From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id AAD7DA04B3; Mon, 16 Dec 2019 09:47:32 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 79FEE1C1A8; Mon, 16 Dec 2019 09:47:32 +0100 (CET) Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) by dpdk.org (Postfix) with ESMTP id EAF141C191 for ; Mon, 16 Dec 2019 09:47:30 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576486050; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=QyGREIKsOF7/I8pVK5sFz6/LOVjsO5wfhwhArg15Jl4=; b=KHEIafWCpFEwQvO/hpzQhuuvNuS/HFPexBdGc9out043KMAOIUIYARG8nh4jmMwKDWY+fM 74SbTiNLW5DzV0QonAAqp4T90XFxHizaqwPrLnDQhUZa1/Flk/dDgxGBS8n7AON6M/NeNL 5imOwBHPrB6Fb4xdE6uiMXRQ9WM1YVo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-60-0YQmPbZ4MCiuY9NJsohMfA-1; Mon, 16 Dec 2019 03:47:22 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 07ECA800D41; Mon, 16 Dec 2019 08:47:20 +0000 (UTC) Received: from [10.36.112.19] (ovpn-112-19.ams2.redhat.com [10.36.112.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7210A60BF7; Mon, 16 Dec 2019 08:47:15 +0000 (UTC) To: Matan Azrad , Tiwei Bie , Thomas Monjalon Cc: Andrew Rybchenko , Ori Kam , "Liang, Cunming" , "Wang, Xiao W" , "Wang, Zhihong" , "Yigit, Ferruh" , Shahaf Shuler , "dev@dpdk.org" , Slava Ovsiienko , Asaf Penso , Olga Shern References: From: Maxime Coquelin Autocrypt: addr=maxime.coquelin@redhat.com; keydata= mQINBFOEQQIBEADjNLYZZqghYuWv1nlLisptPJp+TSxE/KuP7x47e1Gr5/oMDJ1OKNG8rlNg kLgBQUki3voWhUbMb69ybqdMUHOl21DGCj0BTU3lXwapYXOAnsh8q6RRM+deUpasyT+Jvf3a gU35dgZcomRh5HPmKMU4KfeA38cVUebsFec1HuJAWzOb/UdtQkYyZR4rbzw8SbsOemtMtwOx YdXodneQD7KuRU9IhJKiEfipwqk2pufm2VSGl570l5ANyWMA/XADNhcEXhpkZ1Iwj3TWO7XR uH4xfvPl8nBsLo/EbEI7fbuUULcAnHfowQslPUm6/yaGv6cT5160SPXT1t8U9QDO6aTSo59N jH519JS8oeKZB1n1eLDslCfBpIpWkW8ZElGkOGWAN0vmpLfdyiqBNNyS3eGAfMkJ6b1A24un /TKc6j2QxM0QK4yZGfAxDxtvDv9LFXec8ENJYsbiR6WHRHq7wXl/n8guyh5AuBNQ3LIK44x0 KjGXP1FJkUhUuruGyZsMrDLBRHYi+hhDAgRjqHgoXi5XGETA1PAiNBNnQwMf5aubt+mE2Q5r qLNTgwSo2dpTU3+mJ3y3KlsIfoaxYI7XNsPRXGnZi4hbxmeb2NSXgdCXhX3nELUNYm4ArKBP LugOIT/zRwk0H0+RVwL2zHdMO1Tht1UOFGfOZpvuBF60jhMzbQARAQABtCxNYXhpbWUgQ29x dWVsaW4gPG1heGltZS5jb3F1ZWxpbkByZWRoYXQuY29tPokCOAQTAQIAIgUCV3u/5QIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQyjiNKEaHD4ma2g/+P+Hg9WkONPaY1J4AR7Uf kBneosS4NO3CRy0x4WYmUSLYMLx1I3VH6SVjqZ6uBoYy6Fs6TbF6SHNc7QbB6Qjo3neqnQR1 71Ua1MFvIob8vUEl3jAR/+oaE1UJKrxjWztpppQTukIk4oJOmXbL0nj3d8dA2QgHdTyttZ1H xzZJWWz6vqxCrUqHU7RSH9iWg9R2iuTzii4/vk1oi4Qz7y/q8ONOq6ffOy/t5xSZOMtZCspu Mll2Szzpc/trFO0pLH4LZZfz/nXh2uuUbk8qRIJBIjZH3ZQfACffgfNefLe2PxMqJZ8mFJXc RQO0ONZvwoOoHL6CcnFZp2i0P5ddduzwPdGsPq1bnIXnZqJSl3dUfh3xG5ArkliZ/++zGF1O wvpGvpIuOgLqjyCNNRoR7cP7y8F24gWE/HqJBXs1qzdj/5Hr68NVPV1Tu/l2D1KMOcL5sOrz 2jLXauqDWn1Okk9hkXAP7+0Cmi6QwAPuBT3i6t2e8UdtMtCE4sLesWS/XohnSFFscZR6Vaf3 gKdWiJ/fW64L6b9gjkWtHd4jAJBAIAx1JM6xcA1xMbAFsD8gA2oDBWogHGYcScY/4riDNKXi