[ovs-dev] netdev-dpdk: Doubt about rings in dpdkr port type

[Mauricio Vásquez]

On Mon, May 18, 2015 at 7:09 PM, Traynor, Kevin <kevin.traynor at intel.com>
wrote:

>
> > -----Original Message-----
> > From: dev [mailto:dev-bounces at openvswitch.org] On Behalf Of Mauricio
> Vásquez
> > Sent: Monday, May 18, 2015 9:31 AM
> > To: dev at openvswitch.org; ivano cerrato
> > Subject: [ovs-dev] netdev-dpdk: Doubt about rings in dpdkr port type
> >
> > I'm performing a series of VM2VM communication testing where a virtual
> > machine is a packet generator while the other one just receives all the
> > packets.
> >
> > When I tested dpdk-ovs[1] I used a port type called dpdkclient: this port
> > has 4 rings, (tx, rx, alloc_q and free_q), alloc_q and free_q are used
> > because, due to a issue with DPDK[2], it's not possible to call
> > rte_pktmbuf_alloc or rte_pktmbuf_free inside a guest. (dpdk-ovs provides
> > packets to the guest application through alloc_q and the guest
> application
> > request freeing packets through  free_q).
> >
> > I'm trying to do the same tests using ovs with dpdk[3] but I realized
> that
> > dpdkr port type has just the rx and tx rings, so at this moment the
> sender
> > application does not have a way to get new mbufs.
> >
> > Basically my questions are:
> > * Is there another way to get mbufs in a guest application?
>
> I don't know of another safe way to do this other than alloc/free queues.
>
> > * If not, are the alloc_q and free_q planned to be added in dpdkr port?
>
> No immediate plans for this. Depending on what the purpose of your testing
> is,
> you could use vhost to source in one VM and sink in another.
>
> The purpose consists of comparing the performance of vm2vm communication
in the case ovs is in the middle and in the case of a direct vm2vm
communication channel.
We are considering only the IVSHMEM case so unfortunately vhost it's not
fine for us.

Thanks for your answer.


> >
> > Thanks in advance.
> >
> > [1] https://github.com/01org/dpdk-ovs
> > [2]
> > https://github.com/01org/dpdk-
> > ovs/blob/development/guest/ovs_client/ovs_client.c#L158-L175
> > [3] https://github.com/openvswitch/ovs
> > _______________________________________________
> > dev mailing list
> > dev at openvswitch.org
> > http://openvswitch.org/mailman/listinfo/dev
>