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? > 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. Thanks > > Thanks. >
