audk/OvmfPkg/AmdSevDxe/AmdSevDxe.inf

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

60 lines
1.4 KiB
INI
Raw Normal View History

#/** @file
#
# Driver clears the encryption attribute from MMIO regions when SEV is enabled
#
OvmfPkg/AmdSevDxe: Clear encryption bit on PCIe MMCONFIG range BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108 The PCIe MMCONFIG range should be treated as an MMIO range. However, there is a comment in the code explaining why AddIoMemoryBaseSizeHob() is not called. The AmdSevDxe walks the GCD map looking for MemoryMappedIo or NonExistent type memory and will clear the encryption bit for these ranges. Since the MMCONFIG range does not have one of these types, the encryption bit is not cleared for this range. Add support to detect the presence of the MMCONFIG range and clear the encryption bit. This will be needed for follow-on support that will validate that MMIO is not being performed to an encrypted address range under SEV-ES. Even though the encryption bit was set for this range, this still worked under both SEV and SEV-ES because the address range is marked by the hypervisor as MMIO in the nested page tables: - For SEV, access to this address range triggers a nested page fault (NPF) and the hardware supplies the guest physical address (GPA) in the VMCB's EXITINFO2 field as part of the exit information. However, the encryption bit is not set in the GPA, so the hypervisor can process the request without any issues. - For SEV-ES, access to this address range triggers a #VC. Since OVMF runs identity mapped (VA == PA), the virtual address is used to avoid the lookup of the physical address. The virtual address does not have the encryption bit set, so the hypervisor can process the request without any issues. Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Message-Id: <711ae2dcb6cb29e4c60862c18330cff627269b81.1610045305.git.thomas.lendacky@amd.com>
2021-01-07 19:48:18 +01:00
# Copyright (c) 2017 - 2020, AMD Inc. All rights reserved.<BR>
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
#**/
[Defines]
INF_VERSION = 1.25
BASE_NAME = AmdSevDxe
FILE_GUID = 2ec9da37-ee35-4de9-86c5-6d9a81dc38a7
MODULE_TYPE = DXE_DRIVER
VERSION_STRING = 1.0
ENTRY_POINT = AmdSevDxeEntryPoint
[Sources]
AmdSevDxe.c
[Packages]
MdeModulePkg/MdeModulePkg.dec
MdePkg/MdePkg.dec
OvmfPkg/OvmfPkg.dec
[LibraryClasses]
OvmfPkg/AmdSevDxe: decrypt the pages of the initial SMRAM save state map Based on the following patch from Brijesh Singh <brijesh.singh@amd.com>: [PATCH v2 1/2] OvmfPkg/AmdSevDxe: Clear the C-bit from SMM Saved State http://mid.mail-archive.com/20180228161415.28723-2-brijesh.singh@amd.com https://lists.01.org/pipermail/edk2-devel/2018-February/022016.html Original commit message from Brijesh: > When OVMF is built with SMM, SMMSaved State area (SMM_DEFAULT_SMBASE + > SMRAM_SAVE_STATE_MAP_OFFSET) contains data which need to be accessed by > both guest and hypervisor. Since the data need to be accessed by both > hence we must map the SMMSaved State area as unencrypted (i.e C-bit > cleared). > > This patch clears the SavedStateArea address before SMBASE relocation. > Currently, we do not clear the SavedStateArea address after SMBASE is > relocated due to the following reasons: > > 1) Guest BIOS never access the relocated SavedStateArea. > > 2) The C-bit works on page-aligned address, but the SavedStateArea > address is not a page-aligned. Theoretically, we could roundup the > address and clear the C-bit of aligned address but looking carefully we > found that some portion of the page contains code -- which will causes a > bigger issue for the SEV guest. When SEV is enabled, all the code must > be encrypted otherwise hardware will cause trap. Changes by Laszlo: - separate AmdSevDxe bits from SmmCpuFeaturesLib bits; - spell out PcdLib dependency with #include and in LibraryClasses; - replace (SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET) calculation with call to new MemEncryptSevLocateInitialSmramSaveStateMapPages() function; - consequently, pass page-aligned BaseAddress to MemEncryptSevClearPageEncMask(); - zero the pages before clearing the C-bit; - pass Flush=TRUE to MemEncryptSevClearPageEncMask(); - harden the treatment of MemEncryptSevClearPageEncMask() failure. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Jordan Justen <jordan.l.justen@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
