vz: support "lima: shared" networking using VZNATNetworkDeviceAttachment

[AkihiroSuda]

See examples/experimental/vz.yaml .

Unlike QEMU, VZ does not need sudoers for enabling vmnet.

Fix #1161

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No support for bridged mode, as VZBridgedNetworkDeviceAttachment requires the com.apple.vm.networkingentitlement which needs to contact an Apple representative.

• https://developer.apple.com/documentation/virtualization/vzbridgednetworkdeviceattachment?language=objc
• https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_vm_networking?language=objc

Probably we need to use socket_vmnet too for supporting bridged mode with VZ.
(The socket protocol is different, so we need to modify socket_vmnet)

[AkihiroSuda]

cc @balajiv113 @jandubois

[balajiv113]

@AkihiroSuda
My suggestion here would be to provide a new config like networks.vzNAT: true (Like we discussed before). And this will be supported only for vz driver

Reasons for this would be, If we use lima: shared for vzNAT, even with this we cannot communicate across vm's (qemu vm talking to vz vm). But from config it clearly state lima: shared not driver specific

Once we are able to provide support for vz in socket_vmnet (Surely doable) then it will provide support for cross driver communication as well. Using lima: shared for vzNAT now would cause confusions at that time.

What is needed to provide support for vz in socket_vmnet ?
This is from my initial analysis, i might be missing something as well,

1. vz network packets doesn't contain header packet of 4bytes (contains length of original packet in qemu). So some logics have to be modified
2. dgram_socket based connectivity (Optional, as we can pipe dgram packets to unix socket as well)

[AkihiroSuda]

we cannot communicate across vm's (qemu vm talking to vz vm)

Why can't?

[AkihiroSuda]

Opened a new PR:

• vz: support .[]networks.vzNAT networking #1207

[balajiv113]

we cannot communicate across vm's (qemu vm talking to vz vm)

Why can't?

I thought since the vmnet interfaces will be different for vzNAT and the socket_vmnet. So they maynot support cross communication

[AkihiroSuda]

Looks like VZ uses vmnet_enable_isolation_key and it is not configurable 😞
(/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/vmnet.framework/Versions/Current/Headers/vmnet.h)