[edk2-devel] [PATCH v4 07/40] UefiCpuPkg: Implement library support for VMGEXIT
Lendacky, Thomas
thomas.lendacky at amd.com
Fri Feb 14 17:56:07 UTC 2020
On 2/13/20 6:42 PM, Dong, Eric wrote:
> Hi Tom,
>
> For this patch, I found the function implementations not have function header comments for them. This is not follow edk2 coding style, please update them.
Yup, missed them, will do.
Thanks,
Tom
>
> Thanks,
> Eric
>
> -----Original Message-----
> From: devel at edk2.groups.io <devel at edk2.groups.io> On Behalf Of Lendacky, Thomas
> Sent: Wednesday, February 5, 2020 7:01 AM
> To: devel at edk2.groups.io
> Cc: Justen, Jordan L <jordan.l.justen at intel.com>; Laszlo Ersek <lersek at redhat.com>; Ard Biesheuvel <ard.biesheuvel at linaro.org>; Kinney, Michael D <michael.d.kinney at intel.com>; Gao, Liming <liming.gao at intel.com>; Dong, Eric <eric.dong at intel.com>; Ni, Ray <ray.ni at intel.com>; Brijesh Singh <brijesh.singh at amd.com>
> Subject: [edk2-devel] [PATCH v4 07/40] UefiCpuPkg: Implement library support for VMGEXIT
>
> BZ: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D2198&data=02%7C01%7Cthomas.lendacky%40amd.com%7Ca5720d7a6a5d4e744f9108d7b0e6bf80%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637172377418610890&sdata=OpW4YzwW9NW4qr9PRvh%2FTgWO28Dt3vGXxA7%2FnYwUsjw%3D&reserved=0
>
> To support issuing a VMGEXIT instruction, create a library that can be used to perform GHCB and VMGEXIT related operations and to issue the actual VMGEXIT instruction when using the GHCB.
>
> Additionally, two VMGEXIT / MMIO related functions are created to support flash emulation. Flash emulation currently is done by marking the flash area as read-only and taking a nested page fault to perform the emulation of the instruction. However, emulation cannot be performed because there is no instruction decode assist support when SEV-ES is enabled. Provide routines to initiate an MMIO request to perform actual writes to flash.
>
> Cc: Eric Dong <eric.dong at intel.com>
> Cc: Ray Ni <ray.ni at intel.com>
> Cc: Laszlo Ersek <lersek at redhat.com>
> Acked-by: Laszlo Ersek <lersek at redhat.com>
> Signed-off-by: Tom Lendacky <thomas.lendacky at amd.com>
> ---
> UefiCpuPkg/UefiCpuPkg.dec | 3 +
> UefiCpuPkg/UefiCpuPkg.dsc | 5 +
> UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf | 33 ++++
> UefiCpuPkg/Include/Library/VmgExitLib.h | 111 +++++++++++
> UefiCpuPkg/Library/VmgExitLib/VmgExitLib.c | 187 +++++++++++++++++++
> UefiCpuPkg/Library/VmgExitLib/VmgExitLib.uni | 15 ++
> 6 files changed, 354 insertions(+)
> create mode 100644 UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf
> create mode 100644 UefiCpuPkg/Include/Library/VmgExitLib.h
> create mode 100644 UefiCpuPkg/Library/VmgExitLib/VmgExitLib.c
> create mode 100644 UefiCpuPkg/Library/VmgExitLib/VmgExitLib.uni
>
> diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec index 005703d8a3e7..893d2d06b0f2 100644
> --- a/UefiCpuPkg/UefiCpuPkg.dec
> +++ b/UefiCpuPkg/UefiCpuPkg.dec
> @@ -53,6 +53,9 @@ [LibraryClasses.IA32, LibraryClasses.X64]
> ##
> MpInitLib|Include/Library/MpInitLib.h
>
> + ## @libraryclass Provides function to support VMGEXIT processing.
