Jiaxin, I provide separate review comments for each patch. Can you please make sure the copy right year is updated for every file change? I may not emphasize this for each patch.
> -----Original Message----- > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Wu, Jiaxin > Sent: Friday, February 10, 2023 2:05 PM > To: devel@edk2.groups.io > Subject: [edk2-devel] [PATCH v4 0/5] Simplify SMM Relocation Process > > Existing SMBASE Relocation is in the PiSmmCpuDxeSmm driver, which > will relocate the SMBASE of each processor by setting the SMBASE > field in the saved state map (at offset 7EF8h) to a new value. > The RSM instruction reloads the internal SMBASE register with the > value in SMBASE field when each time it exits SMM. All subsequent > SMI requests will use the new SMBASE to find the starting address > for the SMI handler (at SMBASE + 8000h). > > Due to the default SMBASE for all x86 processors is 0x30000, the > APs' 1st SMI for rebase has to be executed one by one to avoid > the CPUs over-writing each other's SMM Save State Area (see > existing SmmRelocateBases() function), which means the next AP has > to wait for the previous AP to finish its 1st SMI, then it can call > into its 1st SMI for rebase via Smi Ipi command, thus leading the > existing SMBASE Relocation has to be running in series. Besides, it > needs very complex code to handle the AP exit semaphore > (mRebased[Index]), which will hook return address of SMM Save State > so that semaphore code can be executed immediately after AP exits > SMM for SMBASE relocation (see existing SemaphoreHook() function). > > This series is to add the new SMM Base HOB for any PEI module to do > the SmBase relocation ahead of PiSmmCpuDxeSmm driver and store the > relocated SmBase address in array for each Processors. When the > SMBASE relocation happens in a PEI module, the PEI module shall > produce the SMM_BASE_HOB in HOB database which tells the > PiSmmCpuDxeSmm driver (runs at a later phase) about the new SMBASE > for each CPU thread. PiSmmCpuDxeSmm driver installs the SMI handler > at the SMM_BASE_HOB.SmBase[Index]+0x8000 for CPU thread Index. When > the HOB doesn't exist, PiSmmCpuDxeSmm driver shall relocate and > program the new SMBASE itself (keep existing SMBASE Relocation way). > > With SMM Base Hob support, PiSmmCpuDxeSmm does not need the RSM > instruction to do the SMBASE Relocation. SMBASE Register for each > processors have already been programmed and all SMBASE address have > recorded in SMM Base Hob. So the same default SMBASE Address > (0x30000) will not be used, thus the CPUs over-writing each other's > SMM Save State Area will not happen in PiSmmCpuDxeSmm driver. This > way makes the first SMI init can be executed in parallel and save > boot time on multi-core system. Besides, Semaphore Hook code logic > is also not required, which will greatly simplify the SMBASE > Relocation flow. > > Note: > This is the new way that firmware can program the SMBASE > independently of the RSM instruction. The PEI code performing > this logic will not be open sourced, similarly to other things > that are kept binary-only in the FSP. Due to the register > difference in different vender, and it has not been documented > in the Intel SDM yet, we need a new binary-only interface for > SMM Base HOB. > > Jiaxin Wu (5): > UefiCpuPkg/PiSmmCpuDxeSmm: Fix invalid InitializeMpSyncData call > UefiCpuPkg/SmmBaseHob.h: Add SMM Base HOB Data > UefiCpuPkg/PiSmmCpuDxeSmm: Consume SMM Base Hob for SmBase info > UefiCpuPkg/SmmCpuFeaturesLib: Skip SMBASE configuration > OvmfPkg/SmmCpuFeaturesLib: Check SmBase relocation supported or not > > .../Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c | 8 + > .../SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf | 4 + > UefiCpuPkg/Include/Guid/SmmBaseHob.h | 64 +++++++ > .../Library/SmmCpuFeaturesLib/CpuFeaturesLib.h | 2 + > .../SmmCpuFeaturesLib/IntelSmmCpuFeaturesLib.c | 23 ++- > .../SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf | 4 + > .../SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf | 1 + > UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmStm.c | 1 - > .../StandaloneMmCpuFeaturesLib.inf | 4 + > UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c | 29 +++- > UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 23 +++ > UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 191 > ++++++++++++++++----- > UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h | 24 +++ > UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf | 1 + > UefiCpuPkg/UefiCpuPkg.dec | 3 + > 15 files changed, 332 insertions(+), 50 deletions(-) > create mode 100644 UefiCpuPkg/Include/Guid/SmmBaseHob.h > > -- > 2.16.2.windows.1 > > > > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#100012): https://edk2.groups.io/g/devel/message/100012 Mute This Topic: https://groups.io/mt/96871371/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/leave/9847357/21656/1706620634/xyzzy [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