lw92d6IEHnSf6y7KJCKq8F+Jrj2BwRJiFKTJ6ChbOpyyR6nGTckzsLgday2KxBIyuh4w+hMq TGDSp2rmWGJjASq5Ag0EVPSbkwEQAMkaNc084Qvql+XW+wcUIY+Dn9A2D1gMr2BVwdSfVDN7 0ZYxo9PvSkzh6eQmnZNQtl8WSHl3VG3IEDQzsMQ2ftZn2sxjcCadexrQQv3Lu60Tgj7YVYRM H+fLYt9W5YuWduJ+FPLbjIKynBf6JCRMWr75QAOhhhaI0tsie3eDsKQBA0w7WCuPiZiheJaL 4MDe9hcH4rM3ybnRW7K2dLszWNhHVoYSFlZGYh+MGpuODeQKDS035+4H2rEWgg+iaOwqD7bg CQXwTZ1kSrm8NxIRVD3MBtzp9SZdUHLfmBl/tLVwDSZvHZhhvJHC6Lj6VL4jPXF5K2+Nn/Su CQmEBisOmwnXZhhu8ulAZ7S2tcl94DCo60ReheDoPBU8PR2TLg8rS5f9w6mLYarvQWL7cDtT d2eX3Z6TggfNINr/RTFrrAd7NHl5h3OnlXj7PQ1f0kfufduOeCQddJN4gsQfxo/qvWVB7PaE 1WTIggPmWS+Xxijk7xG6x9McTdmGhYaPZBpAxewK8ypl5+yubVsE9yOOhKMVo9DoVCjh5To5 aph7CQWfQsV7cd9PfSJjI2lXI0dhEXhQ7lRCFpf3V3mD6CyrhpcJpV6XVGjxJvGUale7+IOp sQIbPKUHpB2F+ZUPWds9yyVxGwDxD8WLqKKy0WLIjkkSsOb9UBNzgRyzrEC9lgQ/ABEBAAGJ Ah8EGAECAAkFAlT0m5MCGwwACgkQyjiNKEaHD4nU8hAAtt0xFJAy0sOWqSmyxTc7FUcX+pbD KVyPlpl6urKKMk1XtVMUPuae/+UwvIt0urk1mXi6DnrAN50TmQqvdjcPTQ6uoZ8zjgGeASZg jj0/bJGhgUr9U7oG7Hh2F8vzpOqZrdd65MRkxmc7bWj1k81tOU2woR/Gy8xLzi0k0KUa8ueB iYOcZcIGTcs9CssVwQjYaXRoeT65LJnTxYZif2pfNxfINFzCGw42s3EtZFteczClKcVSJ1+L +QUY/J24x0/ocQX/M1PwtZbB4c/2Pg/t5FS+s6UB1Ce08xsJDcwyOPIH6O3tccZuriHgvqKP yKz/Ble76+NFlTK1mpUlfM7PVhD5XzrDUEHWRTeTJSvJ8TIPL4uyfzhjHhlkCU0mw7Pscyxn DE8G0UYMEaNgaZap8dcGMYH/96EfE5s/nTX0M6MXV0yots7U2BDb4soLCxLOJz4tAFDtNFtA wLBhXRSvWhdBJZiig/9CG3dXmKfi2H+wdUCSvEFHRpgo7GK8/Kh3vGhgKmnnxhl8ACBaGy9n fxjSxjSO6rj4/MeenmlJw1yebzkX8ZmaSi8BHe+n6jTGEFNrbiOdWpJgc5yHIZZnwXaW54QT UhhSjDL1rV2B4F28w30jYmlRmm2RdN7iCZfbyP3dvFQTzQ4ySquuPkIGcOOHrvZzxbRjzMx1 Mwqu3GQ= Message-ID: <13720362-c1cc-3e74-39d9-3eeb00317727@redhat.com> Date: Mon, 16 Dec 2019 09:47:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: 0YQmPbZ4MCiuY9NJsohMfA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] discussion: creating a new class for vdpa drivers 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi, On 12/16/19 9:29 AM, Matan Azrad wrote: >=20 > Hi all >=20 > I understand all of you agree \ not object with the new class for vdpa dr= ivers. >=20 > Based on that, I'm going to start it. Please go ahead, I'll rebase my virtio vDPA series on top of it. Thanks, Maxime > From: Tiwei Bie >> On Tue, Dec 10, 2019 at 09:00:33AM +0100, Thomas Monjalon wrote: >>> 10/12/2019 03:41, Tiwei Bie: >>>> On Mon, Dec 09, 2019 at 02:22:27PM +0300, Andrew Rybchenko wrote: >>>>> On 12/9/19 1:41 PM, Ori Kam wrote: >>>>>> From: Andrew Rybchenko >>>>>>> On 12/8/19 10:06 AM, Matan Azrad wrote: >>>>>>>> From: Andrew Rybchenko >>>>>>>>> On 12/6/19 8:32 AM, Liang, Cunming wrote: >>>>>>>>>> From: Bie, Tiwei >>>>>>>>>>> On Thu, Dec 05, 2019 at 01:26:36PM +0000, Matan Azrad wrote: >>>>>>>>>>>> Hi all >>>>>>>>>>>> >>>>>>>>>>>> As described in RFC =E2=80=9C[RFC] net: new vdpa PMD for Mella= nox >>>>>>>>>>>> devices=E2=80=9D, a new vdpa drivers is going to be added for >>>>>>>>>>>> Mellanox