2018-03-01 22:05:55 +01:00
BaseLib
BaseMemoryLib
DebugLib
DxeServicesTableLib
MemEncryptSevLib
MemoryAllocationLib
OvmfPkg/AmdSevDxe: decrypt the pages of the initial SMRAM save state map Based on the following patch from Brijesh Singh <brijesh.singh@amd.com>: [PATCH v2 1/2] OvmfPkg/AmdSevDxe: Clear the C-bit from SMM Saved State http://mid.mail-archive.com/20180228161415.28723-2-brijesh.singh@amd.com https://lists.01.org/pipermail/edk2-devel/2018-February/022016.html Original commit message from Brijesh: > When OVMF is built with SMM, SMMSaved State area (SMM_DEFAULT_SMBASE + > SMRAM_SAVE_STATE_MAP_OFFSET) contains data which need to be accessed by > both guest and hypervisor. Since the data need to be accessed by both > hence we must map the SMMSaved State area as unencrypted (i.e C-bit > cleared). > > This patch clears the SavedStateArea address before SMBASE relocation. > Currently, we do not clear the SavedStateArea address after SMBASE is > relocated due to the following reasons: > > 1) Guest BIOS never access the relocated SavedStateArea. > > 2) The C-bit works on page-aligned address, but the SavedStateArea > address is not a page-aligned. Theoretically, we could roundup the > address and clear the C-bit of aligned address but looking carefully we > found that some portion of the page contains code -- which will causes a > bigger issue for the SEV guest. When SEV is enabled, all the code must > be encrypted otherwise hardware will cause trap. Changes by Laszlo: - separate AmdSevDxe bits from SmmCpuFeaturesLib bits; - spell out PcdLib dependency with #include and in LibraryClasses; - replace (SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET) calculation with call to new MemEncryptSevLocateInitialSmramSaveStateMapPages() function; - consequently, pass page-aligned BaseAddress to MemEncryptSevClearPageEncMask(); - zero the pages before clearing the C-bit; - pass Flush=TRUE to MemEncryptSevClearPageEncMask(); - harden the treatment of MemEncryptSevClearPageEncMask() failure. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Jordan Justen <jordan.l.justen@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
2018-03-01 22:05:55 +01:00
PcdLib
UefiDriverEntryPoint
[Depex]
TRUE
OvmfPkg/AmdSevDxe: decrypt the pages of the initial SMRAM save state map Based on the following patch from Brijesh Singh <brijesh.singh@amd.com>: [PATCH v2 1/2] OvmfPkg/AmdSevDxe: Clear the C-bit from SMM Saved State http://mid.mail-archive.com/20180228161415.28723-2-brijesh.singh@amd.com https://lists.01.org/pipermail/edk2-devel/2018-February/022016.html Original commit message from Brijesh: > When OVMF is built with SMM, SMMSaved State area (SMM_DEFAULT_SMBASE + > SMRAM_SAVE_STATE_MAP_OFFSET) contains data which need to be accessed by > both guest and hypervisor. Since the data need to be accessed by both > hence we must map the SMMSaved State area as unencrypted (i.e C-bit > cleared). > > This patch clears the SavedStateArea address before SMBASE relocation. > Currently, we do not clear the SavedStateArea address after SMBASE is > relocated due to the following reasons: > > 1) Guest BIOS never access the relocated SavedStateArea. > > 2) The C-bit works on page-aligned address, but the SavedStateArea > address is not a page-aligned. Theoretically, we could roundup the > address and clear the C-bit of aligned address but looking carefully we > found that some portion of the page contains code -- which will causes a > bigger issue for the SEV guest. When SEV is enabled, all the code must > be encrypted otherwise hardware will cause trap. Changes by Laszlo: - separate AmdSevDxe bits from SmmCpuFeaturesLib bits; - spell out PcdLib dependency with #include and in LibraryClasses; - replace (SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET) calculation with call to new MemEncryptSevLocateInitialSmramSaveStateMapPages() function; - consequently, pass page-aligned BaseAddress to MemEncryptSevClearPageEncMask(); - zero the pages before clearing the C-bit; - pass Flush=TRUE to MemEncryptSevClearPageEncMask(); - harden the treatment of MemEncryptSevClearPageEncMask() failure. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Jordan Justen <jordan.l.justen@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
