Re: [PATCH] MdeModulePkg: Add EFI_GCD_MEMORY_SPACE_NOTIFY_PROTOCOL

[Laszlo Ersek <lersek@redhat.com>]

Mike,

On 04/12/17 21:39, Kinney, Michael D wrote:
> Hi Leo,
> 
> DXE Main is supposed to use Arch Protocols for platform specific behavior.
> 
> In this case, can the CPU Arch Protocol SetMemoryAttributes() function
> be used to customize behavior?
> 
> In other modules that add/remove/modify MMIO, gDS->SetMemorySpaceAttributes()
> Is called to set memory space attributed such as cachability.  Can the
> module that is adding/removing memory regions from GCD also call
> gDS-> SetMemorySpaceAttributes() so a CPU specific module can perform
> extra actions?

The goal is to clear the "C" bit in the PTEs (--> disable encryption in
SEV guests) for all MMIO areas in the GCD memory space map, when they
are added, and to re-set the "C" bit when the area is removed (or the
area's GCD type is changed to something non-MMIO).

This behavior should cover all possible gDS->AddMemorySpace() calls (for
the MMIO type), regardless of what driver calls gDS->AddMemorySpace().
In other words, drivers that add MMIO space should remain unaware of SEV
/ the "C" bit in PTEs. Otherwise we'd have to enable SEV detection and
"C" bit massaging in every affected driver individually (even future
ones, possibly pulled in from under MdeModulePkg or UefiCpuPkg).
Cacheability and similar attributes for memory ranges are quite
universal on all architectures, and it is okay to expect all drivers to
manage those attributes manually (whenever that's necessary), but (a)
SEV / memory encryption is not that universal, and (b) clearing "C" for
MMIO ranges affects all drivers alike, so it would be good to generalize
it at a low level.

What would be the best general location or API to hook the "C" bit
manipulation into MMIO GCD memory space addition / removal?

