with preempt-rt kernel, UEFI boot very slow for kvm virtual machine

[wanglmb]

I am trying to boot kvm virtual machine with preempt-rt kernel (6.12) on aarch64 hardware,
it will take about 70s to boot with UEFI, while it is only ~20s on normal linux kernel.
rebuild edk2 with DEBUG mode, indicate that the most time elapsed in UpdateVariable call with nvram update operation.

[wanglmb]

I found there are many CoreAcquireLock() call during UEFI boot.
the UEFI CoreAcquireLock() is implement with TPL （task priority level)，
it was desigend with the assumption of not be preempted?
but they are really be preempted with preempt-rt kernel?