audk/OvmfPkg/TdxDxe/TdxAcpiTable.h

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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>
2021-09-22 07:26:01 +02:00
/** @file
Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#ifndef TDX_ACPI_TABLE_H_
#define TDX_ACPI_TABLE_H_
#include <PiDxe.h>
#include <Protocol/AcpiTable.h>
#include <Protocol/FirmwareVolume2.h>
#include <Protocol/PciIo.h>
#include <Library/BaseLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/DebugLib.h>
#include <Library/PcdLib.h>
#include <IndustryStandard/IntelTdx.h>
#include <IndustryStandard/Acpi.h>
VOID
EFIAPI
AsmGetRelocationMap (
OUT MP_RELOCATION_MAP *AddressMap
);
/**
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
);
/**
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
);
#endif