xref: /linux/arch/x86/include/asm/sev.h (revision 0340dc4c82590d8735c58cf904a8aa1173273ab5)
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/coco.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 struct boot_params;
25 
26 enum es_result {
27 	ES_OK,			/* All good */
28 	ES_UNSUPPORTED,		/* Requested operation not supported */
29 	ES_VMM_ERROR,		/* Unexpected state from the VMM */
30 	ES_DECODE_FAILED,	/* Instruction decoding failed */
31 	ES_EXCEPTION,		/* Instruction caused exception */
32 	ES_RETRY,		/* Retry instruction emulation */
33 };
34 
35 struct es_fault_info {
36 	unsigned long vector;
37 	unsigned long error_code;
38 	unsigned long cr2;
39 };
40 
41 struct pt_regs;
42 
43 /* ES instruction emulation context */
44 struct es_em_ctxt {
45 	struct pt_regs *regs;
46 	struct insn insn;
47 	struct es_fault_info fi;
48 };
49 
50 /*
51  * AMD SEV Confidential computing blob structure. The structure is
52  * defined in OVMF UEFI firmware header:
53  * https://github.com/tianocore/edk2/blob/master/OvmfPkg/Include/Guid/ConfidentialComputingSevSnpBlob.h
54  */
55 #define CC_BLOB_SEV_HDR_MAGIC	0x45444d41
56 struct cc_blob_sev_info {
57 	u32 magic;
58 	u16 version;
59 	u16 reserved;
60 	u64 secrets_phys;
61 	u32 secrets_len;
62 	u32 rsvd1;
63 	u64 cpuid_phys;
64 	u32 cpuid_len;
65 	u32 rsvd2;
66 } __packed;
67 
68 void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code);
69 
70 static inline u64 lower_bits(u64 val, unsigned int bits)
71 {
72 	u64 mask = (1ULL << bits) - 1;
73 
74 	return (val & mask);
75 }
76 
77 struct real_mode_header;
78 enum stack_type;
79 
80 /* Early IDT entry points for #VC handler */
81 extern void vc_no_ghcb(void);
82 extern void vc_boot_ghcb(void);
83 extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
84 
85 /* PVALIDATE return codes */
86 #define PVALIDATE_FAIL_SIZEMISMATCH	6
87 
88 /* Software defined (when rFlags.CF = 1) */
89 #define PVALIDATE_FAIL_NOUPDATE		255
90 
91 /* RMUPDATE detected 4K page and 2MB page overlap. */
92 #define RMPUPDATE_FAIL_OVERLAP		4
93 
94 /* RMP page size */
95 #define RMP_PG_SIZE_4K			0
96 #define RMP_PG_SIZE_2M			1
97 #define RMP_TO_PG_LEVEL(level)		(((level) == RMP_PG_SIZE_4K) ? PG_LEVEL_4K : PG_LEVEL_2M)
98 #define PG_LEVEL_TO_RMP(level)		(((level) == PG_LEVEL_4K) ? RMP_PG_SIZE_4K : RMP_PG_SIZE_2M)
99 
100 struct rmp_state {
101 	u64 gpa;
102 	u8 assigned;
103 	u8 pagesize;
104 	u8 immutable;
105 	u8 rsvd;
106 	u32 asid;
107 } __packed;
108 
109 #define RMPADJUST_VMSA_PAGE_BIT		BIT(16)
110 
111 /* SNP Guest message request */
112 struct snp_req_data {
113 	unsigned long req_gpa;
114 	unsigned long resp_gpa;
115 	unsigned long data_gpa;
116 	unsigned int data_npages;
117 };
118 
119 struct sev_guest_platform_data {
120 	u64 secrets_gpa;
121 };
122 
123 /*
124  * The secrets page contains 96-bytes of reserved field that can be used by
125  * the guest OS. The guest OS uses the area to save the message sequence
126  * number for each VMPCK.
127  *
128  * See the GHCB spec section Secret page layout for the format for this area.
