From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Date: Wed, 16 Mar 2016 06:44:56 +0000 (+0800)
Subject: vhost: remove unnecessary memset when enqueueing
X-Git-Tag: spdx-start~7252
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=b3869ebebfb1267d81bc4cdc8b12c0d0d484a03d;p=dpdk.git

vhost: remove unnecessary memset when enqueueing

We have to reset the virtio net hdr at virtio_enqueue_offload()
before, due to all mbufs share a single virtio_hdr structure:

	struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, }, 0};

	foreach (mbuf) {
		virtio_enqueue_offload(mbuf, &virtio_hdr.hdr);

		copy net hdr and mbuf to desc buf
	}

However, after the vhost rxtx refactor, the code looks like:

	copy_mbuf_to_desc(mbuf)
	{
		struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, }, 0}

		virtio_enqueue_offload(mbuf, &virtio_hdr.hdr);

		copy net hdr and mbuf to desc buf
	}

	foreach (mbuf) {
		copy_mbuf_to_desc(mbuf);
	}

Therefore, the memset at virtio_enqueue_offload() is not necessary
any more; remove it.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Huawei Xie <huawei.xie@intel.com>
---

diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index a6330f8f52..b4da66563c 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -94,8 +94,6 @@ is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t qp_nb)
 static void
 virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 {
-	memset(net_hdr, 0, sizeof(struct virtio_net_hdr));
-
 	if (m_buf->ol_flags & PKT_TX_L4_MASK) {
 		net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 		net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;