Virtualization exception is a fault exception caused by specific type of
EPT violations. The vector is 20, which is not defined in linux kernel
(traps.h), also no exception handling function is defined (traps.c). So is
there any way to implement it as a LKM? As it is needed to
set virtualization-exception information area and virtualization exception
handler ((for example, by executing the EPTP-switching VM function), it is
inflexible to implement it in linux kernel directly.