From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) by dpdk.org (Postfix) with ESMTP id 1EEB42BBE for ; Mon, 4 Feb 2019 08:43:18 +0100 (CET) Received: by mail-wm1-f54.google.com with SMTP id a62so12011244wmh.4 for ; Sun, 03 Feb 2019 23:43:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=CkfPIPYy7XUWNfBkGH2jbdfecJM7RbwhDrL3rAz5UH8=; b=PKcoLk40bqlZVwM0vnTeIBG4U8GKmSW56JpOJaSwYVxr7N33fLCcqlp+y8/+FFPV+u Ccf9J69/qDf+eAm/fS4NP1XlmaXFHOuNeCDYk0o533srDLaE/agyfnM0ORBcNxUZXqII Lok1LqSJkwi7SurHXJBZIAbYfyBoNF+DMRh21ea7oL96+tOlJNvcCfmIyYOrLjrkERd9 8JY/gDCAa4JuKFuYBZBIux79abrlFcqex004rbDjTaupN+ntVH2+3zL3YC2oPWOuw+JF Lv8UJHuPXxNrHN04WrlZZ1m31n4guWfuZFj8J3qMUrrlH/nYJl/p5SSGRGID3HMTWyGd hMDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=CkfPIPYy7XUWNfBkGH2jbdfecJM7RbwhDrL3rAz5UH8=; b=d9+iTryqy29dfpqavuyd86PoSKyS4Cx53U2fdOZeBca7OqF53xfqa771ryL822Qc9t gixEV1XoK19idJKamMEC712rIEZZoaJoX/2BX13r2s0ktMzgx/uBOSjBjoUnwWhaLMi1 IRwm2wd9DsYqZ7ltoyDFPgKQ6XGi7gLG7E4KF5zFp3AP2uKzMZIgFkWm5J/6vWeBk8XM oN8nmAGy1wDlx6FH/tKI/sa8h/FGBLIC2zzzp70hAR1JkcjbE1F7OdBzT8rnTOUcMCQ6 eToICGkNZzjrakt2dkudpxLsnRFXJu1EipITLEaR09cKB0HD2t6fn0ihLtZIQXeY0iAM sEEQ== X-Gm-Message-State: AHQUAuacl34f4BHLxSDcj6CJ8mgY4CWids7iAT9eS7cCCdcMSBAOTlfo VjYTatCGKrD5JfWJVkjpCY3PXy9T3lzuz4+QFhbFiNK3 X-Google-Smtp-Source: AHgI3IYnZivCdbd5orBcHX3HlPRzUrHvTiKwmbVoNa0o3fgDYSHB1RbU3O9NuNdPt/YggmFEuvJabm3NeQK3amcKLxg= X-Received: by 2002:a1c:c008:: with SMTP id q8mr11054753wmf.99.1549266197379; Sun, 03 Feb 2019 23:43:17 -0800 (PST) MIME-Version: 1.0 From: Rami Rosen Date: Mon, 4 Feb 2019 09:43:06 +0200 Message-ID: To: dev@dpdk.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: [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 07:43:18 -0000 Hello all, Now that DPDK 19.02 was released three days ago (on time!!), hopefully there will be time for people to answer the following question: According to the "DPDK Getting Started Guide", "If UEFI secure boot is enabled, the Linux kernel may disallow the use of UIO on the system. Therefore, devices for use by DPDK should be bound to the vfio-pci kernel module rather than igb_uio or uio_pci_generic. For more details see Binding and Unbinding Network Ports to/from the Kernel Modules." See: http://doc.dpdk.org/guides/linux_gsg/sys_reqs.html#bios-setting-prerequisite-on-x86 Now, when you bind a PCI device with vfio-pci, then the "max_vfs" entry is *not* created under /sys/bus/pci/devices// (as opposed to the case when you bind with igb_uio). This means that you cannot create DPDK VFS in this case (as you cannot write num_vfs to the non existing max_vfs entry). You can however create Kernel VFs (by echoing into the sriov_num_vfs sysfs entry). So I assume there are deployments of DPDK (with secure boot) when the PMDs are being binded not by igb_uio but by vfio_pci. So the question is: As explained above, t probably there are setups when you cannot generated PMD VFs. Most PMD Ethernet Vendors *do* provide VF PMDs in the DPDK official repo; but what are the benefits of providing DPDK VFs PMD? is it mandatory in some use cases ? Is there any advantage for using a DPDK PF/DPDK VF combination over using Kernel VF? Regards, Rami Rosen