/**
Returns a boolean to indicate whether SEV is enabled
@retval TRUE SEV is enabled
@retval FALSE SEV is not enabled
**/
STATIC
BOOLEAN
EFIAPI
InternalMemEncryptSevIsEnabled (
VOID
)
{
UINT32 RegEax;
MSR_SEV_STATUS_REGISTER Msr;
CPUID_MEMORY_ENCRYPTION_INFO_EAX Eax;
//
// Check if memory encryption leaf exist
//
AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL);
if (RegEax >= CPUID_MEMORY_ENCRYPTION_INFO) {
//
// CPUID Fn8000_001F[EAX] Bit 1 (Sev supported)
//
AsmCpuid (CPUID_MEMORY_ENCRYPTION_INFO, &Eax.Uint32, NULL, NULL, NULL);
if (Eax.Bits.SevBit) {
//
// Check MSR_0xC0010131 Bit 0 (Sev Enabled)
//
Msr.Uint32 = AsmReadMsr32 (MSR_SEV_STATUS);
if (Msr.Bits.SevBit) {
return TRUE;
}
}
}
return FALSE;
}
/**
Read from a local APIC register.
This function reads from a local APIC register either in xAPIC or x2APIC mode.
It is required that in xAPIC mode wider registers (64-bit or 256-bit) must be
accessed using multiple 32-bit loads or stores, so this function only performs
32-bit read.
@param MmioOffset The MMIO offset of the local APIC register in xAPIC mode.
It must be 16-byte aligned.
@return 32-bit Value read from the register.
**/
UINT32
EFIAPI
ReadLocalApicReg (
IN UINTN MmioOffset
)
{
UINT32 MsrIndex;
ASSERT ((MmioOffset & 0xf) == 0);
if (GetApicMode () == LOCAL_APIC_MODE_XAPIC) {
return MmioRead32 (PcdGet32 (PcdCpuLocalApicBaseAddress) + MmioOffset);
} else {
//
// DFR is not supported in x2APIC mode.
//
ASSERT (MmioOffset != XAPIC_ICR_DFR_OFFSET);
//
// Note that in x2APIC mode, ICR is a 64-bit MSR that needs special treatment. It
// is not supported in this function for simplicity.
//
ASSERT (MmioOffset != XAPIC_ICR_HIGH_OFFSET);
MsrIndex = (UINT32)(MmioOffset >> 4) + X2APIC_MSR_BASE_ADDRESS;
return AsmReadMsr32 (MsrIndex);
}
}