include/linux/cc_platform.h

   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_HOST_SEV_SNP: AMD SNP enabled on the host.
  86          *
  87          * The host kernel is running with the necessary features
  88          * enabled to run SEV-SNP guests.
  89          */
  90         CC_ATTR_HOST_SEV_SNP,
  91 };
  92
  93 #ifdef CONFIG_ARCH_HAS_CC_PLATFORM
  94
  95 /**
  96  * cc_platform_has() - Checks if the specified cc_attr attribute is active
  97  * @attr: Confidential computing attribute to check
  98  *
  99  * The cc_platform_has() function will return an indicator as to whether the
 100  * specified Confidential Computing attribute is currently active.
 101  *
 102  * Context: Any context
 103  * Return:
 104  * * TRUE  - Specified Confidential Computing attribute is active
 105  * * FALSE - Specified Confidential Computing attribute is not active
 106  */
 107 bool cc_platform_has(enum cc_attr attr);
 108 void cc_platform_set(enum cc_attr attr);
 109 void cc_platform_clear(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 static inline void cc_platform_set(enum cc_attr attr) { }
 115 static inline void cc_platform_clear(enum cc_attr attr) { }
 116
 117 #endif  /* CONFIG_ARCH_HAS_CC_PLATFORM */
 118
 119 #endif  /* _LINUX_CC_PLATFORM_H */