macOS kernel panic during boot due to non-monotonic TSC

[sej7278]

Hi, this is possibly not even an opencore issue, but does anything jump out at you as being an obvious problem?

Got a VM running 11.6.1 with your oc 0.7.4 install on my Xeon E5-2650v2, but it simply will not take the Monterey update (also didn't do one of the beta's i tried or a fresh install) it starts the upgrade but after a couple of reboots seems to panic and get stuck at mach reboot.

It gets past the time-out here:

But then panics here:

And finally hangs completely here trying to reboot i guess:

My config.plist is basically the same as yours but with some smbios stuff added by opencore-configurator (serials etc.) oc-validator had nothing bad to say about it.

libvirt xml is: libvirt.txt

Host is Debian Sid, qemu 6.1.0, libvirt 7.6.0, kernel 5.14.12

[thenickdude]

High IO on the host during the upgrade might be triggering a kernel panic due to timeouts in the guest. Try adding the parameters I identified here to your boot-args:

https://www.nicksherlock.com/2020/08/solving-macos-vm-kernel-panics-on-heavily-loaded-proxmox-qemu-kvm-servers/

tlbto_us=0 vti=9

[sej7278]

ok thanks, will try in the morning and report back.

[sej7278]

ok tried that and thought it was going to make a difference as cpu usage went through the roof (like 100% on half my 16 cores!) but it still ended up at the mach reboot crash.

it seems to reboot a lot at this disk crypto stage (not crash, just reboot back to opencore chooser):

i might try reducing the vcpu's to 4, maybe its a thread timeout/race or something....?

[thenickdude]

That's curious, if CPU usage increased it seems like a kernel thread is spinning in an infinite loop. tlbto_us=0 causes failures in a core to respond in a timely fashion to a TLB flush to be completely ignored instead of triggering a panic.

I'll check out your VM config

[thenickdude]

Where did you get your OVMF image by the way? You might try switching to one provided by your distro just in case

[sej7278]

I think the ovmf was from osx-kvm, I'll try the Debian one, might also try a fresh install again instead of an upgrade or maybe try without gpu passthrough.

Reducing the core count made no difference nor did switching to virtio-net from vmxnet3 (didn't realize that worked).

It seems to stall at various points for a few minutes then reboot, but once it gets to Mach reboot it's definitely dead.

[thenickdude]

I've never observed behaviour like that so I'm a bit in the dark on what might cause it, sorry!

If you've got any passthrough devices defined, does it boot if they're removed?

[sej7278]

OVMF_CODE.fd or OVMF_CODE_4M.fd from debian seem to reduce cpu usage to almost nothing, also reduced the reboots but still ends up at MACH Reboot i'll try removing the gpu next as that seemed to work for someone on reddit

[thenickdude]

I definitely recommend removing passthrough GPUs during upgrades because the repeated restarts asks a lot of the shitty AMD GPU drivers.

[sej7278]

i'm going to close this and give up, as a completely fresh install with fresh oc15 and ovmf and no passthrough doesn't even get as far as disk utility, so i'm assuming monterey is a lot more fussy about hardware or software (as bigsur runs fine on the same vm).

thanks for your time.

[thenickdude]

The only real hardware the guest can even see is your CPU, which is perfectly compatible (same generation as mine)

[thenickdude]

Oh your CPU argument is missing +hypervisor. The macOS kernel gives all sorts of timing slack to you if it knows it's running in a VM, which requires +hypervisor

[sej7278]

i tried adding that to my existing flags and i tried changing completely to:

-cpu host,kvm=on,vendor=GenuineIntel,+kvm_pv_unhalt,+kvm_pv_eoi,+hypervisor,+invtsc

but it didn't make any difference. this is really confusing as i've never really had a problem before (other than bigsur which just needed a new opencore) but monterey seems unsurmountable to me - i can't even get to the installer let alone an upgrade!