From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id ABFEB239 for ; Tue, 12 Mar 2019 11:57:20 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Mar 2019 03:57:19 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,471,1544515200"; d="scan'208";a="130929158" Received: from aburakov-mobl1.ger.corp.intel.com (HELO [10.237.220.66]) ([10.237.220.66]) by fmsmga008.fm.intel.com with ESMTP; 12 Mar 2019 03:57:18 -0700 To: Bruce Richardson , Jason Wang Cc: Thanneeru Srinivasulu , dev@dpdk.org References: <20190312093826.GA914268@bricha3-MOBL.ger.corp.intel.com> <20190312102009.GA932176@bricha3-MOBL.ger.corp.intel.com> From: "Burakov, Anatoly" Message-ID: <38327cd0-7fa2-9172-5343-0cded8e51594@intel.com> Date: Tue, 12 Mar 2019 10:57:16 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.3 MIME-Version: 1.0 In-Reply-To: <20190312102009.GA932176@bricha3-MOBL.ger.corp.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] Query : Does Binding with vfio-pci is supported inside qemu-kvm guest/vm instance.? 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: Tue, 12 Mar 2019 10:57:21 -0000 On 12-Mar-19 10:20 AM, Bruce Richardson wrote: > On Tue, Mar 12, 2019 at 05:54:39PM +0800, Jason Wang wrote: >> >> On 2019/3/12 下午5:42, Thanneeru Srinivasulu wrote: >>> Thanks Bruce.. >>> >>> On Tue, Mar 12, 2019 at 3:08 PM Bruce Richardson >>> wrote: >>>> On Tue, Mar 12, 2019 at 10:57:55AM +0530, Thanneeru Srinivasulu wrote: >>>>> Hi Everyone. >>>>> >>>>> I did attached pice to Guest VM using vfio-pci with qemu command, and then >>>>> tried binding the pcie bdf with vfio-pci, observing binding failure with >>>>> vfio-pci. >>>>> >>>>> Where as when tryied with igb_uio, everything works fine. >>>>> >>>>> Does Binding with vfio-pci is supported inside VM/guest? >>>>> >>>> vfio support requires the presence of an IOMMU, and you generally don't >>>> have an IOMMU available in a VM. >>>> >>>> /Bruce >> >> >> Actually, Qemu support vIOMMU + VFIO in guest[1], all you need is to add a >> intel IOMMU and enabling caching mode. >> >> Thanks >> >> >> [1] >> >> https://www.lfasiallc.com/wp-content/uploads/2017/11/Device-Assignment-with-Nested-Guests-and-DPDK_Peter-Xu.pdf >> > Thanks for the info. > > /Bruce > One more thing: even without vIOMMU, VFIO has no-IOMMU mode which can be enabled (for a recent-enough kernel). This will make VFIO work even in cases where the guest doesn't have IOMMU emulation. See? There's no reason to use igb_uio, ever! :D -- Thanks, Anatoly