[dpdk-users] OVS vs OVS-DPDK

[Avi Cohen (A)]

Hello
Let me  ask it in a different way:
I want to understand the reasons for the  differences in performance between OVS-DPDK and standard OVS My setup is:  ovs/ovs-dpdk is running @ host communicating with a VM

OVS-DPDK
1. packet is received via physical port to the device. 

2.DMA  transfer   to mempools on huge-pages  allocated by dpdk-ovs - in  user-space.

3. OVS-DPDK  copies this packet to the shared-vring of the associated  guest (shared between ovs-dpdk userspace process and guest) 

4. guest OS copies the packet to  userspace application on VM .

Standard OVS

1. packet is received via physical port to the device. 

2.packet is processed by the OVS and transferred to a virtio device connected to the VM - whar are the additional overhead here ?  QEMU processing  - translation , VM exit ??  other ?

3. guest OS copies the packet to  userspace application on VM .


Question:  what are the additional overhead in the standard OVS   that cause to poor performance related to the OVS-DPDK setup ?
I'm not talking about  the PMD improvements (OVS-DPDK)  running on the host - but on overhead in the VM context in the standard OVS setup

Best Regards
avi