/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Confidential Computing Platform Capability checks
*
* Copyright (C) 2021 Advanced Micro Devices, Inc.
*
* Author: Tom Lendacky <[email protected]>
*/
#ifndef _LINUX_CC_PLATFORM_H
#define _LINUX_CC_PLATFORM_H
#include <linux/types.h>
#include <linux/stddef.h>
/**
* enum cc_attr - Confidential computing attributes
*
* These attributes represent confidential computing features that are
* currently active.
*/
enum cc_attr {
/**
* @CC_ATTR_MEM_ENCRYPT: Memory encryption is active
*
* The platform/OS is running with active memory encryption. This
* includes running either as a bare-metal system or a hypervisor
* and actively using memory encryption or as a guest/virtual machine
* and actively using memory encryption.
*
* Examples include SME, SEV and SEV-ES.
*/
CC_ATTR_MEM_ENCRYPT,
/**
* @CC_ATTR_HOST_MEM_ENCRYPT: Host memory encryption is active
*
* The platform/OS is running as a bare-metal system or a hypervisor
* and actively using memory encryption.
*
* Examples include SME.
*/
CC_ATTR_HOST_MEM_ENCRYPT,
/**
* @CC_ATTR_GUEST_MEM_ENCRYPT: Guest memory encryption is active
*
* The platform/OS is running as a guest/virtual machine and actively
* using memory encryption.
*
* Examples include SEV and SEV-ES.
*/
CC_ATTR_GUEST_MEM_ENCRYPT,
/**
* @CC_ATTR_GUEST_STATE_ENCRYPT: Guest state encryption is active
*
* The platform/OS is running as a guest/virtual machine and actively
* using memory encryption and register state encryption.
*
* Examples include SEV-ES.
*/
CC_ATTR_GUEST_STATE_ENCRYPT,
/**
* @CC_ATTR_GUEST_UNROLL_STRING_IO: String I/O is implemented with
* IN/OUT instructions
*
* The platform/OS is running as a guest/virtual machine and uses
* IN/OUT instructions in place of string I/O.
*
* Examples include TDX guest & SEV.
*/
CC_ATTR_GUEST_UNROLL_STRING_IO,
/**
* @CC_ATTR_SEV_SNP: Guest SNP is active.
*
* The platform/OS is running as a guest/virtual machine and actively
* using AMD SEV-SNP features.
*/
CC_ATTR_GUEST_SEV_SNP,
/**
* @CC_ATTR_HOST_SEV_SNP: AMD SNP enabled on the host.
*
* The host kernel is running with the necessary features
* enabled to run SEV-SNP guests.
*/
CC_ATTR_HOST_SEV_SNP,
};
#ifdef CONFIG_ARCH_HAS_CC_PLATFORM
/**
* cc_platform_has() - Checks if the specified cc_attr attribute is active
* @attr: Confidential computing attribute to check
*
* The cc_platform_has() function will return an indicator as to whether the
* specified Confidential Computing attribute is currently active.
*
* Context: Any context
* Return:
* * TRUE - Specified Confidential Computing attribute is active
* * FALSE - Specified Confidential Computing attribute is not active
*/
bool cc_platform_has(enum cc_attr attr);
void cc_platform_set(enum cc_attr attr);
void cc_platform_clear(enum cc_attr attr);
#else /* !CONFIG_ARCH_HAS_CC_PLATFORM */
static inline bool cc_platform_has(enum cc_attr attr) { return false; }
static inline void cc_platform_set(enum cc_attr attr) { }
static inline void cc_platform_clear(enum cc_attr attr) { }
#endif /* CONFIG_ARCH_HAS_CC_PLATFORM */
#endif /* _LINUX_CC_PLATFORM_H */