45388d046c
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108 The early assembler code performs validation for some of the SEV-related information, specifically the encryption bit position. The new MemEncryptSevGetEncryptionMask() interface provides access to this validated value. To ensure that we always use a validated encryption mask for an SEV-ES guest, update all locations that use CPUID to calculate the encryption mask to use the new interface. Also, clean up some call areas where extra masking was being performed and where a function call was being used instead of the local variable that was just set using the function. Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com> Cc: Rebecca Cran <rebecca@bsdio.com> Cc: Peter Grehan <grehan@freebsd.org> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Anthony Perard <anthony.perard@citrix.com> Cc: Julien Grall <julien@xen.org> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Message-Id: <9de678c0d66443c6cc33e004a4cac0a0223c2ebc.1610045305.git.thomas.lendacky@amd.com>
99 lines
2.9 KiB
C
99 lines
2.9 KiB
C
/**@file
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Initialize Secure Encrypted Virtualization (SEV) support
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Copyright (c) 2017 - 2020, Advanced Micro Devices. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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//
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// The package level header files this module uses
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//
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#include <IndustryStandard/Q35MchIch9.h>
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#include <Library/DebugLib.h>
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#include <Library/HobLib.h>
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#include <Library/MemEncryptSevLib.h>
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#include <Library/PcdLib.h>
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#include <PiPei.h>
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#include <Register/Intel/SmramSaveStateMap.h>
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#include "Platform.h"
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/**
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Function checks if SEV support is available, if present then it sets
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the dynamic PcdPteMemoryEncryptionAddressOrMask with memory encryption mask.
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**/
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VOID
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AmdSevInitialize (
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VOID
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)
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{
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UINT64 EncryptionMask;
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RETURN_STATUS PcdStatus;
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//
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// Check if SEV is enabled
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//
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if (!MemEncryptSevIsEnabled ()) {
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return;
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}
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//
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// Set Memory Encryption Mask PCD
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//
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EncryptionMask = MemEncryptSevGetEncryptionMask ();
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PcdStatus = PcdSet64S (PcdPteMemoryEncryptionAddressOrMask, EncryptionMask);
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ASSERT_RETURN_ERROR (PcdStatus);
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DEBUG ((DEBUG_INFO, "SEV is enabled (mask 0x%lx)\n", EncryptionMask));
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//
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// Set Pcd to Deny the execution of option ROM when security
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// violation.
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//
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PcdStatus = PcdSet32S (PcdOptionRomImageVerificationPolicy, 0x4);
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ASSERT_RETURN_ERROR (PcdStatus);
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//
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// When SMM is required, cover the pages containing the initial SMRAM Save
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// State Map with a memory allocation HOB:
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//
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// There's going to be a time interval between our decrypting those pages for
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// SMBASE relocation and re-encrypting the same pages after SMBASE
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// relocation. We shall ensure that the DXE phase stay away from those pages
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// until after re-encryption, in order to prevent an information leak to the
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// hypervisor.
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//
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if (FeaturePcdGet (PcdSmmSmramRequire) && (mBootMode != BOOT_ON_S3_RESUME)) {
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RETURN_STATUS LocateMapStatus;
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UINTN MapPagesBase;
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UINTN MapPagesCount;
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LocateMapStatus = MemEncryptSevLocateInitialSmramSaveStateMapPages (
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&MapPagesBase,
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&MapPagesCount
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);
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ASSERT_RETURN_ERROR (LocateMapStatus);
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if (mQ35SmramAtDefaultSmbase) {
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//
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// The initial SMRAM Save State Map has been covered as part of a larger
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// reserved memory allocation in InitializeRamRegions().
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//
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ASSERT (SMM_DEFAULT_SMBASE <= MapPagesBase);
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ASSERT (
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(MapPagesBase + EFI_PAGES_TO_SIZE (MapPagesCount) <=
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SMM_DEFAULT_SMBASE + MCH_DEFAULT_SMBASE_SIZE)
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);
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} else {
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BuildMemoryAllocationHob (
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MapPagesBase, // BaseAddress
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EFI_PAGES_TO_SIZE (MapPagesCount), // Length
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EfiBootServicesData // MemoryType
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);
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}
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}
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}
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