On Tue, Apr 02, 2019 at 04:19:25AM +0000, Alex Bennée wrote:
>
> Stefano Garzarella <sgarz...@redhat.com> writes:
>
> > Hi Alex,
> > I'm sending you some benchmarks and information about VSOCK CCing qemu-devel
> > and linux-netdev (maybe this info could be useful for others :))
> >
> > One of the VSOCK advantages is the simple configuration: you don't need to
> > set
> > up IP addresses for guest/host, and it can be used with the standard POSIX
> > socket API. [1]
> >
> > I'm currently working on it, so the "optimized" values are still work in
> > progress and I'll send the patches upstream (Linux) as soon as possible.
> > (I hope in 1 or 2 weeks)
> >
> > Optimizations:
> > + reducing the number of credit update packets
> > - RX side sent, on every packet received, an empty packet only to inform
> > the
> > TX side about the space in the RX buffer.
> > + increase RX buffers size to 64 KB (from 4 KB)
> > + merge packets to fill RX buffers
> >
> > As benchmark tool I used iperf3 [2] modified with VSOCK support:
> >
> > host -> guest [Gbps] guest -> host [Gbps]
> > pkt_size before opt. optimized before opt. optimized
> > 1K 0.5 1.6 1.4 1.4
> > 2K 1.1 3.1 2.3 2.5
> > 4K 2.0 5.6 4.2 4.4
> > 8K 3.2 10.2 7.2 7.5
> > 16K 6.4 14.2 9.4 11.3
> > 32K 9.8 18.9 9.2 17.8
> > 64K 13.8 22.9 8.8 25.0
> > 128K 17.6 24.5 7.7 25.7
> > 256K 19.0 24.8 8.1 25.6
> > 512K 20.8 25.1 8.1 25.4
> >
> >
> > How to reproduce:
> >
> > host$ modprobe vhost_vsock
> > host$ qemu-system-x86_64 ... -device vhost-vsock-pci,guest-cid=3
> > # Note: Guest CID should be >= 3
> > # (0, 1 are reserved and 2 identify the host)
> >
> > guest$ iperf3 --vsock -s
> >
> > host$ iperf3 --vsock -c 3 -l ${pkt_size} # host -> guest
> > host$ iperf3 --vsock -c 3 -l ${pkt_size} -R # guest -> host
> >
> >
> > If you want, I can do a similar benchmark (with iperf3) using a networking
> > card (do you have a specific configuration?).
>
> My main interest is how it stacks up against:
>
> --device virtio-net-pci and I guess the vhost equivalent
I'll do some tests with virtio-net and vhost.
>
> AIUI one of the motivators was being able to run something like NFS for
> a guest FS over vsock instead of the overhead from UDP and having to
> deal with the additional complication of having a working network setup.
>
CCing Stefan.
I know he is working on virtio-fs that maybe suite better with your use cases.
He also worked on VSOCK support for NFS, but I think it is not merged upstream.
Thanks,
Stefano
