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 #ifdef CONFIG_ARCH_HAS_CC_PLATFORM
67
68 /**
69 * cc_platform_has() - Checks if the specified cc_attr attribute is active
70 * @attr: Confidential computing attribute to check
71 *
72 * The cc_platform_has() function will return an indicator as to whether the
73 * specified Confidential Computing attribute is currently active.
74 *
75 * Context: Any context
76 * Return:
77 * * TRUE - Specified Confidential Computing attribute is active
78 * * FALSE - Specified Confidential Computing attribute is not active
79 */
80 bool cc_platform_has(enum cc_attr attr);
81
82 #else /* !CONFIG_ARCH_HAS_CC_PLATFORM */
83
cc_platform_has(enum cc_attr attr)84 static inline bool cc_platform_has(enum cc_attr attr) { return false; }
85
86 #endif /* CONFIG_ARCH_HAS_CC_PLATFORM */
87
88 #endif /* _LINUX_CC_PLATFORM_H */
89