From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by dpdk.org (Postfix) with ESMTP id D80E91B05 for ; Thu, 24 May 2018 16:15:56 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 May 2018 07:15:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,436,1520924400"; d="scan'208";a="43607574" Received: from fyigit-mobl.ger.corp.intel.com (HELO [10.237.221.77]) ([10.237.221.77]) by orsmga007.jf.intel.com with ESMTP; 24 May 2018 07:15:54 -0700 From: Ferruh Yigit To: Alejandro Lucero Cc: dev , "Varghese, Vipin" References: <1527078536-1443-1-git-send-email-alejandro.lucero@netronome.com> Openpgp: preference=signencrypt Autocrypt: addr=ferruh.yigit@intel.com; prefer-encrypt=mutual; keydata= xsFNBFXZCFABEADCujshBOAaqPZpwShdkzkyGpJ15lmxiSr3jVMqOtQS/sB3FYLT0/d3+bvy qbL9YnlbPyRvZfnP3pXiKwkRoR1RJwEo2BOf6hxdzTmLRtGtwWzI9MwrUPj6n/ldiD58VAGQ +iR1I/z9UBUN/ZMksElA2D7Jgg7vZ78iKwNnd+vLBD6I61kVrZ45Vjo3r+pPOByUBXOUlxp9 GWEKKIrJ4eogqkVNSixN16VYK7xR+5OUkBYUO+sE6etSxCr7BahMPKxH+XPlZZjKrxciaWQb +dElz3Ab4Opl+ZT/bK2huX+W+NJBEBVzjTkhjSTjcyRdxvS1gwWRuXqAml/sh+KQjPV1PPHF YK5LcqLkle+OKTCa82OvUb7cr+ALxATIZXQkgmn+zFT8UzSS3aiBBohg3BtbTIWy51jNlYdy ezUZ4UxKSsFuUTPt+JjHQBvF7WKbmNGS3fCid5Iag4tWOfZoqiCNzxApkVugltxoc6rG2TyX CmI2rP0mQ0GOsGXA3+3c1MCdQFzdIn/5tLBZyKy4F54UFo35eOX8/g7OaE+xrgY/4bZjpxC1 1pd66AAtKb3aNXpHvIfkVV6NYloo52H+FUE5ZDPNCGD0/btFGPWmWRmkPybzColTy7fmPaGz cBcEEqHK4T0aY4UJmE7Ylvg255Kz7s6wGZe6IR3N0cKNv++O7QARAQABzSVGZXJydWggWWln aXQgPGZlcnJ1aC55aWdpdEBpbnRlbC5jb20+wsF+BBMBAgAoAhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgAUCWZR3VQUJB33WBQAKCRD5M+tD3xNhH6DWEACVhEb8q1epPwZrUDoxzu7E TS1b8tmabOmnjXZRs6+EXgUVHkp2xxkCfDmL3pa5bC0G/74aJnWjNsdvE05V1cb4YK4kRQ62 FwDQ+hlrFrwFB3PtDZk1tpkzCRHvJgnIil+0MuEh32Y57ig6hy8yO8ql7Lohyrnpfk/nNpm4 jQGEF5qEeHcEFe1AZQlPHN/STno8NZSz2nl0b2cw+cujN1krmvB52Ah/2KugQ6pprVyrGrzB c34ZQO9OsmSjJlETCZk6EZzuhfe16iqBFbOSadi9sPcJRwaUQBid+xdFWl7GQ8qC3zNPibSF HmU43yBZUqJDZlhIcl6/cFpOSjv2sDWdtjEXTDn5y/0FsuY0mFE78ItC4kCTIVk17VZoywcd fmbbnwOSWzDq7hiUYuQGkIudJw5k/A1CMsyLkoUEGN3sLfsw6KASgS4XrrmPO4UVr3mH5bP1 yC7i1OVNpzvOxtahmzm481ID8sk72GC2RktTOHb0cX+qdoiMMfYgo3wRRDYCBt6YoGYUxF1p msjocXyqToKhhnFbXLaZlVfnQ9i2i8jsj9SKig+ewC2p3lkPj6ncye9q95bzhmUeJO6sFhJg Hiz6syOMg8yCcq60j07airybAuHIDNFWk0gaWAmtHZxLObZx2PVn2nv9kLYGohFekw0AOsIW ta++5m48dnCoAc7BTQRX1ky+ARAApzQNvXvE2q1LAS+Z+ni2R13Bb1cDS1ZYq1jgpR13+OKN ipzd8MPngRJilXxBaPTErhgzR0vGcNTYhjGMSyFIHVOoBq1VbP1a0Fi/NqWzJOowo/fDfgVy