OvmfPkg: Add TdxDxe driver

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

TdxDxe driver is dispatched early in DXE, due to being list in APRIORI.
This module is responsible for below features:
 - Sets max logical cpus based on TDINFO
 - Sets PCI PCDs based on resource hobs
 - Set shared bit in MMIO region
 - Relocate Td mailbox and set its address in MADT table.

1. Set shared bit in MMIO region

Qemu allows a ROM device to set to ROMD mode (default) or MMIO mode.
When it is in ROMD mode, the device is mapped to guest memory and
satisfies read access directly.

In EDK2 Option ROM is treated as MMIO region. So Tdx guest access
Option ROM via TDVMCALL(MMIO). But as explained above, since Qemu set
the Option ROM to ROMD mode, the call of TDVMCALL(MMIO) always return
INVALID_OPERAND. Tdvf then falls back to direct access. This requires
to set the shared bit to corresponding PageTable entry. Otherwise it
triggers GP fault.

TdxDxe's entry point is the right place to set the shared bit in MMIO
region because Option ROM has not been discoverd yet.

2. Relocate Td mailbox and set the new address in MADT Mutiprocessor
Wakeup Table.

In TDX the guest firmware is designed to publish a multiprocessor-wakeup
structure to let the guest-bootstrap processor wake up guest-application
processors with a mailbox. The mailbox is memory that the guest firmware
can reserve so each guest virtual processor can have the guest OS send
a message to them. The address of the mailbox is recorded in the MADT
table. See [ACPI].

TdxDxe registers for protocol notification
(gQemuAcpiTableNotifyProtocolGuid) to call the AlterAcpiTable(), in
which MADT table is altered by the above Mailbox address. The protocol
will be installed in AcpiPlatformDxe when the MADT table provided by
Qemu is ready. This is to maintain the simplicity of the AcpiPlatformDxe.

AlterAcpiTable is the registered function which traverses the ACPI
table list to find the original MADT from Qemu. After the new MADT is
configured and installed, the original one will be uninstalled.

[ACPI] https://uefi.org/specs/ACPI/6.4/05_ACPI_Software_Programming_Model
/ACPI_Software_Programming_Model.html#multiprocessor-wakeup-structure

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>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>

1 files changed, 213 insertions, 0 deletions

diff --git a/OvmfPkg/TdxDxe/TdxAcpiTable.c b/OvmfPkg/TdxDxe/TdxAcpiTable.c
new file mode 100644
index 0000000..8a1abe8
--- /dev/null
+++ b/OvmfPkg/TdxDxe/TdxAcpiTable.c
@@ -0,0 +1,213 @@
+/** @file

+  OVMF ACPI QEMU support

+

+  Copyright (c) 2008 - 2014, Intel Corporation. All rights reserved.<BR>

+

+  Copyright (C) 2012-2014, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+

+**/

+

+#include <Library/DebugLib.h>

+#include <Library/BaseLib.h>

+#include <Library/BaseMemoryLib.h>

+#include <Library/MemoryAllocationLib.h>

+#include <Library/QemuFwCfgLib.h>

+#include <Library/DxeServicesTableLib.h>

+#include <Library/PcdLib.h>

+#include <Library/OrderedCollectionLib.h>

+#include <Library/TdxLib.h>

+#include <IndustryStandard/Acpi.h>

+#include <Protocol/AcpiSystemDescriptionTable.h>

+#include <Protocol/AcpiTable.h>

+#include <Library/UefiBootServicesTableLib.h>

+#include <Library/UefiLib.h>

+#include <Library/TdxMailboxLib.h>

+#include <Protocol/Cpu.h>

+#include <Uefi.h>

+#include <TdxAcpiTable.h>

+

+/**

+  At the beginning of system boot, a 4K-aligned, 4K-size memory (Td mailbox) is

+  pre-allocated by host VMM. BSP & APs do the page accept together in that memory

+  region.

