This issue is still present in Questing. It's actually not related to
the "microvm build" and can be reproduced with the standard qemu-
system-x86_64 binary using the microvm machine.

What is happening is that the default config for the microvm machine
seems to have rtc disabled: using -machine microvm,rtc=on fixes the
issue.

However, I think this is an opinionated default choice as microvms are
intended to run with KVM acceleration enabled and thus the kvm-clock
present. Using SeaBIOS (ie dropping the -bios argument), I don't get the
same issue and the serial console shows:

[    0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00
[    0.000001] kvm-clock: using sched offset of 127547126 cycles
[    0.000004] clocksource: kvm-clock: mask: 0xffffffffffffffff max_cycles: 
0x1cd42e4dffb, max_idle_ns: 881590591483 ns

So I just think there is something missing in qboot that prevents the
kvm-clock from showing up in the guest.

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https://bugs.launchpad.net/bugs/2074073

Title:
  RTC access broken in microvm

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