[PATCH 16/23] OvmfPkg: Add TdxMailboxLib

["Min Xu" <min.m.xu@intel.com>]

RFC： https://bugzilla.tianocore.org/show_bug.cgi?id=3429

In Tdx BSP may issues commands to APs for some task, for example, to
accept pages paralelly. BSP also need to wait until all the APs have
done the task. TdxMailboxLib wraps these common funtions for BSP.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
---
 OvmfPkg/Include/Library/TdxMailboxLib.h       |  75 ++++++++++
 OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c    | 138 ++++++++++++++++++
 .../Library/TdxMailboxLib/TdxMailboxLib.inf   |  52 +++++++
 .../Library/TdxMailboxLib/TdxMailboxNull.c    |  86 +++++++++++
 OvmfPkg/OvmfPkg.dec                           |   4 +
 5 files changed, 355 insertions(+)
 create mode 100644 OvmfPkg/Include/Library/TdxMailboxLib.h
 create mode 100644 OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c
 create mode 100644 OvmfPkg/Library/TdxMailboxLib/TdxMailboxLib.inf
 create mode 100644 OvmfPkg/Library/TdxMailboxLib/TdxMailboxNull.c

diff --git a/OvmfPkg/Include/Library/TdxMailboxLib.h b/OvmfPkg/Include/Library/TdxMailboxLib.h
new file mode 100644
index 000000000000..a410a9618495
--- /dev/null
+++ b/OvmfPkg/Include/Library/TdxMailboxLib.h
@@ -0,0 +1,75 @@
+/** @file
+
+  Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+#ifndef __TDX_MAILBOX_LIB_H__
+#define __TDX_MAILBOX_LIB_H__
+
+#include <Library/BaseLib.h>
+#include <Uefi/UefiBaseType.h>
+#include <Uefi/UefiSpec.h>
+#include <Pi/PiPeiCis.h>
+#include <Library/DebugLib.h>
+#include <Protocol/DebugSupport.h>
+
+/**
+  This function will be called by BSP to get the CPU number.
+
+  @retval   CPU number
+**/
+UINT32
+EFIAPI
+GetCpusNum (
+  VOID
+);
+
+/**
+  Get the address of Td mailbox.
+**/
+volatile VOID *
+EFIAPI
+GetTdxMailBox (
+  VOID
+);
+
+/**
+  This function will be called by BSP to wakeup APs the are spinning on mailbox
+  in protected mode
+
+  @param[in] Command          Command to send APs
+  @param[in] WakeupVector     If used, address for APs to start executing
+  @param[in] WakeArgsX        Args to pass to APs for excuting commands
+**/
+VOID
+EFIAPI
+MpSendWakeupCommand(
+  IN UINT16 Command,
+  IN UINT64 WakeupVector,
+  IN UINT64 WakeupArgs1,
+  IN UINT64 WakeupArgs2,
+  IN UINT64 WakeupArgs3,
+  IN UINT64 WakeupArgs4
+);
+
+/**
+  BSP wait until all the APs arriving. It means the task triggered by BSP is started.
+**/
+VOID
+EFIAPI
+MpSerializeStart (
+  VOID
+  );
+
+/**
+  BSP wait until all the APs arriving. It means the task triggered by BSP is ended.
+**/
+VOID
+EFIAPI
+MpSerializeEnd (
+  VOID
+  );
+
+#endif
diff --git a/OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c b/OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c
new file mode 100644
index 000000000000..688ac6ca8262
--- /dev/null
+++ b/OvmfPkg/Library/TdxMailboxLib/TdxMailbox.c
@@ -0,0 +1,138 @@
+/** @file
+
+  Copyright (c) 2008, Intel Corporation. All rights reserved.<BR>
+  (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/PcdLib.h>
+#include <Library/UefiCpuLib.h>
+#include <Library/SynchronizationLib.h>
+#include <Library/TdxLib.h>
+#include <IndustryStandard/IntelTdx.h>
