61a044c6c1
In the next three patches, we're going to modify three modules under OvmfPkg. When OVMF is built with -D SMM_REQUIRE and runs in an SEV guest, each affected module will have to know the page range that covers the initial (pre-SMBASE relocation) SMRAM save state map. Add a helper function to MemEncryptSevLib that calculates the "base address" and "number of pages" constants for this page range. (In a RELEASE build -- i.e., with assertions disabled and optimization enabled --, the helper function can be compiled to store two constants determined at compile time.) Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Jordan Justen <jordan.l.justen@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
113 lines
4.1 KiB
C
113 lines
4.1 KiB
C
/** @file
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Define Secure Encrypted Virtualization (SEV) base library helper function
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Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
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This program and the accompanying materials are licensed and made available
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under the terms and conditions of the BSD License which accompanies this
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distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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#ifndef _MEM_ENCRYPT_SEV_LIB_H_
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#define _MEM_ENCRYPT_SEV_LIB_H_
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#include <Base.h>
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/**
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Returns a boolean to indicate whether SEV is enabled
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@retval TRUE SEV is enabled
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@retval FALSE SEV is not enabled
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**/
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BOOLEAN
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EFIAPI
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MemEncryptSevIsEnabled (
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VOID
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);
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/**
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This function clears memory encryption bit for the memory region specified by
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BaseAddress and NumPages from the current page table context.
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@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
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current CR3)
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@param[in] BaseAddress The physical address that is the start
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address of a memory region.
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@param[in] NumPages The number of pages from start memory
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region.
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@param[in] Flush Flush the caches before clearing the bit
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(mostly TRUE except MMIO addresses)
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@retval RETURN_SUCCESS The attributes were cleared for the
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memory region.
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@retval RETURN_INVALID_PARAMETER Number of pages is zero.
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@retval RETURN_UNSUPPORTED Clearing the memory encryption attribute
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is not supported
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**/
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RETURN_STATUS
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EFIAPI
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MemEncryptSevClearPageEncMask (
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IN PHYSICAL_ADDRESS Cr3BaseAddress,
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IN PHYSICAL_ADDRESS BaseAddress,
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IN UINTN NumPages,
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IN BOOLEAN Flush
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);
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/**
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This function sets memory encryption bit for the memory region specified by
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BaseAddress and NumPages from the current page table context.
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@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
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current CR3)
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@param[in] BaseAddress The physical address that is the start
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address of a memory region.
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@param[in] NumPages The number of pages from start memory
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region.
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@param[in] Flush Flush the caches before setting the bit
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(mostly TRUE except MMIO addresses)
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@retval RETURN_SUCCESS The attributes were set for the memory
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region.
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@retval RETURN_INVALID_PARAMETER Number of pages is zero.
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@retval RETURN_UNSUPPORTED Setting the memory encryption attribute
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is not supported
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**/
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RETURN_STATUS
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EFIAPI
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MemEncryptSevSetPageEncMask (
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IN PHYSICAL_ADDRESS Cr3BaseAddress,
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IN PHYSICAL_ADDRESS BaseAddress,
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IN UINTN NumPages,
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IN BOOLEAN Flush
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);
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/**
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Locate the page range that covers the initial (pre-SMBASE-relocation) SMRAM
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Save State Map.
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@param[out] BaseAddress The base address of the lowest-address page that
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covers the initial SMRAM Save State Map.
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@param[out] NumberOfPages The number of pages in the page range that covers
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the initial SMRAM Save State Map.
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@retval RETURN_SUCCESS BaseAddress and NumberOfPages have been set on
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output.
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@retval RETURN_UNSUPPORTED SMM is unavailable.
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**/
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RETURN_STATUS
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EFIAPI
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MemEncryptSevLocateInitialSmramSaveStateMapPages (
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OUT UINTN *BaseAddress,
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OUT UINTN *NumberOfPages
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);
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#endif // _MEM_ENCRYPT_SEV_LIB_H_
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