From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id B93B25595 for ; Mon, 5 Sep 2016 08:31:58 +0200 (CEST) Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F0A76C057FA7; Mon, 5 Sep 2016 06:31:57 +0000 (UTC) Received: from [10.72.4.13] (vpn1-4-13.pek2.redhat.com [10.72.4.13]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u856VrD1003017 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 5 Sep 2016 02:31:55 -0400 To: Alejandro Lucero , "Michael S. Tsirkin" References: <1472798220-7121-1-git-send-email-jasowang@redhat.com> <1472798220-7121-2-git-send-email-jasowang@redhat.com> <1631660.hGMgJuvotI@xps13> <20160902202613-mutt-send-email-mst@kernel.org> Cc: Thomas Monjalon , dev , huawei.xie@intel.com, yuanhan.liu@linux.intel.com From: Jason Wang Message-ID: Date: Mon, 5 Sep 2016 14:31:52 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 05 Sep 2016 06:31:58 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH 2/2] virtio: support IOMMU platform 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: Mon, 05 Sep 2016 06:31:59 -0000 On 2016年09月04日 16:08, Alejandro Lucero wrote: > I know RedHat is working on a vIOMMU so I guess this work is related > to that effort, but it is a surprise virtio using IOMMU. I thought > IOMMU just made sense when using SRIOV. My second guess is using IOMMU > with virtio is a matter of security, but by other hand, virtio + IOMMU > could imply serious performance degradation when multiple VMs are in use. We will use qemu vIOMMU for virito, so there's no such issue. > I'm talking about IOMMU contention, exactly about IOTLB contention. I thought device IOTLB (ATS) was just designed to solve this contention. > This performance issue is complex to describe or even analyze as there > are several factors having an impact on it. For example, 1GB hugepages > can avoid most of it and the same if TX & RX rings are not bigger than > 256. So, my question: is RedHat aware of this potential IOMMU > contention which can limit scalability? For virtio, we use vIOMMU per VM and implement a device IOTLB in vhost side. Technically, it does not have such issue I think. Thanks > > On Fri, Sep 2, 2016 at 6:26 PM, Michael S. Tsirkin > wrote: > > On Fri, Sep 02, 2016 at 03:04:56PM +0200, Thomas Monjalon wrote: > > 2016-09-02 14:37, Jason Wang: > > > Virtio pmd doesn't support VFIO in the past since devices > bypass IOMMU > > > completely. But recently, the work of making virtio device > work with > > > IOMMU is near to complete. > > > > Good news! > > What are the requirements for Qemu and Linux version numbers please? > > I expect QEMU 2.8 and Linux 4.8 to have the support. > > 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 7A2D88F9E for ; Thu, 8 Sep 2016 06:17:40 +0200 (CEST) Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP; 07 Sep 2016 21:17:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,298,1470726000"; d="scan'208";a="5854792" Received: from orsmsx102.amr.corp.intel.com ([10.22.225.129]) by fmsmga006.fm.intel.com with ESMTP; 07 Sep 2016 21:17:39 -0700 Received: from orsmsx158.amr.corp.intel.com (10.22.240.20) by ORSMSX102.amr.corp.intel.com (10.22.225.129) with Microsoft SMTP Server (TLS) id 14.3.248.2; Wed, 7 Sep 2016 21:17:38 -0700 Received: from rrsmsp801.amr.corp.intel.com (10.9.230.203) by ORSMSX158.amr.corp.intel.com (10.22.240.20) with Microsoft SMTP Server (TLS) id 14.3.248.2; Wed, 7 Sep 2016 21:17:38 -0700 Received: from Pickup by RRSMSP801.amr.corp.intel.com with Microsoft SMTP Server id 14.3.301.0; Wed, 7 Sep 2016 20:54:07 +0000 From: Jason Wang Sender: dev To: Alejandro Lucero , "Michael S. Tsirkin" CC: Thomas Monjalon , dev , "Xie, Huawei" , References: <1472798220-7121-1-git-send-email-jasowang@redhat.com> <1472798220-7121-2-git-send-email-jasowang@redhat.com> <1631660.hGMgJuvotI@xps13> <20160902202613-mutt-send-email-mst@kernel.org> In-Reply-To: Date: Mon, 5 Sep 2016 00:31:52 -0600 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQKyy1v8v+X7HJqdklT5hP6lSkGSugKasjHaAlgEG7QDiBO7gwInRDEpAf7Y8E4= Subject: Re: [dpdk-dev] [PATCH 2/2] virtio: support IOMMU platform 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: Thu, 08 Sep 2016 04:17:41 -0000 Message-ID: <20160905063152.dsHogkyRtakWWKqgqORcCrkvWt44N0xRvgXTVO_y8Cc@z> On 2016=E5=B9=B409=E6=9C=8804=E6=97=A5 16:08, Alejandro Lucero wrote: > I know RedHat is working on a vIOMMU so I guess this work is related=20 > to that effort, but it is a surprise virtio using IOMMU. I thought=20 > IOMMU just made sense when using SRIOV. My second guess is using IOMMU=20 > with virtio