From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: [PATCH V3 0/7] mdev based hardware virtio offloading support Date: Tue, 15 Oct 2019 11:37:17 +0800 Message-ID: <6d12ad8f-8137-e07d-d735-da59a326e8ed@redhat.com> References: <20191011081557.28302-1-jasowang@redhat.com> <20191014174946.GC5359@stefanha-x1.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20191014174946.GC5359@stefanha-x1.localdomain> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Stefan Hajnoczi Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, kwankhede@nvidia.com, alex.williamson@redhat.com, mst@redhat.com, tiwei.bie@intel.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, cohuck@redhat.com, maxime.coquelin@redhat.com, cunming.liang@intel.com, zhihong.wang@intel.com, rob.miller@broadcom.com, xiao.w.wang@intel.com, haotian.wang@sifive.com, zhenyuw@linux.intel.com, zhi.a.wang@intel.com, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, airlied@linux.ie, daniel@ffwll.ch, farman@linux.ibm.com, pasic@linux.ibm.com, sebott@linux.ibm.com, oberpar@linux.ibm.com, heiko.carstens@de.ibm.c List-Id: intel-gfx@lists.freedesktop.org On 2019/10/15 上午1:49, Stefan Hajnoczi wrote: > On Fri, Oct 11, 2019 at 04:15:50PM +0800, Jason Wang wrote: >> There are hardware that can do virtio datapath offloading while having >> its own control path. This path tries to implement a mdev based >> unified API to support using kernel virtio driver to drive those >> devices. This is done by introducing a new mdev transport for virtio >> (virtio_mdev) and register itself as a new kind of mdev driver. Then >> it provides a unified way for kernel virtio driver to talk with mdev >> device implementation. >> >> Though the series only contains kernel driver support, the goal is to >> make the transport generic enough to support userspace drivers. This >> means vhost-mdev[1] could be built on top as well by resuing the >> transport. >> >> A sample driver is also implemented which simulate a virito-net >> loopback ethernet device on top of vringh + workqueue. This could be >> used as a reference implementation for real hardware driver. >> >> Consider mdev framework only support VFIO device and driver right now, >> this series also extend it to support other types. This is done >> through introducing class id to the device and pairing it with >> id_talbe claimed by the driver. On top, this seris also decouple >> device specific parents ops out of the common ones. > I was curious so I took a quick look and posted comments. > > I guess this driver runs inside the guest since it registers virtio > devices? It could run in either guest or host. But the main focus is to run in the host then we can use virtio drivers in containers. > > If this is used with physical PCI devices that support datapath > offloading then how are physical devices presented to the guest without > SR-IOV? We will do control path meditation through vhost-mdev[1] and vhost-vfio[2]. Then we will present a full virtio compatible ethernet device for guest. SR-IOV is not a must, any mdev device that implements the API defined in patch 5 can be used by this framework. Thanks [1] https://lkml.org/lkml/2019/9/26/15 [2] https://patchwork.ozlabs.org/cover/984763/ > > Stefan