One of the very few VZFileHandleNetworkDeviceAttachment implementations
There are multiple network modes available for Apple's Virtualization framework on Apple Silicon. sock-vmnet is a userspace VZFileHandleNetworkDeviceAttachment implementation in golang. Compared to VZNATNetworkDeviceAttachment network mode, sock-vmnet gives you full control over the traffic groing through the VM. sock-vmnet solves VZNATNetworkDeviceAttachment's ARP spoofing problem.
sock-vmnet doesn't try to solve the dhcp exhaustion problem dhcpd/bootpd(8) has.
sock-vmnetneeds to run as root. As an alternative, you could ask for an entitlement from Apple.- Altough it was load and performance tested thoroughly,
sock-vmnetwas never used in production. - Neither
softnetnorsock-vmnetcan compete with the superior TCP network performance ofVZNATNetworkDeviceAttachment(at least beased on my benchmark). I am not sure if there is a huge difference when it comes to real life workloads.
sock-vmnet is heavily inspired by softnet. Softnet is a beautiful piece of software, and I am really glad that cirruslabs made it Open Source. Apple is famously gatekeeping, their documentations tend to be poor and secretive. Softnet is a beacon in the dark that provides valuable insights that Apple should have provided in the first place. softnet implies huge amounts of domain knowledge and experince with macOS internals, which I can only admire. The goal of this repository is to (more-or-less) mimic what softnet does while maintaining similar performance, just in golang.
# UDP
iperf3 -u -c <address> -p 5201 -bandwidth 10G
# TCP
iperf3 -c <address> -p 5201 -bandwidth 10G| Solution | HOST->VM (TCP) | VM->HOST (TCP) | HOST->VM (UDP) | VM->HOST (UDP) |
|---|---|---|---|---|
| VZNATNetworkDeviceAttachment | 17.6 Gbits/sec 🎉 | 20.5 Gbits/sec 🎉 | 2.73 Gbits/sec (~0 loss) | 3.10 Gbits/sec (~30% loss) |
| Softnet | 1.16 Gbits/sec | 3.64 Gbits/sec | 2.79 Gbits/sec (~0.2 loss) 🎉 | 3.64 Gbits/sec (~20% loss) |
| sock-vmnet | 1.16 Gbits/sec | 2.73 Gbits/sec | 2.62 Gbits/sec (~0.003 loss) | 3.66 Gbits/sec (~19% loss) 🎉 |
| Solution | avg idle CPU | avg memory |
|---|---|---|
| Softnet | 0.3% | 3 MB 🎉 |
| sock-vmnet | 0.1% 🎉 | 24.8 MB |
Launch sock-vmnet from your Virtualization.Framework hypervisor implementation as subprocess.
sock-vmnet
--fd=<fd> \
--mac=<mac_addr> \
[--start-addr=<addr>] \
[--end-addr=<addr>] \
[--subnet-mask=<addr>] \
[--debug=<bool>]
fd: Create & configure a SOCK_DGRAM socketpair, then pass one of the fds
mac: Unique MAC address of your VM
start-addr: The starting address of the subnet range you want to assign from. default: 192.168.64.1
end-addr: The last address of the subnet range you want to assign from. default: 192.168.64.255
subnet-mask: Subnet mask for the assignable subnet range. default: 255.255.255.0
debug: Debug logs. default: false