Re: [PATCH 0/5] vDPA support

From: Jason Wang <jasowang@redhat.com>
To: "Tian, Kevin" <kevin.tian@intel.com>,
	"mst@redhat.com" <mst@redhat.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"virtualization@lists.linux-foundation.org" 
	<virtualization@lists.linux-foundation.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Cc: "Bie, Tiwei" <tiwei.bie@intel.com>,
	"jgg@mellanox.com" <jgg@mellanox.com>,
	"maxime.coquelin@redhat.com" <maxime.coquelin@redhat.com>,
	"Liang, Cunming" <cunming.liang@intel.com>,
	"Wang, Zhihong" <zhihong.wang@intel.com>,
	"rob.miller@broadcom.com" <rob.miller@broadcom.com>,
	"Wang, Xiao W" <xiao.w.wang@intel.com>,
	"haotian.wang@sifive.com" <haotian.wang@sifive.com>,
	"Zhu, Lingshan" <lingshan.zhu@intel.com>,
	"eperezma@redhat.com" <eperezma@redhat.com>,
	"lulu@redhat.com" <lulu@redhat.com>,
	"parav@mellanox.com" <parav@mellanox.com>,
	"stefanha@redhat.com" <stefanha@redhat.com>,
	"rdunlap@infradead.org" <rdunlap@infradead.org>,
	"hch@infradead.org" <hch@infradead.org>,
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	"jakub.kicinski@netronome.com" <jakub.kicinski@netronome.com>,
	"jiri@mellanox.com" <jiri@mellanox.com>,
	"shahafs@mellanox.com" <shahafs@mellanox.com>,
	"hanand@xilinx.com" <hanand@xilinx.com>,
	"mhabets@solarflare.com" <mhabets@solarflare.com>
Subject: Re: [PATCH 0/5] vDPA support
Date: Tue, 21 Jan 2020 17:39:15 +0800	[thread overview]
Message-ID: <0185b91a-f984-681e-b7c0-af8eca81d053@redhat.com> (raw)
In-Reply-To: <AADFC41AFE54684AB9EE6CBC0274A5D19D73EC6B@SHSMSX104.ccr.corp.intel.com>

On 2020/1/21 下午4:44, Tian, Kevin wrote:
>> From: Jason Wang
>> Sent: Thursday, January 16, 2020 8:42 PM
>>
>> Hi all:
>>
>> Based on the comments and discussion for mdev based hardware virtio
>> offloading support[1]. A different approach to support vDPA device is
>> proposed in this series.
> Can you point to the actual link which triggered the direction change?
> A quick glimpse in that thread doesn't reveal such information...

Right, please see this link, the actual discussion happens on the thread 
of virtual-bus for some reasons...

https://patchwork.ozlabs.org/patch/1195895/

Thanks

>
>> Instead of leveraging VFIO/mdev which may not work for some
>> vendors. This series tries to introduce a dedicated vDPA bus and
>> leverage vhost for userspace drivers. This help for the devices that
>> are not fit for VFIO and may reduce the conflict when try to propose a
>> bus template for virtual devices in [1].
>>
>> The vDPA support is split into following parts:
>>
>> 1) vDPA core (bus, device and driver abstraction)
>> 2) virtio vDPA transport for kernel virtio driver to control vDPA
>>     device
>> 3) vhost vDPA bus driver for userspace vhost driver to control vDPA
>>     device
>> 4) vendor vDPA drivers
>> 5) management API
>>
>> Both 1) and 2) are included in this series. Tiwei will work on part
>> 3). For 4), Ling Shan will work and post IFCVF driver. For 5) we leave
>> it to vendor to implement, but it's better to come into an agreement
>> for management to create/configure/destroy vDPA device.
>>
>> The sample driver is kept but renamed to vdap_sim. An on-chip IOMMU
>> implementation is added to sample device to make it work for both
>> kernel virtio driver and userspace vhost driver. It implements a sysfs
>> based management API, but it can switch to any other (e.g devlink) if
>> necessary.
>>
>> Please refer each patch for more information.
>>
>> Comments are welcomed.
>>
>> [1] https://lkml.org/lkml/2019/11/18/261
>>
>> Jason Wang (5):
>>    vhost: factor out IOTLB
>>    vringh: IOTLB support
>>    vDPA: introduce vDPA bus
>>    virtio: introduce a vDPA based transport
>>    vdpasim: vDPA device simulator
>>
>>   MAINTAINERS                    |   2 +
>>   drivers/vhost/Kconfig          |   7 +
>>   drivers/vhost/Kconfig.vringh   |   1 +
>>   drivers/vhost/Makefile         |   2 +
>>   drivers/vhost/net.c            |   2 +-
>>   drivers/vhost/vhost.c          | 221 +++------
>>   drivers/vhost/vhost.h          |  36 +-
>>   drivers/vhost/vhost_iotlb.c    | 171 +++++++
>>   drivers/vhost/vringh.c         | 434 +++++++++++++++++-
>>   drivers/virtio/Kconfig         |  15 +
>>   drivers/virtio/Makefile        |   2 +
>>   drivers/virtio/vdpa/Kconfig    |  26 ++
>>   drivers/virtio/vdpa/Makefile   |   3 +
>>   drivers/virtio/vdpa/vdpa.c     | 141 ++++++
>>   drivers/virtio/vdpa/vdpa_sim.c | 796
>> +++++++++++++++++++++++++++++++++
>>   drivers/virtio/virtio_vdpa.c   | 400 +++++++++++++++++
>>   include/linux/vdpa.h           | 191 ++++++++
>>   include/linux/vhost_iotlb.h    |  45 ++
>>   include/linux/vringh.h         |  36 ++
>>   19 files changed, 2327 insertions(+), 204 deletions(-)
>>   create mode 100644 drivers/vhost/vhost_iotlb.c
>>   create mode 100644 drivers/virtio/vdpa/Kconfig
>>   create mode 100644 drivers/virtio/vdpa/Makefile
>>   create mode 100644 drivers/virtio/vdpa/vdpa.c
>>   create mode 100644 drivers/virtio/vdpa/vdpa_sim.c
>>   create mode 100644 drivers/virtio/virtio_vdpa.c
>>   create mode 100644 include/linux/vdpa.h
>>   create mode 100644 include/linux/vhost_iotlb.h
>>
>> --
>> 2.19.1