mirror of https://github.com/acidanthera/audk.git
144 lines
2.7 KiB
C
144 lines
2.7 KiB
C
/** @file
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Secure Encrypted Virtualization (SEV) library helper function
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Copyright (c) 2020, AMD Incorporated. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#include <Library/BaseLib.h>
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#include <Library/DebugLib.h>
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#include <Library/MemEncryptSevLib.h>
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#include <Library/PcdLib.h>
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#include <Register/Amd/Cpuid.h>
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#include <Register/Amd/Msr.h>
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#include <Register/Cpuid.h>
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#include <Uefi/UefiBaseType.h>
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/**
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Read the workarea to determine whether SEV is enabled. If enabled,
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then return the SevEsWorkArea pointer.
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**/
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STATIC
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SEC_SEV_ES_WORK_AREA *
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EFIAPI
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GetSevEsWorkArea (
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VOID
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)
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{
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OVMF_WORK_AREA *WorkArea;
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WorkArea = (OVMF_WORK_AREA *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
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//
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// If its not SEV guest then SevEsWorkArea is not valid.
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//
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if ((WorkArea == NULL) || (WorkArea->Header.GuestType != CcGuestTypeAmdSev)) {
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return NULL;
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}
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return (SEC_SEV_ES_WORK_AREA *)FixedPcdGet32 (PcdSevEsWorkAreaBase);
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}
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/**
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Read the SEV Status MSR value from the workarea
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**/
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STATIC
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UINT32
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EFIAPI
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InternalMemEncryptSevStatus (
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VOID
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)
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{
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SEC_SEV_ES_WORK_AREA *SevEsWorkArea;
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SevEsWorkArea = GetSevEsWorkArea ();
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if (SevEsWorkArea == NULL) {
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return 0;
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}
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return (UINT32)(UINTN)SevEsWorkArea->SevStatusMsrValue;
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}
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/**
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Returns a boolean to indicate whether SEV-SNP is enabled.
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@retval TRUE SEV-SNP is enabled
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@retval FALSE SEV-SNP is not enabled
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**/
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BOOLEAN
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EFIAPI
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MemEncryptSevSnpIsEnabled (
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VOID
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)
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{
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MSR_SEV_STATUS_REGISTER Msr;
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Msr.Uint32 = InternalMemEncryptSevStatus ();
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return Msr.Bits.SevSnpBit ? TRUE : FALSE;
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}
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/**
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Returns a boolean to indicate whether SEV-ES is enabled.
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@retval TRUE SEV-ES is enabled
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@retval FALSE SEV-ES is not enabled
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**/
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BOOLEAN
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EFIAPI
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MemEncryptSevEsIsEnabled (
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VOID
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)
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{
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MSR_SEV_STATUS_REGISTER Msr;
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Msr.Uint32 = InternalMemEncryptSevStatus ();
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return Msr.Bits.SevEsBit ? TRUE : FALSE;
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}
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/**
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Returns a boolean to indicate whether SEV is enabled.
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@retval TRUE SEV is enabled
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@retval FALSE SEV is not enabled
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**/
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BOOLEAN
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EFIAPI
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MemEncryptSevIsEnabled (
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VOID
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)
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{
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MSR_SEV_STATUS_REGISTER Msr;
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Msr.Uint32 = InternalMemEncryptSevStatus ();
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return Msr.Bits.SevBit ? TRUE : FALSE;
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}
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/**
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Returns the SEV encryption mask.
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@return The SEV pagtable encryption mask
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**/
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UINT64
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EFIAPI
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MemEncryptSevGetEncryptionMask (
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VOID
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)
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{
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SEC_SEV_ES_WORK_AREA *SevEsWorkArea;
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SevEsWorkArea = GetSevEsWorkArea ();
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if (SevEsWorkArea == NULL) {
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return 0;
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}
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return SevEsWorkArea->EncryptionMask;
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}
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