> + VmgExitLib|Include/Library/VmgExitLib.h
> +
> [Guids]
> gUefiCpuPkgTokenSpaceGuid = { 0xac05bf33, 0x995a, 0x4ed4, { 0xaa, 0xb8, 0xef, 0x7a, 0xe8, 0xf, 0x5c, 0xb0 }}
> gMsegSmramGuid = { 0x5802bce4, 0xeeee, 0x4e33, { 0xa1, 0x30, 0xeb, 0xad, 0x27, 0xf0, 0xe4, 0x39 }}
> diff --git a/UefiCpuPkg/UefiCpuPkg.dsc b/UefiCpuPkg/UefiCpuPkg.dsc index d28cb5cccb52..5ab7e423e8ab 100644
> --- a/UefiCpuPkg/UefiCpuPkg.dsc
> +++ b/UefiCpuPkg/UefiCpuPkg.dsc
> @@ -63,6 +63,7 @@ [LibraryClasses.common.SEC]
> HobLib|MdePkg/Library/PeiHobLib/PeiHobLib.inf
> PeiServicesTablePointerLib|MdePkg/Library/PeiServicesTablePointerLibIdt/PeiServicesTablePointerLibIdt.inf
> MemoryAllocationLib|MdePkg/Library/PeiMemoryAllocationLib/PeiMemoryAllocationLib.inf
> + VmgExitLib|UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf
>
> [LibraryClasses.common.PEIM]
> MemoryAllocationLib|MdePkg/Library/PeiMemoryAllocationLib/PeiMemoryAllocationLib.inf
> @@ -74,6 +75,7 @@ [LibraryClasses.common.PEIM] [LibraryClasses.IA32.PEIM, LibraryClasses.X64.PEIM]
> PeiServicesTablePointerLib|MdePkg/Library/PeiServicesTablePointerLibIdt/PeiServicesTablePointerLibIdt.inf
> CpuExceptionHandlerLib|UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuExceptionHandlerLib.inf
> + VmgExitLib|UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf
>
> [LibraryClasses.common.DXE_DRIVER]
> MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
> @@ -81,12 +83,14 @@ [LibraryClasses.common.DXE_DRIVER]
> CpuExceptionHandlerLib|UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeCpuExceptionHandlerLib.inf
> MpInitLib|UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf
> RegisterCpuFeaturesLib|UefiCpuPkg/Library/RegisterCpuFeaturesLib/DxeRegisterCpuFeaturesLib.inf
> + VmgExitLib|UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf
>
> [LibraryClasses.common.DXE_SMM_DRIVER]
> SmmServicesTableLib|MdePkg/Library/SmmServicesTableLib/SmmServicesTableLib.inf
> MemoryAllocationLib|MdePkg/Library/SmmMemoryAllocationLib/SmmMemoryAllocationLib.inf
> HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
> CpuExceptionHandlerLib|UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmCpuExceptionHandlerLib.inf
> + VmgExitLib|UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf
>
> [LibraryClasses.common.UEFI_APPLICATION]
> UefiApplicationEntryPoint|MdePkg/Library/UefiApplicationEntryPoint/UefiApplicationEntryPoint.inf
> @@ -136,6 +140,7 @@ [Components.IA32, Components.X64]
> UefiCpuPkg/Library/SmmCpuPlatformHookLibNull/SmmCpuPlatformHookLibNull.inf
> UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
> UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf
> + UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf
> UefiCpuPkg/PiSmmCommunication/PiSmmCommunicationPei.inf
> UefiCpuPkg/PiSmmCommunication/PiSmmCommunicationSmm.inf
> UefiCpuPkg/SecCore/SecCore.inf
> diff --git a/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf b/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf
> new file mode 100644
> index 000000000000..6acfa779e75a
> --- /dev/null
> +++ b/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.inf
> @@ -0,0 +1,33 @@
> +## @file
> +# VMGEXIT Support Library.
