From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f193.google.com (mail-lj1-f193.google.com [209.85.208.193]) by dpdk.org (Postfix) with ESMTP id 88998316B for ; Fri, 25 Jan 2019 09:10:38 +0100 (CET) Received: by mail-lj1-f193.google.com with SMTP id v1-v6so7643522ljd.0 for ; Fri, 25 Jan 2019 00:10:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=semihalf-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=YtNRAFXCgAo7zxbcXVuSuG4kMeAwt6MZeXa/0z8AVDg=; b=huz2SrGkKwuuhjYPMQu6eM4GSLushijiRInsx9x3Dhqkq4FJVY9+XyRAWf16woM6i4 eBqAKBsy1tpCCodykk+DOd2acv4ltOJMSZoV34I5vBVg0bzEYdUUbV/5vDPrwsOjX641 yflMWVwYROqjbeNUYpsSBeYzZbJpo8xtuHY3ETSE8e1UQBh6mSjDnr+etXIWgi8AUSBV rDnZXPpRP9o+enffw32m6hOREtqNcITBlUMFrkgFwBWxhkAnaUUjOhoeBnZJP1oZcb59 rHJD0DVAOXDyBpiqb9VFt1DJN0WPzualhCFRa7Dn+AUPrnK93lDL1h2jp4eVL+u7iF34 EPxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=YtNRAFXCgAo7zxbcXVuSuG4kMeAwt6MZeXa/0z8AVDg=; b=cxnc+UaVgU716nFgB1KA32LeYzVh9mjE370ybdBq13+tKrVfjD5Esd9/BQhFoNDMz2 g4HiEpnZG+Cwd+dJ/53A2Wc53wzHl18tmkyriyuzAXpoHlPxEw2eDp9OIdXrJlSCicUg 9Fx+8nX2QSiJwsE+eVgFZEy38X0bcWHnArFPVNNzYZX+uf4uHMS5aBNLI9D6sSaUkvlG lfVPGWkLNpaM3iApOGKjmpwLBBbIfV2rbQ6qxTkziPD+ShaHD+HUEoFR0o+q8ZyXF4cw RcEEjEtRM2DuRx5ovwYTvQu2vza1KeSrDTSaNrhPI1RzoOG2rokJKbI2PhCOI6p6EbS0 jkJg== X-Gm-Message-State: AJcUukfyB9wYvkqXchVvC/5cLWQj09eYQk4EPU1O6VJhyWde8bsxbdQW aUs3UFYwFkD7mUgZ+dFFza8NZRAPGEg= X-Google-Smtp-Source: ALg8bN4HfIEUJ3AZnUGszWPLHOXCd28vrlPELJ7BpwdONX5nsiGsgr56GlumlQHz81jhLE9Eijkiig== X-Received: by 2002:a05:651c:14e:: with SMTP id c14mr8326692ljd.20.1548403837996; Fri, 25 Jan 2019 00:10:37 -0800 (PST) Received: from localhost.localdomain ([185.157.12.197]) by smtp.gmail.com with ESMTPSA id m21sm1358664lfl.97.2019.01.25.00.10.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 25 Jan 2019 00:10:37 -0800 (PST) From: Michal Krawczyk To: gtzalik@amazon.com, mw@semihalf.com, matua@amazon.com Cc: rk@semihalf.com, dev@dpdk.org Date: Fri, 25 Jan 2019 09:10:28 +0100 Message-Id: <1548403828-31870-6-git-send-email-mk@semihalf.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1548403828-31870-1-git-send-email-mk@semihalf.com> References: <1548403828-31870-1-git-send-email-mk@semihalf.com> Subject: [dpdk-dev] [PATCH 5/5] doc: add instructions for enabling WC in ENAv2 PMD 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: Fri, 25 Jan 2019 08:10:38 -0000 From: Rafal Kozik ENAv2 hardware provides Low Latency Queue v2 (LLQv2). It needs kernel PCI driver to support write combining (WC). This patch add information how to use it with igb_uio and vfio-pci drivers. Signed-off-by: Rafal Kozik Acked-by: Michal Krawczyk --- doc/guides/nics/ena.rst | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/doc/guides/nics/ena.rst b/doc/guides/nics/ena.rst index 9f0a650..80da4b6 100644 --- a/doc/guides/nics/ena.rst +++ b/doc/guides/nics/ena.rst @@ -183,10 +183,22 @@ Prerequisites #. Prepare the system as recommended by DPDK suite. This includes environment variables, hugepages configuration, tool-chains and configuration. -#. ENA PMD can operate with ``vfio-pci`` or ``igb_uio`` driver. +#. ENA PMD can operate with ``vfio-pci``(*) or ``igb_uio`` driver. + + (*) ENAv2 hardware supports Low Latency Queue v2 (LLQv2). This feature + reduces the latency of the packets by pushing the header directly through + the PCI to the device, before the DMA is even triggered. For proper work + kernel PCI driver must support write combining (WC). In mainline version of + ``igb_uio`` (in DPDK repo) it must be enabled by loding module with + ``wc_activate=1`` flag (example below). However, mainline's vfio-pci + driver in kernel doesn't have WC support yet (planed to be added). + If vfio-pci used user should be either turn off ENAv2 (to avoid performance + impact) or recompile vfio-pci driver with patch provided in + `amzn-github `_. #. Insert ``vfio-pci`` or ``igb_uio`` kernel module using the command - ``modprobe vfio-pci`` or ``modprobe igb_uio`` respectively. + ``modprobe vfio-pci`` or ``modprobe uio; insmod igb_uio.ko wc_activate=1`` + respectively. #. For ``vfio-pci`` users only: Please make sure that ``IOMMU`` is enabled in your system, -- 2.7.4