1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Confidential Computing Platform Capability checks 4 * 5 * Copyright (C) 2021 Advanced Micro Devices, Inc. 6 * 7 * Author: Tom Lendacky <thomas.lendacky@amd.com> 8 */ 9 10 #ifndef _LINUX_CC_PLATFORM_H 11 #define _LINUX_CC_PLATFORM_H 12 13 #include <linux/types.h> 14 #include <linux/stddef.h> 15 16 /** 17 * enum cc_attr - Confidential computing attributes 18 * 19 * These attributes represent confidential computing features that are 20 * currently active. 21 */ 22 enum cc_attr { 23 /** 24 * @CC_ATTR_MEM_ENCRYPT: Memory encryption is active 25 * 26 * The platform/OS is running with active memory encryption. This 27 * includes running either as a bare-metal system or a hypervisor 28 * and actively using memory encryption or as a guest/virtual machine 29 * and actively using memory encryption. 30 * 31 * Examples include SME, SEV and SEV-ES. 32 */ 33 CC_ATTR_MEM_ENCRYPT, 34 35 /** 36 * @CC_ATTR_HOST_MEM_ENCRYPT: Host memory encryption is active 37 * 38 * The platform/OS is running as a bare-metal system or a hypervisor 39 * and actively using memory encryption. 40 * 41 * Examples include SME. 42 */ 43 CC_ATTR_HOST_MEM_ENCRYPT, 44 45 /** 46 * @CC_ATTR_GUEST_MEM_ENCRYPT: Guest memory encryption is active 47 * 48 * The platform/OS is running as a guest/virtual machine and actively 49 * using memory encryption. 50 * 51 * Examples include SEV and SEV-ES. 52 */ 53 CC_ATTR_GUEST_MEM_ENCRYPT, 54 55 /** 56 * @CC_ATTR_GUEST_STATE_ENCRYPT: Guest state encryption is active 57 * 58 * The platform/OS is running as a guest/virtual machine and actively 59 * using memory encryption and register state encryption. 60 * 61 * Examples include SEV-ES. 62 */ 63 CC_ATTR_GUEST_STATE_ENCRYPT, 64 65 /** 66 * @CC_ATTR_GUEST_UNROLL_STRING_IO: String I/O is implemented with 67 * IN/OUT instructions 68 * 69 * The platform/OS is running as a guest/virtual machine and uses 70 * IN/OUT instructions in place of string I/O. 71 * 72 * Examples include TDX guest & SEV. 73 */ 74 CC_ATTR_GUEST_UNROLL_STRING_IO, 75 76 /** 77 * @CC_ATTR_SEV_SNP: Guest SNP is active. 78 * 79 * The platform/OS is running as a guest/virtual machine and actively 80 * using AMD SEV-SNP features. 81 */ 82 CC_ATTR_GUEST_SEV_SNP, 83 84 /** 85 * @CC_ATTR_HOTPLUG_DISABLED: Hotplug is not supported or disabled. 86 * 87 * The platform/OS is running as a guest/virtual machine does not 88 * support CPU hotplug feature. 89 * 90 * Examples include TDX Guest. 91 */ 92 CC_ATTR_HOTPLUG_DISABLED, 93 }; 94 95 #ifdef CONFIG_ARCH_HAS_CC_PLATFORM 96 97 /** 98 * cc_platform_has() - Checks if the specified cc_attr attribute is active 99 * @attr: Confidential computing attribute to check 100 * 101 * The cc_platform_has() function will return an indicator as to whether the 102 * specified Confidential Computing attribute is currently active. 103 * 104 * Context: Any context 105 * Return: 106 * * TRUE - Specified Confidential Computing attribute is active 107 * * FALSE - Specified Confidential Computing attribute is not active 108 */ 109 bool cc_platform_has(enum cc_attr attr); 110 111 #else /* !CONFIG_ARCH_HAS_CC_PLATFORM */ 112 113 static inline bool cc_platform_has(enum cc_attr attr) { return false; } 114 115 #endif /* CONFIG_ARCH_HAS_CC_PLATFORM */ 116 117 #endif /* _LINUX_CC_PLATFORM_H */ 118