BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275 Use the MemEncryptSevClearMmioPageEncMask() to clear memory encryption mask for the Mmio address range. Cc: James Bottomley <jejb@linux.ibm.com> Cc: Min Xu <min.m.xu@intel.com> Cc: Jiewen Yao <jiewen.yao@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Erdem Aktas <erdemaktas@google.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Message-Id: <20210519181949.6574-12-brijesh.singh@amd.com>
		
			
				
	
	
		
			64 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			64 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /** @file
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|   Define the module hooks used while probing the QEMU flash device.
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| 
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|   Copyright (C) 2018, Advanced Micro Devices. All rights reserved.
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| 
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|   SPDX-License-Identifier: BSD-2-Clause-Patent
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| 
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| **/
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| 
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| #include <Library/BaseMemoryLib.h>
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| #include <Library/DebugLib.h>
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| #include <Library/PcdLib.h>
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| #include <Library/MemEncryptSevLib.h>
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| 
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| #include "QemuFlash.h"
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| 
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| VOID
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| QemuFlashBeforeProbe (
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|   IN  EFI_PHYSICAL_ADDRESS    BaseAddress,
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|   IN  UINTN                   FdBlockSize,
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|   IN  UINTN                   FdBlockCount
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|   )
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| {
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|   EFI_STATUS              Status;
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| 
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|   ASSERT (FeaturePcdGet (PcdSmmSmramRequire));
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| 
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|   if (!MemEncryptSevIsEnabled ()) {
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|     return;
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|   }
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| 
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|   //
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|   // When SEV is enabled, AmdSevDxe runs early in DXE phase and clears the
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|   // C-bit from the NonExistent entry -- which is later split and accommodate
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|   // the flash MMIO but the driver runs in non SMM context hence it cleared the
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|   // flash ranges from non SMM page table. When SMM is enabled, the flash
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|   // services are accessed from the SMM mode hence we explicitly clear the
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|   // C-bit on flash ranges from SMM page table.
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|   //
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| 
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|   Status = MemEncryptSevClearMmioPageEncMask (
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|              0,
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|              BaseAddress,
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|              EFI_SIZE_TO_PAGES (FdBlockSize * FdBlockCount)
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|              );
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|   ASSERT_EFI_ERROR (Status);
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| }
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| 
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| /**
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|   Write to QEMU Flash
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| 
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|   @param[in] Ptr    Pointer to the location to write.
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|   @param[in] Value  The value to write.
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| 
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| **/
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| VOID
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| QemuFlashPtrWrite (
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|   IN        volatile UINT8    *Ptr,
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|   IN        UINT8             Value
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|   )
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| {
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|   *Ptr = Value;
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| }
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