siderolabs
Use ptp_kvm for time sync when running on top of KVM hypervisor
Feature Request
Sync clock to the host using ptp_kvm kernel module.
Description
This could be helpful to possibly reduce startup time and increase clock precision as we can typically expect host machines' clocks to have good sync. The module seems to already be built in siderolabs/pkgs/kernel config for amd64. When ptp_kvm hasn't found necessary hypercalls (e.g. running bare metal or on unsupported hypervisor) it will not probe so /dev/ptp0 only exists when there's supported clock.
If accepted, I can work on adding support for this feature.
I'm not sure if we want to make this configurable for the user, but this is a good thing to do
Perhaps we can check the driver providing each PTP device and only use ones like KVM, Hyper-V or VMware. No point in syncing to others (located on NICs) unless we bring ptp4l or statime in to sync those to real network clocks.
Will try to implement!