> +#
> +# Copyright (c) 2019, Advanced Micro Devices, Inc. All rights
> +reserved.<BR> # SPDX-License-Identifier: BSD-2-Clause-Patent # ##
> +
> +[Defines]
> + INF_VERSION = 0x00010005
> + BASE_NAME = VmgExitLib
> + MODULE_UNI_FILE = VmgExitLib.uni
> + FILE_GUID = 3cd7368f-ef9b-4a9b-9571-2ed93813677e
> + MODULE_TYPE = BASE
> + VERSION_STRING = 1.0
> + LIBRARY_CLASS = VmgExitLib
> +
> +#
> +# The following information is for reference only and not required by the build tools.
> +#
> +# VALID_ARCHITECTURES = IA32 X64
> +#
> +
> +[Sources]
> + VmgExitLib.c
> +
> +[Packages]
> + MdePkg/MdePkg.dec
> + UefiCpuPkg/UefiCpuPkg.dec
> +
> +[LibraryClasses]
> + BaseLib
> +
> diff --git a/UefiCpuPkg/Include/Library/VmgExitLib.h b/UefiCpuPkg/Include/Library/VmgExitLib.h
> new file mode 100644
> index 000000000000..602b213f1f63
> --- /dev/null
> +++ b/UefiCpuPkg/Include/Library/VmgExitLib.h
> @@ -0,0 +1,111 @@
> +/** @file
> + Public header file for the VMGEXIT Support library class.
> +
> + This library class defines some routines used when invoking the
> + VMGEXIT instruction in support of SEV-ES.
> +
> + Copyright (c) 2019, Advanced Micro Devices, Inc. All rights
> + reserved.<BR>
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#ifndef __VMG_EXIT_LIB_H__
> +#define __VMG_EXIT_LIB_H__
> +
> +#include <Register/Amd/Ghcb.h>
> +
> +
> +/**
> + Perform VMGEXIT.
> +
> + Sets the necessary fields of the GHCB, invokes the VMGEXIT
> + instruction and then handles the return actions.
> +
> + @param[in] GHCB A pointer to the GHCB
> + @param[in] ExitCode VMGEXIT code to be assigned to the SwExitCode field of
> + the GHCB.
> + @param[in] ExitInfo1 VMGEXIT information to be assigned to the SwExitInfo1
> + field of the GHCB.
> + @param[in] ExitInfo2 VMGEXIT information to be assigned to the SwExitInfo2
> + field of the GHCB.
> +
> + @retval 0 VMGEXIT succeeded.
> + @retval Others VMGEXIT processing did not succeed. Exception number to
> + be issued.
> +
> +**/
> +UINTN
> +EFIAPI
> +VmgExit (
> + GHCB *Ghcb,
> + UINT64 ExitCode,
> + UINT64 ExitInfo1,
> + UINT64 ExitInfo2
> + );
> +
> +/**
> + Perform pre-VMGEXIT initialization/preparation.
> +
> + Performs the necessary steps in preparation for invoking VMGEXIT.
> +
> + @param[in] GHCB A pointer to the GHCB
> +
> +**/
> +VOID
> +EFIAPI
> +VmgInit (
> + GHCB *Ghcb
> + );
> +
> +/**
> + Perform post-VMGEXIT cleanup.
> +
> + Performs the necessary steps to cleanup after invoking VMGEXIT.
> +
> + @param[in] GHCB A pointer to the GHCB
> +
> +**/
> +VOID
> +EFIAPI
> +VmgDone (
> + GHCB *Ghcb
> + );
> +
> +#define VMGMMIO_READ False
> +#define VMGMMIO_WRITE True
> +
> +/**
> + Perform MMIO write of a buffer to a non-MMIO marked range.
> +
> + Performs an MMIO write without taking a #VC. This is useful for
> + Flash devices, which are marked read-only.
