From: Sophia Wolf <phiaw...@google.com> When a guest OS does not support unaccepted memory, the unaccepted memory must be accepted before returning a memory map to the caller.
EfiMemoryAcceptProtocol is defined in MdePkg and is implemented / Installed in AmdSevDxe for AMD SEV-SNP memory acceptance. Cc: Gerd Hoffmann <kra...@redhat.com> Cc: James Bottomley <j...@linux.ibm.com> Cc: Jiewen Yao <jiewen....@intel.com> Cc: Tom Lendacky <thomas.lenda...@amd.com> Signed-off-by: Sophia Wolf <phiaw...@google.com> --- OvmfPkg/AmdSevDxe/AmdSevDxe.c | 34 ++++++++++++++++++++ OvmfPkg/AmdSevDxe/AmdSevDxe.inf | 3 ++ OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c | 24 +++++++++++--- 3 files changed, 57 insertions(+), 4 deletions(-) diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.c b/OvmfPkg/AmdSevDxe/AmdSevDxe.c index 662d3c4ccb..09aa15165d 100644 --- a/OvmfPkg/AmdSevDxe/AmdSevDxe.c +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.c @@ -20,6 +20,7 @@ #include <Library/UefiBootServicesTableLib.h> #include <Guid/ConfidentialComputingSevSnpBlob.h> #include <Library/PcdLib.h> +#include <Protocol/MemoryAccept.h> STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = { SIGNATURE_32 ('A', 'M', 'D', 'E'), @@ -31,6 +32,29 @@ STATIC CONFIDENTIAL_COMPUTING_SNP_BLOB_LOCATION mSnpBootDxeTable = { FixedPcdGet32 (PcdOvmfCpuidSize), }; +STATIC EFI_HANDLE mAmdSevDxeHandle = NULL; + +STATIC +EFI_STATUS +EFIAPI +AmdSevMemoryAccept ( + IN EFI_MEMORY_ACCEPT_PROTOCOL *This, + IN EFI_PHYSICAL_ADDRESS StartAddress, + IN UINTN Size +) +{ + MemEncryptSevSnpPreValidateSystemRam ( + StartAddress, + EFI_SIZE_TO_PAGES (Size) + ); + + return EFI_SUCCESS; +} + +STATIC EFI_MEMORY_ACCEPT_PROTOCOL mMemoryAcceptProtocol = { + AmdSevMemoryAccept +}; + EFI_STATUS EFIAPI AmdSevDxeEntryPoint ( @@ -147,6 +171,16 @@ AmdSevDxeEntryPoint ( } } + Status = gBS->InstallProtocolInterface ( + &mAmdSevDxeHandle, + &gEfiMemoryAcceptProtocolGuid, + EFI_NATIVE_INTERFACE, + &mMemoryAcceptProtocol + ); + if (EFI_ERROR (Status)) { + DEBUG ((DEBUG_ERROR, "Install EfiMemoryAcceptProtocol failed.\n")); + } + // // If its SEV-SNP active guest then install the CONFIDENTIAL_COMPUTING_SEV_SNP_BLOB. // It contains the location for both the Secrets and CPUID page. diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf index 9acf860cf2..5ddddabc32 100644 --- a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf @@ -47,6 +47,9 @@ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize +[Protocols] + gEfiMemoryAcceptProtocolGuid + [Guids] gConfidentialComputingSevSnpBlobGuid diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c index d3a95e4913..ee3710f7b3 100644 --- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/DxeSnpSystemRamValidate.c @@ -14,6 +14,7 @@ #include <Library/MemEncryptSevLib.h> #include "SnpPageStateChange.h" +#include "VirtualMemory.h" /** Pre-validate the system RAM when SEV-SNP is enabled in the guest VM. @@ -29,12 +30,27 @@ MemEncryptSevSnpPreValidateSystemRam ( IN UINTN NumPages ) { + EFI_STATUS Status; + if (!MemEncryptSevSnpIsEnabled ()) { return; } - // - // All the pre-validation must be completed in the PEI phase. - // - ASSERT (FALSE); + // DXE pre-validation may happen with the memory accept protocol. + // The protocol should only be called outside the prevalidated ranges + // that the PEI stage code explicitly skips. Specifically, only memory + // ranges that are classified as unaccepted. + if (BaseAddress >= SIZE_4GB) { + Status = InternalMemEncryptSevCreateIdentityMap1G ( + 0, + BaseAddress, + EFI_PAGES_TO_SIZE (NumPages) + ); + if (EFI_ERROR (Status)) { + ASSERT (FALSE); + CpuDeadLoop (); + } + } + + InternalSetPageState (BaseAddress, NumPages, SevSnpPagePrivate, TRUE); } -- 2.37.3.998.g577e59143f-goog -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#94469): https://edk2.groups.io/g/devel/message/94469 Mute This Topic: https://groups.io/mt/93975245/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-