129  */
130 struct secrets_os_area {
131 	u32 msg_seqno_0;
132 	u32 msg_seqno_1;
133 	u32 msg_seqno_2;
134 	u32 msg_seqno_3;
135 	u64 ap_jump_table_pa;
136 	u8 rsvd[40];
137 	u8 guest_usage[32];
138 } __packed;
139 
140 #define VMPCK_KEY_LEN		32
141 
142 /* See the SNP spec version 0.9 for secrets page format */
143 struct snp_secrets_page_layout {
144 	u32 version;
145 	u32 imien	: 1,
146 	    rsvd1	: 31;
147 	u32 fms;
148 	u32 rsvd2;
149 	u8 gosvw[16];
150 	u8 vmpck0[VMPCK_KEY_LEN];
151 	u8 vmpck1[VMPCK_KEY_LEN];
152 	u8 vmpck2[VMPCK_KEY_LEN];
153 	u8 vmpck3[VMPCK_KEY_LEN];
154 	struct secrets_os_area os_area;
155 	u8 rsvd3[3840];
156 } __packed;
157 
158 #ifdef CONFIG_AMD_MEM_ENCRYPT
159 extern void __sev_es_ist_enter(struct pt_regs *regs);
160 extern void __sev_es_ist_exit(void);
161 static __always_inline void sev_es_ist_enter(struct pt_regs *regs)
162 {
163 	if (cc_vendor == CC_VENDOR_AMD &&
164 	    cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
165 		__sev_es_ist_enter(regs);
166 }
167 static __always_inline void sev_es_ist_exit(void)
168 {
169 	if (cc_vendor == CC_VENDOR_AMD &&
170 	    cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
171 		__sev_es_ist_exit();
172 }
173 extern int sev_es_setup_ap_jump_table(struct real_mode_header *rmh);
174 extern void __sev_es_nmi_complete(void);
175 static __always_inline void sev_es_nmi_complete(void)
176 {
177 	if (cc_vendor == CC_VENDOR_AMD &&
178 	    cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
179 		__sev_es_nmi_complete();
180 }
181 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
182 extern void sev_enable(struct boot_params *bp);
183 
184 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
185 {
186 	int rc;
187 
188 	/* "rmpadjust" mnemonic support in binutils 2.36 and newer */
189 	asm volatile(".byte 0xF3,0x0F,0x01,0xFE\n\t"
190 		     : "=a"(rc)
191 		     : "a"(vaddr), "c"(rmp_psize), "d"(attrs)
192 		     : "memory", "cc");
193 
194 	return rc;
195 }
196 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
197 {
198 	bool no_rmpupdate;
199 	int rc;
200 
201 	/* "pvalidate" mnemonic support in binutils 2.36 and newer */
202 	asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFF\n\t"
203 		     CC_SET(c)
204 		     : CC_OUT(c) (no_rmpupdate), "=a"(rc)
205 		     : "a"(vaddr), "c"(rmp_psize), "d"(validate)
206 		     : "memory", "cc");
207 
208 	if (no_rmpupdate)
209 		return PVALIDATE_FAIL_NOUPDATE;
210 
211 	return rc;
212 }
213 
214 struct snp_guest_request_ioctl;
215 
216 void setup_ghcb(void);
217 void early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
218 				  unsigned long npages);
219 void early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
220 				 unsigned long npages);
221 void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);
222 void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
223 void snp_set_wakeup_secondary_cpu(void);
224 bool snp_init(struct boot_params *bp);
225 void __noreturn snp_abort(void);
226 void snp_dmi_setup(void);
227 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
228 void snp_accept_memory(phys_addr_t start, phys_addr_t end);
229 u64 snp_get_unsupported_features(u64 status);
230 u64 sev_get_status(void);
231 void sev_show_status(void);
232 #else
233 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
234 static inline void sev_es_ist_exit(void) { }
235 static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
236 static inline void sev_es_nmi_complete(void) { }
237 static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
238 static inline void sev_enable(struct boot_params *bp) { }
239 static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) { return 0; }
240 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
241 static inline void setup_ghcb(void) { }
242 static inline void __init
243 early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
244 static inline void __init
245 early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
246 static inline void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { }
247 static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { }
248 static inline void snp_set_wakeup_secondary_cpu(void) { }
249 static inline bool snp_init(struct boot_params *bp) { return false; }
250 static inline void snp_abort(void) { }
251 static inline void snp_dmi_setup(void) { }
252 static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
253 {
254 	return -ENOTTY;
255 }
256 
257 static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
258 static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
259 static inline u64 sev_get_status(void) { return 0; }
260 static inline void sev_show_status(void) { }
261 #endif
262 
263 #ifdef CONFIG_KVM_AMD_SEV
264 bool snp_probe_rmptable_info(void);
265 int snp_lookup_rmpentry(u64 pfn, bool *assigned, int *level);
266 void snp_dump_hva_rmpentry(unsigned long address);
267 int psmash(u64 pfn);
268 int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, u32 asid, bool immutable);
269 int rmp_make_shared(u64 pfn, enum pg_level level);
270 void snp_leak_pages(u64 pfn, unsigned int npages);
271 void kdump_sev_callback(void);
272 #else
273 static inline bool snp_probe_rmptable_info(void) { return false; }
274 static inline int snp_lookup_rmpentry(u64 pfn, bool *assigned, int *level) { return -ENODEV; }
275 static inline void snp_dump_hva_rmpentry(unsigned long address) {}
276 static inline int psmash(u64 pfn) { return -ENODEV; }
277 static inline int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, u32 asid,
278 				   bool immutable)
279 {
280 	return -ENODEV;
281 }
282 static inline int rmp_make_shared(u64 pfn, enum pg_level level) { return -ENODEV; }
283 static inline void snp_leak_pages(u64 pfn, unsigned int npages) {}
284 static inline void kdump_sev_callback(void) { }
285 #endif
286 
287 #endif
288