devices =E2=80=93 mlx5_vdpa >>>>>>>>>>>> >>>>>>>>>>>> The only vdpa driver now is the IFC driver that is located >>>>>>>>>>>> in net >>>>>>> directory. >>>>>>>>>>>> >>>>>>>>>>>> The IFC driver and the new mlx5_vdpa driver provide the >>>>>>>>>>>> vdpa ops >>>>>>> and >>>>>>>>>>>> not the eth_dev ops. >>>>>>>>>>>> >>>>>>>>>>>> All the others drivers in net provide the eth-dev ops. >>>>>>>>>>>> >>>>>>>>>>>> I suggest to create a new class for vdpa drivers, to move >>>>>>>>>>>> IFC to this class and to add the mlx5_vdpa to this class too. >>>>>>>>>>>> >>>>>>>>>>>> Later, all the new drivers that implements the vdpa ops >>>>>>>>>>>> will be added to the vdpa class. >>>>>>>>>>> >>>>>>>>>>> +1. Sounds like a good idea to me. >>>>>>>>>> +1 >>>>>>>>> >>>>>>>>> vDPA drivers are vendor-specific and expected to talk to vendor >> NIC. I.e. >>>>>>>>> there are significant chances to share code with network drivers >> (e.g. >>>>>>> base >>>>>>>>> driver). Should base driver be moved to drivers/common in >>>>>>>>> this case or is >>>>>>> it >>>>>>>>> still allows to have vdpa driver in drivers/net together with eth= dev >> driver? >>>>>>>> >>>>>>>> Yes, I think this should be the method, shared code should be >>>>>>>> moved to >>>>>>> the drivers/common directory. >>>>>>>> I think there is a precedence with shared code in common which >>>>>>>> shares a >>>>>>> vendor specific code between crypto and net. >>>>>>> >>>>>>> I see motivation behind driver/vdpa. However, vdpa and net >>>>>>> drivers tightly related and I would prefer to avoid extra >>>>>>> complexity here. Right now simplicity over-weights for me. >>>>>>> No strong opinion on the topic, but it definitely requires >>>>>>> better and more clear motivation why a new class should be >>>>>>> introduced and existing drivers restructured. >>>>>>> >>>>>> >>>>>> Why do you think there is extra complexity? >>>>> >>>>> Even grep becomes a bit more complicated J >>>>> >>>>>> I think from design correctness it is more correct to create a dedic= ated >> class for the following reasons: >>>>>> 1. All of the classes implements a different set of ops. For >>>>>> example the cryptodev has a defined set of ops, same goes for the >> compress driver and the ethdev driver. Each ones of them has different o= ps. >> Going by this definition since VDPA has a different set of ops, it makes= sense >> that it will be in a different class. >>>>>> >>>>>> 2. even that both drivers (eth/vdpa) handle traffic from the nic >>>>>> most of the code is different (the difference is also dependent on t= he >> manufacture) So even the shared code base is not large and can be shared >> using the common directory. For example ifc doesn't have any shared code= . >>>>>> >>>>>> What do you think? >>>>> >>>>> The true reason is: if the difference in ops implemented is a key >>>>> difference