[pve-devel] vhost-user & snabbswitch

[Alexandre DERUMIER]

>>Interesting, but why is it faster? 

Best description I have found.

"
Snabb Switch can also run as a high performance NFV switch for OpenStack environments. The way it can do this is by removing the kernel from the forwarding path and allowing the user space program to talk directly to the device driver on the guest VM. The VMs are only able to address their own memory that they have allocated themselves. A software switch cannot allocate memory to a VM. Instead, for each VM, a separate TX/RX queue in hardware is provisioned in the NIC. So when a VM gives a buffer for packets, the buffer is translated from a standard virtio format (in KVM) directly to hardware format. In other words, when a packet comes in from the network, the NIC determines which VM should get it (typically by looking up the destination MAC address and VLAN ID), picks the appropriate hardware queue with memory that belongs to that VM, grabs a buffer and copies the data from the NIC to that VM. Since Snabb Switch acts as the translation engine between standard virtio and native hardware on the standard Intel NIC, there is no need to write or install a specific device driver for guest VMs to access the hardware.


it's bypass all kernel layer, physical nic talk directly with vhost-net (something like DMA).

That's also mean than nic "drivers" need to be done in snabbswitch.
Currently only intel 10GB is supported, but I known that mellanox and others vendor are currently working on it.(all for >= 10GB nic)

So, I don't think it'll be for everybody soon, they are missing features like bonding, but maybe a small implementation without pve-manager could be great.


But the projet seem to evolve fast, really small code, and with openstack adoption I think it'll grown even faster.


----- Mail original -----
De: "dietmar" <dietmar at proxmox.com>
À: "aderumier" <aderumier at odiso.com>, "pve-devel" <pve-devel at pve.proxmox.com>
Envoyé: Jeudi 12 Mars 2015 15:41:44
Objet: Re: [pve-devel] vhost-user & snabbswitch

> It's an userland switch (no tap devices, no linux bridges/ovs), which announce 
> same performance than srv-io passthrough. ( 200 Gbps on a single core!) 
> 
> I'm looking for this, because next year I'll have need for big videos 
> bandwidth virtual machines. 
> 
> snabbswitch will be integrated in openstack, so it'll be supported on the long 
> time. 
> 
> All features like like vlans,firewall,vpn are implement in snabbswitch with 
> lua language. 

Interesting, but why is it faster?