xref: /openbmc/linux/arch/x86/include/asm/sev.h (revision fce96cf0443083e37455eff8f78fd240c621dae3)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * AMD Encrypted Register State Support
4  *
5  * Author: Joerg Roedel <jroedel@suse.de>
6  */
7 
8 #ifndef __ASM_ENCRYPTED_STATE_H
9 #define __ASM_ENCRYPTED_STATE_H
10 
11 #include <linux/types.h>
12 #include <asm/insn.h>
13 #include <asm/sev-common.h>
14 #include <asm/bootparam.h>
15 
16 #define GHCB_PROTOCOL_MIN	1ULL
17 #define GHCB_PROTOCOL_MAX	2ULL
18 #define GHCB_DEFAULT_USAGE	0ULL
19 
20 #define	VMGEXIT()			{ asm volatile("rep; vmmcall\n\r"); }
21 
22 enum es_result {
23 	ES_OK,			/* All good */
24 	ES_UNSUPPORTED,		/* Requested operation not supported */
25 	ES_VMM_ERROR,		/* Unexpected state from the VMM */
26 	ES_DECODE_FAILED,	/* Instruction decoding failed */
27 	ES_EXCEPTION,		/* Instruction caused exception */
28 	ES_RETRY,		/* Retry instruction emulation */
29 };
30 
31 struct es_fault_info {
32 	unsigned long vector;
33 	unsigned long error_code;
34 	unsigned long cr2;
35 };
36 
37 struct pt_regs;
38 
39 /* ES instruction emulation context */
40 struct es_em_ctxt {
41 	struct pt_regs *regs;
42 	struct insn insn;
43 	struct es_fault_info fi;
44 };
45 
46 /*
47  * AMD SEV Confidential computing blob structure. The structure is
48  * defined in OVMF UEFI firmware header:
49  * https://github.com/tianocore/edk2/blob/master/OvmfPkg/Include/Guid/ConfidentialComputingSevSnpBlob.h
50  */
51 #define CC_BLOB_SEV_HDR_MAGIC	0x45444d41
52 struct cc_blob_sev_info {
53 	u32 magic;
54 	u16 version;
55 	u16 reserved;
56 	u64 secrets_phys;
57 	u32 secrets_len;
58 	u32 rsvd1;
59 	u64 cpuid_phys;
60 	u32 cpuid_len;
61 	u32 rsvd2;
62 } __packed;
63 
64 void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code);
65 
66 static inline u64 lower_bits(u64 val, unsigned int bits)
67 {
68 	u64 mask = (1ULL << bits) - 1;
69 
70 	return (val & mask);
71 }
72 
73 struct real_mode_header;
74 enum stack_type;
75 struct ghcb;
76 
77 /* Early IDT entry points for #VC handler */
78 extern void vc_no_ghcb(void);
79 extern void vc_boot_ghcb(void);
80 extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
81 
82 /* Software defined (when rFlags.CF = 1) */
83 #define PVALIDATE_FAIL_NOUPDATE		255
84 
85 /* RMP page size */
86 #define RMP_PG_SIZE_4K			0
87 
88 #define RMPADJUST_VMSA_PAGE_BIT		BIT(16)
89 
90 /* SNP Guest message request */
91 struct snp_req_data {
92 	unsigned long req_gpa;
93 	unsigned long resp_gpa;
94 	unsigned long data_gpa;
95 	unsigned int data_npages;
96 };
97 
98 struct snp_guest_platform_data {
99 	u64 secrets_gpa;
100 };
101 
102 #ifdef CONFIG_AMD_MEM_ENCRYPT
103 extern struct static_key_false sev_es_enable_key;
104 extern void __sev_es_ist_enter(struct pt_regs *regs);
105 extern void __sev_es_ist_exit(void);
106 static __always_inline void sev_es_ist_enter(struct pt_regs *regs)
107 {
108 	if (static_branch_unlikely(&sev_es_enable_key))
109 		__sev_es_ist_enter(regs);
110 }
111 static __always_inline void sev_es_ist_exit(void)
112 {
113 	if (static_branch_unlikely(&sev_es_enable_key))
114 		__sev_es_ist_exit();
115 }
116 extern int sev_es_setup_ap_jump_table(struct real_mode_header *rmh);
117 extern void __sev_es_nmi_complete(void);
118 static __always_inline void sev_es_nmi_complete(void)
119 {
120 	if (static_branch_unlikely(&sev_es_enable_key))
121 		__sev_es_nmi_complete();
122 }
123 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
124 extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
125 					  bool set_ghcb_msr,
126 					  struct es_em_ctxt *ctxt,
127 					  u64 exit_code, u64 exit_info_1,
128 					  u64 exit_info_2);
129 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
130 {
131 	int rc;
132 
133 	/* "rmpadjust" mnemonic support in binutils 2.36 and newer */
134 	asm volatile(".byte 0xF3,0x0F,0x01,0xFE\n\t"
135 		     : "=a"(rc)
136 		     : "a"(vaddr), "c"(rmp_psize), "d"(attrs)
137 		     : "memory", "cc");
138 
139 	return rc;
140 }
141 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
142 {
143 	bool no_rmpupdate;
144 	int rc;
145 
146 	/* "pvalidate" mnemonic support in binutils 2.36 and newer */
147 	asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFF\n\t"
148 		     CC_SET(c)
149 		     : CC_OUT(c) (no_rmpupdate), "=a"(rc)
150 		     : "a"(vaddr), "c"(rmp_psize), "d"(validate)
151 		     : "memory", "cc");
152 
153 	if (no_rmpupdate)
154 		return PVALIDATE_FAIL_NOUPDATE;
155 
156 	return rc;
157 }
158 void setup_ghcb(void);
159 void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
160 					 unsigned int npages);
161 void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
162 					unsigned int npages);
163 void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op);
164 void snp_set_memory_shared(unsigned long vaddr, unsigned int npages);
165 void snp_set_memory_private(unsigned long vaddr, unsigned int npages);
166 void snp_set_wakeup_secondary_cpu(void);
167 bool snp_init(struct boot_params *bp);
168 void snp_abort(void);
169 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err);
170 #else
171 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
172 static inline void sev_es_ist_exit(void) { }
173 static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
174 static inline void sev_es_nmi_complete(void) { }
175 static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
176 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) { return 0; }
177 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
178 static inline void setup_ghcb(void) { }
179 static inline void __init
180 early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
181 static inline void __init
182 early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
183 static inline void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) { }
184 static inline void snp_set_memory_shared(unsigned long vaddr, unsigned int npages) { }
185 static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npages) { }
186 static inline void snp_set_wakeup_secondary_cpu(void) { }
187 static inline bool snp_init(struct boot_params *bp) { return false; }
188 static inline void snp_abort(void) { }
189 static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input,
190 					  unsigned long *fw_err)
191 {
192 	return -ENOTTY;
193 }
194 #endif
195 
196 #endif
197