\#MC is a NMI-like exception. But do not do any setup that NMIs need.
This will lead to console_owner_lock issue and HPET dead loop issue.
For example, The HPET dead loop issue:
CPU x CPU x
---- ----
read_hpet()
arch_spin_trylock(&hpet.lock)
[CPU x got the hpet.lock] #MCE happened
do_machine_check()
mce_panic()
panic()
kmsg_dump()
pstore_dump()
pstore_record_init()
ktime_get_real_fast_ns()
read_hpet()
[dead loops]
This may lead to read_hpet dead loops.
The console_owner_lock issue is similar.
To avoid these issues, add NMIs setup When Handling #MC Exceptions.
Signed-off-by: LeoLiu-oc <leoliu-oc@zhaoxin.com>
