audk/OvmfPkg/CpuHotplugSmm/FirstSmiHandlerContext.h

48 lines
1.6 KiB
C

/** @file
Define the FIRST_SMI_HANDLER_CONTEXT structure, which is an exchange area
between the SMM Monarch and the hot-added CPU, for relocating the SMBASE of
the hot-added CPU.
Copyright (c) 2020, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#ifndef FIRST_SMI_HANDLER_CONTEXT_H_
#define FIRST_SMI_HANDLER_CONTEXT_H_
//
// The following structure is used to communicate between the SMM Monarch
// (running the root MMI handler) and the hot-added CPU (handling its first
// SMI). It is placed at SMM_DEFAULT_SMBASE, which is in SMRAM under QEMU's
// "SMRAM at default SMBASE" feature.
//
#pragma pack (1)
typedef struct {
//
// When ApicIdGate is MAX_UINT64, then no hot-added CPU may proceed with
// SMBASE relocation.
//
// Otherwise, the hot-added CPU whose APIC ID equals ApicIdGate may proceed
// with SMBASE relocation.
//
// This field is intentionally wider than APIC_ID (UINT32) because we need a
// "gate locked" value that is different from all possible APIC_IDs.
//
UINT64 ApicIdGate;
//
// The new SMBASE value for the hot-added CPU to set in the SMRAM Save State
// Map, before leaving SMM with the RSM instruction.
//
UINT32 NewSmbase;
//
// The hot-added CPU sets this field to 1 right before executing the RSM
// instruction. This tells the SMM Monarch to proceed to polling the last
// byte of the normal RAM reserved page (Post-SMM Pen).
//
UINT8 AboutToLeaveSmm;
} FIRST_SMI_HANDLER_CONTEXT;
#pragma pack ()
#endif // FIRST_SMI_HANDLER_CONTEXT_H_