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Ovmfpkg/AmdSvsmLib: Create AmdSvsmLib to handle SVSM related services 

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654

Add initial support for the new AmdSvsmLib library to OvmfPkg. The initial
implementation fully implements the library interfaces.

The SVSM presence check, AmdSvsmIsSvsmPresent(), determines the presence
of an SVSM by checking if an SVSM has been advertised in the SEV-SNP
Secrets Page.

The VMPL API, AmdSvsmSnpGetVmpl(), returns the VMPL level at which OVMF is
currently running.

The CAA API, AmdSvsmSnpGetCaa(), returns the Calling Area Address when an
SVSM is present, 0 otherwise.

The PVALIDATE API, AmdSvsmSnpPvalidate(), copies the PVALIDATE logic from
the BaseMemEncryptSevLib library for the initial implementation. The
BaseMemEncryptSevLib library will be changed to use this new API so that
the decision as to whether the SVSM is needed to perform the operation
can be isolated to this library.

The VMSA API, AmdSvsmSnpVmsaRmpAdjust(), copies the RMPUPDATE logic from
the MpInitLib library for the initial implementation. The MpInitLib
library will be changed to use this new API so that the decision as to
whether the SVSM is needed to perform the operation can be isolated to
this library.

Cc: Anatol Belski <anbelski@linux.microsoft.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jianyong Wu <jianyong.wu@arm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Min Xu <min.m.xu@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Tom Lendacky 2024-03-08 07:31:53 -08:00 committed by mergify[bot]
parent 789727ccf3
commit 6ced1e91ef
6 changed files with 309 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
OvmfPkg/AmdSev/AmdSevX64.dsc
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@ -204,7 +204,7 @@
!include OvmfPkg/Include/Dsc/ShellLibs.dsc.inc
[LibraryClasses.common]
AmdSvsmLib|UefiCpuPkg/Library/AmdSvsmLibNull/AmdSvsmLibNull.inf
AmdSvsmLib|OvmfPkg/Library/AmdSvsmLib/AmdSvsmLib.inf
BaseCryptLib|CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
CcExitLib|OvmfPkg/Library/CcExitLib/CcExitLib.inf
TdxLib|MdePkg/Library/TdxLib/TdxLib.inf

2
OvmfPkg/CloudHv/CloudHvX64.dsc
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@ -242,7 +242,7 @@
!include OvmfPkg/Include/Dsc/OvmfTpmLibs.dsc.inc
[LibraryClasses.common]
AmdSvsmLib|UefiCpuPkg/Library/AmdSvsmLibNull/AmdSvsmLibNull.inf
AmdSvsmLib|OvmfPkg/Library/AmdSvsmLib/AmdSvsmLib.inf
BaseCryptLib|CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
CcExitLib|OvmfPkg/Library/CcExitLib/CcExitLib.inf
TdxLib|MdePkg/Library/TdxLib/TdxLib.inf

