From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id CA21C2A5E for ; Sat, 9 Jul 2016 09:09:09 +0200 (CEST) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP; 09 Jul 2016 00:09:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,334,1464678000"; d="scan'208";a="1003620645" Received: from unknown (HELO [10.255.170.100]) ([10.255.170.100]) by fmsmga001.fm.intel.com with ESMTP; 09 Jul 2016 00:09:04 -0700 To: Thomas Monjalon , Zhe Tao References: <1462879301-13570-1-git-send-email-zhe.tao@intel.com> <57336AD6.1050809@intel.com> <2574807.bEb98RZhNN@xps13> Cc: dev@dpdk.org, Alejandro Lucero , Stephen Hemminger From: Ferruh Yigit Message-ID: <5780A30E.9080106@intel.com> Date: Sat, 9 Jul 2016 08:09:02 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <2574807.bEb98RZhNN@xps13> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v1] igu_uio: fix IOMMU domain issue 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: Sat, 09 Jul 2016 07:09:10 -0000 On 7/8/2016 6:27 PM, Thomas Monjalon wrote: > 2016-05-11 18:24, Ferruh Yigit: >> On 5/11/2016 8:35 AM, Alejandro Lucero wrote: >>> On Tue, May 10, 2016 at 4:59 PM, Stephen Hemminger < >>> stephen@networkplumber.org> wrote: >>> >>>> On Tue, 10 May 2016 19:21:41 +0800 >>>> Zhe Tao wrote: >>>> >>>>> Problem: >>>>> The following operations will cause the igb_uio based DPDK >>>>> operation failed. >>>>> --Any device assignment through the kvm_assign_device interface, >>>>> this can be the pci-assign method in QEMU >>>>> --VFIO group attachment operation(attach to the container) >>>>> this can happens in vfio-pci assignment in QEMU >>>> >>>> >>>> If you have an IOMMU why not use VFIO instead, it is better. >>>> >>> >>> It is not about VFIO against UIO but about how iommu domains are created >>> and destroyed by the (old) kernel when iommu=pt. So even with VFIO you can >>> have problems. >> >> Problem is in IOMMU driver but we are adding a workaround to igb_uio, if >> using VFIO solves the issue, I believe that is better workaround. >> >> 1) Is there any case IOMMU supported but VFIO is not supported? Is there >> anything forces to use igb_uio? >> >> 2) Does using VFIO solves the issue defined in problem statement? >> >>> >>> We have had problems like this and other due to our device (NFP) just >>> mapping up to 40 bits of address space. Old kernels used in LTS >>> distributions like Ubuntu are iommu buggy and you need to do things like >>> this mapping inside the driver for solving problems. By the way, using >>> SRIOV just adds more problems. It is not safe to use iommu=pt with 3.13.x >>> Ubuntu kernels. >>> >>> It would be a good thing for the original patch to identify those kernels >>> where the problem was detected. Of course, there could be more kernels with >>> the same problem but that is more work to do. >>> >B > Ping, this patch is stalled. > I am for rejecting this patch. The patch is useful for tester / developers who use both vfio and igb_uio. But if end user has environment support to use vfio, she should use vfio instead of having workaround to use both. Thanks, ferruh