Thank you,
Laszlo


> 
> Thanks,
> 
> Mike
> 
> 
> 
>> -----Original Message-----
>> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Leo Duran
>> Sent: Wednesday, April 12, 2017 11:57 AM
>> To: edk2-devel@ml01.01.org
>> Cc: Laszlo Ersek <lersek@redhat.com>; Tian, Feng <feng.tian@intel.com>; Leo Duran
>> <leo.duran@amd.com>; Brijesh Singh <brijesh.singh@amd.com>; Zeng, Star
>> <star.zeng@intel.com>
>> Subject: [edk2] [PATCH] MdeModulePkg: Add EFI_GCD_MEMORY_SPACE_NOTIFY_PROTOCOL
>>
>> GCD consumes the protocol to issue a Notify() on Add/Remove operations.
>>
>> The intended use-case is to allow OvmfPkg take actions on behalf of an
>> SEV-enabled guest.
>>
>> The new protocol is simply added to the list of optional protocols handled
>> by DxeMain, and as such leverages the existing DxeProtocolNotify framework.
>>
>> Cc: Feng Tian <feng.tian@intel.com>
>> Cc: Star Zeng <star.zeng@intel.com>
>> Cc: Laszlo Ersek <lersek@redhat.com>
>> Cc: Brijesh Singh <brijesh.singh@amd.com>
>> Contributed-under: TianoCore Contribution Agreement 1.0
>> Signed-off-by: Leo Duran <leo.duran@amd.com>
>> ---
>>  MdeModulePkg/Core/Dxe/DxeMain.h                    | 10 +++-
>>  MdeModulePkg/Core/Dxe/DxeMain.inf                  |  4 ++
>>  MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c            |  7 +++
>>  MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c  |  9 ++-
>>  MdeModulePkg/Core/Dxe/Gcd/Gcd.c                    |  8 +++
>>  .../Include/Protocol/GcdMemorySpaceNotify.h        | 65 ++++++++++++++++++++++
>>  MdeModulePkg/MdeModulePkg.dec                      |  3 +
>>  7 files changed, 100 insertions(+), 6 deletions(-)
>>  create mode 100644 MdeModulePkg/Include/Protocol/GcdMemorySpaceNotify.h
>>
>> diff --git a/MdeModulePkg/Core/Dxe/DxeMain.h b/MdeModulePkg/Core/Dxe/DxeMain.h
>> index 1a0babb..8a037ff 100644
>> --- a/MdeModulePkg/Core/Dxe/DxeMain.h
>> +++ b/MdeModulePkg/Core/Dxe/DxeMain.h
>> @@ -3,6 +3,8 @@
>>    internal structure and functions used by DxeCore module.
>>
>>  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
>> +Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
>> +
>>  This program and the accompanying materials
>>  are licensed and made available under the terms and conditions of the BSD
>> License
>>  which accompanies this distribution.  The full text of the license may be found
>> at
>> @@ -17,7 +19,6 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>> EXPRESS OR IMPLIED.
>>  #define _DXE_MAIN_H_
>>
>>
>> -
>>  #include <PiDxe.h>
>>
>>  #include <Protocol/LoadedImage.h>
>> @@ -53,6 +54,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>> EXPRESS OR IMPLIED.
>>  #include <Protocol/TcgService.h>
>>  #include <Protocol/HiiPackageList.h>
>>  #include <Protocol/SmmBase2.h>
>> +#include <Protocol/GcdMemorySpaceNotify.h>
>> +
>>  #include <Guid/MemoryTypeInformation.h>
>>  #include <Guid/FirmwareFileSystem2.h>
>>  #include <Guid/FirmwareFileSystem3.h>
>> @@ -296,12 +299,13 @@ extern EFI_RUNTIME_ARCH_PROTOCOL
>> gRuntimeTemplate;
>>
>>  extern EFI_LOAD_FIXED_ADDRESS_CONFIGURATION_TABLE
>> gLoadModuleAtFixAddressConfigurationTable;
>>  extern BOOLEAN
>> gLoadFixedAddressCodeMemoryReady;
>> +
>> +extern EFI_GCD_MEMORY_SPACE_NOTIFY_PROTOCOL     *gGcdMemorySpaceNotify;
>> +
>>  //
>>  // Service Initialization Functions
>>  //
>>
>> -
>> -
>>  /**
>>    Called to initialize the pool.
>>
>> diff --git a/MdeModulePkg/Core/Dxe/DxeMain.inf
>> b/MdeModulePkg/Core/Dxe/DxeMain.inf
>> index 30d5984..888a16f 100644
>> --- a/MdeModulePkg/Core/Dxe/DxeMain.inf
>> +++ b/MdeModulePkg/Core/Dxe/DxeMain.inf
>> @@ -4,6 +4,8 @@
>>  #  It provides an implementation of DXE Core that is compliant with DXE CIS.
>>  #
>>  #  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
>> +#  Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
>> +#
>>  #  This program and the accompanying materials
>>  #  are licensed and made available under the terms and conditions of the BSD
