On Wed, Feb 16, 2022 at 2:50 PM Junji Wei <weijunji@xxxxxxxxxxxxx> wrote: > > > > > On Feb 16, 2022, at 1:54 PM, Jason Wang <jasowang@xxxxxxxxxx> wrote: > > > > On Tue, Feb 15, 2022 at 6:02 PM Junji Wei <weijunji@xxxxxxxxxxxxx> wrote: > >> > >> > >>> On Feb 15, 2022, at 4:44 PM, Jason Wang <jasowang@xxxxxxxxxx> wrote: > >>> > >>> On Tue, Feb 15, 2022 at 4:15 PM Junji Wei <weijunji@xxxxxxxxxxxxx> wrote: > >>>> > >>>> Hi all, > >>>> > >>>> This RFC aims to introduce our recent work on VirtIO-RDMA. > >>>> > >>>> We have finished a draft of VirtIO-RDMA specification and a vhost-user > >>>> RDMA demo based on the spec.This demo can work with CM/Socket > >>>> and UD/RC QP now. > >>>> > >>>> NOTE that this spec now only focuses on emulating a soft > >>>> RoCE (RDMA over Converged Ethernet) device with normal Network Interface > >>>> Card (without RDMA capability). So most Infiniband (IB) specific features > >>>> such as Subnet Manager (SM), Local Identifier (LID) and Automatic Path > >>>> Migration (APM) are not covered in this specification. > >>>> > >>>> There are four parts of our work: > >>>> > >>>> 1. VirtIO-RDMA driver in linux kernel: > >>>> https://github.com/weijunji/linux/tree/virtio-rdma-patch > >>>> > >>>> 2. VirtIO-RDMA userspace provider in rdma-core: > >>>> https://github.com/weijunji/rdma-core/tree/virtio-rdma > >>>> > >>>> 3. VHost-User RDMA backend in QEMU: > >>>> https://github.com/weijunji/qemu/tree/vhost-user-rdma > >>>> > >>>> 4. VHost-User RDMA demo implements with DPDK: > >>>> https://github.com/weijunji/dpdk-rdma > >>>> > >>>> > >>>> To test with our demo: > >>>> > >>>> 1. Build Linux kernel with config INFINIBAND_VIRTIO_RDMA > >>>> > >>>> 2. Build QEMU with config VHOST_USER_RDMA > >>>> > >>>> 3. Build rdma-core and install it to VM image > >>>> > >>>> 4. Build and install DPDK(NOTE that we only tested on DPDK 20.11.3) > >>>> > >>>> 5. Build dpdk-rdma: > >>>> $ cd dpdk-rdma > >>>> $ meson build > >>>> $ cd build > >>>> $ ninja > >>>> > >>>> 6. Run dpdk-rdma: > >>>> $ sudo ./dpdk-rdma --vdev 'net_vhost0,iface=/tmp/sock0,queues=1' \ > >>>> --vdev 'net_tap0' --lcore '1-3' > >>>> $ sudo brctl addif virbr0 dtap0 > >>>> > >>>> 7. Boot kernel with qemu with following args using libvirt: > >>>> <qemu:commandline> > >>>> <qemu:arg value='-chardev'/> > >>>> <qemu:arg value='socket,path=/tmp/sock0,id=vunet'/> > >>>> <qemu:arg value='-netdev'/> > >>>> <qemu:arg value='vhost-user,id=net1,chardev=vunet,vhostforce,queues=1'/> > >>>> <qemu:arg value='-device'/> > >>>> <qemu:arg value='virtio-net-pci,netdev=net1,bus=pci.0,multifunction=on,addr=0x2'/> > >>>> <qemu:arg value='-chardev'/> > >>>> <qemu:arg value='socket,path=/tmp/vhost-rdma0,id=vurdma'/> > >>>> <qemu:arg value='-device'/> > >>>> <qemu:arg value='vhost-user-rdma-pci,page-per-vq,disable-legacy=on,addr=2.1,chardev=vurdma'/> > >>>> </qemu:commandline> > >>>> > >>>> NOTE that virtio-net-pci and vhost-user-rdma-pci MUST in same PCI addresss. > >>>> > >>> > >>> A silly question, if RoCE is the focus, why not extending virtio-net instead? > >> > >> I think it's OK to extend virtio-net to implement virtio-rdma. But if we want to > >> support IB in the future, would it be better to implement the virtio-rdma in an > >> independent way? > > > > I'm not sure but a question is whether IB is useful to be visible by > > the guest. E.g can you implement the soft RoCE backend via IB > > hardware? > > We can't. So do you mean we can implement virtio-rdma only for IB in the future? It's probably virtio-IB but we need to listen to others. > > >> And currently virtio-rdma doesn't have a strong dependency on > >> virtio-net (except for gid and ah stuffs). Is it OK to mix them up? > > > > There are a bunch of hardware vendors that ship a converged Ethernet > > adapter. It simplifies the management and deployment. > > Virtio-rdma is not depend on virtio-net, we can bind it to another ethernet device > via mac address in the future. And is it too mass to mix up two different device > in one spec? So either should be fine, we just need to figure out which one is better. What I meant is to extend the virtio-net to be capable of converged ethernet. Thanks >
