linux/arch/x86/kvm/vmx/vmcs12.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __KVM_X86_VMX_VMCS12_H
#define __KVM_X86_VMX_VMCS12_H

#include <linux/build_bug.h>

#include "vmcs.h"

/*
 * struct vmcs12 describes the state that our guest hypervisor (L1) keeps for a
 * single nested guest (L2), hence the name vmcs12. Any VMX implementation has
 * a VMCS structure, and vmcs12 is our emulated VMX's VMCS. This structure is
 * stored in guest memory specified by VMPTRLD, but is opaque to the guest,
 * which must access it using VMREAD/VMWRITE/VMCLEAR instructions.
 * More than one of these structures may exist, if L1 runs multiple L2 guests.
 * nested_vmx_run() will use the data here to build the vmcs02: a VMCS for the
 * underlying hardware which will be used to run L2.
 * This structure is packed to ensure that its layout is identical across
 * machines (necessary for live migration).
 *
 * IMPORTANT: Changing the layout of existing fields in this structure
 * will break save/restore compatibility with older kvm releases. When
 * adding new fields, either use space in the reserved padding* arrays
 * or add the new fields to the end of the structure.
 */
natural_width;
struct __packed vmcs12 { … };

/*
 * VMCS12_REVISION is KVM's arbitrary ID for the layout of struct vmcs12.  KVM
 * enumerates this value to L1 via MSR_IA32_VMX_BASIC, and checks the revision
 * ID during nested VMPTRLD to verify that L1 is loading a VMCS that adhere's
 * to KVM's virtual CPU definition.
 *
 * DO NOT change this value, as it will break save/restore compatibility with
 * older KVM releases.
 */
#define VMCS12_REVISION …

/*
 * VMCS12_SIZE is the number of bytes L1 should allocate for the VMXON region
 * and any VMCS region. Although only sizeof(struct vmcs12) are used by the
 * current implementation, 4K are reserved to avoid future complications and
 * to preserve userspace ABI.
 */
#define VMCS12_SIZE …

/*
 * For save/restore compatibility, the vmcs12 field offsets must not change,
 * although appending fields and/or filling gaps is obviously allowed.
 */
#define CHECK_OFFSET(field, loc) …

static inline void vmx_check_vmcs12_offsets(void)
{ … }

extern const unsigned short vmcs12_field_offsets[];
extern const unsigned int nr_vmcs12_fields;

static inline short get_vmcs12_field_offset(unsigned long field)
{ … }

static inline u64 vmcs12_read_any(struct vmcs12 *vmcs12, unsigned long field,
				  u16 offset)
{ … }

static inline void vmcs12_write_any(struct vmcs12 *vmcs12, unsigned long field,
				    u16 offset, u64 field_value)
{ … }

#endif /* __KVM_X86_VMX_VMCS12_H */