AmdSev.c File Reference

#include <Library/BaseLib.h>
#include <Library/CpuLib.h>
#include <Library/CpuPageTableLib.h>
#include <Library/DebugLib.h>
#include <Library/LocalApicLib.h>
#include <Library/MemEncryptSevLib.h>
#include <Library/BaseMemoryLib.h>
#include <Register/Amd/Ghcb.h>
#include <Register/Amd/Msr.h>
#include "AmdSev.h"

Go to the source code of this file.

Functions
VOID	SevEsProtocolFailure (IN UINT8 ReasonCode)
BOOLEAN	SevSnpIsEnabled (VOID)
STATIC VOID	SevSnpGhcbRegister (EFI_PHYSICAL_ADDRESS Address)
STATIC BOOLEAN	HypervisorSnpFeatureCheck (VOID)
VOID	SevEsProtocolCheck (VOID)
BOOLEAN	IsSevGuest (VOID)
BOOLEAN	SevEsIsEnabled (VOID)
VOID	SecValidateSystemRam (VOID)
VOID	SecMapApicBaseUnencrypted (VOID)

Detailed Description

File defines the Sec routines for the AMD SEV

Copyright (c) 2021, Advanced Micro Devices, Inc. All rights reserved.

SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file AmdSev.c.

Function Documentation

HypervisorSnpFeatureCheck()

STATIC BOOLEAN HypervisorSnpFeatureCheck

(

VOID

)

Verify that Hypervisor supports the SNP feature.

Definition at line 122 of file AmdSev.c.

IsSevGuest()

BOOLEAN IsSevGuest

(

VOID

)

Determine if the SEV is active.

During the early booting, GuestType is set in the work area. Verify that it is an SEV guest.

Return values

TRUE	SEV is enabled
FALSE	SEV is not enabled

Definition at line 240 of file AmdSev.c.

SecMapApicBaseUnencrypted()

VOID SecMapApicBaseUnencrypted

(

VOID

)

Map known MMIO regions unencrypted if SEV-ES is active.

During early booting, page table entries default to having the encryption bit set for SEV-ES/SEV-SNP guests. In cases where there is MMIO to an address, the encryption bit should be cleared. Clear it here for any known MMIO accesses during SEC, which is currently just the APIC base address.

Definition at line 318 of file AmdSev.c.

SecValidateSystemRam()

VOID SecValidateSystemRam

(

VOID

)

Validate System RAM used for decompressing the PEI and DXE firmware volumes when SEV-SNP is active. The PCDs SecValidatedStart and SecValidatedEnd are set in OvmfPkg/Include/Fdf/FvmainCompactScratchEnd.fdf.inc.

Definition at line 294 of file AmdSev.c.

SevEsIsEnabled()

BOOLEAN SevEsIsEnabled

(

VOID

)

Determine if SEV-ES is active.

During early booting, SEV-ES support code will set a flag to indicate that SEV-ES is enabled. Return the value of this flag as an indicator that SEV-ES is enabled.

Return values

TRUE	SEV-ES is enabled
FALSE	SEV-ES is not enabled

Definition at line 272 of file AmdSev.c.

SevEsProtocolCheck()

VOID SevEsProtocolCheck

(

VOID

)

Validate the SEV-ES/GHCB protocol level.

Verify that the level of SEV-ES/GHCB protocol supported by the hypervisor and the guest intersect. If they don't intersect, request termination.

Definition at line 159 of file AmdSev.c.

SevEsProtocolFailure()

VOID SevEsProtocolFailure

(

IN UINT8

ReasonCode

)

Handle an SEV-ES/GHCB protocol check failure.

Notify the hypervisor using the VMGEXIT instruction that the SEV-ES guest wishes to be terminated.

Parameters

[in]

ReasonCode

Reason code to provide to the hypervisor for the termination request.

Definition at line 33 of file AmdSev.c.

SevSnpGhcbRegister()

STATIC VOID SevSnpGhcbRegister

(

EFI_PHYSICAL_ADDRESS

Address

)

Register the GHCB GPA

Definition at line 89 of file AmdSev.c.

SevSnpIsEnabled()

BOOLEAN SevSnpIsEnabled

(

VOID

)

Determine if SEV-SNP is active.

Return values

TRUE	SEV-SNP is enabled
FALSE	SEV-SNP is not enabled

Definition at line 62 of file AmdSev.c.