Sorry, forgot to mention I am using " git clone -b vhost-user-v5 https://github.com/virtualopensystems/qemu.git"; for vhost-user backend implementation.
and "git clone https://github.com/virtualopensystems/vapp.git " for reference implementation. Anshul Makkar On Tue, Nov 18, 2014 at 5:29 PM, Anshul Makkar < anshul.mak...@profitbricks.com> wrote: > Hi, > > I am developing an application that is using vhost-user backend for packet > transfer. > > The architecture: > > 1) VM1 is using Vhost-user and executing on server1. > > ".qemu-system-x86_64 -m 1024 -mem-path /dev/hugepages,prealloc=on,share=on > -drive > file=/home/amakkar/test.img,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native > -device > virtio-blk-pci,bus=pci.0,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=2 > -vga std -vnc 0.0.0.0:3 -netdev > type=vhost-user,id=net0,file=/home/amakkar/qemu.sock -device > virtio-net-pci,netdev=net0" > > 2) App1 on server1: executing in user-mode connects with vhost-user > backend over qemu.sock. As expected, initialization is done and guest > addresses including addresses of descriptor ring , available ring and used > ring and mapped to my userspace app and I can directly access them. > > I launch PACKETH on VM1 and transfer some packets using eth0 on VM1 > (packet transfer uses virtio-net backend. ifconfig eth0 shows correct TX > stats) > > In App1 I directly access the avail_ring buffer and consume the packet and > then I do RDMA transfer to server 2 . > > 3) VM2 and App2 executing on server2 and again using VHost-User. > > App2: Vring initializations are successfully done and vring buffers are > mapped. I get the buffer from App1 and now *I want to transfer this > buffer (Raw packet) to VM2.* > > To transfer the buffer from App2 to VM2, I directly access the descriptor > ring, place the buffer in it and update the available index and then issue > the kick. > > code snippet for it: > > dest_buf = (void *)handler->map_handler(handler->context, > desc[a_idx].addr); > memcpy(dest_buf + hdr_len, buf, size); > avail->ring[avail->idx % num] = a_idx; > avail->idx++; > fprintf(stdout, "put_vring, synching memory \n"); > sync_shm(dest_buf, size); > sync_shm((void *)&(avail), sizeof(struct vring_avail)); > > kick(&vhost_user->vring_table, rx_idx); > > But the buffer never reaches to VM2. (I do ifconfig eth0 in VM2 and RX > stats are 0) > > Please can you share if my approach is correct in transferring the packet > from App2 to VM. Can I directly place the buffer in descriptor ring and > issue a kick to notify virtio-net that a packet is available or you can > smell some implementation problem. > > Thanks > Anshul Makkar > >
