xref: /openbmc/linux/arch/x86/include/asm/sev.h (revision 7272b8bf)
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 #include <asm/coco.h>
18 
19 #define GHCB_PROTOCOL_MIN	1ULL
20 #define GHCB_PROTOCOL_MAX	2ULL
21 #define GHCB_DEFAULT_USAGE	0ULL
22 
23 #define	VMGEXIT()			{ asm volatile("rep; vmmcall\n\r"); }
24 
25 enum es_result {
26 	ES_OK,			/* All good */
27 	ES_UNSUPPORTED,		/* Requested operation not supported */
28 	ES_VMM_ERROR,		/* Unexpected state from the VMM */
29 	ES_DECODE_FAILED,	/* Instruction decoding failed */
30 	ES_EXCEPTION,		/* Instruction caused exception */
31 	ES_RETRY,		/* Retry instruction emulation */
32 };
33 
34 struct es_fault_info {
35 	unsigned long vector;
36 	unsigned long error_code;
37 	unsigned long cr2;
38 };
39 
40 struct pt_regs;
41 
42 /* ES instruction emulation context */
43 struct es_em_ctxt {
44 	struct pt_regs *regs;
45 	struct insn insn;
46 	struct es_fault_info fi;
47 };
48 
49 /*
50  * AMD SEV Confidential computing blob structure. The structure is
51  * defined in OVMF UEFI firmware header:
52  * https://github.com/tianocore/edk2/blob/master/OvmfPkg/Include/Guid/ConfidentialComputingSevSnpBlob.h
53  */
54 #define CC_BLOB_SEV_HDR_MAGIC	0x45444d41
55 struct cc_blob_sev_info {
56 	u32 magic;
57 	u16 version;
58 	u16 reserved;
59 	u64 secrets_phys;
60 	u32 secrets_len;
61 	u32 rsvd1;
62 	u64 cpuid_phys;
63 	u32 cpuid_len;
64 	u32 rsvd2;
65 } __packed;
66 
67 void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code);
68 
69 static inline u64 lower_bits(u64 val, unsigned int bits)
70 {
71 	u64 mask = (1ULL << bits) - 1;
72 
73 	return (val & mask);
74 }
75 
76 struct real_mode_header;
77 enum stack_type;
78 
79 /* Early IDT entry points for #VC handler */
80 extern void vc_no_ghcb(void);
81 extern void vc_boot_ghcb(void);
82 extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
83 
84 /* PVALIDATE return codes */
85 #define PVALIDATE_FAIL_SIZEMISMATCH	6
86 
87 /* Software defined (when rFlags.CF = 1) */
88 #define PVALIDATE_FAIL_NOUPDATE		255
89 
90 /* RMP page size */
91 #define RMP_PG_SIZE_4K			0
92 #define RMP_PG_SIZE_2M			1
93 
94 #define RMPADJUST_VMSA_PAGE_BIT		BIT(16)
95 
96 /* SNP Guest message request */
97 struct snp_req_data {
98 	unsigned long req_gpa;
99 	unsigned long resp_gpa;
100 	unsigned long data_gpa;
101 	unsigned int data_npages;
102 };
103 
104 struct sev_guest_platform_data {
105 	u64 secrets_gpa;
106 };
107 
108 /*
109  * The secrets page contains 96-bytes of reserved field that can be used by
110  * the guest OS. The guest OS uses the area to save the message sequence
111  * number for each VMPCK.
112  *
113  * See the GHCB spec section Secret page layout for the format for this area.