>> License
>>  #  which accompanies this distribution.  The full text of the license may be
>> found at
>> @@ -162,6 +164,8 @@
>>    gEfiSmmBase2ProtocolGuid                      ## SOMETIMES_CONSUMES
>>    gEfiBlockIoProtocolGuid                       ## SOMETIMES_CONSUMES
>>
>> +  gEfiGcdMemorySpaceNotifyProtocolGuid          ## CONSUMES
>> +
>>    # Arch Protocols
>>    gEfiBdsArchProtocolGuid                       ## CONSUMES
>>    gEfiCpuArchProtocolGuid                       ## CONSUMES
>> diff --git a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
>> b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
>> index 91e94a7..46b68da 100644
>> --- a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
>> +++ b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
>> @@ -2,6 +2,8 @@
>>    DXE Core Main Entry Point
>>
>>  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
>> +Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
>> +
>>  This program and the accompanying materials
>>  are licensed and made available under the terms and conditions of the BSD
>> License
>>  which accompanies this distribution.  The full text of the license may be found
>> at
>> @@ -42,6 +44,11 @@ EFI_GUID                           *gDxeCoreFileName;
>>  EFI_LOADED_IMAGE_PROTOCOL          *gDxeCoreLoadedImage;
>>
>>  //
>> +// DXE Core global for GCD notification protocol
>> +//
>> +EFI_GCD_MEMORY_SPACE_NOTIFY_PROTOCOL  *gGcdMemorySpaceNotify = NULL;
>> +
>> +//
>>  // DXE Core Module Variables
>>  //
>>  EFI_BOOT_SERVICES mBootServices = {
>> diff --git a/MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c
>> b/MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c
>> index ea7c610..2314e34 100644
>> --- a/MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c
>> +++ b/MdeModulePkg/Core/Dxe/DxeMain/DxeProtocolNotify.c
>> @@ -4,6 +4,8 @@
>>    events that represent the Architectural Protocols.
>>
>>  Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
>> +Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
>> +
>>  This program and the accompanying materials
>>  are licensed and made available under the terms and conditions of the BSD
>> License
>>  which accompanies this distribution.  The full text of the license may be found
>> at
>> @@ -45,9 +47,10 @@ EFI_CORE_PROTOCOL_NOTIFY_ENTRY  mArchProtocols[] = {
>>  // Optional protocols that the DXE Core will use if they are present
>>  //
>>  EFI_CORE_PROTOCOL_NOTIFY_ENTRY  mOptionalProtocols[] = {
>> -  { &gEfiSecurity2ArchProtocolGuid,        (VOID **)&gSecurity2,     NULL, NULL,
>> FALSE },
>> -  { &gEfiSmmBase2ProtocolGuid,             (VOID **)&gSmmBase2,      NULL, NULL,
>> FALSE },
>> -  { NULL,                                  (VOID **)NULL,            NULL, NULL,
>> FALSE }
>> +  { &gEfiSecurity2ArchProtocolGuid,        (VOID **)&gSecurity2,
>> NULL, NULL, FALSE },
>> +  { &gEfiSmmBase2ProtocolGuid,             (VOID **)&gSmmBase2,
>> NULL, NULL, FALSE },
>> +  { &gEfiGcdMemorySpaceNotifyProtocolGuid, (VOID **)&gGcdMemorySpaceNotify,
>> NULL, NULL, FALSE },
>> +  { NULL,                                  (VOID **)NULL,
>> NULL, NULL, FALSE }
>>  };
>>
>>  //
>> diff --git a/MdeModulePkg/Core/Dxe/Gcd/Gcd.c b/MdeModulePkg/Core/Dxe/Gcd/Gcd.c
>> index a06f8bb..223fcd8 100644
>> --- a/MdeModulePkg/Core/Dxe/Gcd/Gcd.c
>> +++ b/MdeModulePkg/Core/Dxe/Gcd/Gcd.c
>> @@ -4,6 +4,8 @@
>>    are accessible to the CPU that is executing the DXE core.
>>
>>  Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
>> +Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
>> +
>>  This program and the accompanying materials
>>  are licensed and made available under the terms and conditions of the BSD
>> License
>>  which accompanies this distribution.  The full text of the license may be found
>> at
>> @@ -896,6 +898,9 @@ CoreConvertSpace (
>>        } else {
>>          Entry->Capabilities  = Capabilities | EFI_MEMORY_RUNTIME;
