#include <CpuHotPlugData.h>
#include <IndustryStandard/Q35MchIch9.h>
#include <IndustryStandard/QemuCpuHotplug.h>
#include <Library/BaseLib.h>
#include <Library/CpuLib.h>
#include <Library/DebugLib.h>
#include <Library/MmServicesTableLib.h>
#include <Library/PcdLib.h>
#include <Library/SafeIntLib.h>
#include <Pcd/CpuHotEjectData.h>
#include <Protocol/MmCpuIo.h>
#include <Protocol/SmmCpuService.h>
#include <Register/Intel/ArchitecturalMsr.h>
#include <Uefi/UefiBaseType.h>
#include "ApicId.h"
#include "QemuCpuhp.h"
#include "Smbase.h"

Functions
STATIC EFI_STATUS	ProcessHotAddedCpus (IN APIC_ID *PluggedApicIds, IN UINT32 PluggedCount)

STATIC BOOLEAN	CheckIfBsp (VOID)

VOID EFIAPI	EjectCpu (IN UINTN ProcessorNum)

STATIC EFI_STATUS	UnplugCpus (IN APIC_ID ToUnplugApicIds, IN UINT32 ToUnplugSelectors, IN UINT32 ToUnplugCount)

STATIC EFI_STATUS EFIAPI	CpuHotplugMmi (IN EFI_HANDLE DispatchHandle, IN CONST VOID Context OPTIONAL, IN OUT VOID CommBuffer OPTIONAL, IN OUT UINTN *CommBufferSize OPTIONAL)

EFI_STATUS EFIAPI	CpuHotplugEntry (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

Variables
STATIC EFI_MM_CPU_IO_PROTOCOL *	mMmCpuIo

STATIC EFI_SMM_CPU_SERVICE_PROTOCOL *	mMmCpuService

STATIC CPU_HOT_PLUG_DATA *	mCpuHotPlugData

STATIC CPU_HOT_EJECT_DATA *	mCpuHotEjectData

STATIC APIC_ID *	mPluggedApicIds

STATIC APIC_ID *	mToUnplugApicIds

STATIC UINT32 *	mToUnplugSelectors

STATIC UINT32	mPostSmmPenAddress

STATIC EFI_HANDLE	mDispatchHandle

Detailed Description

Root SMI handler for VCPU hotplug SMIs.

SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file CpuHotplug.c.

Function Documentation

◆ CheckIfBsp()

STATIC BOOLEAN CheckIfBsp ( VOID )

EjectCpu needs to know the BSP at SMI exit at a point when some of the EFI_SMM_CPU_SERVICE_PROTOCOL state has been torn down. Reuse the logic from OvmfPkg::PlatformSmmBspElection() to do that.

Return values

TRUE	If the CPU executing this function is the BSP.
FALSE	If the CPU executing this function is an AP.

Definition at line 238 of file CpuHotplug.c.

◆ CpuHotplugEntry()

EFI_STATUS EFIAPI CpuHotplugEntry	(	IN EFI_HANDLE	ImageHandle,
		IN EFI_SYSTEM_TABLE *	SystemTable
	)

Definition at line 709 of file CpuHotplug.c.

◆ CpuHotplugMmi()

STATIC EFI_STATUS EFIAPI CpuHotplugMmi	(	IN EFI_HANDLE	DispatchHandle,
		IN CONST VOID *Context	OPTIONAL,
		IN OUT VOID *CommBuffer	OPTIONAL,
		IN OUT UINTN *CommBufferSize	OPTIONAL
	)

CPU Hotplug MMI handler function.

This is a root MMI handler.

Parameters

[in]	DispatchHandle	The unique handle assigned to this handler by EFI_MM_SYSTEM_TABLE.MmiHandlerRegister().
[in]	Context	Context passed in by EFI_MM_SYSTEM_TABLE.MmiManage(). Due to CpuHotplugMmi() being a root MMI handler, Context is ASSERT()ed to be NULL.
[in,out]	CommBuffer	Ignored, due to CpuHotplugMmi() being a root MMI handler.
[in,out]	CommBufferSize	Ignored, due to CpuHotplugMmi() being a root MMI handler.

Return values

EFI_SUCCESS	The MMI was handled and the MMI source was quiesced. When returned by a non-root MMI handler, EFI_SUCCESS terminates the processing of MMI handlers in EFI_MM_SYSTEM_TABLE.MmiManage(). For a root MMI handler (i.e., for the present function too), EFI_SUCCESS behaves identically to EFI_WARN_INTERRUPT_SOURCE_QUIESCED, as further root MMI handlers are going to be called by EFI_MM_SYSTEM_TABLE.MmiManage() anyway.
EFI_WARN_INTERRUPT_SOURCE_QUIESCED	The MMI source has been quiesced, but other handlers should still be called.
EFI_WARN_INTERRUPT_SOURCE_PENDING	The MMI source is still pending, and other handlers should still be called.
EFI_INTERRUPT_PENDING	The MMI source could not be quiesced.

Definition at line 605 of file CpuHotplug.c.

