Files
system76-edk2/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c
Tom Lendacky b098f5e9e9 MdeModulePkg/DxeIplPeim: Support GHCB pages when creating page tables
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

GHCB pages must be mapped as shared pages, so modify the process of
creating identity mapped pagetable entries so that GHCB entries are
created without the encryption bit set. The GHCB range consists of
two pages per CPU, the first being the GHCB and the second being a
per-CPU variable page. Only the GHCB page is mapped as shared.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Dandan Bi <dandan.bi@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Acked-by: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-16 16:45:42 +00:00

133 lines
3.9 KiB
C

/** @file
x64-specifc functionality for DxeLoad.
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "DxeIpl.h"
#include "X64/VirtualMemory.h"
/**
Transfers control to DxeCore.
This function performs a CPU architecture specific operations to execute
the entry point of DxeCore with the parameters of HobList.
It also installs EFI_END_OF_PEI_PPI to signal the end of PEI phase.
@param DxeCoreEntryPoint The entry point of DxeCore.
@param HobList The start of HobList passed to DxeCore.
**/
VOID
HandOffToDxeCore (
IN EFI_PHYSICAL_ADDRESS DxeCoreEntryPoint,
IN EFI_PEI_HOB_POINTERS HobList
)
{
VOID *BaseOfStack;
VOID *TopOfStack;
EFI_STATUS Status;
UINTN PageTables;
UINT32 Index;
EFI_VECTOR_HANDOFF_INFO *VectorInfo;
EFI_PEI_VECTOR_HANDOFF_INFO_PPI *VectorHandoffInfoPpi;
VOID *GhcbBase;
UINTN GhcbSize;
//
// Clear page 0 and mark it as allocated if NULL pointer detection is enabled.
//
if (IsNullDetectionEnabled ()) {
ClearFirst4KPage (HobList.Raw);
BuildMemoryAllocationHob (0, EFI_PAGES_TO_SIZE (1), EfiBootServicesData);
}
//
// Get Vector Hand-off Info PPI and build Guided HOB
//
Status = PeiServicesLocatePpi (
&gEfiVectorHandoffInfoPpiGuid,
0,
NULL,
(VOID **)&VectorHandoffInfoPpi
);
if (Status == EFI_SUCCESS) {
DEBUG ((EFI_D_INFO, "Vector Hand-off Info PPI is gotten, GUIDed HOB is created!\n"));
VectorInfo = VectorHandoffInfoPpi->Info;
Index = 1;
while (VectorInfo->Attribute != EFI_VECTOR_HANDOFF_LAST_ENTRY) {
VectorInfo ++;
Index ++;
}
BuildGuidDataHob (
&gEfiVectorHandoffInfoPpiGuid,
VectorHandoffInfoPpi->Info,
sizeof (EFI_VECTOR_HANDOFF_INFO) * Index
);
}
//
// Allocate 128KB for the Stack
//
BaseOfStack = AllocatePages (EFI_SIZE_TO_PAGES (STACK_SIZE));
ASSERT (BaseOfStack != NULL);
//
// Compute the top of the stack we were allocated. Pre-allocate a UINTN
// for safety.
//
TopOfStack = (VOID *) ((UINTN) BaseOfStack + EFI_SIZE_TO_PAGES (STACK_SIZE) * EFI_PAGE_SIZE - CPU_STACK_ALIGNMENT);
TopOfStack = ALIGN_POINTER (TopOfStack, CPU_STACK_ALIGNMENT);
//
// Get the address and size of the GHCB pages
//
GhcbBase = (VOID *) PcdGet64 (PcdGhcbBase);
GhcbSize = PcdGet64 (PcdGhcbSize);
PageTables = 0;
if (FeaturePcdGet (PcdDxeIplBuildPageTables)) {
//
// Create page table and save PageMapLevel4 to CR3
//
PageTables = CreateIdentityMappingPageTables ((EFI_PHYSICAL_ADDRESS) (UINTN) BaseOfStack, STACK_SIZE,
(EFI_PHYSICAL_ADDRESS) (UINTN) GhcbBase, GhcbSize);
} else {
//
// Set NX for stack feature also require PcdDxeIplBuildPageTables be TRUE
// for the DxeIpl and the DxeCore are both X64.
//
ASSERT (PcdGetBool (PcdSetNxForStack) == FALSE);
ASSERT (PcdGetBool (PcdCpuStackGuard) == FALSE);
}
//
// End of PEI phase signal
//
Status = PeiServicesInstallPpi (&gEndOfPeiSignalPpi);
ASSERT_EFI_ERROR (Status);
if (FeaturePcdGet (PcdDxeIplBuildPageTables)) {
AsmWriteCr3 (PageTables);
}
//
// Update the contents of BSP stack HOB to reflect the real stack info passed to DxeCore.
//
UpdateStackHob ((EFI_PHYSICAL_ADDRESS)(UINTN) BaseOfStack, STACK_SIZE);
//
// Transfer the control to the entry point of DxeCore.
//
SwitchStack (
(SWITCH_STACK_ENTRY_POINT)(UINTN)DxeCoreEntryPoint,
HobList.Raw,
NULL,
TopOfStack
);
}