xref: /linux/arch/x86/include/asm/shared/tdx.h (revision 79ac11393328fb1717d17c12e3c0eef0e9fa0647)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_SHARED_TDX_H
3 #define _ASM_X86_SHARED_TDX_H
4 
5 #include <linux/bits.h>
6 #include <linux/types.h>
7 
8 #define TDX_HYPERCALL_STANDARD  0
9 
10 #define TDX_CPUID_LEAF_ID	0x21
11 #define TDX_IDENT		"IntelTDX    "
12 
13 /* TDX module Call Leaf IDs */
14 #define TDG_VP_VMCALL			0
15 #define TDG_VP_INFO			1
16 #define TDG_VP_VEINFO_GET		3
17 #define TDG_MR_REPORT			4
18 #define TDG_MEM_PAGE_ACCEPT		6
19 #define TDG_VM_WR			8
20 
21 /* TDCS fields. To be used by TDG.VM.WR and TDG.VM.RD module calls */
22 #define TDCS_NOTIFY_ENABLES		0x9100000000000010
23 
24 /* TDX hypercall Leaf IDs */
25 #define TDVMCALL_MAP_GPA		0x10001
26 #define TDVMCALL_GET_QUOTE		0x10002
27 #define TDVMCALL_REPORT_FATAL_ERROR	0x10003
28 
29 #define TDVMCALL_STATUS_RETRY		1
30 
31 /*
32  * Bitmasks of exposed registers (with VMM).
33  */
34 #define TDX_RDX		BIT(2)
35 #define TDX_RBX		BIT(3)
36 #define TDX_RSI		BIT(6)
37 #define TDX_RDI		BIT(7)
38 #define TDX_R8		BIT(8)
39 #define TDX_R9		BIT(9)
40 #define TDX_R10		BIT(10)
41 #define TDX_R11		BIT(11)
42 #define TDX_R12		BIT(12)
43 #define TDX_R13		BIT(13)
44 #define TDX_R14		BIT(14)
45 #define TDX_R15		BIT(15)
46 
47 /*
48  * These registers are clobbered to hold arguments for each
49  * TDVMCALL. They are safe to expose to the VMM.
50  * Each bit in this mask represents a register ID. Bit field
51  * details can be found in TDX GHCI specification, section
52  * titled "TDCALL [TDG.VP.VMCALL] leaf".
53  */
54 #define TDVMCALL_EXPOSE_REGS_MASK	\
55 	(TDX_RDX | TDX_RBX | TDX_RSI | TDX_RDI | TDX_R8  | TDX_R9  | \
56 	 TDX_R10 | TDX_R11 | TDX_R12 | TDX_R13 | TDX_R14 | TDX_R15)
57 
58 #ifndef __ASSEMBLY__
59 
60 #include <linux/compiler_attributes.h>
61 
62 /*
63  * Used in __tdcall*() to gather the input/output registers' values of the
64  * TDCALL instruction when requesting services from the TDX module. This is a
65  * software only structure and not part of the TDX module/VMM ABI
66  */
67 struct tdx_module_args {
68 	/* callee-clobbered */
69 	u64 rcx;
70 	u64 rdx;
71 	u64 r8;
72 	u64 r9;
73 	/* extra callee-clobbered */
74 	u64 r10;
75 	u64 r11;
76 	/* callee-saved + rdi/rsi */
77 	u64 r12;
78 	u64 r13;
79 	u64 r14;
80 	u64 r15;
81 	u64 rbx;
82 	u64 rdi;
83 	u64 rsi;
84 };
85 
86 /* Used to communicate with the TDX module */
87 u64 __tdcall(u64 fn, struct tdx_module_args *args);
88 u64 __tdcall_ret(u64 fn, struct tdx_module_args *args);
89 u64 __tdcall_saved_ret(u64 fn, struct tdx_module_args *args);
90 
91 /* Used to request services from the VMM */
92 u64 __tdx_hypercall(struct tdx_module_args *args);
93 
94 /*
95  * Wrapper for standard use of __tdx_hypercall with no output aside from
96  * return code.
97  */
98 static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15)
99 {
100 	struct tdx_module_args args = {
101 		.r10 = TDX_HYPERCALL_STANDARD,
102 		.r11 = fn,
103 		.r12 = r12,
104 		.r13 = r13,
105 		.r14 = r14,
106 		.r15 = r15,
107 	};
108 
109 	return __tdx_hypercall(&args);
110 }
111 
112 
113 /* Called from __tdx_hypercall() for unrecoverable failure */
114 void __noreturn __tdx_hypercall_failed(void);
115 
116 bool tdx_accept_memory(phys_addr_t start, phys_addr_t end);
117 
118 /*
119  * The TDG.VP.VMCALL-Instruction-execution sub-functions are defined
120  * independently from but are currently matched 1:1 with VMX EXIT_REASONs.
121  * Reusing the KVM EXIT_REASON macros makes it easier to connect the host and
122  * guest sides of these calls.
123  */
124 static __always_inline u64 hcall_func(u64 exit_reason)
125 {
126         return exit_reason;
127 }
128 
129 #endif /* !__ASSEMBLY__ */
130 #endif /* _ASM_X86_SHARED_TDX_H */
131