xref: /openbmc/linux/arch/x86/include/asm/sev.h (revision c059ee9d)
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 sev_guest_platform_data {
99 	u64 secrets_gpa;
100 };
101 
102 /*
103  * The secrets page contains 96-bytes of reserved field that can be used by
104  * the guest OS. The guest OS uses the area to save the message sequence
105  * number for each VMPCK.
106  *
107  * See the GHCB spec section Secret page layout for the format for this area.
108  */
109 struct secrets_os_area {
110 	u32 msg_seqno_0;
111 	u32 msg_seqno_1;
112 	u32 msg_seqno_2;
113 	u32 msg_seqno_3;
114 	u64 ap_jump_table_pa;
115 	u8 rsvd[40];
116 	u8 guest_usage[32];
117 } __packed;
118 
119 #define VMPCK_KEY_LEN		32
120 
121 /* See the SNP spec version 0.9 for secrets page format */
122 struct snp_secrets_page_layout {
123 	u32 version;
124 	u32 imien	: 1,
125 	    rsvd1	: 31;
126 	u32 fms;
127 	u32 rsvd2;
128 	u8 gosvw[16];
129 	u8 vmpck0[VMPCK_KEY_LEN];
130 	u8 vmpck1[VMPCK_KEY_LEN];
131 	u8 vmpck2[VMPCK_KEY_LEN];
132 	u8 vmpck3[VMPCK_KEY_LEN];
133 	struct secrets_os_area os_area;
134 	u8 rsvd3[3840];
135 } __packed;
136 
137 #ifdef CONFIG_AMD_MEM_ENCRYPT
138 extern struct static_key_false sev_es_enable_key;
139 extern void __sev_es_ist_enter(struct pt_regs *regs);
140 extern void __sev_es_ist_exit(void);
141 static __always_inline void sev_es_ist_enter(struct pt_regs *regs)
142 {
143 	if (static_branch_unlikely(&sev_es_enable_key))
144 		__sev_es_ist_enter(regs);
145 }
146 static __always_inline void sev_es_ist_exit(void)
147 {
148 	if (static_branch_unlikely(&sev_es_enable_key))
149 		__sev_es_ist_exit();
150 }
151 extern int sev_es_setup_ap_jump_table(struct real_mode_header *rmh);
152 extern void __sev_es_nmi_complete(void);
153 static __always_inline void sev_es_nmi_complete(void)
154 {
155 	if (static_branch_unlikely(&sev_es_enable_key))
156 		__sev_es_nmi_complete();
157 }
158 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
159 extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
160 					  bool set_ghcb_msr,
161 					  struct es_em_ctxt *ctxt,
162 					  u64 exit_code, u64 exit_info_1,
163 					  u64 exit_info_2);
164 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
165 {
166 	int rc;
167 
168 	/* "rmpadjust" mnemonic support in binutils 2.36 and newer */
169 	asm volatile(".byte 0xF3,0x0F,0x01,0xFE\n\t"
170 		     : "=a"(rc)
171 		     : "a"(vaddr), "c"(rmp_psize), "d"(attrs)
172 		     : "memory", "cc");
173 
174 	return rc;
175 }
176 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
177 {
178 	bool no_rmpupdate;
179 	int rc;
180 
181 	/* "pvalidate" mnemonic support in binutils 2.36 and newer */
182 	asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFF\n\t"
183 		     CC_SET(c)
184 		     : CC_OUT(c) (no_rmpupdate), "=a"(rc)
185 		     : "a"(vaddr), "c"(rmp_psize), "d"(validate)
186 		     : "memory", "cc");
187 
188 	if (no_rmpupdate)
189 		return PVALIDATE_FAIL_NOUPDATE;
190 
191 	return rc;
192 }
193 void setup_ghcb(void);
194 void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
195 					 unsigned int npages);
196 void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
197 					unsigned int npages);
198 void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op);
199 void snp_set_memory_shared(unsigned long vaddr, unsigned int npages);
200 void snp_set_memory_private(unsigned long vaddr, unsigned int npages);
201 void snp_set_wakeup_secondary_cpu(void);
202 bool snp_init(struct boot_params *bp);
203 void snp_abort(void);
204 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err);
205 #else
206 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
207 static inline void sev_es_ist_exit(void) { }
208 static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
209 static inline void sev_es_nmi_complete(void) { }
210 static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
211 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) { return 0; }
212 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
213 static inline void setup_ghcb(void) { }
214 static inline void __init
215 early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
216 static inline void __init
217 early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
218 static inline void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) { }
219 static inline void snp_set_memory_shared(unsigned long vaddr, unsigned int npages) { }
220 static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npages) { }
221 static inline void snp_set_wakeup_secondary_cpu(void) { }
222 static inline bool snp_init(struct boot_params *bp) { return false; }
223 static inline void snp_abort(void) { }
224 static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input,
225 					  unsigned long *fw_err)
226 {
227 	return -ENOTTY;
228 }
229 #endif
230 
231 #endif
232