>>        }
>> +      if (gGcdMemorySpaceNotify) {
>> +        gGcdMemorySpaceNotify->MemorySpaceAddNotify (GcdMemoryType, BaseAddress,
>> Length, Entry->Capabilities);
>> +      }
>>        break;
>>      case GCD_ADD_IO_OPERATION:
>>        Entry->GcdIoType = GcdIoType;
>> @@ -914,6 +919,9 @@ CoreConvertSpace (
>>      case GCD_REMOVE_MEMORY_OPERATION:
>>        Entry->GcdMemoryType = EfiGcdMemoryTypeNonExistent;
>>        Entry->Capabilities  = 0;
>> +      if (gGcdMemorySpaceNotify) {
>> +        gGcdMemorySpaceNotify->MemorySpaceRemoveNotify (BaseAddress, Length);
>> +      }
>>        break;
>>      case GCD_REMOVE_IO_OPERATION:
>>        Entry->GcdIoType = EfiGcdIoTypeNonExistent;
>> diff --git a/MdeModulePkg/Include/Protocol/GcdMemorySpaceNotify.h
>> b/MdeModulePkg/Include/Protocol/GcdMemorySpaceNotify.h
>> new file mode 100644
>> index 0000000..9174957
>> --- /dev/null
>> +++ b/MdeModulePkg/Include/Protocol/GcdMemorySpaceNotify.h
>> @@ -0,0 +1,65 @@
>> +/** @file
>> +  This file declares the GcdMemorySpaceNotify Protocol.
>> +
>> +  This Protocol is consumed by GCD to issue notications during ADD/REMOVE
>> operations.
>> +
>> +  Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
>> +
>> +  This program and the accompanying materials
>> +  are licensed and made available under the terms and conditions of the BSD
>> License
>> +  which accompanies this distribution.  The full text of the license may be
>> found at
>> +  http://opensource.org/licenses/bsd-license.php
>> +
>> +  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
>> +  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
>> +
>> +**/
>> +
>> +#ifndef __EFI_GCD_MEMORY_SPACE_NOTIFY_H__
>> +#define __EFI_GCD_MEMORY_SPACE_NOTIFY_H__
>> +
>> +#define EFI_GCD_MEMORY_SPACE_NOTIFY_GUID \
>> +  { \
>> +    0xc842db69, 0x610e, 0x401a, {0x90, 0xd0, 0x88, 0x41, 0xf1, 0xdc, 0x53, 0x79
>> } \
>> +  }
>> +
>> +/**
>> +  Notify on: Add a segment of memory to GCD map.
>> +
>> +  @param  GcdMemoryType          Memory type of the segment.
>> +  @param  BaseAddress            Base address of the segment.
>> +  @param  Length                 Length of the segment.
>> +  @param  Capabilities           Alterable attributes of the segment.
>> +
>> +**/
>> +typedef
>> +VOID
>> +(EFIAPI *GCD_ADD_MEMORY_NOTIFY) (
>> +  IN EFI_GCD_MEMORY_TYPE   GcdMemoryType,
>> +  IN EFI_PHYSICAL_ADDRESS  BaseAddress,
>> +  IN UINT64                Length,
>> +  IN UINT64                Capabilities
>> +);
>> +
>> +/**
>> +  Notify on: Remove a segment of memory to GCD map.
>> +
>> +  @param  BaseAddress            Base address of the segment.
>> +  @param  Length                 Length of the segment.
>> +
>> +**/
>> +typedef
>> +VOID
>> +(EFIAPI *GCD_REMOVE_MEMORY_NOTIFY) (
>> +  IN EFI_PHYSICAL_ADDRESS  BaseAddress,
>> +  IN UINT64                Length
>> +);
>> +
>> +typedef struct {
>> +  GCD_ADD_MEMORY_NOTIFY     MemorySpaceAddNotify;
>> +  GCD_REMOVE_MEMORY_NOTIFY  MemorySpaceRemoveNotify;
>> +} EFI_GCD_MEMORY_SPACE_NOTIFY_PROTOCOL;
>> +
>> +extern EFI_GUID gEfiGcdMemorySpaceNotifyProtocolGuid;
>> +
>> +#endif
>> diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
>> index ca09cbc..95f9311 100644
>> --- a/MdeModulePkg/MdeModulePkg.dec
>> +++ b/MdeModulePkg/MdeModulePkg.dec
>> @@ -546,6 +546,9 @@
>>    ## Include/Protocol/NonDiscoverableDevice.h
>>    gEdkiiNonDiscoverableDeviceProtocolGuid = { 0x0d51905b, 0xb77e, 0x452a, {0xa2,
>> 0xc0, 0xec, 0xa0, 0xcc, 0x8d, 0x51, 0x4a } }
>>
>> +  ## Include/Protocol/GcdMemorySpaceNotify.h
>> +  gEfiGcdMemorySpaceNotifyProtocolGuid  = { 0xc842db69, 0x610e, 0x401a, {0x90,
>> 0xd0, 0x88, 0x41, 0xf1, 0xdc, 0x53, 0x79 } }
>> +
>>  #
>>  # [Error.gEfiMdeModulePkgTokenSpaceGuid]
>>  #   0x80000001 | Invalid value provided.
>> --
>> 2.7.4
>>
>> _______________________________________________
>> edk2-devel mailing list
>> edk2-devel@lists.01.org
>> https://lists.01.org/mailman/listinfo/edk2-devel