Re: [PATCH v3] net/vhost: fix segfault when creating vdev dynamically

[Jens Freimann <jfreimann@redhat.com>]

Hi,

On Fri, Mar 30, 2018 at 02:58:31PM +0800, Junjie Chen wrote:
>When creating vdev dynamically, vhost pmd driver starts directly without
>checking TX/RX queues are ready or not, and thus causes segmentation fault
>when vhost library accesses queues. This patch adds a flag to check whether
>queues are setup or not, and adds queues setup into dev_start function to
>allow user to start them after setting up.

for me, with this patch vhost enqueue/dequeue code is never called because 

  if (unlikely(rte_atomic32_read(&r->allow_queuing) == 0))
 
this check in eth_vhost_rx() is always true. 

When I revert this patch it works as usual. 

My testpmd cmdline is: 

gdb --args $RTE_SDK/install/bin/testpmd -l 0,2,3,4,5 --socket-mem=1024 -n 4 \
    --vdev 'net_vhost0,iface=/tmp/vhost-user1' \
    --vdev 'net_vhost1,iface=/tmp/vhost-user2' -- \
    --portmask=f  --rxq=1 --txq=1 \
    --nb-cores=4 --forward-mode=io  -i

After starting testpmd I issue commands "set portlist 0,2,1,3", start
my guest and start another testpmd issue in the guest. 

Another problem I see: Before this patch I could start testpmd, issue
the portlist command and type "start". If I do this now I get an infinite
loop of "VHOST CONFIG device not found" messages.


regards,
Jens