audk/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c

85 lines
3.1 KiB
C

/** @file
Secure Encrypted Virtualization (SEV) library helper function
Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/MemEncryptSevLib.h>
#include <Register/Amd/Cpuid.h>
#include <Register/Amd/Msr.h>
#include <Register/Cpuid.h>
/**
This function clears memory encryption bit for the memory region specified by
BaseAddress and NumPages from the current page table context.
@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
current CR3)
@param[in] BaseAddress The physical address that is the start
address of a memory region.
@param[in] NumPages The number of pages from start memory
region.
@param[in] Flush Flush the caches before clearing the bit
(mostly TRUE except MMIO addresses)
@retval RETURN_SUCCESS The attributes were cleared for the
memory region.
@retval RETURN_INVALID_PARAMETER Number of pages is zero.
@retval RETURN_UNSUPPORTED Clearing the memory encryption attribute
is not supported
**/
RETURN_STATUS
EFIAPI
MemEncryptSevClearPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
IN UINTN NumPages,
IN BOOLEAN Flush
)
{
//
// Memory encryption bit is not accessible in 32-bit mode
//
return RETURN_UNSUPPORTED;
}
/**
This function sets memory encryption bit for the memory region specified by
BaseAddress and NumPages from the current page table context.
@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
current CR3)
@param[in] BaseAddress The physical address that is the start
address of a memory region.
@param[in] NumPages The number of pages from start memory
region.
@param[in] Flush Flush the caches before setting the bit
(mostly TRUE except MMIO addresses)
@retval RETURN_SUCCESS The attributes were set for the memory
region.
@retval RETURN_INVALID_PARAMETER Number of pages is zero.
@retval RETURN_UNSUPPORTED Setting the memory encryption attribute
is not supported
**/
RETURN_STATUS
EFIAPI
MemEncryptSevSetPageEncMask (
IN PHYSICAL_ADDRESS Cr3BaseAddress,
IN PHYSICAL_ADDRESS BaseAddress,
IN UINTN NumPages,
IN BOOLEAN Flush
)
{
//
// Memory encryption bit is not accessible in 32-bit mode
//
return RETURN_UNSUPPORTED;
}