267
OvmfPkg/Library/AmdSvsmLib/AmdSvsmLib.c Normal file
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@ -0,0 +1,267 @@
/** @file
SVSM Support Library.
Copyright (C) 2024, Advanced Micro Devices, Inc. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Base.h>
#include <Uefi.h>
#include <Library/AmdSvsmLib.h>
#include <Register/Amd/Msr.h>
#include <Register/Amd/Svsm.h>
#define PAGES_PER_2MB_ENTRY 512
/**
Issue a GHCB termination request for termination.
Request termination using the GHCB MSR protocol.
**/
STATIC
VOID
SnpTerminate (
VOID
)
{
MSR_SEV_ES_GHCB_REGISTER Msr;
//
// Use the GHCB MSR Protocol to request termination by the hypervisor
//
Msr.Uint64 = 0;
Msr.GhcbTerminate.Function = GHCB_INFO_TERMINATE_REQUEST;
Msr.GhcbTerminate.ReasonCodeSet = GHCB_TERMINATE_GHCB;
Msr.GhcbTerminate.ReasonCode = GHCB_TERMINATE_GHCB_GENERAL;
AsmWriteMsr64 (MSR_SEV_ES_GHCB, Msr.Uint64);
AsmVmgExit ();
ASSERT (FALSE);
CpuDeadLoop ();
}
/**
Report the presence of an Secure Virtual Services Module (SVSM).
Determines the presence of an SVSM.
@retval TRUE An SVSM is present
@retval FALSE An SVSM is not present
**/
BOOLEAN
EFIAPI
AmdSvsmIsSvsmPresent (
VOID
)
{
SVSM_INFORMATION *SvsmInfo;
SvsmInfo = (SVSM_INFORMATION *)(UINTN)PcdGet32 (PcdOvmfSnpSecretsBase);
return (SvsmInfo != NULL && SvsmInfo->SvsmSize != 0);
}
/**
Report the VMPL level at which the SEV-SNP guest is running.
Determines the VMPL level at which the guest is running. If an SVSM is
not present, then it must be VMPL0, otherwise return what is reported
by the SVSM.
@return The VMPL level
**/
UINT8
EFIAPI
AmdSvsmSnpGetVmpl (
VOID
)
{
SVSM_INFORMATION *SvsmInfo;
SvsmInfo = (SVSM_INFORMATION *)(UINTN)PcdGet32 (PcdOvmfSnpSecretsBase);
return AmdSvsmIsSvsmPresent () ? SvsmInfo->SvsmGuestVmpl : 0;
}
/**
Report the Calling Area address (CAA) for the BSP of the SEV-SNP guest.
If an SVSM is present, the CAA for the BSP is returned.
@return The CAA
**/
UINT64
EFIAPI
AmdSvsmSnpGetCaa (
VOID
)
{
SVSM_INFORMATION *SvsmInfo;
SvsmInfo = (SVSM_INFORMATION *)(UINTN)PcdGet32 (PcdOvmfSnpSecretsBase);
return AmdSvsmIsSvsmPresent () ? SvsmInfo->SvsmCaa : 0;
}
/**
Perform a native PVALIDATE operation for the page ranges specified.
Validate or rescind the validation of the specified pages.
@param[in] Info Pointer to a page state change structure
**/
STATIC
VOID
BasePvalidate (
IN SNP_PAGE_STATE_CHANGE_INFO *Info
)
{
UINTN RmpPageSize;
UINTN StartIndex;
UINTN EndIndex;
UINTN Index;
UINTN Ret;
EFI_PHYSICAL_ADDRESS Address;
BOOLEAN Validate;
StartIndex = Info->Header.CurrentEntry;
EndIndex = Info->Header.EndEntry;
for ( ; StartIndex <= EndIndex; StartIndex++) {
//
// Get the address and the page size from the Info.
//
Address = ((EFI_PHYSICAL_ADDRESS)Info->Entry[StartIndex].GuestFrameNumber) << EFI_PAGE_SHIFT;
RmpPageSize = Info->Entry[StartIndex].PageSize;
Validate = Info->Entry[StartIndex].Operation == SNP_PAGE_STATE_PRIVATE;
Ret = AsmPvalidate (RmpPageSize, Validate, Address);
//
// If we fail to validate due to size mismatch then try with the
// smaller page size. This senario will occur if the backing page in
// the RMP entry is 4K and we are validating it as a 2MB.
//
if ((Ret == PVALIDATE_RET_SIZE_MISMATCH) && (RmpPageSize == PvalidatePageSize2MB)) {
for (Index = 0; Index < PAGES_PER_2MB_ENTRY; Index++) {
Ret = AsmPvalidate (PvalidatePageSize4K, Validate, Address);
if (Ret) {
break;
}
Address = Address + EFI_PAGE_SIZE;
}
}
//
// If validation failed then do not continue.
//
if (Ret) {
DEBUG ((
DEBUG_ERROR,
"%a:%a: Failed to %a address 0x%Lx Error code %d\n",
gEfiCallerBaseName,
__func__,
Validate ? "Validate" : "Invalidate",
Address,
Ret
));
SnpTerminate ();
}
}
}
/**
Perform a PVALIDATE operation for the page ranges specified.
Validate or rescind the validation of the specified pages.
@param[in] Info Pointer to a page state change structure
**/
VOID
EFIAPI
AmdSvsmSnpPvalidate (
IN SNP_PAGE_STATE_CHANGE_INFO *Info
)
{
BasePvalidate (Info);
}
/**
Perform a native RMPADJUST operation to alter the VMSA setting of a page.
Add or remove the VMSA attribute for a page.
@param[in] Vmsa Pointer to an SEV-ES save area page
@param[in] SetVmsa Boolean indicator as to whether to set or
or clear the VMSA setting for the page
@retval EFI_SUCCESS RMPADJUST operation successful
@retval EFI_INVALID_PARAMETER RMPADJUST operation failed, an invalid
parameter was supplied
**/
STATIC
EFI_STATUS
BaseVmsaRmpAdjust (
IN SEV_ES_SAVE_AREA *Vmsa,
IN BOOLEAN SetVmsa
)
{
UINT64 Rdx;
UINT32 Ret;
//
// The RMPADJUST instruction is used to set or clear the VMSA bit for a
// page. The VMSA change is only made when running at VMPL0 and is ignored
// otherwise. If too low a target VMPL is specified, the instruction can
// succeed without changing the VMSA bit when not running at VMPL0. Using a
// target VMPL level of 1, RMPADJUST will return a FAIL_PERMISSION error if
// not running at VMPL0, thus ensuring that the VMSA bit is set appropriately
// when no error is returned.
//
Rdx = 1;
if (SetVmsa) {
Rdx |= RMPADJUST_VMSA_PAGE_BIT;
}
Ret = AsmRmpAdjust ((UINT64)(UINTN)Vmsa, 0, Rdx);
return (Ret == 0) ? EFI_SUCCESS : EFI_INVALID_PARAMETER;
}
/**
Perform an RMPADJUST operation to alter the VMSA setting of a page.
Add or remove the VMSA attribute for a page.
@param[in] Vmsa Pointer to an SEV-ES save area page
@param[in] ApicId APIC ID associated with the VMSA
@param[in] SetVmsa Boolean indicator as to whether to set or
or clear the VMSA setting for the page
@retval EFI_SUCCESS RMPADJUST operation successful
@retval EFI_UNSUPPORTED Operation is not supported
@retval EFI_INVALID_PARAMETER RMPADJUST operation failed, an invalid
parameter was supplied
**/
EFI_STATUS
EFIAPI
AmdSvsmSnpVmsaRmpAdjust (
IN SEV_ES_SAVE_AREA *Vmsa,
IN UINT32 ApicId,
IN BOOLEAN SetVmsa
)
{
return BaseVmsaRmpAdjust (Vmsa, SetVmsa);
}