> +
> + @param[in] UINT8 A pointer to the destination buffer
> + @param[in] UINTN The immediate value to write
> + @param[in] UINTN Number of bytes to write
> +
> +**/
> +VOID
> +EFIAPI
> +VmgMmioWrite (
> + UINT8 *Dest,
> + UINT8 *Src,
> + UINTN Bytes
> + );
> +
> +/**
> + Issue the GHCB set AP Jump Table VMGEXIT.
> +
> + Performs a VMGEXIT using the GHCB AP Jump Table exit code to save the
> + AP Jump Table address with the hypervisor for retrieval at a later time.
> +
> + @param[in] EFI_PHYSICAL_ADDRESS Physical address of the AP Jump
> + Table
> +
> +**/
> +UINTN
> +EFIAPI
> +VmgExitSetAPJumpTable (
> + EFI_PHYSICAL_ADDRESS Address
> + );
> +
> +#endif
> diff --git a/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.c b/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.c
> new file mode 100644
> index 000000000000..4e7315a58202
> --- /dev/null
> +++ b/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.c
> @@ -0,0 +1,187 @@
> +/** @file
> + VMGEXIT Support Library.
> +
> + Copyright (c) 2019, Advanced Micro Devices, Inc. All rights
> + reserved.<BR>
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <Base.h>
> +#include <Uefi.h>
> +#include <Library/BaseMemoryLib.h>
> +#include <Register/Amd/Ghcb.h>
> +#include <Register/Amd/Msr.h>
> +
> +STATIC
> +UINT64
> +VmgExitErrorCheck (
> + GHCB *Ghcb
> + )
> +{
> + GHCB_EVENT_INJECTION Event;
> + GHCB_EXIT_INFO ExitInfo;
> + UINT64 Status;
> +
> + ExitInfo.Uint64 = Ghcb->SaveArea.SwExitInfo1; ASSERT
> + ((ExitInfo.Elements.Lower32Bits == 0) ||
> + (ExitInfo.Elements.Lower32Bits == 1));
> +
> + Status = 0;
> + if (ExitInfo.Elements.Lower32Bits == 0) {
> + return Status;
> + }
> +
> + if (ExitInfo.Elements.Lower32Bits == 1) {
> + ASSERT (Ghcb->SaveArea.SwExitInfo2 != 0);
> +
> + // Check that the return event is valid
> + Event.Uint64 = Ghcb->SaveArea.SwExitInfo2;
> + if (Event.Elements.Valid &&
> + Event.Elements.Type == GHCB_EVENT_INJECTION_TYPE_EXCEPTION) {
> + switch (Event.Elements.Vector) {
> + case GP_EXCEPTION:
> + case UD_EXCEPTION:
> + // Use returned event as return code
> + Status = Event.Uint64;
> + }
> + }
> + }
> +
> + if (Status == 0) {
> + GHCB_EVENT_INJECTION Event;
> +
> + Event.Uint64 = 0;
> + Event.Elements.Vector = GP_EXCEPTION;
> + Event.Elements.Type = GHCB_EVENT_INJECTION_TYPE_EXCEPTION;
> + Event.Elements.Valid = 1;
> +
> + Status = Event.Uint64;
> + }
> +
> + return Status;
> +}
> +
> +UINT64
> +EFIAPI
> +VmgExit (
> + GHCB *Ghcb,
> + UINT64 ExitCode,
> + UINT64 ExitInfo1,
> + UINT64 ExitInfo2
> + )
> +{
> + Ghcb->SaveArea.SwExitCode = ExitCode;
> + Ghcb->SaveArea.SwExitInfo1 = ExitInfo1;
> + Ghcb->SaveArea.SwExitInfo2 = ExitInfo2;
> +
> + //
> + // Guest memory is used for the guest-hypervisor communication, so
> + fence // the invocation of the VMGEXIT instruction to ensure GHCB
> + accesses are // synchronized properly.
