From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 9112CB12A for ; Fri, 13 Jun 2014 20:02:28 +0200 (CEST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 13 Jun 2014 11:02:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,472,1400050800"; d="scan'208";a="555196975" Received: from irsmsx101.ger.corp.intel.com ([163.33.3.153]) by fmsmga002.fm.intel.com with ESMTP; 13 Jun 2014 11:02:41 -0700 Received: from irsmsx152.ger.corp.intel.com (163.33.192.66) by IRSMSX101.ger.corp.intel.com (163.33.3.153) with Microsoft SMTP Server (TLS) id 14.3.123.3; Fri, 13 Jun 2014 19:02:40 +0100 Received: from irsmsx103.ger.corp.intel.com ([169.254.3.58]) by IRSMSX152.ger.corp.intel.com ([169.254.6.197]) with mapi id 14.03.0123.003; Fri, 13 Jun 2014 19:02:40 +0100 From: "Richardson, Bruce" To: Chris Wright , Stephen Hemminger Thread-Topic: [PATCH] igb_uio: cap max VFs at 7 to reserve one for PF Thread-Index: AQHPhzAqE+tSWt1HbE+aLvZBFKv/wJtvUxjA Date: Fri, 13 Jun 2014 18:02:39 +0000 Message-ID: <59AF69C657FD0841A61C55336867B5B01AA36117@IRSMSX103.ger.corp.intel.com> References: <20140606235028.189345212@networkplumber.org> <2240300.rVk2eNDOWK@xps13> <20140613102440.19537123@nehalam.linuxnetplumber.net> <20140613175137.GS1384@x220.localdomain> In-Reply-To: <20140613175137.GS1384@x220.localdomain> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [163.33.239.182] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH] igb_uio: cap max VFs at 7 to reserve one for PF X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Jun 2014 18:02:29 -0000 > -----Original Message----- > From: Chris Wright [mailto:chrisw@redhat.com] > Sent: Friday, June 13, 2014 10:52 AM > To: Richardson, Bruce; Stephen Hemminger > Cc: Thomas Monjalon; dev@dpdk.org > Subject: [PATCH] igb_uio: cap max VFs at 7 to reserve one for PF >=20 > To keep from confusing users, cap max VFs at 7, despite PCI SR-IOV config > space showing a max of 8. This reserves a queue pair for the PF. >=20 > This issue was cited here: >=20 > http://dpdk.org/ml/archives/dev/2014-April/001832.html >=20 > Cc: Bruce Richardson > Cc: Stephen Hemminger > Signed-off-by: Chris Wright > --- >=20 > This is what Linux kernel driver does. I have only > compile tested it. Stephen sending to you and Bruce > in case you want to Ack and add to your current queue. >=20 Sorry, NAK - at least for this implementation. Hardcoding this to 7 is a bad idea, as the actual max number of VFs support= ed will depend on the actual hardware used. For someone using an 82599, the= y can have up to 64 VFs, or 63+PF, so limiting so 7 in that case is a major= reduction in capability. What might work there is querying the max number = of VFs and limiting to max - 1. However, even with that, I would suggest that any limit should be possible = to override. It's entirely possible that someone max actually want to reser= ve the full number of VFs, either because they don't want to use the NIC on= the host at all, or because they are happy to use a VF on the host instead= . Module parameter to allow override might work - and information on it cou= ld be added to the error message when we limit the VFs inside the driver. /Bruce