2018-03-01 22:05:55 +01:00
[FeaturePcd]
gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire
OvmfPkg/AmdSevDxe: Clear encryption bit on PCIe MMCONFIG range BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108 The PCIe MMCONFIG range should be treated as an MMIO range. However, there is a comment in the code explaining why AddIoMemoryBaseSizeHob() is not called. The AmdSevDxe walks the GCD map looking for MemoryMappedIo or NonExistent type memory and will clear the encryption bit for these ranges. Since the MMCONFIG range does not have one of these types, the encryption bit is not cleared for this range. Add support to detect the presence of the MMCONFIG range and clear the encryption bit. This will be needed for follow-on support that will validate that MMIO is not being performed to an encrypted address range under SEV-ES. Even though the encryption bit was set for this range, this still worked under both SEV and SEV-ES because the address range is marked by the hypervisor as MMIO in the nested page tables: - For SEV, access to this address range triggers a nested page fault (NPF) and the hardware supplies the guest physical address (GPA) in the VMCB's EXITINFO2 field as part of the exit information. However, the encryption bit is not set in the GPA, so the hypervisor can process the request without any issues. - For SEV-ES, access to this address range triggers a #VC. Since OVMF runs identity mapped (VA == PA), the virtual address is used to avoid the lookup of the physical address. The virtual address does not have the encryption bit set, so the hypervisor can process the request without any issues. Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Message-Id: <711ae2dcb6cb29e4c60862c18330cff627269b81.1610045305.git.thomas.lendacky@amd.com>
2021-01-07 19:48:18 +01:00
[FixedPcd]
gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidSize
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize
[Protocols]
gEdkiiMemoryAcceptProtocolGuid
gOvmfSevMemoryAcceptanceProtocolGuid
[Guids]
gConfidentialComputingSevSnpBlobGuid
gEfiEventBeforeExitBootServicesGuid
OvmfPkg/AmdSevDxe: Clear encryption bit on PCIe MMCONFIG range BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108 The PCIe MMCONFIG range should be treated as an MMIO range. However, there is a comment in the code explaining why AddIoMemoryBaseSizeHob() is not called. The AmdSevDxe walks the GCD map looking for MemoryMappedIo or NonExistent type memory and will clear the encryption bit for these ranges. Since the MMCONFIG range does not have one of these types, the encryption bit is not cleared for this range. Add support to detect the presence of the MMCONFIG range and clear the encryption bit. This will be needed for follow-on support that will validate that MMIO is not being performed to an encrypted address range under SEV-ES. Even though the encryption bit was set for this range, this still worked under both SEV and SEV-ES because the address range is marked by the hypervisor as MMIO in the nested page tables: - For SEV, access to this address range triggers a nested page fault (NPF) and the hardware supplies the guest physical address (GPA) in the VMCB's EXITINFO2 field as part of the exit information. However, the encryption bit is not set in the GPA, so the hypervisor can process the request without any issues. - For SEV-ES, access to this address range triggers a #VC. Since OVMF runs identity mapped (VA == PA), the virtual address is used to avoid the lookup of the physical address. The virtual address does not have the encryption bit set, so the hypervisor can process the request without any issues. Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Message-Id: <711ae2dcb6cb29e4c60862c18330cff627269b81.1610045305.git.thomas.lendacky@amd.com>
2021-01-07 19:48:18 +01:00
[Pcd]
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId