xref: /openbmc/linux/arch/x86/include/asm/sev.h (revision 726ccdba)
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 <linux/sev-guest.h>
13 
14 #include <asm/insn.h>
15 #include <asm/sev-common.h>
16 #include <asm/bootparam.h>
17 
18 #define GHCB_PROTOCOL_MIN	1ULL
19 #define GHCB_PROTOCOL_MAX	2ULL
20 #define GHCB_DEFAULT_USAGE	0ULL
21 
22 #define	VMGEXIT()			{ asm volatile("rep; vmmcall\n\r"); }
23 
24 enum es_result {
25 	ES_OK,			/* All good */
26 	ES_UNSUPPORTED,		/* Requested operation not supported */
27 	ES_VMM_ERROR,		/* Unexpected state from the VMM */
28 	ES_DECODE_FAILED,	/* Instruction decoding failed */
29 	ES_EXCEPTION,		/* Instruction caused exception */
30 	ES_RETRY,		/* Retry instruction emulation */
31 };
32 
33 struct es_fault_info {
34 	unsigned long vector;
35 	unsigned long error_code;
36 	unsigned long cr2;
37 };
38 
39 struct pt_regs;
40 
41 /* ES instruction emulation context */
42 struct es_em_ctxt {
43 	struct pt_regs *regs;
44 	struct insn insn;
45 	struct es_fault_info fi;
46 };
47 
48 /*
49  * AMD SEV Confidential computing blob structure. The structure is
50  * defined in OVMF UEFI firmware header:
51  * https://github.com/tianocore/edk2/blob/master/OvmfPkg/Include/Guid/ConfidentialComputingSevSnpBlob.h
52  */
53 #define CC_BLOB_SEV_HDR_MAGIC	0x45444d41
54 struct cc_blob_sev_info {
55 	u32 magic;
56 	u16 version;
57 	u16 reserved;
58 	u64 secrets_phys;
59 	u32 secrets_len;
60 	u32 rsvd1;
61 	u64 cpuid_phys;
62 	u32 cpuid_len;
63 	u32 rsvd2;
64 } __packed;
65 
66 void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code);
67 
68 static inline u64 lower_bits(u64 val, unsigned int bits)
69 {
70 	u64 mask = (1ULL << bits) - 1;
71 
72 	return (val & mask);
73 }
74 
75 struct real_mode_header;
76 enum stack_type;
77 
78 /* Early IDT entry points for #VC handler */
79 extern void vc_no_ghcb(void);
80 extern void vc_boot_ghcb(void);
81 extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
82 
83 /* Software defined (when rFlags.CF = 1) */
84 #define PVALIDATE_FAIL_NOUPDATE		255
85 
86 /* RMP page size */
87 #define RMP_PG_SIZE_4K			0
88 
89 #define RMPADJUST_VMSA_PAGE_BIT		BIT(16)
90 
91 /* SNP Guest message request */
92 struct snp_req_data {
93 	unsigned long req_gpa;
94 	unsigned long resp_gpa;
95 	unsigned long data_gpa;
96 	unsigned int data_npages;
97 };
98 
99 struct sev_guest_platform_data {
100 	u64 secrets_gpa;
101 };
102 
103 /*
104  * The secrets page contains 96-bytes of reserved field that can be used by
105  * the guest OS. The guest OS uses the area to save the message sequence
106  * number for each VMPCK.
107  *
108  * See the GHCB spec section Secret page layout for the format for this area.
109  */
110 struct secrets_os_area {
111 	u32 msg_seqno_0;
112 	u32 msg_seqno_1;
113 	u32 msg_seqno_2;
114 	u32 msg_seqno_3;
115 	u64 ap_jump_table_pa;
116 	u8 rsvd[40];
117 	u8 guest_usage[32];
118 } __packed;
119 
120 #define VMPCK_KEY_LEN		32
121 
122 /* See the SNP spec version 0.9 for secrets page format */
123 struct snp_secrets_page_layout {
124 	u32 version;
125 	u32 imien	: 1,
126 	    rsvd1	: 31;
127 	u32 fms;
128 	u32 rsvd2;
129 	u8 gosvw[16];
130 	u8 vmpck0[VMPCK_KEY_LEN];
131 	u8 vmpck1[VMPCK_KEY_LEN];
132 	u8 vmpck2[VMPCK_KEY_LEN];
133 	u8 vmpck3[VMPCK_KEY_LEN];
134 	struct secrets_os_area os_area;
135 	u8 rsvd3[3840];
136 } __packed;
137 
138 #ifdef CONFIG_AMD_MEM_ENCRYPT
139 extern struct static_key_false sev_es_enable_key;
140 extern void __sev_es_ist_enter(struct pt_regs *regs);
141 extern void __sev_es_ist_exit(void);
142 static __always_inline void sev_es_ist_enter(struct pt_regs *regs)
143 {
144 	if (static_branch_unlikely(&sev_es_enable_key))
145 		__sev_es_ist_enter(regs);
146 }
147 static __always_inline void sev_es_ist_exit(void)
148 {
149 	if (static_branch_unlikely(&sev_es_enable_key))
150 		__sev_es_ist_exit();
151 }
152 extern int sev_es_setup_ap_jump_table(struct real_mode_header *rmh);
153 extern void __sev_es_nmi_complete(void);
154 static __always_inline void sev_es_nmi_complete(void)
155 {
156 	if (static_branch_unlikely(&sev_es_enable_key))
157 		__sev_es_nmi_complete();
158 }
159 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
160 
161 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
162 {
163 	int rc;
164 
165 	/* "rmpadjust" mnemonic support in binutils 2.36 and newer */
166 	asm volatile(".byte 0xF3,0x0F,0x01,0xFE\n\t"
167 		     : "=a"(rc)
168 		     : "a"(vaddr), "c"(rmp_psize), "d"(attrs)
169 		     : "memory", "cc");
170 
171 	return rc;
172 }
173 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
174 {
175 	bool no_rmpupdate;
176 	int rc;
177 
178 	/* "pvalidate" mnemonic support in binutils 2.36 and newer */
179 	asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFF\n\t"
180 		     CC_SET(c)
181 		     : CC_OUT(c) (no_rmpupdate), "=a"(rc)
182 		     : "a"(vaddr), "c"(rmp_psize), "d"(validate)
183 		     : "memory", "cc");
184 
185 	if (no_rmpupdate)
186 		return PVALIDATE_FAIL_NOUPDATE;
187 
188 	return rc;
189 }
190 
191 struct snp_guest_request_ioctl;
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 __init __noreturn snp_abort(void);
204 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
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, struct snp_guest_request_ioctl *rio)
225 {
226 	return -ENOTTY;
227 }
228 #endif
229 
230 #endif
231