From 0cb242e33693a07a5ac3b877d9661e981368c375 Mon Sep 17 00:00:00 2001 From: Ankur Arora Date: Thu, 11 Mar 2021 22:26:47 -0800 Subject: [PATCH] OvmfPkg/CpuHotplugSmm: refactor hotplug logic Refactor CpuHotplugMmi() to pull out the CPU hotplug logic into ProcessHotAddedCpus(). This is in preparation for supporting CPU hot-unplug. Cc: Laszlo Ersek Cc: Jordan Justen Cc: Ard Biesheuvel Cc: Igor Mammedov Cc: Boris Ostrovsky Cc: Aaron Young Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3132 Signed-off-by: Ankur Arora Reviewed-by: Laszlo Ersek Message-Id: <20210312062656.2477515-2-ankur.a.arora@oracle.com> --- OvmfPkg/CpuHotplugSmm/CpuHotplug.c | 210 +++++++++++++++++------------ 1 file changed, 126 insertions(+), 84 deletions(-) diff --git a/OvmfPkg/CpuHotplugSmm/CpuHotplug.c b/OvmfPkg/CpuHotplugSmm/CpuHotplug.c index cfe698ed2b..bf68fcd429 100644 --- a/OvmfPkg/CpuHotplugSmm/CpuHotplug.c +++ b/OvmfPkg/CpuHotplugSmm/CpuHotplug.c @@ -62,6 +62,129 @@ STATIC UINT32 mPostSmmPenAddress; // STATIC EFI_HANDLE mDispatchHandle; +/** + Process CPUs that have been hot-added, per QemuCpuhpCollectApicIds(). + + For each such CPU, relocate the SMBASE, and report the CPU to PiSmmCpuDxeSmm + via EFI_SMM_CPU_SERVICE_PROTOCOL. If the supposedly hot-added CPU is already + known, skip it silently. + + @param[in] PluggedApicIds The APIC IDs of the CPUs that have been + hot-plugged. + + @param[in] PluggedCount The number of filled-in APIC IDs in + PluggedApicIds. + + @retval EFI_SUCCESS CPUs corresponding to all the APIC IDs are + populated. + + @retval EFI_OUT_OF_RESOURCES Out of APIC ID space in "mCpuHotPlugData". + + @return Error codes propagated from SmbaseRelocate() + and mMmCpuService->AddProcessor(). +**/ +STATIC +EFI_STATUS +ProcessHotAddedCpus ( + IN APIC_ID *PluggedApicIds, + IN UINT32 PluggedCount + ) +{ + EFI_STATUS Status; + UINT32 PluggedIdx; + UINT32 NewSlot; + + // + // The Post-SMM Pen need not be reinstalled multiple times within a single + // root MMI handling. Even reinstalling once per root MMI is only prudence; + // in theory installing the pen in the driver's entry point function should + // suffice. + // + SmbaseReinstallPostSmmPen (mPostSmmPenAddress); + + PluggedIdx = 0; + NewSlot = 0; + while (PluggedIdx < PluggedCount) { + APIC_ID NewApicId; + UINT32 CheckSlot; + UINTN NewProcessorNumberByProtocol; + + NewApicId = PluggedApicIds[PluggedIdx]; + + // + // Check if the supposedly hot-added CPU is already known to us. + // + for (CheckSlot = 0; + CheckSlot < mCpuHotPlugData->ArrayLength; + CheckSlot++) { + if (mCpuHotPlugData->ApicId[CheckSlot] == NewApicId) { + break; + } + } + if (CheckSlot < mCpuHotPlugData->ArrayLength) { + DEBUG ((DEBUG_VERBOSE, "%a: APIC ID " FMT_APIC_ID " was hot-plugged " + "before; ignoring it\n", __FUNCTION__, NewApicId)); + PluggedIdx++; + continue; + } + + // + // Find the first empty slot in CPU_HOT_PLUG_DATA. + // + while (NewSlot < mCpuHotPlugData->ArrayLength && + mCpuHotPlugData->ApicId[NewSlot] != MAX_UINT64) { + NewSlot++; + } + if (NewSlot == mCpuHotPlugData->ArrayLength) { + DEBUG ((DEBUG_ERROR, "%a: no room for APIC ID " FMT_APIC_ID "\n", + __FUNCTION__, NewApicId)); + return EFI_OUT_OF_RESOURCES; + } + + // + // Store the APIC ID of the new processor to the slot. + // + mCpuHotPlugData->ApicId[NewSlot] = NewApicId; + + // + // Relocate the SMBASE of the new CPU. + // + Status = SmbaseRelocate (NewApicId, mCpuHotPlugData->SmBase[NewSlot], + mPostSmmPenAddress); + if (EFI_ERROR (Status)) { + goto RevokeNewSlot; + } + + // + // Add the new CPU with