> + //
> + MemoryFence ();
> + AsmVmgExit ();
> + MemoryFence ();
> +
> + return VmgExitErrorCheck (Ghcb);
> +}
> +
> +VOID
> +EFIAPI
> +VmgInit (
> + GHCB *Ghcb
> + )
> +{
> + SetMem (&Ghcb->SaveArea, sizeof (Ghcb->SaveArea), 0); }
> +
> +VOID
> +EFIAPI
> +VmgDone (
> + GHCB *Ghcb
> + )
> +{
> +}
> +
> +UINTN
> +EFIAPI
> +VmgMmio (
> + UINT8 *MmioAddress,
> + UINT8 *Buffer,
> + UINTN Bytes,
> + BOOLEAN Write
> + )
> +{
> + UINT64 MmioOp, ExitInfo1, ExitInfo2, Status;
> + GHCB *Ghcb;
> + MSR_SEV_ES_GHCB_REGISTER Msr;
> +
> + Msr.GhcbPhysicalAddress = AsmReadMsr64 (MSR_SEV_ES_GHCB); Ghcb =
> + Msr.Ghcb;
> +
> + VmgInit (Ghcb);
> +
> + if (Write) {
> + MmioOp = SvmExitMmioWrite;
> + } else {
> + MmioOp = SvmExitMmioRead;
> + }
> +
> + ExitInfo1 = (UINT64) (UINTN) MmioAddress;
> + ExitInfo2 = Bytes;
> +
> + if (Write) {
> + CopyMem (Ghcb->SharedBuffer, Buffer, Bytes); }
> +
> + Ghcb->SaveArea.SwScratch = (UINT64) (UINTN) Ghcb->SharedBuffer;
> + Status = VmgExit (Ghcb, MmioOp, ExitInfo1, ExitInfo2); if (Status !=
> + 0) {
> + return Status;
> + }
> +
> + if (!Write) {
> + CopyMem (Buffer, Ghcb->SharedBuffer, Bytes); }
> +
> + VmgDone (Ghcb);
> +
> + return 0;
> +}
> +
> +VOID
> +EFIAPI
> +VmgMmioWrite (
> + UINT8 *Dest,
> + UINT8 *Src,
> + UINTN Bytes
> + )
> +{
> + VmgMmio (Dest, Src, Bytes, TRUE);
> +}
> +
> +UINTN
> +EFIAPI
> +VmgExitSetAPJumpTable (
> + EFI_PHYSICAL_ADDRESS Address
> + )
> +{
> + UINT64 ExitInfo1, ExitInfo2, Status;
> + GHCB *Ghcb;
> + MSR_SEV_ES_GHCB_REGISTER Msr;
> +
> + Msr.GhcbPhysicalAddress = AsmReadMsr64 (MSR_SEV_ES_GHCB); Ghcb =
> + Msr.Ghcb;
> +
> + VmgInit (Ghcb);
> +
> + ExitInfo1 = 0;
> + ExitInfo2 = (UINT64) (UINTN) Address;
> +
> + Status = VmgExit (Ghcb, SvmExitApJumpTable, ExitInfo1, ExitInfo2);
> +
> + VmgDone (Ghcb);
> +
> + return Status;
> +}
> +
> diff --git a/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.uni b/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.uni
> new file mode 100644
> index 000000000000..e8656aae4726
> --- /dev/null
> +++ b/UefiCpuPkg/Library/VmgExitLib/VmgExitLib.uni
> @@ -0,0 +1,15 @@
> +// /** @file
> +// VMGEXIT support library instance.
> +//
> +// VMGEXIT support library instance.
> +//
> +// Copyright (c) 2019, Advanced Micro Devices, Inc. All rights
> +reserved.<BR> // SPDX-License-Identifier: BSD-2-Clause-Patent // // **/
> +
> +
> +#string STR_MODULE_ABSTRACT #language en-US "VMGEXIT Support Library."
> +
> +#string STR_MODULE_DESCRIPTION #language en-US "VMGEXIT Support Library."
> +
> --
> 2.17.1
>
>
>
>
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