+

+  After that TDVF is designed to relocate the mailbox to a 4K-aligned, 4K-size

+  memory block which is allocated in the ACPI Nvs memory. APs are waken up and

+  spin around the relocated mailbox for further command.

+

+  @return   EFI_PHYSICAL_ADDRESS    Address of the relocated mailbox

+**/

+EFI_PHYSICAL_ADDRESS

+EFIAPI

+RelocateMailbox (

+  VOID

+  )

+{

+  EFI_PHYSICAL_ADDRESS  Address;

+  VOID                  *ApLoopFunc;

+  UINT32                RelocationPages;

+  MP_RELOCATION_MAP     RelocationMap;

+  MP_WAKEUP_MAILBOX     *RelocatedMailBox;

+  EFI_STATUS            Status;

+

+  Address    = 0;

+  ApLoopFunc = NULL;

+  ZeroMem (&RelocationMap, sizeof (RelocationMap));

+

+  //

+  // Get information needed to setup aps running in their

+  // run loop in allocated acpi reserved memory

+  // Add another page for mailbox

+  //

+  AsmGetRelocationMap (&RelocationMap);

+  if ((RelocationMap.RelocateApLoopFuncAddress == 0) || (RelocationMap.RelocateApLoopFuncSize == 0)) {

+    DEBUG ((DEBUG_ERROR, "Failed to get the RelocationMap.\n"));

+    return 0;

+  }

+

+  RelocationPages = EFI_SIZE_TO_PAGES ((UINT32)RelocationMap.RelocateApLoopFuncSize) + 1;

+

+  Status = gBS->AllocatePages (AllocateAnyPages, EfiACPIMemoryNVS, RelocationPages, &Address);

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "Failed to allocate pages for MailboxRelocation. %r\n", Status));

+    return 0;

+  }

+

+  ZeroMem ((VOID *)Address, EFI_PAGES_TO_SIZE (RelocationPages));

+

+  ApLoopFunc = (VOID *)((UINTN)Address + EFI_PAGE_SIZE);

+

+  CopyMem (

+    ApLoopFunc,

+    RelocationMap.RelocateApLoopFuncAddress,

+    RelocationMap.RelocateApLoopFuncSize

+    );

+

+  DEBUG ((

+    DEBUG_INFO,

+    "Ap Relocation: mailbox %llx, loop %p\n",

+    Address,

+    ApLoopFunc

+    ));

+

+  //

+  // Initialize mailbox

+  //

+  RelocatedMailBox               = (MP_WAKEUP_MAILBOX *)Address;

+  RelocatedMailBox->Command      = MpProtectedModeWakeupCommandNoop;

+  RelocatedMailBox->ApicId       = MP_CPU_PROTECTED_MODE_MAILBOX_APICID_INVALID;

+  RelocatedMailBox->WakeUpVector = 0;

+

+  //

+  // Wakup APs and have been move to the finalized run loop

+  // They will spin until guest OS wakes them

+  //

+  MpSerializeStart ();

+

+  MpSendWakeupCommand (

+    MpProtectedModeWakeupCommandWakeup,

+    (UINT64)ApLoopFunc,

+    (UINT64)RelocatedMailBox,

+    0,

+    0,

+    0

+    );

+

+  return Address;

+}

+

+/**

+  Alter the MADT when ACPI Table from QEMU is available.

+

+  @param[in]  Event     Event whose notification function is being invoked

+  @param[in]  Context   Pointer to the notification function's context

+**/

+VOID

+EFIAPI

+AlterAcpiTable (

+  IN EFI_EVENT  Event,

+  IN VOID       *Context

+  )

+{

+  EFI_ACPI_SDT_PROTOCOL                                *AcpiSdtProtocol;

+  EFI_ACPI_TABLE_PROTOCOL                              *AcpiTableProtocol;

+  EFI_STATUS                                           Status;

+  UINTN                                                Index;

+  EFI_ACPI_SDT_HEADER                                  *Table;

+  EFI_ACPI_TABLE_VERSION                               Version;

