From 7f3fc78011c3915612cccf0858820d6caa8c3e08 Mon Sep 17 00:00:00 2001
From: Vlad Zolotarov <vladz@cloudius-systems.com>
Date: Wed, 21 May 2014 18:13:02 +0300
Subject: [PATCH] virtio::net::txq: Fix the bug causing the false asserts
vec_sz in net::txq::try_xmit_one_locked(net_req*) should be initialized to 1 and not to 0
since there is always net_hdr element and vec_sz is incremented only for fragments not taking
into an account the header element.
This miscalculation caused vqueue->add_buf() return false while vqueue->avail_ring_has_room(vec_sz)
was returning true when the amount of elements in the avail ring was equal to vec_sz
since the actual size of the _sg_vec was "vec_sz + 1".
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
---
drivers/virtio-net.cc | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/virtio-net.cc b/drivers/virtio-net.cc
index 8cc6708ed..f861b319b 100644
--- a/drivers/virtio-net.cc
+++ b/drivers/virtio-net.cc
@@ -616,7 +616,7 @@ inline int net::txq::xmit_prep(mbuf* m_head, void*& cooky)
int net::txq::try_xmit_one_locked(net_req* req)
{
mbuf *m_head = req->mb, *m;
- u16 vec_sz = 0;
+ u16 vec_sz = 1;
u64 tx_bytes = 0;
if (_parent->_mergeable_bufs) {
--
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