+#include <IndustryStandard/Tdx.h>
+#include <Library/TdxMailboxLib.h>
+
+volatile VOID *mMailBox = NULL;
+UINT32  mNumOfCpus = 0;
+
+/**
+  This function will be called by BSP to get the CPU number.
+
+  @retval   CPU number
+**/
+UINT32
+EFIAPI
+GetCpusNum (
+  VOID
+  )
+{
+  if (mNumOfCpus == 0) {
+    mNumOfCpus = TdVCpuNum ();
+  }
+
+  return mNumOfCpus;
+}
+
+/**
+  Get the address of Td mailbox.
+**/
+volatile VOID *
+EFIAPI
+GetTdxMailBox (
+  VOID
+  )
+{
+  if (mMailBox == NULL) {
+    mMailBox = (VOID *)(UINTN) PcdGet32 (PcdOvmfSecGhcbBackupBase);
+  }
+
+  return mMailBox;
+}
+
+/**
+  This function will be called by BSP to wakeup APs the are spinning on mailbox
+  in protected mode
+
+  @param[in] Command          Command to send APs
+  @param[in] WakeupVector     If used, address for APs to start executing
+  @param[in] WakeArgsX        Args to pass to APs for excuting commands
+**/
+VOID
+EFIAPI
+MpSendWakeupCommand (
+  IN UINT16 Command,
+  IN UINT64 WakeupVector,
+  IN UINT64 WakeupArgs1,
+  IN UINT64 WakeupArgs2,
+  IN UINT64 WakeupArgs3,
+  IN UINT64 WakeupArgs4
+)
+{
+  volatile MP_WAKEUP_MAILBOX  *MailBox;
+
+  MailBox = (volatile MP_WAKEUP_MAILBOX *) GetTdxMailBox ();
+  MailBox->ApicId = MP_CPU_PROTECTED_MODE_MAILBOX_APICID_INVALID;
+  MailBox->WakeUpVector = 0;
+  MailBox->Command = MpProtectedModeWakeupCommandNoop;
+  MailBox->ApicId = MP_CPU_PROTECTED_MODE_MAILBOX_APICID_BROADCAST;
+  MailBox->WakeUpVector = WakeupVector;
+  MailBox->WakeUpArgs1 = WakeupArgs1;
+  MailBox->WakeUpArgs2 = WakeupArgs2;
+  MailBox->WakeUpArgs3 = WakeupArgs3;
+  MailBox->WakeUpArgs4 = WakeupArgs4;
+  AsmCpuid (0x01, NULL, NULL, NULL, NULL);
+  MailBox->Command = Command;
+  AsmCpuid (0x01, NULL, NULL, NULL, NULL);
+  return;
+}
+
+/**
+  BSP wait until all the APs arriving. It means the task triggered by BSP is started.
+**/
+VOID
+EFIAPI
+MpSerializeStart (
+  VOID
+  )
+{
+  volatile MP_WAKEUP_MAILBOX  *MailBox;
+  UINT32                      NumOfCpus;
+
+  NumOfCpus = GetCpusNum ();
+  MailBox = (volatile MP_WAKEUP_MAILBOX *) GetTdxMailBox ();
+
+  DEBUG ((DEBUG_VERBOSE, "Waiting for APs to arriving. NumOfCpus=%d, MailBox=%p\n", NumOfCpus, MailBox));
+  while (MailBox->NumCpusArriving != ( NumOfCpus -1 )) {
+    CpuPause ();
+  }
+  DEBUG ((DEBUG_VERBOSE, "Releasing APs\n"));
+  MailBox->NumCpusExiting = NumOfCpus;
+  InterlockedIncrement ((UINT32 *) &MailBox->NumCpusArriving);
+}
+
+/**
+  BSP wait until all the APs arriving. It means the task triggered by BSP is ended.
+**/
+VOID
+EFIAPI
+MpSerializeEnd (
+  VOID
+  )
+{
+  volatile MP_WAKEUP_MAILBOX  *MailBox;
+
+  MailBox = (volatile MP_WAKEUP_MAILBOX *) GetTdxMailBox ();
+  DEBUG ((DEBUG_VERBOSE, "Waiting for APs to finish\n"));
+  while (MailBox->NumCpusExiting != 1 ) {
+    CpuPause ();
+  }
+  DEBUG ((DEBUG_VERBOSE, "Restarting APs\n"));
+  MailBox->Command = MpProtectedModeWakeupCommandNoop;
+  MailBox->NumCpusArriving = 0;
+  InterlockedDecrement ((UINT32 *) &MailBox->NumCpusExiting);
+}
diff --git a/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLib.inf b/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLib.inf
