Re: [dpdk-dev] seg fault in InterVM communication using virtio

[mitali <mitaliyada@cse.iitb.ac.in>]

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Hi Yuanhan,

We are using virt-manager to start the VMs. We are attaching the image 
which shows the vNIC setup for the VMs.

We have written our own dpdk application to send and receive UDP 
packets. The command we are using is

*./build/app/dpdkapi -c 1 -- -p 1* where dpdkapi is our application.

Inside the application we are sending and receiving packets from vNIC 
using rte_eth_tx_burst() and rte_eth_rx_burst().

At the sender side after 127 packets the application stops and we 
observe a seg fault in dmesg. Using the print statements we observed 
that it faults in rte_eth_tx_burst(). All the 127 were received at the 
receiving VM.

Thanks,

Mitali


On Wednesday 22 February 2017 02:13 PM, Yuanhan Liu wrote:
> On Mon, Feb 20, 2017 at 04:00:12PM +0530, Priyanka wrote:
>> Hi All,
>>
>> We have 2 VM running on qemu-kvm hypervisor. We have provided vNIC to the
>> VMs using macvtap device and virtio as the device model in bridge mode. We
>> are running DPDK applications (udp client and server) on the VMs. We observe
>> that the inter-VM communication is not happening using drivers i.e igb_uio
>> and uio_pci_generic. We were able to communicate between the VMs properly
>> using SRIOV. But we were not getting performance as expected so we switched
>> to virtio. But using virtio the DPDK communication hangs after sending 128
>> packets. We also observe a seg fault in the dmesg of the VM.
>>
>> Please provide us some guideline to do the inter-VM communication using
>> virtio. Are we correct if we are using rte_eth_tx/rx_burst to send and
>> receive packets from the vNIC.
> Would you provide more info, say how do you start the vm, and how do you
> run the dpdk apps? Providing all the commands that could reproduce your
> issue will be better.
>
> 	--yliu


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