vz: configure Rosetta’s ahead of time (AOT) caching options using an abstract socket

[norio-nomura]

This change allows starting the /mnt/lima-rosetta/rosttad daemon in the VM. Without this change, it cannot be started as shown below:

$ sudo /mnt/lima-rosetta/rosettad daemon
rosetta error: Failed bind socket: 98
Trace/breakpoint trap

Since rosettad needs to run in the same namespace as rosetta and must be executed directly from /mnt/lima-rosetta/rosettad (copies of rosettad do not work), it is difficult to use during container image builds or similar processes.

In a container, rosettad can be run as follows:

$ docker run -it --rm --platform linux/amd64 --name test-rosettad -v/mnt/lima-rosetta:/mnt/lima-rosetta ubuntu
root@45f887cb0eaa:/# ls -la ~/.cache/rosettad
/usr/bin/ls: cannot access '/root/.cache/rosettad': No such file or directory
root@45f887cb0eaa:/# /mnt/lima-rosetta/rosettad daemon&
[1] 10
root@45f887cb0eaa:/# ls -la ~/.cache/rosettad
total 2700
drwxr-xr-x 2 root root    4096 Jul 17 04:16 .
drwxr-xr-x 3 root root    4096 Jul 17 04:16 ..
-rwxr-xr-x 1 root root  186600 Jul 17 04:16 169a47096736cdeb5714fa040c30ef80426e439f02a3f4e4137733cbaae1fec5.aotcache
-rwxr-xr-x 1 root root  104848 Jul 17 04:16 1bea8094b78a3910345d80af3d182390fda07ae5788352651eb7773505dc39af.aotcache
-rwxr-xr-x 1 root root  121772 Jul 17 04:16 9fb501baf5ceec1ff4c9abb0473492ab4a66893203b932e28dfaa5c73c05e191.aotcache
-rwxr-xr-x 1 root root  244608 Jul 17 04:16 b7695da977e205398b33922d61493cc1e436cd2321bb2e54fbdc39b95fabeff7.aotcache
-rwxr-xr-x 1 root root 2092260 Jul 17 04:16 fc4c52f3910ed57a088d19ab86c671358f5e917cd4e95b21fd08e4fd922c0aa2.aotcache

Even if rosettad is not running, it does not affect the operation of rosetta, so the existing functionality remains unchanged.

There is also a configuration to use Unix Domain Sockets instead of Abstract Sockets. However, it appears that some preparation is required on the VM guest side before mounting, and I was unable to make it work. Therefore, I am using the configuration with Abstract Sockets.

SeeAlso: https://developer.apple.com/documentation/virtualization/running_intel_binaries_in_linux_vms_with_rosetta#4239539

[jandubois]

Thanks, the change looks fine to me.

I wonder how useful it is though to enable AOT compilation inside individual containers. Ideally you would want to share the rosettad cache between host and containers, but I wonder if that has potential race conditions.

Also the fact that you have to run rosettad inside each container makes it hard to use it with e.g. Kubernetes.

Anyways, tested successfully with Alpine and Ubuntu.

[norio-nomura]

Thanks 🙏🏻

I feel we should add tests on macOS 14 to the CI, but there are already many tests that fail randomly, which makes me hesitant.