From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rami Rosen Subject: Re: A Question about the necessity of DPDK VF for Ethernet PMDs Date: Mon, 4 Feb 2019 14:19:19 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: dev To: Alejandro Lucero Return-path: Received: from mail-wr1-f41.google.com (mail-wr1-f41.google.com [209.85.221.41]) by dpdk.org (Postfix) with ESMTP id B01D45B2A for ; Mon, 4 Feb 2019 13:19:30 +0100 (CET) Received: by mail-wr1-f41.google.com with SMTP id s12so14157735wrt.4 for ; Mon, 04 Feb 2019 04:19:30 -0800 (PST) In-Reply-To: List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi, Alejandro, Thanks for you quick response. >When SRIOV is used by VMs, the slow path will always be faster (and >with lower latency) with DPDK. Yes, I am referring primarily to the SRIOV case in my question, when assigning PCI VF to a VM (most likely QEMU VM) Can you please explain what you mean about slow path in this context ? Not sure the OVS setup is relevant here, it seems (if I understand correctly) that VFIO is more commonly used in OVS setups, so this query is not relevant here (unless you use igb_uio which is less common) According to http://docs.openvswitch.org/en/latest/intro/install/dpdk/ "VFIO is prefered to the UIO driver when using recent versions of DPDK. " Regards, Rami Rosen