> -----Original Message----- > From: Morten Brørup <m...@smartsharesystems.com> > Sent: Thursday, April 13, 2023 3:41 AM > To: Maxime Coquelin <maxime.coque...@redhat.com>; Ferruh Yigit > <ferruh.yi...@amd.com>; dev@dpdk.org; david.march...@redhat.com; Xia, > Chenbo <chenbo....@intel.com>; m...@redhat.com; f...@redhat.com; > jasow...@redhat.com; Liang, Cunming <cunming.li...@intel.com>; Xie, Yongji > <xieyon...@bytedance.com>; echau...@redhat.com; epere...@redhat.com; > amore...@redhat.com > Subject: RE: [RFC 00/27] Add VDUSE support to Vhost library > > > From: Maxime Coquelin [mailto:maxime.coque...@redhat.com] > > Sent: Wednesday, 12 April 2023 17.28 > > > > Hi Ferruh, > > > > On 4/12/23 13:33, Ferruh Yigit wrote: > > > On 3/31/2023 4:42 PM, Maxime Coquelin wrote: > > >> This series introduces a new type of backend, VDUSE, > > >> to the Vhost library. > > >> > > >> VDUSE stands for vDPA device in Userspace, it enables > > >> implementing a Virtio device in userspace and have it > > >> attached to the Kernel vDPA bus. > > >> > > >> Once attached to the vDPA bus, it can be used either by > > >> Kernel Virtio drivers, like virtio-net in our case, via > > >> the virtio-vdpa driver. Doing that, the device is visible > > >> to the Kernel networking stack and is exposed to userspace > > >> as a regular netdev. > > >> > > >> It can also be exposed to userspace thanks to the > > >> vhost-vdpa driver, via a vhost-vdpa chardev that can be > > >> passed to QEMU or Virtio-user PMD. > > >> > > >> While VDUSE support is already available in upstream > > >> Kernel, a couple of patches are required to support > > >> network device type: > > >> > > >> https://gitlab.com/mcoquelin/linux/-/tree/vduse_networking_poc > > >> > > >> In order to attach the created VDUSE device to the vDPA > > >> bus, a recent iproute2 version containing the vdpa tool is > > >> required. > > > > > > Hi Maxime, > > > > > > Is this a replacement to the existing DPDK vDPA framework? What is the > > > plan for long term? > > > > > > > No, this is not a replacement for DPDK vDPA framework. > > > > We (Red Hat) don't have plans to support DPDK vDPA framework in our > > products, but there are still contribution to DPDK vDPA by several vDPA > > hardware vendors (Intel, Nvidia, Xilinx), so I don't think it is going > > to be deprecated soon. > > Ferruh's question made me curious... > > I don't know anything about VDUSE or vDPA, and don't use any of it, so > consider me ignorant in this area. > > Is VDUSE an alternative to the existing DPDK vDPA framework? What are the > differences, e.g. in which cases would an application developer (or user) > choose one or the other?
Maxime should give better explanation.. but let me just explain a bit. Vendors have vDPA HW that support vDPA framework (most likely in their DPU/IPU products). This work is introducing a way to emulate a SW vDPA device in userspace (DPDK), and this SW vDPA device also supports vDPA framework. So it's not an alternative to existing DPDK vDPA framework :) Thanks, Chenbo > > And if it is a better alternative, perhaps the documentation should > mention that it is recommended over DPDK vDPA. Just like we started > recommending alternatives to the KNI driver, so we could phase it out and > eventually get rid of it. > > > > > Regards, > > Maxime
