Issue: when using virtio nic to transmit pkts, it causes segment fault.
How to reproduce:
a. start testpmd with vhost.
$testpmd -c 0x3 -n 4 --socket-mem 1024,0 --no-pci \
--vdev 'eth_vhost0,iface=/tmp/sock0,queues=1' -- -i --nb-cores=1
b. start a qemu with a virtio nic connected with the vhost-user port.
$qemu -smp cores=2,sockets=1 -cpu host -enable-kvm vm-0.img -vnc :5 -m 4G \
-object memory-backend-file,id=mem,size=4096M,mem-path=<path>,share=on \
-numa node,memdev=mem -mem-prealloc \
-chardev socket,id=char1,path=$sock_vhost \
-netdev type=vhost-user,id=net1,chardev=char1 \
-device virtio-net-pci,netdev=net1,mac=00:01:02:03:04:05
c. enable testpmd on the host.
testpmd> set fwd io
testpmd> start
d. start testpmd in VM.
$testpmd -c 0x3 -n 4 -m 1024 -- -i --disable-hw-vlan-filter --txqflags=0xf01
testpmd> set fwd txonly
testpmd> start
How to fix: this bug is because inside virtqueue_enqueue_xmit(), the flag of
desc has been updated inside the do {} while (); and after the loop, all descs
could have run out, so idx is VQ_RING_DESC_CHAIN_END (32768), use this idx to
reference the start_dp array will lead to segment fault.
Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
---
drivers/net/virtio/virtio_rxtx.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index ef21d8e..432aeab 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -271,8 +271,6 @@ virtqueue_enqueue_xmit(struct virtqueue *txvq, struct
rte_mbuf *cookie,
idx = start_dp[idx].next;
} while ((cookie = cookie->next) != NULL);
- start_dp[idx].flags &= ~VRING_DESC_F_NEXT;
-
if (use_indirect)
idx = txvq->vq_ring.desc[head_idx].next;
--
2.1.4
