mirror of https://github.com/acidanthera/audk.git
146 lines
3.0 KiB
C
146 lines
3.0 KiB
C
/** @file
|
|
|
|
Secure Encrypted Virtualization (SEV) library helper function
|
|
|
|
Copyright (c) 2017 - 2020, AMD Incorporated. All rights reserved.<BR>
|
|
|
|
SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
|
|
**/
|
|
|
|
#include <Library/BaseLib.h>
|
|
#include <Library/DebugLib.h>
|
|
#include <Library/MemEncryptSevLib.h>
|
|
#include <Library/PcdLib.h>
|
|
#include <Register/Amd/Cpuid.h>
|
|
#include <Register/Amd/Msr.h>
|
|
#include <Register/Cpuid.h>
|
|
#include <Uefi/UefiBaseType.h>
|
|
|
|
STATIC BOOLEAN mSevStatus = FALSE;
|
|
STATIC BOOLEAN mSevEsStatus = FALSE;
|
|
STATIC BOOLEAN mSevStatusChecked = FALSE;
|
|
|
|
STATIC UINT64 mSevEncryptionMask = 0;
|
|
STATIC BOOLEAN mSevEncryptionMaskSaved = FALSE;
|
|
|
|
/**
|
|
Reads and sets the status of SEV features.
|
|
|
|
**/
|
|
STATIC
|
|
VOID
|
|
EFIAPI
|
|
InternalMemEncryptSevStatus (
|
|
VOID
|
|
)
|
|
{
|
|
UINT32 RegEax;
|
|
MSR_SEV_STATUS_REGISTER Msr;
|
|
CPUID_MEMORY_ENCRYPTION_INFO_EAX Eax;
|
|
BOOLEAN ReadSevMsr;
|
|
UINT64 EncryptionMask;
|
|
|
|
ReadSevMsr = FALSE;
|
|
|
|
EncryptionMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask);
|
|
if (EncryptionMask != 0) {
|
|
//
|
|
// The MSR has been read before, so it is safe to read it again and avoid
|
|
// having to validate the CPUID information.
|
|
//
|
|
ReadSevMsr = TRUE;
|
|
} else {
|
|
//
|
|
// 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) {
|
|
ReadSevMsr = TRUE;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ReadSevMsr) {
|
|
//
|
|
// Check MSR_0xC0010131 Bit 0 (Sev Enabled)
|
|
//
|
|
Msr.Uint32 = AsmReadMsr32 (MSR_SEV_STATUS);
|
|
if (Msr.Bits.SevBit) {
|
|
mSevStatus = TRUE;
|
|
}
|
|
|
|
//
|
|
// Check MSR_0xC0010131 Bit 1 (Sev-Es Enabled)
|
|
//
|
|
if (Msr.Bits.SevEsBit) {
|
|
mSevEsStatus = TRUE;
|
|
}
|
|
}
|
|
|
|
mSevStatusChecked = TRUE;
|
|
}
|
|
|
|
/**
|
|
Returns a boolean to indicate whether SEV-ES is enabled.
|
|
|
|
@retval TRUE SEV-ES is enabled
|
|
@retval FALSE SEV-ES is not enabled
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
MemEncryptSevEsIsEnabled (
|
|
VOID
|
|
)
|
|
{
|
|
if (!mSevStatusChecked) {
|
|
InternalMemEncryptSevStatus ();
|
|
}
|
|
|
|
return mSevEsStatus;
|
|
}
|
|
|
|
/**
|
|
Returns a boolean to indicate whether SEV is enabled.
|
|
|
|
@retval TRUE SEV is enabled
|
|
@retval FALSE SEV is not enabled
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
MemEncryptSevIsEnabled (
|
|
VOID
|
|
)
|
|
{
|
|
if (!mSevStatusChecked) {
|
|
InternalMemEncryptSevStatus ();
|
|
}
|
|
|
|
return mSevStatus;
|
|
}
|
|
|
|
/**
|
|
Returns the SEV encryption mask.
|
|
|
|
@return The SEV pagtable encryption mask
|
|
**/
|
|
UINT64
|
|
EFIAPI
|
|
MemEncryptSevGetEncryptionMask (
|
|
VOID
|
|
)
|
|
{
|
|
if (!mSevEncryptionMaskSaved) {
|
|
mSevEncryptionMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask);
|
|
mSevEncryptionMaskSaved = TRUE;
|
|
}
|
|
|
|
return mSevEncryptionMask;
|
|
}
|