This feature flag enables SMM/SMRAM support. Note that it also requires
such support from the underlying QEMU instance; if that support is not
present, the firmware will reject continuing after a certain point.
The flag also acts as a general "security switch"; when TRUE, many
components will change behavior, with the goal of preventing a malicious
runtime OS from tampering with firmware structures (special memory ranges
used by OVMF, the varstore pflash chip, LockBox etc).

PCD Information

Name	Token Space	Token number	Data Type	Default Value
PcdSmmSmramRequire	gUefiOvmfPkgTokenSpaceGuid	0x1e	BOOLEAN	FALSE