From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0745C433E0 for ; Tue, 9 Mar 2021 05:51:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BC6565248 for ; Tue, 9 Mar 2021 05:51:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229623AbhCIFvE (ORCPT ); Tue, 9 Mar 2021 00:51:04 -0500 Received: from mga03.intel.com ([134.134.136.65]:26342 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229481AbhCIFup (ORCPT ); Tue, 9 Mar 2021 00:50:45 -0500 IronPort-SDR: zTsIF8QdPj/DEcmjbc4Grobmt5IhBDiQ2eMDYURy43MZ48yW6Ha2K1qu4/bvozjGyUGa8c/oQz 8EJxKuRjQuQg== X-IronPort-AV: E=McAfee;i="6000,8403,9917"; a="188211755" X-IronPort-AV: E=Sophos;i="5.81,234,1610438400"; d="scan'208";a="188211755" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2021 21:50:44 -0800 IronPort-SDR: eBfZNne6GFYr0HVLC5ATPoAVGAgEzKJ8YYJ4noZ2rarbc2fN4gbwEvvNKaVjtkHN9azhPg4kKw 0rxeOXHMlf0A== X-IronPort-AV: E=Sophos;i="5.81,234,1610438400"; d="scan'208";a="447383043" Received: from lingshan-mobl5.ccr.corp.intel.com (HELO [10.255.31.165]) ([10.255.31.165]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2021 21:50:42 -0800 Subject: Re: [PATCH V2 2/4] vDPA/ifcvf: enable Intel C5000X-PL virtio-net for vDPA To: Jason Wang , mst@redhat.com, lulu@redhat.com Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210308083525.382514-1-lingshan.zhu@intel.com> <20210308083525.382514-3-lingshan.zhu@intel.com> <93aabf0c-3ea0-72d7-e7d7-1d503fe6cc75@intel.com> <91c08fdd-0a36-ddca-5b8c-ef2eef7cddc2@redhat.com> From: "Zhu, Lingshan" Message-ID: <0e72009d-60af-980d-a43e-495733f6f6f7@intel.com> Date: Tue, 9 Mar 2021 13:50:39 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <91c08fdd-0a36-ddca-5b8c-ef2eef7cddc2@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 3/9/2021 10:42 AM, Jason Wang wrote: > > On 2021/3/9 10:28 上午, Zhu, Lingshan wrote: >> >> >> On 3/9/2021 10:23 AM, Jason Wang wrote: >>> >>> On 2021/3/8 4:35 下午, Zhu Lingshan wrote: >>>> This commit enabled Intel FPGA SmartNIC C5000X-PL virtio-net >>>> for vDPA >>>> >>>> Signed-off-by: Zhu Lingshan >>>> --- >>>>   drivers/vdpa/ifcvf/ifcvf_base.h | 5 +++++ >>>>   drivers/vdpa/ifcvf/ifcvf_main.c | 5 +++++ >>>>   2 files changed, 10 insertions(+) >>>> >>>> diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h >>>> b/drivers/vdpa/ifcvf/ifcvf_base.h >>>> index 64696d63fe07..75d9a8052039 100644 >>>> --- a/drivers/vdpa/ifcvf/ifcvf_base.h >>>> +++ b/drivers/vdpa/ifcvf/ifcvf_base.h >>>> @@ -23,6 +23,11 @@ >>>>   #define IFCVF_SUBSYS_VENDOR_ID    0x8086 >>>>   #define IFCVF_SUBSYS_DEVICE_ID    0x001A >>>>   +#define C5000X_PL_VENDOR_ID        0x1AF4 >>>> +#define C5000X_PL_DEVICE_ID        0x1000 >>>> +#define C5000X_PL_SUBSYS_VENDOR_ID    0x8086 >>>> +#define C5000X_PL_SUBSYS_DEVICE_ID    0x0001 >>> >>> >>> I just notice that the device is a transtitional one. Any reason for >>> doing this? >>> >>> Note that IFCVF is a moden device anyhow (0x1041). Supporting legacy >>> drive may bring many issues (e.g the definition is non-nomartive). >>> One example is the support of VIRTIO_F_IOMMU_PLATFORM, legacy driver >>> may assume the device can bypass IOMMU. >>> >>> Thanks >> Hi Jason, >> >> This device will support virtio1.0 by default, so has >> VIRTIO_F_IOMMU_PLATFORM by default. > > > If you device want to force VIRTIO_F_IOMMU_PLATFORM you probably need > to do what has been done by mlx5 (verify_min_features). > > According to the spec, if VIRTIO_F_IOMMU_PLATFORM is not mandatory, > when it's not negotiated, device needs to disable or bypass IOMMU: > > > " > > If this feature bit is set to 0, then the device has same access to > memory addresses supplied to it as the driver has. In particular, the > device will always use physical addresses matching addresses used by > the driver (typically meaning physical addresses used by the CPU) and > not translated further, and can access any address supplied to it by > the driver. > > " sure, I can implement code to check the feature bits. > > >> Transitional device gives the software a chance to fall back to >> virtio 0.95. > > > This only applies if you want to passthrough the card to guest > directly without the help of vDPA. > > If we go with vDPA, it doesn't hlep. For virtio-vdpa, we know it will > negotiated IOMMU_PLATFORM. For vhost-vdpa, Qemu can provide a legacy > or transitional device on top of a modern vDPA device. > > Thanks For some cases, users may run quite out of date OS does not have vDPA nor virtio 1.0 support, transitional characters give them a chance to use the devices. Thanks Zhu Lingshan > > >> ifcvf drives this device in virtio 1.0 mode, set features >> VIRTIO_F_IOMMU_PLATFORM successfully. >> >> Thanks, >> Zhu Lingshan >>> >>> >>>> + >>>>   #define IFCVF_SUPPORTED_FEATURES \ >>>>           ((1ULL << VIRTIO_NET_F_MAC)            | \ >>>>            (1ULL << VIRTIO_F_ANY_LAYOUT) | \ >>>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c >>>> b/drivers/vdpa/ifcvf/ifcvf_main.c >>>> index e501ee07de17..26a2dab7ca66 100644 >>>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c >>>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c >>>> @@ -484,6 +484,11 @@ static struct pci_device_id ifcvf_pci_ids[] = { >>>>           IFCVF_DEVICE_ID, >>>>           IFCVF_SUBSYS_VENDOR_ID, >>>>           IFCVF_SUBSYS_DEVICE_ID) }, >>>> +    { PCI_DEVICE_SUB(C5000X_PL_VENDOR_ID, >>>> +             C5000X_PL_DEVICE_ID, >>>> +             C5000X_PL_SUBSYS_VENDOR_ID, >>>> +             C5000X_PL_SUBSYS_DEVICE_ID) }, >>>> + >>>>       { 0 }, >>>>   }; >>>>   MODULE_DEVICE_TABLE(pci, ifcvf_pci_ids); >>> >> >