K4vuitc/gCJs+2se4hdZA4EQJxVlNM51lgYDNpjPGIA43MX15OLAip73+ho6NPBMuc5qse3X pAClNhBKfENRCWN428pi3WVkT+ABRTE0taxjJNP7bb+9TQYNRqGwnGzX5/XISv44asWIQCaq vOkXSUJLd//cdVNTqtL1wreCVVR5pMXj7VIrlk07fmmJVALCmGbFr53BMb8O+8dgK2A5mitM n44d+8KdJWOwziRxcaMk/LclmZS3Iv1TERtiWt98Y9AjeAtcgYPkA3ld0BcUKONogP8pHVz1 Ed3s5rDQ91yr1S0wuAzW91fxGUO4wY+uPmxCtFVuBgd9VT9NAKTUL0qHM7CDgCnZPe0TW6Zj 8OqtdCCyAfvU9cW5xWM7Icxhde6AtPxhDSBwE8fL2ZmrDmaA4jmUKXp3i4JxRPSX84S08b+s DWXHPxy10UFU5A7EK/BEbZAKBwn9ROfm+WK+6X5xOGLoRE++OqNuUudxC1GDyLOPaqCbBCS9 +P6HsTHzxsjyJa27n4jcrcuY3P9TEcFJYSZSeSDh8mVGvugi0exnSJrrBZDyVCcAEQEAAcLB ZQQYAQIADwIbDAUCWZR1ZwUJA59cIQAKCRD5M+tD3xNhH5b+D/9XG44Ci6STdcA5RO/ur05J EE3Ux1DCHZ5V7vNAtX/8Wg4l4GZfweauXwuJ1w7Sp7fklwcNC6wsceI+EmNjGMqfIaukGetG +jBGqsQ7moOZodfXUoCK98gblKgt/BPYMVidzlGC8Q/+lZg1+o29sPnwImW+MXt/Z5az/Z17 Qc265g+p5cqJHzq6bpQdnF7Fu6btKU/kv6wJghENvgMXBuyThqsyFReJWFh2wfaKyuix3Zyj ccq7/blkhzIKmtFWgDcgaSc2UAuJU+x9nuYjihW6WobpKP/nlUDu3BIsbIq09UEke+uE/QK+ FJ8PTJkAsXOf1Bc2C0XbW4Y2hf103+YY6L8weUCBsWC5VH5VtVmeuh26ENURclwfeXhWQ9Og 77yzpTXWr5g1Z0oLpYpWPv745J4bE7pv+dzxOrFdM1xNkzY2pvXph/A8OjxZNQklDkHQ7PIB Lki5L2F4XkEOddUUQchJwzMqTPsggPDmGjgLZrqgO+s4ECZK5+nLD3HEpAbPa3JLDaScy+90 Nu1lAqPUHSnP3vYZVw85ZYm6UCxHE4VLMnnJsN09ZhsOSVR+GyP5Nyw9rT1V3lcsuH7M5Naa 2Xobn9m7l9bRCD/Ji8kG15eV1WTxx1HXVQGjdUYDI7UwegBNbwMLh17XDy+3sn/6SgcqtECA Q6pZKA2mTQxEKMLBZQQYAQIADwIbDAUCWZR3hQUJA59eRwAKCRD5M+tD3xNhH4a/D/4jLAZu UhvU1swWcNEVVCELZ0D3LOV14XcY2MXa3QOpeZ9Bgq7YYJ4S5YXK+SBQS0FkRZdjGNvlGZoG ZdpU+NsQmQFhqHGwX0IT9MeTFM8uvKgxNKGwMVcV9g0IOqwBhGHne+BFboRA9362fgGW5AYQ zT0mzzRKEoOh4r3AQvbM6kLISxo0k1ujdYiI5nj/5WoKDqxTwwfuN1uDUHsWo3tzenRmpMyU NyW3Dc+1ajvXLyo09sRRq7BnM99Rix1EGL8Qhwy+j0YAv+FuspWxUX9FxXYho5PvGLHLsHfK FYQ7x/RRbpMjkJWVfIe/xVnfvn4kz+MTA5yhvsuNi678fLwY9hBP0y4lO8Ob2IhEPdfnTuIs tFVxXuelJ9xAe5TyqP0f+fQjf1ixsBZkqOohsBXDfje0iaUpYa/OQ/BBeej0dUdg2JEu4jAC x41HpVCnP9ipLpD0fYz1d/dX0F/VY2ovW6Eba/y/ngOSAR6C+u881m7oH2l0G47MTwkaQCBA bLGXPj4TCdX3lftqt4bcBPBJ+rFAnJmRHtUuyyaewBnZ81ZU2YAptqFM1kTh+aSvMvGhfVsQ qZL2rk2OPN1hg+KXhErlbTZ6oPtLCFhSHQmuxQ4oc4U147wBTUuOdwNjtnNatUhRCp8POc+3 XphVR5G70mnca1E2vzC77z+XSlTyRA== Message-ID: Date: Thu, 24 May 2018 15:15:54 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] [PATCH] net/nfp: fix lock file usage 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: Thu, 24 May 2018 14:15:57 -0000 On 5/24/2018 3:13 PM, Ferruh Yigit wrote: > On 5/24/2018 3:02 PM, Alejandro Lucero wrote: >> >> >> On Thu, May 24, 2018 at 11:18 AM, Ferruh Yigit > > wrote: >> >> On 