38
OvmfPkg/Library/AmdSvsmLib/AmdSvsmLib.inf Normal file
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@ -0,0 +1,38 @@
## @file
# CcExitLib Library.
#
# Copyright (C) 2024, Advanced Micro Devices, Inc. All rights reserved.<BR>
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
##
[Defines]
INF_VERSION = 1.29
BASE_NAME = AmdSvsmLib
FILE_GUID = 288e3588-87d8-4c2c-b568-bf900de0fb36
MODULE_TYPE = BASE
VERSION_STRING = 1.0
LIBRARY_CLASS = AmdSvsmLib
#
# The following information is for reference only and not required by the build tools.
#
# VALID_ARCHITECTURES = X64
#
[Sources.common]
AmdSvsmLib.c
[Packages]
MdePkg/MdePkg.dec
OvmfPkg/OvmfPkg.dec
UefiCpuPkg/UefiCpuPkg.dec
[LibraryClasses]
BaseLib
BaseMemoryLib
DebugLib
[Pcd]
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize

2
OvmfPkg/Microvm/MicrovmX64.dsc
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@ -246,7 +246,7 @@
!include OvmfPkg/Include/Dsc/ShellLibs.dsc.inc
[LibraryClasses.common]
AmdSvsmLib|UefiCpuPkg/Library/AmdSvsmLibNull/AmdSvsmLibNull.inf
AmdSvsmLib|OvmfPkg/Library/AmdSvsmLib/AmdSvsmLib.inf
BaseCryptLib|CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
CcExitLib|OvmfPkg/Library/CcExitLib/CcExitLib.inf
SerialPortLib|MdeModulePkg/Library/BaseSerialPortLib16550/BaseSerialPortLib16550.inf

2
OvmfPkg/OvmfPkgX64.dsc
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@ -268,7 +268,7 @@
!include OvmfPkg/Include/Dsc/ShellLibs.dsc.inc
[LibraryClasses.common]
AmdSvsmLib|UefiCpuPkg/Library/AmdSvsmLibNull/AmdSvsmLibNull.inf
AmdSvsmLib|OvmfPkg/Library/AmdSvsmLib/AmdSvsmLib.inf
BaseCryptLib|CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
CcExitLib|OvmfPkg/Library/CcExitLib/CcExitLib.inf
TdxLib|MdePkg/Library/TdxLib/TdxLib.inf