+  UINTN                                                OriginalTableKey;

+  UINTN                                                NewTableKey;

+  UINT8                                                *NewMadtTable;

+  UINTN                                                NewMadtTableLength;

+  EFI_PHYSICAL_ADDRESS                                 RelocateMailboxAddress;

+  EFI_ACPI_6_4_MULTIPROCESSOR_WAKEUP_STRUCTURE         *MadtMpWk;

+  EFI_ACPI_1_0_MULTIPLE_APIC_DESCRIPTION_TABLE_HEADER  *MadtHeader;

+

+  Index        = 0;

+  NewMadtTable = NULL;

+  MadtHeader   = NULL;

+

+  Status = gBS->LocateProtocol (&gEfiAcpiSdtProtocolGuid, NULL, (void **)&AcpiSdtProtocol);

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "Unable to locate ACPI SDT protocol.\n"));

+    return;

+  }

+

+  RelocateMailboxAddress = RelocateMailbox ();

+  if (RelocateMailboxAddress == 0) {

+    ASSERT (FALSE);

+    DEBUG ((DEBUG_ERROR, "Failed to relocate Td mailbox\n"));

+    return;

+  }

+

+  do {

+    Status = AcpiSdtProtocol->GetAcpiTable (Index, &Table, &Version, &OriginalTableKey);

+

+    if (!EFI_ERROR (Status) && (Table->Signature == EFI_ACPI_1_0_APIC_SIGNATURE)) {

+      Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (void **)&AcpiTableProtocol);

+      if (EFI_ERROR (Status)) {

+        DEBUG ((DEBUG_ERROR, "Unable to locate ACPI Table protocol.\n"));

+        break;

+      }

+

+      NewMadtTableLength = Table->Length + sizeof (EFI_ACPI_6_4_MULTIPROCESSOR_WAKEUP_STRUCTURE);

+      NewMadtTable       = AllocatePool (NewMadtTableLength);

+      if (NewMadtTable == NULL) {

+        DEBUG ((DEBUG_ERROR, "%a: OUT_OF_SOURCES error.\n", __FUNCTION__));

+        break;

+      }

+

+      CopyMem (NewMadtTable, (UINT8 *)Table, Table->Length);

+      MadtHeader                = (EFI_ACPI_1_0_MULTIPLE_APIC_DESCRIPTION_TABLE_HEADER *)NewMadtTable;

+      MadtHeader->Header.Length = (UINT32)NewMadtTableLength;

+

+      MadtMpWk                 = (EFI_ACPI_6_4_MULTIPROCESSOR_WAKEUP_STRUCTURE *)(NewMadtTable + Table->Length);

+      MadtMpWk->Type           = EFI_ACPI_6_4_MULTIPROCESSOR_WAKEUP;

+      MadtMpWk->Length         = sizeof (EFI_ACPI_6_4_MULTIPROCESSOR_WAKEUP_STRUCTURE);

+      MadtMpWk->MailBoxVersion = 1;

+      MadtMpWk->Reserved       = 0;

+      MadtMpWk->MailBoxAddress = RelocateMailboxAddress;

+

+      Status = AcpiTableProtocol->InstallAcpiTable (AcpiTableProtocol, NewMadtTable, NewMadtTableLength, &NewTableKey);

+      if (EFI_ERROR (Status)) {

+        DEBUG ((DEBUG_ERROR, "Failed to install new MADT table. %r\n", Status));

+        break;

+      }

+

+      Status = AcpiTableProtocol->UninstallAcpiTable (AcpiTableProtocol, OriginalTableKey);

+      if (EFI_ERROR (Status)) {

+        DEBUG ((DEBUG_ERROR, "Uninstall old MADT table error.\n"));

+      }

+

+      break;

+    }

+

+    Index++;

+  } while (!EFI_ERROR (Status));

+

+  if (NewMadtTable != NULL) {

+    FreePool (NewMadtTable);

+  }

+}