◆ EjectCpu()

VOID EFIAPI EjectCpu ( IN UINTN ProcessorNum )

CPU Hot-eject handler, called from SmmCpuFeaturesRendezvousExit() on each CPU at exit from SMM.

If, the executing CPU is neither the BSP, nor being ejected, nothing to be done. If, the executing CPU is being ejected, wait in a halted loop until ejected. If, the executing CPU is the BSP, set QEMU CPU status to eject for CPUs being ejected.

Parameters

[in] ProcessorNum ProcessorNum denotes the CPU exiting SMM, and will be used as an index into CPU_HOT_EJECT_DATA->QemuSelectorMap. It is identical to the processor handle number in EFI_SMM_CPU_SERVICE_PROTOCOL.

Definition at line 269 of file CpuHotplug.c.

◆ ProcessHotAddedCpus()

STATIC EFI_STATUS ProcessHotAddedCpus	(	IN APIC_ID *	PluggedApicIds,
		IN UINT32	PluggedCount
	)

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.

Parameters

[in]	PluggedApicIds	The APIC IDs of the CPUs that have been hot-plugged.
[in]	PluggedCount	The number of filled-in APIC IDs in PluggedApicIds.

Return values

EFI_SUCCESS	CPUs corresponding to all the APIC IDs are populated.
EFI_OUT_OF_RESOURCES	Out of APIC ID space in "mCpuHotPlugData".

Returns: Error codes propagated from SmbaseRelocate() and mMmCpuService->AddProcessor().

Definition at line 95 of file CpuHotplug.c.

◆ UnplugCpus()

STATIC EFI_STATUS UnplugCpus	(	IN APIC_ID *	ToUnplugApicIds,
		IN UINT32 *	ToUnplugSelectors,
		IN UINT32	ToUnplugCount
	)

Process to be hot-unplugged CPUs, per QemuCpuhpCollectApicIds().

For each such CPU, report the CPU to PiSmmCpuDxeSmm via EFI_SMM_CPU_SERVICE_PROTOCOL and stash the QEMU Cpu Selectors for later ejection. If the to be hot-unplugged CPU is unknown, skip it silently.

Additonally, if we do stash any Cpu Selectors, also install a CPU eject handler which would handle the ejection.

Parameters

[in]	ToUnplugApicIds	The APIC IDs of the CPUs that are about to be hot-unplugged.
[in]	ToUnplugSelectors	The QEMU Selectors of the CPUs that are about to be hot-unplugged.
[in]	ToUnplugCount	The number of filled-in APIC IDs in ToUnplugApicIds.

Return values

EFI_ALREADY_STARTED	For the ProcessorNum that EFI_SMM_CPU_SERVICE_PROTOCOL had assigned to one of the APIC IDs in ToUnplugApicIds, mCpuHotEjectData->QemuSelectorMap already has the QemuSelector value stashed. (This should never happen.)
EFI_SUCCESS	Known APIC IDs have been removed from SMM data structures.

Returns: Error codes propagated from mMmCpuService->RemoveProcessor().

Definition at line 413 of file CpuHotplug.c.

Variable Documentation

◆ mCpuHotEjectData

STATIC CPU_HOT_EJECT_DATA* mCpuHotEjectData

Definition at line 43 of file CpuHotplug.c.

◆ mCpuHotPlugData

STATIC CPU_HOT_PLUG_DATA* mCpuHotPlugData

Definition at line 42 of file CpuHotplug.c.

◆ mDispatchHandle

STATIC EFI_HANDLE mDispatchHandle

Definition at line 70 of file CpuHotplug.c.

◆ mMmCpuIo

STATIC EFI_MM_CPU_IO_PROTOCOL* mMmCpuIo

Definition at line 31 of file CpuHotplug.c.

◆ mMmCpuService

STATIC EFI_SMM_CPU_SERVICE_PROTOCOL* mMmCpuService

Definition at line 36 of file CpuHotplug.c.

◆ mPluggedApicIds

STATIC APIC_ID* mPluggedApicIds

Definition at line 59 of file CpuHotplug.c.

◆ mPostSmmPenAddress

STATIC UINT32 mPostSmmPenAddress

Definition at line 66 of file CpuHotplug.c.

◆ mToUnplugApicIds

STATIC APIC_ID* mToUnplugApicIds

Definition at line 60 of file CpuHotplug.c.

◆ mToUnplugSelectors

STATIC UINT32* mToUnplugSelectors

Definition at line 61 of file CpuHotplug.c.

Functions

Variables

Detailed Description

Function Documentation

◆ CheckIfBsp()

◆ CpuHotplugEntry()

◆ CpuHotplugMmi()

◆ EjectCpu()

◆ ProcessHotAddedCpus()

◆ UnplugCpus()

Variable Documentation

◆ mCpuHotEjectData

◆ mCpuHotPlugData

◆ mDispatchHandle

◆ mMmCpuIo

◆ mMmCpuService

◆ mPluggedApicIds

◆ mPostSmmPenAddress

◆ mToUnplugApicIds

◆ mToUnplugSelectors