On Mon, Feb 4, 2019 at 10:44 AM Rami Rosen <ramir...@gmail.com> wrote:
> Hi Alejandro, > > >Your concern is related to this thread > > Thanks for your reply, I was aware of this thread. > OK > Still, I am not sure, in current kernels and currently available Ethernet > DPDK PMDs about the answer to my queries (I don't think this mail thread > gives info about it), like about what are the benefits of providing DPDK > VFs, is it mandatory in some use cases, and are there any advantage for > using a DPDK PF/DPDK VF combination over using Kernel VF? > > That is an interesting discussion. I know there is some interest in this case from OVS people, exactly for running an OVS instance inside a VM. I can see other reasons: - when SRIOV is used by VMs, the slow path will always be faster (and with lower latency) with DPDK. - When more VMs/containers than VFs, DPDK will allow to use SRIOV (for higher priority VMs/containers) and vhost-user (for low-priority), and with the low-priority being faster than through the kernel. - If SRIOV is not used by VMs, DPDK forwarding path using vhost-user along with VF PMDs is faster than through the kernel. - Having the PF managed by user space could potentially mean faster VM migration. - PF flow management, inserting/deleting flow rules, faster in user space. Regards, > > Rami Rosen > > >