114  */
115 struct secrets_os_area {
116 	u32 msg_seqno_0;
117 	u32 msg_seqno_1;
118 	u32 msg_seqno_2;
119 	u32 msg_seqno_3;
120 	u64 ap_jump_table_pa;
121 	u8 rsvd[40];
122 	u8 guest_usage[32];
123 } __packed;
124 
125 #define VMPCK_KEY_LEN		32
126 
127 /* See the SNP spec version 0.9 for secrets page format */
128 struct snp_secrets_page_layout {
129 	u32 version;
130 	u32 imien	: 1,
131 	    rsvd1	: 31;
132 	u32 fms;
133 	u32 rsvd2;
134 	u8 gosvw[16];
135 	u8 vmpck0[VMPCK_KEY_LEN];
136 	u8 vmpck1[VMPCK_KEY_LEN];
137 	u8 vmpck2[VMPCK_KEY_LEN];
138 	u8 vmpck3[VMPCK_KEY_LEN];
139 	struct secrets_os_area os_area;
140 	u8 rsvd3[3840];
141 } __packed;
142 
143 #ifdef CONFIG_AMD_MEM_ENCRYPT
144 extern void __sev_es_ist_enter(struct pt_regs *regs);
145 extern void __sev_es_ist_exit(void);
146 static __always_inline void sev_es_ist_enter(struct pt_regs *regs)
147 {
148 	if (cc_vendor == CC_VENDOR_AMD &&
149 	    cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
150 		__sev_es_ist_enter(regs);
151 }
152 static __always_inline void sev_es_ist_exit(void)
153 {
154 	if (cc_vendor == CC_VENDOR_AMD &&
155 	    cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
156 		__sev_es_ist_exit();
157 }
158 extern int sev_es_setup_ap_jump_table(struct real_mode_header *rmh);
159 extern void __sev_es_nmi_complete(void);
160 static __always_inline void sev_es_nmi_complete(void)
161 {
162 	if (cc_vendor == CC_VENDOR_AMD &&
163 	    cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
164 		__sev_es_nmi_complete();
165 }
166 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
167 extern void sev_enable(struct boot_params *bp);
168 
169 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
170 {
171 	int rc;
172 
173 	/* "rmpadjust" mnemonic support in binutils 2.36 and newer */
174 	asm volatile(".byte 0xF3,0x0F,0x01,0xFE\n\t"
175 		     : "=a"(rc)
176 		     : "a"(vaddr), "c"(rmp_psize), "d"(attrs)
177 		     : "memory", "cc");
178 
179 	return rc;
180 }
181 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
182 {
183 	bool no_rmpupdate;
184 	int rc;
185 
186 	/* "pvalidate" mnemonic support in binutils 2.36 and newer */
187 	asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFF\n\t"
188 		     CC_SET(c)
189 		     : CC_OUT(c) (no_rmpupdate), "=a"(rc)
190 		     : "a"(vaddr), "c"(rmp_psize), "d"(validate)
191 		     : "memory", "cc");
192 
193 	if (no_rmpupdate)
194 		return PVALIDATE_FAIL_NOUPDATE;
195 
196 	return rc;
197 }
198 
199 struct snp_guest_request_ioctl;
200 
201 void setup_ghcb(void);
202 void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
203 					 unsigned long npages);
204 void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
205 					unsigned long npages);
206 void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op);
207 void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);
208 void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
209 void snp_set_wakeup_secondary_cpu(void);
210 bool snp_init(struct boot_params *bp);
211 void __init __noreturn snp_abort(void);
212 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
213 void snp_accept_memory(phys_addr_t start, phys_addr_t end);
214 u64 snp_get_unsupported_features(u64 status);
215 u64 sev_get_status(void);
216 #else
217 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
218 static inline void sev_es_ist_exit(void) { }
219 static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
220 static inline void sev_es_nmi_complete(void) { }
221 static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
222 static inline void sev_enable(struct boot_params *bp) { }
223 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) { return 0; }
224 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
225 static inline void setup_ghcb(void) { }
226 static inline void __init
227 early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
228 static inline void __init
229 early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
230 static inline void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) { }
231 static inline void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { }
232 static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { }
233 static inline void snp_set_wakeup_secondary_cpu(void) { }
234 static inline bool snp_init(struct boot_params *bp) { return false; }
235 static inline void snp_abort(void) { }
236 static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
237 {
238 	return -ENOTTY;
239 }
240 
241 static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
242 static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
243 static inline u64 sev_get_status(void) { return 0; }
244 #endif
245 
246 #endif
247