which should enforce location in different directories. >>>>> Or underlying device class is a key. >>>>> Roughly: >>>>> - net driver is a control+data path >>>>> - vdpa driver is a control path only My fear is that control path >>>>> will grow more and more (Rx mode, RSS, filters and so on) >>>> >>>> I think this is a reasonable concern. >>>> >>>> One thing needs to be clarified is that, the control path (ops) in >>>> vdpa driver is something very different with the control path in net >>>> driver. vdpa is very generic (or more precisely vhost-related), >>>> instead of network related: >>>> >>>> https://eur03.safelinks.protection.outlook.com/?url=3Dhttps%3A%2F%2Fgi >>>> >> thub.com%2FDPDK%2Fdpdk%2Fblob%2Faef1d0733179%2Flib%2Flibrte_vhos >> t%2F >>>> rte_vdpa.h%23L40- >> L78&data=3D02%7C01%7Cmatan%40mellanox.com%7Cfac15 >>>> >> 729a67c4c81ee7608d77d7434a2%7Ca652971c7d2e4d9ba6a4d149256f461b%7C >> 0%7 >>>> >> C0%7C637115810358231304&sdata=3D%2BZa39vxadtKx5Ov7vmqcU3RuZhz >> kOP9o >>>> 8roEB0d5j6M%3D&reserved=3D0 >>>> >>>> It's built on top of vhost-user protocol, manipulates virtqueues, >>>> virtio/vhost features, memory table, ... >>>> >>>> Technically, it's possible to have blk, crypto, ... >>>> vdpa devices as well (we already have vhost-user-blk, >>>> vhost-user-crypto, ...). >>>> >>>> But network specific features will come eventually, e.g. RSS. One >>>> possible way to solve it is to define a generic event callback in >>>> vdpa ops, and vdpa driver can request the corresponding info from >>>> vhost based on the event received. >>>> >>>> Another thing needs to be clarified is that, the control path >>>> supposed to be used by DPDK apps directly in vdpa should always be >>>> generic, it should just be something like: >>>> >>>> int rte_vdpa_find_device_id(struct rte_vdpa_dev_addr *addr); int >>>> rte_vhost_driver_attach_vdpa_device(const char *path, int did); int >>>> rte_vhost_driver_detach_vdpa_device(const char *path); ... >>>> >>>> That is to say, users just need to bind the vdpa device to the vhost >>>> connection. The control path ops in vdpa is supposed to be called by >>>> vhost-library transparently based on the events on the vhost-user >>>> connection, i.e. >>>> the vdpa device will be configured (including RSS) by the guest >>>> driver in QEMU "directly" via the vhost-user protocol instead of the >>>> DPDK app in the host. >>> >>> Tiwei, in order to be clear, >>> You think vDPA drivers should be in drivers/vdpa directory? >> >> I was just trying to clarify two facts in vDPA to address Andrew's conce= rn. >> And back to the question, to make sure that we don't miss anything >> important, (although maybe not very related) it might be helpful to also >> clarify how to support vDPA in OvS at the same time which isn't quite cl= ear to >> me yet.. >> >> Regards, >> Tiwei >> >>> >>>