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Tue, 17 Dec 2019 05:20:26 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0A17D801E53; Tue, 17 Dec 2019 10:20:25 +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 514FA605C9; Tue, 17 Dec 2019 10:20:20 +0000 (UTC) From: Maxime Coquelin To: Jiayu Hu , dev@dpdk.org Cc: tiwei.bie@intel.com, zhihong.wang@intel.com, bruce.richardson@intel.com, Honnappa Nagarahalli , Hemant Agrawal , "jerinj@marvell.com" References: <1569507973-247570-1-git-send-email-jiayu.hu@intel.com> <1572598450-245091-1-git-send-email-jiayu.hu@intel.com> <1572598450-245091-3-git-send-email-jiayu.hu@intel.com> 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: Date: Tue, 17 Dec 2019 11:20:18 +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 10.5.11.11 X-MC-Unique: L7J1oGClOp2gwu3JGiJ3Ew-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] [RFC v2 2/2] net/vhost_dma: add vHost DMA driver 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" On 12/17/19 9:27 AM, Maxime Coquelin wrote: > Hi Jiayu, >=20 > On 11/1/19 9:54 AM, Jiayu Hu wrote: >> This patch introduces a new PMD for DMA accelerated vhost-user, which >> provides basic functionality of packet reception and transmission. This >> PMD leverages librte_vhost to handle vhost messages, but it implements >> own vring's enqueue and dequeue operations. >> >> The PMD leverages DMA engines (e.g., I/OAT, a DMA engine in Intel's >> processor), to accelerate large data movements in enqueue and dequeue >> operations. Large copies are offloaded to the DMA in an asynchronous mod= e. >> That is, the CPU just submits copy jobs to the DMA but without waiting >> for its completion; there is no CPU intervention during data transfer. >> Thus, we can save precious CPU cycles and improve the overall performanc= e >> for vhost-user based applications, like OVS. The PMD still uses the CPU = to >> performs small copies, due to startup overheads associated with the DMA. >> >> Note that the PMD is able to support various DMA engines to accelerate >> data movements in enqueue and dequeue operations; currently the supporte= d >> DMA engine is I/OAT. The PMD just supports I/OAT acceleration in the >> enqueue operation, and it still uses the CPU to perform all copies in >> the dequeue operation. In addition, the PMD only supports the split ring= . >> >> The DMA device used by a queue is assigned by users; for the queue >> without assigning a DMA device, the PMD will use the CPU to perform >> all copies for both enqueue and dequeue operations. Currently, the PMD >> just supports I/OAT, and a queue can only use one I/OAT device, and an >> I/OAT device can only be used by one queue at a time. >> >> The PMD has 4 parameters. >> - iface: The parameter is used to specify a path to connect to a >> =09front end device. >> - queues: The parameter is used to specify the number of the queues >> =09front end device has (Default is 1). >> - client: The parameter is used to specify the vhost port working as >> =09client mode or server mode (Default is server mode). >> - dmas: This parameter is used to specify the assigned DMA device >> =09of a queue. >> >> Here is an example. >> $ ./testpmd -c f -n 4 \ >> --vdev 'dma_vhost0,iface=3D/tmp/sock0,queues=3D1,dmas=3Dtxq0@00:04.0,cli= ent=3D0' >=20 > dma_vhost0 is not a good name, you have to mention it is net specific. >=20 > Is there a tool to list available DMA engines? Thinking at it again, wouldn't it be possible that the user doesn't specify a specific DMA device ID, but instead allocate one device at init time by specifying all the capabilities the DMA device need to match? If no DMA device available with matching capabilities, then fallback to SW mode. Also, I think we don't want to call directly IOAT API directly here, but instead introduce a DMA library so that the Vhost DMA stuff isn't vendor specific. Adding a few ARM people in cc, to know whether they have plan/interrest in supporting DMA acceleration for Vhost. Regards, Maxime >> >> Signed-off-by: Jiayu Hu >> --- >> config/common_base | 2 + >> config/common_linux | 1 + >> drivers/Makefile | 2 +- >> drivers/net/Makefile | 1 + >> drivers/net/vhost_dma/Makefile | 31 + >> drivers/net/vhost_dma/eth_vhost.c | 1495 +++++++++++++= +++++++ >> drivers/net/vhost_dma/eth_vhost.h | 264 ++++ >> drivers/net/vhost_dma/internal.h | 225 +++ >> .../net/vhost_dma/rte_pmd_vhost_dma_version.map | 4 + >> drivers/net/vhost_dma/virtio_net.c | 1234 +++++++++++++= +++ >> mk/rte.app.mk | 1 + >> 11 files changed, 3259 insertions(+), 1 deletion(-) >> create mode 100644 drivers/net/vhost_dma/Makefile >> create mode 100644 drivers/net/vhost_dma/eth_vhost.c >> create mode 100644 drivers/net/vhost_dma/eth_vhost.h >> create mode 100644 drivers/net/vhost_dma/internal.h >> create mode 100644 drivers/net/vhost_dma/rte_pmd_vhost_dma_version.map >> create mode 100644 drivers/net/vhost_dma/virtio_net.c >=20 > You need to add Meson support. >=20 >=20 > More generally, I have been through the series and I'm not sure having a > dedicated PMD driver for this is a good idea due to all the code > duplication it implies. >=20 > I understand it has been done this way to avoid impacting the pure SW > datapath implementation. But I'm sure the series could be reduced to a > few hundred of lines if it was integrated in vhost-user library. > Moreover, your series does not support packed ring, so it means even > more code would need to be duplicated in the end. >=20 > What do you think? >=20 > Thanks, > Maxime >=20