EFI_SMM_CPU_SERVICE_PROTOCOL. + // + Status = mMmCpuService->AddProcessor (mMmCpuService, NewApicId, + &NewProcessorNumberByProtocol); + if (EFI_ERROR (Status)) { + DEBUG ((DEBUG_ERROR, "%a: AddProcessor(" FMT_APIC_ID "): %r\n", + __FUNCTION__, NewApicId, Status)); + goto RevokeNewSlot; + } + + DEBUG ((DEBUG_INFO, "%a: hot-added APIC ID " FMT_APIC_ID ", SMBASE 0x%Lx, " + "EFI_SMM_CPU_SERVICE_PROTOCOL assigned number %Lu\n", __FUNCTION__, + NewApicId, (UINT64)mCpuHotPlugData->SmBase[NewSlot], + (UINT64)NewProcessorNumberByProtocol)); + + NewSlot++; + PluggedIdx++; + } + + // + // We've processed this batch of hot-added CPUs. + // + return EFI_SUCCESS; + +RevokeNewSlot: + mCpuHotPlugData->ApicId[NewSlot] = MAX_UINT64; + + return Status; +} /** CPU Hotplug MMI handler function. @@ -122,8 +245,6 @@ CpuHotplugMmi ( UINT8 ApmControl; UINT32 PluggedCount; UINT32 ToUnplugCount; - UINT32 PluggedIdx; - UINT32 NewSlot; // // Assert that we are entering this function due to our root MMI handler @@ -179,87 +300,11 @@ CpuHotplugMmi ( goto Fatal; } - // - // Process hot-added CPUs. - // - // The Post-SMM Pen need not be reinstalled multiple times within a single - // root MMI handling. Even reinstalling once per root MMI is only prudence; - // in theory installing the pen in the driver's entry point function should - // suffice. - // - SmbaseReinstallPostSmmPen (mPostSmmPenAddress); - - PluggedIdx = 0; - NewSlot = 0; - while (PluggedIdx < PluggedCount) { - APIC_ID NewApicId; - UINT32 CheckSlot; - UINTN NewProcessorNumberByProtocol; - - NewApicId = mPluggedApicIds[PluggedIdx]; - - // - // Check if the supposedly hot-added CPU is already known to us. - // - for (CheckSlot = 0; - CheckSlot < mCpuHotPlugData->ArrayLength; - CheckSlot++) { - if (mCpuHotPlugData->ApicId[CheckSlot] == NewApicId) { - break; - } - } - if (CheckSlot < mCpuHotPlugData->ArrayLength) { - DEBUG ((DEBUG_VERBOSE, "%a: APIC ID " FMT_APIC_ID " was hot-plugged " - "before; ignoring it\n", __FUNCTION__, NewApicId)); - PluggedIdx++; - continue; - } - - // - // Find the first empty slot in CPU_HOT_PLUG_DATA. - // - while (NewSlot < mCpuHotPlugData->ArrayLength && - mCpuHotPlugData->ApicId[NewSlot] != MAX_UINT64) { - NewSlot++; - } - if (NewSlot == mCpuHotPlugData->ArrayLength) { - DEBUG ((DEBUG_ERROR, "%a: no room for APIC ID " FMT_APIC_ID "\n", - __FUNCTION__, NewApicId)); + if (PluggedCount > 0) { + Status = ProcessHotAddedCpus (mPluggedApicIds, PluggedCount); + if (EFI_ERROR (Status)) { goto Fatal; } - - // - // Store the APIC ID of the new processor to the slot. - // - mCpuHotPlugData->ApicId[NewSlot] = NewApicId; - - // - // Relocate the SMBASE of the new CPU. - // - Status = SmbaseRelocate (NewApicId, mCpuHotPlugData->SmBase[NewSlot], - mPostSmmPenAddress); - if (EFI_ERROR (Status)) { - goto RevokeNewSlot; - } - - // - // Add the new CPU with EFI_SMM_CPU_SERVICE_PROTOCOL. - // - Status = mMmCpuService->AddProcessor (mMmCpuService, NewApicId, - &NewProcessorNumberByProtocol); - if (EFI_ERROR (Status)) { - DEBUG ((DEBUG_ERROR, "%a: AddProcessor(" FMT_APIC_ID "): %r\n", - __FUNCTION__, NewApicId, Status)); - goto RevokeNewSlot; - } - - DEBUG ((DEBUG_INFO, "%a: hot-added APIC ID " FMT_APIC_ID ", SMBASE 0x%Lx, " - "EFI_SMM_CPU_SERVICE_PROTOCOL assigned number %Lu\n", __FUNCTION__, - NewApicId, (UINT64)mCpuHotPlugData->SmBase[NewSlot], - (UINT64)NewProcessorNumberByProtocol)); - - NewSlot++; - PluggedIdx++; } // @@ -267,9 +312,6 @@ CpuHotplugMmi ( // return EFI_SUCCESS; -RevokeNewSlot: - mCpuHotPlugData->ApicId[NewSlot] = MAX_UINT64; - Fatal: ASSERT (FALSE); CpuDeadLoop ();