From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it1-f176.google.com (mail-it1-f176.google.com [209.85.166.176]) by dpdk.org (Postfix) with ESMTP id 9FE715911 for ; Mon, 4 Feb 2019 12:30:23 +0100 (CET) Received: by mail-it1-f176.google.com with SMTP id i145so20206305ita.4 for ; Mon, 04 Feb 2019 03:30:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MMQHmZ2vlOwQa0JKmwivPa9D7b5XbskUch1ITRiWxQM=; b=uP3BpgmPqxPRxJ8BJQmVEgZSblIKBvD3Qf54gQ+HE2GEdFtJSGd6f62vpdb1vbJav5 SEy82JiFAFIUpzXOiophNQjIMOxLharYu1nWIxXmftYyy5dEAYvQJLOOLJbGdhsg6zpq mDoStJGazJq/jxILqgvUK/dqRFUdnLccJ6FFJL9QBoLHGztQGjDlH45hPBr1xHp8z7HR 7Yr1nqL0Izfj+bBYweylyuZgc6K/cp0RiROYv+/ZrC87tet1vSJyPt3AgJkMUfPAVIZc 4tOVFBCNh6uGzg4a9XlIAosLaMVrBDjRG3JNFQkD/j64j6IGRCWauO3+uLGKhZauO/9f TywQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MMQHmZ2vlOwQa0JKmwivPa9D7b5XbskUch1ITRiWxQM=; b=OiegP1slGHctRXRDHc9xV8jG8aXaAvOGK3g+/0zvcGyTB3UOwuJRfBN5Djasf5TX/O kkZ6wjKLmqosZWWrNoyBk3jCYdKg3ObxFfW9gwiB4a4Nj1p7jodSEoJtauSjzQyaaPOT vHwdy6QQ8FEqr+StiVOqEIhu3y+QlIWIH7j39rQ0i6oTSzX/LDQ41KWW+LrRKSVLKsxC yWn79Tnay7pbWKvzMUei8X5FEzIeRNJZEcQENG3bx/KQUb7rBt18m1KaVBD9gUwsrVHD JBl4kx1NOiKpHwM8S2C1an6n92kaOLcKCbdojpgk9r2h7hOxSLd+Z7o3Q6uvbEnT18ec TRvg== X-Gm-Message-State: AHQUAuaun+V4UuK69DSZHk2E/4cpuzZvXTYDDW5lJyLwdB6y2aBhO8Y0 oHS/hc73cvCMMr2QiT8bQKYA6uXHoAtTh30j/3VcSA== X-Google-Smtp-Source: AHgI3IZpA9S80Zux+pnPKZ661mZ80alvCR396q5EYdoQKrkBaB46as9gsJZU8fCVoAl2a5MHODKayXcuhdtEXwxPNrE= X-Received: by 2002:a24:4f07:: with SMTP id c7mr8625388itb.107.1549279823017; Mon, 04 Feb 2019 03:30:23 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Alejandro Lucero Date: Mon, 4 Feb 2019 11:30:11 +0000 Message-ID: To: Rami Rosen Cc: dev Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] A Question about the necessity of DPDK VF for Ethernet PMDs X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Feb 2019 11:30:24 -0000 On Mon, Feb 4, 2019 at 10:44 AM Rami Rosen 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 > > >