Indicate access to non-SMRAM memory is restricted to reserved, runtime and ACPI NVS type after SmmReadyToLock.
MMIO access is always allowed regardless of the value of this PCD.
Loose of such restriction is only required by RAS components in X64 platforms.
The PCD value is considered as constantly TRUE in IA32 platforms.
When the PCD value is TRUE, page table is initialized to cover all memory spaces
and the memory occupied by page table is protected by page table itself as read-only.
In X64 build, it cannot be enabled at the same time with SMM profile feature (PcdCpuSmmProfileEnable).
In X64 build, it could not be enabled also at the same time with heap guard feature for SMM
(PcdHeapGuardPropertyMask in MdeModulePkg).
In IA32 build, page table memory is not marked as read-only when either SMM profile feature (PcdCpuSmmProfileEnable)
or heap guard feature for SMM (PcdHeapGuardPropertyMask in MdeModulePkg) is enabled.
TRUE - Access to non-SMRAM memory is restricted to reserved, runtime and ACPI NVS type after SmmReadyToLock.

FALSE - Access to any type of non-SMRAM memory after SmmReadyToLock is allowed.

Access to non-SMRAM memory is restricted to reserved, runtime and ACPI NVS type after SmmReadyToLock.

PCD Information

Name	Token Space	Token number	Data Type	Default Value
PcdCpuSmmRestrictedMemoryAccess	gUefiCpuPkgTokenSpaceGuid	0x3213210F	BOOLEAN	TRUE