More info: I quick dump the SMRAM info with original SmmAccess implementation, it's same as I produced in the gEfiSmmSmramMemoryGuid HOB.
SmmAccess: SmmAccessPeiEntryPoint: SMRAM map follows, 2 entries SmmAccessPeiEntryPoint: 7F000000 1000 7F000000 1A ---> for the S3 Resume in gEfiAcpiVariableGuid SmmAccessPeiEntryPoint: 7F001000 FFF000 7F001000 A Smram map in the gEfiSmmSmramMemoryGuid: PlatformQemuInitializeRam: 7F000000 1000 7F000000 1A --> ---> for the S3 Resume in gEfiAcpiVariableGuid PlatformQemuInitializeRam: 7F001000 FFF000 7F001000 A Thanks, Jiaxin > -----Original Message----- > From: Wu, Jiaxin > Sent: Tuesday, April 23, 2024 8:19 PM > To: Gerd Hoffmann <kra...@redhat.com> > Cc: devel@edk2.groups.io; Ard Biesheuvel <ardb+tianoc...@kernel.org>; Yao, > Jiewen <jiewen....@intel.com>; Ni, Ray <ray...@intel.com> > Subject: RE: [PATCH v3 08/13] OvmfPkg/PlatformInitLib: Create > gEfiSmmSmramMemoryGuid > > > > > > + SmramHobDescriptorBlock = > > (EFI_SMRAM_HOB_DESCRIPTOR_BLOCK *)(Hob.Raw); > > > > > + SmramHobDescriptorBlock->Descriptor[0].PhysicalStart = > > PlatformInfoHob->LowMemory - TsegSize; > > > + SmramHobDescriptorBlock->Descriptor[0].CpuStart = > > PlatformInfoHob->LowMemory - TsegSize; > > > + SmramHobDescriptorBlock->Descriptor[0].PhysicalSize = > EFI_PAGE_SIZE; > > > + SmramHobDescriptorBlock->Descriptor[0].RegionState = > > EFI_SMRAM_CLOSED | EFI_CACHEABLE | EFI_ALLOCATED; > > > > > + SmramHobDescriptorBlock->Descriptor[1].PhysicalStart = > > SmramHobDescriptorBlock->Descriptor[0].PhysicalStart + EFI_PAGE_SIZE; > > > + SmramHobDescriptorBlock->Descriptor[1].CpuStart = > > SmramHobDescriptorBlock->Descriptor[0].CpuStart + EFI_PAGE_SIZE; > > > + SmramHobDescriptorBlock->Descriptor[1].PhysicalSize = TsegSize - > > EFI_PAGE_SIZE; > > > + SmramHobDescriptorBlock->Descriptor[1].RegionState = > > EFI_SMRAM_CLOSED | EFI_CACHEABLE; > > > > This is not going to fly. > > > > First, smram allocation doesn't work that way. Have a look at > > OvmfPkg/SmmAccess. I guess that easily explains why this series > > breaks S3 suspend. > > > > Oh? Could you explain a bit more for 1) how smram allocation works? 2) > what's the possible reason break the S3? I haven't check yet. > > > Second, storing these descriptors in a HOB (which is PEI memory) > > is questionable from a security point of view. > > > > HOB is only to expose the SMRAM address and size, not the contents in > smram, what's the security concern? > > > Thanks, > Jiaxin -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#118141): https://edk2.groups.io/g/devel/message/118141 Mute This Topic: https://groups.io/mt/105593577/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
