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

91 lines
3.4 KiB
C

/** @file
Secure Encrypted Virtualization (SEV) library helper function
Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
This program and the accompanying materials are licensed and made available
under the terms and conditions of the BSD License which accompanies this
distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#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;
}