Kernel cmdline customisation on hyperkit

[cedws]

It appears from looking at /Library/Logs/Multipass/multipassd.log that the kernel parameters are passed as an argument (hardcoded?) to HyperKit.

I tried to customise the cmdline inside the VM by modifying the GRUB configuration, but it had no effect, which I think confirms my suspicion.

[Saviq]

Hi @cedws yes, currently we're booting the kernel / initramfs directly, we're working on getting that fixed.

May I ask what kernel options you'd like to modify?

[cedws]

I wanted to pass mitigations=off and the kernel 4.x equivalents.

[BenWibking]

This would also be very useful to disable cgroups v1, allowing unprivileged users to create their own child cgroups.

[tonidy]

@Saviq any update regarding this? As I want to enable cgroups v2 and I couldn't find any documentation how to enable cgroups v2 in Multipass.

[BenWibking]

It looks like cgroups v2 will become the default in Ubuntu 21.10, but for all previous releases, it's necessary to modify the kernel cmdline: https://bugs.launchpad.net/ubuntu/+source/snapd/+bug/1850667

[Saviq]

Hi @tonidy, we unfortunately have no way to pass cmdline arguments on macOS. We're working on Apple M1 support (#1857), which may improve the situation, we'll keep this updated.

[tonidy]

@Saviq thanks for your update. Maybe I need waiting for next Ubuntu 21.10 in Multipass or I need to buy new Mac 😄

[Saviq]

@tonidy currently it's looking like we'll be able to use a proper bootloader on macOS soon (M1 or not, doesn't matter), so GRUB will be in play again.

[tonidy]

@Saviq wow, sounds great 😄 . Is it still support for hypervisor framework in Catalina?

[Saviq]

@tonidy as long as https://developer.apple.com/documentation/hypervisor is there, it should work. We'll report more soon. Watch #1857 for updates.

[bobsongplus]

any progress about this? I encounter the same problem that need to pass kernels arguments

[Saviq]

@TinySong please see #1857 for updates there (assuming you're on macOS/hyperkit - elsewhere you can change GRUB configuration to modify kernel options).

In the mean time, VirtualBox is an escape hatch, too.

[Saviq]

This is now possible with the qemu driver on macOS as well, through standard Ubuntu means.

We won't be implementing it for hyperkit.