new file mode 100644
index 000000000000..3cf3690a16c7
--- /dev/null
+++ b/OvmfPkg/Library/TdxMailboxLib/TdxMailboxLib.inf
@@ -0,0 +1,52 @@
+#/** @file
+#
+#  TBD
+#
+#  Copyright (c) 2018, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2008, Apple Inc. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = TdxMailboxLib
+  FILE_GUID                      = 2F81A9BA-748E-4519-BB11-A63A039D561E
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = TdxMailboxLib
+
+#
+#  VALID_ARCHITECTURES           = X64 IA32
+#
+
+[Sources.IA32]
+  TdxMailboxNull.c
+
+[Sources.X64]
+  TdxMailbox.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  UefiCpuPkg/UefiCpuPkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  BaseMemoryLib
+  PcdLib
+  UefiCpuLib
+  DebugAgentLib
+  IoLib
+  SynchronizationLib
+  MemoryAllocationLib
+
+[Guids]
+
+[Pcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupBase
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupSize
diff --git a/OvmfPkg/Library/TdxMailboxLib/TdxMailboxNull.c b/OvmfPkg/Library/TdxMailboxLib/TdxMailboxNull.c
new file mode 100644
index 000000000000..f15222d51f45
--- /dev/null
+++ b/OvmfPkg/Library/TdxMailboxLib/TdxMailboxNull.c
@@ -0,0 +1,86 @@
+/** @file
+
+  Copyright (c) 2008, Intel Corporation. All rights reserved.<BR>
+  (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/TdxMailboxLib.h>
+
+
+/**
+  This function will be called by BSP to get the CPU number.
+
+  @retval   CPU number
+**/
+UINT32
+EFIAPI
+GetCpusNum (
+  VOID
+  )
+{
+  ASSERT (FALSE);
+  return 0;
+}
+
+/**
+  Get the address of Td mailbox.
+**/
+volatile VOID *
+EFIAPI
+GetTdxMailBox (
+  VOID
+  )
+{
+  ASSERT (FALSE);
+  return (volatile VOID *) NULL;
+}
+
+/**
+  This function will be called by BSP to wakeup APs the are spinning on mailbox
+  in protected mode
+
+  @param[in] Command          Command to send APs
+  @param[in] WakeupVector     If used, address for APs to start executing
+  @param[in] WakeArgsX        Args to pass to APs for excuting commands
+**/
+VOID
+EFIAPI
+MpSendWakeupCommand (
+  IN UINT16 Command,
+  IN UINT64 WakeupVector,
+  IN UINT64 WakeupArgs1,
+  IN UINT64 WakeupArgs2,
+  IN UINT64 WakeupArgs3,
+  IN UINT64 WakeupArgs4
+)
+{
+  ASSERT (FALSE);
+}
+
+/**
+  BSP wait until all the APs arriving. It means the task triggered by BSP is started.
+**/
+VOID
+EFIAPI
+MpSerializeStart (
+  VOID
+  )
+{
+  ASSERT (FALSE);
+}
+
+/**
+  BSP wait until all the APs arriving. It means the task triggered by BSP is ended.
+**/
+VOID
+EFIAPI
+MpSerializeEnd (
+  VOID
+  )
+{
+  ASSERT (FALSE);
+}
diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index 8d1f3b03488c..d478a4b8e418 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -109,6 +109,10 @@
   #
   XenPlatformLib|Include/Library/XenPlatformLib.h
 
+  ##  @libraryclass  TdxMailboxLib
+  #
+  TdxMailboxLib|Include/Library/TdxMailboxLib.h
+
 [Guids]
   gUefiOvmfPkgTokenSpaceGuid            = {0x93bb96af, 0xb9f2, 0x4eb8, {0x94, 0x62, 0xe0, 0xba, 0x74, 0x56, 0x42, 0x36}}
   gEfiXenInfoGuid                       = {0xd3b46f3b, 0xd441, 0x1244, {0x9a, 0x12, 0x0, 0x12, 0x27, 0x3f, 0xc1, 0x4d}}
-- 
2.29.2.windows.2