is a matter of security, but by other hand, virtio + IOMMU=20 > could imply serious performance degradation when multiple VMs are in use. We will use qemu vIOMMU for virito, so there's no such issue. > I'm talking about IOMMU contention, exactly about IOTLB contention. I thought device IOTLB (ATS) was just designed to solve this contention. > This performance issue is complex to describe or even analyze as there=20 > are several factors having an impact on it. For example, 1GB hugepages=20 > can avoid most of it and the same if TX & RX rings are not bigger than=20 > 256. So, my question: is RedHat aware of this potential IOMMU=20 > contention which can limit scalability? For virtio, we use vIOMMU per VM and implement a device IOTLB in vhost=20 side. Technically, it does not have such issue I think. Thanks > > On Fri, Sep 2, 2016 at 6:26 PM, Michael S. Tsirkin > wrote: > > On Fri, Sep 02, 2016 at 03:04:56PM +0200, Thomas Monjalon wrote: > > 2016-09-02 14:37, Jason Wang: > > > Virtio pmd doesn't support VFIO in the past since devices > bypass IOMMU > > > completely. But recently, the work of making virtio device > work with > > > IOMMU is near to complete. > > > > Good news! > > What are the requirements for Qemu and Linux version numbers please= ? > > I expect QEMU 2.8 and Linux 4.8 to have the support. > > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id C7A289255 for ; Thu, 8 Sep 2016 06:18:35 +0200 (CEST) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP; 07 Sep 2016 21:18:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,298,1470726000"; d="scan'208";a="1026667793" Received: from orsmsx106.amr.corp.intel.com ([10.22.225.133]) by orsmga001.jf.intel.com with ESMTP; 07 Sep 2016 21:18:35 -0700 Received: from orsmsx155.amr.corp.intel.com (10.22.240.21) by ORSMSX106.amr.corp.intel.com (10.22.225.133) with Microsoft SMTP Server (TLS) id 14.3.248.2; Wed, 7 Sep 2016 21:18:33 -0700 Received: from rrsmsp801.amr.corp.intel.com (10.9.230.203) by ORSMSX155.amr.corp.intel.com (10.22.240.21) with Microsoft SMTP Server (TLS) id 14.3.248.2; Wed, 7 Sep 2016 21:18:33 -0700 Received: from Pickup by RRSMSP801.amr.corp.intel.com with Microsoft SMTP Server id 14.3.301.0; Wed, 7 Sep 2016 20:54:09 +0000 From: Jason Wang To: Alejandro Lucero , "Michael S. Tsirkin" CC: Thomas Monjalon , dev , "Xie, Huawei" , References: <1472798220-7121-1-git-send-email-jasowang@redhat.com> <1472798220-7121-2-git-send-email-jasowang@redhat.com> <1631660.hGMgJuvotI@xps13> <20160902202613-mutt-send-email-mst@kernel.org> In-Reply-To: Date: Mon, 5 Sep 2016 00:31:52 -0600 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQKyy1v8v+X7HJqdklT5hP6lSkGSugKasjHaAlgEG7QDiBO7gwInRDEpAf7Y8E4= Subject: Re: [dpdk-dev] [PATCH 2/2] virtio: support IOMMU platform 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: Thu, 08 Sep 2016 04:18:36 -0000 Message-ID: <20160905063152.G9CnCyxFBkgEuy4PhpgmlKNo3pC5VFv0rTcxldcP9hI@z> On 2016=E5=B9=B409=E6=9C=8804=E6=97=A5 16:08, Alejandro Lucero wrote: > I know RedHat is working on a vIOMMU so I guess this work is related=20 > to that effort, but it is a surprise virtio using IOMMU. I thought=20 > IOMMU just made sense when using SRIOV. My second guess is using IOMMU=20 > with virtio is a matter of security, but by other hand, virtio + IOMMU=20 > could imply serious performance degradation when multiple VMs are in use. We will use qemu vIOMMU for virito, so there's no such issue. > I'm talking about IOMMU contention, exactly about IOTLB contention. I thought device IOTLB (ATS) was just designed to solve this contention. > This performance issue is complex to describe or even analyze as there=20 > are several factors having an impact on it. For example, 1GB hugepages=20 > can avoid most of it and the same if TX & RX rings are not bigger than=20 > 256. So, my question: is RedHat aware of this potential IOMMU=20 > contention which can limit scalability? For virtio, we use vIOMMU per VM and implement a device IOTLB in vhost=20 side. Technically, it does not have such issue I think. Thanks > > On Fri, Sep 2, 2016 at 6:26 PM, Michael S. Tsirkin > wrote: > > On Fri, Sep 02, 2016 at 03:04:56PM +0200, Thomas Monjalon wrote: > > 2016-09-02 14:37, Jason Wang: > > > Virtio pmd doesn't support VFIO in the past since devices > bypass IOMMU > > > completely. But recently, the work of making virtio device > work with > > > IOMMU is near to complete. > > > > Good news! > > What are the requirements for Qemu and Linux version numbers please= ? > > I expect QEMU 2.8 and Linux 4.8 to have the support. > >