5/23/2018 5:50 PM, Alejandro Lucero wrote: >> > >> > >> > On Wed, May 23, 2018 at 4:57 PM, Ferruh Yigit >> > >> wrote: >> > >> >     On 5/23/2018 1:28 PM, Alejandro Lucero wrote: >> >     > DPDK apps can be executed as non-root users but current NFP lock >> >     > file for avoiding concurrent accesses to CPP interface is precluding >> >     > this option or requires to modify system file permissions. >> >     > >> >     > When the NFP device is bound to VFIO, this driver does not allow this >> >     > concurrent access, so the lock file is not required at all. >> >     > >> >     > OVS-DPDK as executed in RedHat distributions is the main NFP user >> >     > needing this fix. >> >     > >> >     > Fixes: c7e9729da6b5 ("net/nfp: support CPP") >> >     > >> >     > Signed-off-by: Alejandro Lucero > >> >> >> > >> >     Hi Alejandro, >> > >> >     As far as I understand this is to fix a common use case for nfp, but it looks >> >     like there is already a workaround and only for non-root users. >> > >> > >> > There is a patch submitted to stable versions because this lock was also with >> > the old NSPU interface, but as far as I know, there is no patch yet for the >> > current upstream tip. >> > >> >   >> > >> >     What is the priority of the patch, only critical but fixes allowed at this >> >     point, can we push this one to next release? >> > >> > >> > This is critical for us because RedHat wants to support OVS with our card, and >> > when OVS-DPDK is used, this problem is precluding non-root users to execute >> > OVS-DPDK. >> >> What exactly this lock for? Does it to prevent multiple primary process to >> access CPP interface? >> >> If so this is the know limitation in DPDK, not two separate process can driver >> same hardware, this is valid for all devices, why adding a lock unique to nfp? >> >> >> Time ago I had, by mistake, two different DPDK processes using same device, and >> with UIO, there is no one avoiding this. >> >> You can bound a device to UIO, igb_uio, and then use two different processes >> opening the /dev/uiox file, and it works. > > But this is not anything specific to nfp, isn't it? Or let me ask something else, is this a fix for ovs-dpdk regular use-case with nfp? Or this is just an extra protection in case multiple process may try to use the NIC. If second, why it is critical? > >> >> The VFIO driver does avoid this situation, but this lock is required for UIO. >> >