NAME_SZ];
 	uint32_t		virt_qp_nb;
diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index 65278bb..c9cd1c5 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -126,10 +126,10 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 }
 
 static inline void
-copy_virtio_net_hdr(struct vhost_virtqueue *vq, uint64_t desc_addr,
+copy_virtio_net_hdr(struct virtio_net *dev, uint64_t desc_addr,
 		    struct virtio_net_hdr_mrg_rxbuf hdr)
 {
-	if (vq->vhost_hlen == sizeof(struct virtio_net_hdr_mrg_rxbuf))
+	if (dev->vhost_hlen == sizeof(struct virtio_net_hdr_mrg_rxbuf))
 		*(struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)desc_addr = hdr;
 	else
 		*(struct virtio_net_hdr *)(uintptr_t)desc_addr = hdr.hdr;
@@ -147,19 +147,19 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 	struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 
 	desc = &vq->desc[desc_idx];
-	if (unlikely(desc->len < vq->vhost_hlen))
+	if (unlikely(desc->len < dev->vhost_hlen))
 		return -1;
 
 	desc_addr = gpa_to_vva(dev, desc->addr);
 	rte_prefetch0((void *)(uintptr_t)desc_addr);
 
 	virtio_enqueue_offload(m, &virtio_hdr.hdr);
-	copy_virtio_net_hdr(vq, desc_addr, virtio_hdr);
-	vhost_log_write(dev, desc->addr, vq->vhost_hlen);
-	PRINT_PACKET(dev, (uintptr_t)desc_addr, vq->vhost_hlen, 0);
+	copy_virtio_net_hdr(dev, desc_addr, virtio_hdr);
+	vhost_log_write(dev, desc->addr, dev->vhost_hlen);
+	PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
 
-	desc_offset = vq->vhost_hlen;
-	desc_avail  = desc->len - vq->vhost_hlen;
+	desc_offset = dev->vhost_hlen;
+	desc_avail  = desc->len - dev->vhost_hlen;
 
 	*copied = rte_pktmbuf_pkt_len(m);
 	mbuf_avail  = rte_pktmbuf_data_len(m);
@@ -300,9 +300,9 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 
 		vq->used->ring[used_idx].id = desc_idx;
 		if (unlikely(err))
-			vq->used->ring[used_idx].len = vq->vhost_hlen;
+			vq->used->ring[used_idx].len = dev->vhost_hlen;
 		else
-			vq->used->ring[used_idx].len = copied + vq->vhost_hlen;
+			vq->used->ring[used_idx].len = copied + dev->vhost_hlen;
 		vhost_log_used_vring(dev, vq,
 			offsetof(struct vring_used, ring[used_idx]),
 			sizeof(vq->used->ring[used_idx]));
@@ -444,7 +444,7 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 	LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
 		dev->vid, cur_idx, res_end_idx);
 
-	if (vq->buf_vec[vec_idx].buf_len < vq->vhost_hlen)
+	if (vq->buf_vec[vec_idx].buf_len < dev->vhost_hlen)
 		return -1;
 
 	desc_addr = gpa_to_vva(dev, vq->buf_vec[vec_idx].buf_addr);
@@ -455,12 +455,12 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 		dev->vid, virtio_hdr.num_buffers);
 
 	virtio_enqueue_offload(m, &virtio_hdr.hdr);
-	copy_virtio_net_hdr(vq, desc_addr, virtio_hdr);
-	vhost_log_write(dev, vq->buf_vec[vec_idx].buf_addr, vq->vhost_hlen);
-	PRINT_PACKET(dev, (uintptr_t)desc_addr, vq->vhost_hlen, 0);
+	copy_virtio_net_hdr(dev, desc_addr, virtio_hdr);
+	vhost_log_write(dev, vq->buf_vec[vec_idx].buf_addr, dev->vhost_hlen);
+	PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
 
-	desc_avail  = vq->buf_vec[vec_idx].buf_len - vq->vhost_hlen;
-	desc_offset = vq->vhost_hlen;
+	desc_avail  = vq->buf_vec[vec_idx].buf_len - dev->vhost_hlen;
+	desc_offset = dev->vhost_hlen;
 
 	mbuf_avail  = rte_pktmbuf_data_len(m);
 	mbuf_offset = 0;
@@ -546,7 +546,7 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 		return 0;
 
 	for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
-		uint32_t pkt_len = pkts[pkt_idx]->pkt_len + vq->vhost_hlen;
+		uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
 
 		if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len,
 							 &start, &end) < 0)) {
@@ -747,7 +747,7 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 	uint32_t nr_desc = 1;
 
 	desc = &vq->desc[desc_idx];
-	if (unlikely(desc->len < vq->vhost_hlen))
+	if (unlikely(desc->len < dev->vhost_hlen))
 		return -1;
 
 	desc_addr = gpa_to_vva(dev, desc->addr);
@@ -755,8 +755,8 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 
 	/* Retrieve virtio net header */
 	hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr);
-	desc_avail  = desc->len - vq->vhost_hlen;
-	desc_offset = vq->vhost_hlen;
+	desc_avail  = desc->len - dev->vhost_hlen;
+	desc_offset = dev->vhost_hlen;
 
 	mbuf_offset = 0;
 	mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 13dc021..835ab3a 100644
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -387,8 +387,6 @@ int
 vhost_set_features(int vid, uint64_t *pu)
 {
 	struct virtio_net *dev;
-	uint16_t vhost_hlen;
-	uint16_t i;
 
 	dev = get_device(vid);
 	if (dev == NULL)
@@ -399,9 +397,9 @@ vhost_set_features(int vid, uint64_t *pu)
 	dev->features = *pu;
 	if (dev->features &
 		((1 << VIRTIO_NET_F_MRG_RXBUF) | (1ULL << VIRTIO_F_VERSION_1))) {
-		vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+		dev->vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 	} else {
-		vhost_hlen = sizeof(struct virtio_net_hdr);
+		dev->vhost_hlen = sizeof(struct virtio_net_hdr);
 	}
 	LOG_DEBUG(VHOST_CONFIG,
 		"(%d) mergeable RX buffers %s, virtio 1 %s\n",
@@ -409,13 +407,6 @@ vhost_set_features(int vid, uint64_t *pu)
 		(dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ? "on" : "off",
 		(dev->features & (1ULL << VIRTIO_F_VERSION_1)) ? "on" : "off");
 
-	for (i = 0; i < dev->virt_qp_nb; i++) {
-		uint16_t base_idx = i * VIRTIO_QNUM;
-
-		dev->virtqueue[base_idx + VIRTIO_RXQ]->vhost_hlen = vhost_hlen;
-		dev->virtqueue[base_idx + VIRTIO_TXQ]->vhost_hlen = vhost_hlen;
-	}
-
 	return 0;
 }
 
-- 
1.9.0