Re: HPET and IRQs

Yan, Like

Hi Tomasz,

If you launched VM with --lapic_pt, then it's a RT VM.
An RT VM is only allowed to be powered-off/reset when initiated inside the RT VM. The design principle here is that the other VMs (even the SOS VM) should not interfere RT VM to guarantee the RT performance.
And there are some limitations as to RT VM, legacy devices are not supported, such as vHPET.
Here are 2 documents for RT VM:


-----Original Message-----
From: acrn-users@... <acrn-users@...> On
Behalf Of Tomasz Bursztyka
Sent: Wednesday, April 29, 2020 2:37 PM
To: acrn-users@...
Subject: Re: [acrn-users] HPET and IRQs

Hi Like,

VM or RT VM, I don't know. It did not occur to me there was an actual
difference, I just used the launcher script for zephyr. I'll check.

I could get LAPIC (which we indeed call LOAPIC) to work using -- lapic_pt
option to acrn-dm. But then I am unable to stop/reset/delete the VM for
some reason (even with --force on stop, it always returns -1).

I'll still investigate about HPET. It "should" work, and if Zephyr is missing
some support - runtime calibration that is - then it will be worth adding it.

Thanks for the inputs,


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