1 // SPDX-License-Identifier: GPL-2.0
2
3 #include "misc.h"
4 #include "error.h"
5 #include "sev.h"
6
7 #include <linux/kernel.h>
8 #include <linux/string.h>
9 #include <asm/insn.h>
10 #include <asm/pgtable_types.h>
11 #include <asm/ptrace.h>
12 #include <asm/sev.h>
13 #include <asm/trapnr.h>
14 #include <asm/trap_pf.h>
15 #include <asm/fpu/xcr.h>
16
17 #define __BOOT_COMPRESSED
18 #undef __init
19 #define __init
20
21 /* Basic instruction decoding support needed */
22 #include "../../lib/inat.c"
23 #include "../../lib/insn.c"
24
25 /*
26 * Copy a version of this function here - insn-eval.c can't be used in
27 * pre-decompression code.
28 */
insn_has_rep_prefix(struct insn * insn)29 bool insn_has_rep_prefix(struct insn *insn)
30 {
31 insn_byte_t p;
32 int i;
33
34 insn_get_prefixes(insn);
35
36 for_each_insn_prefix(insn, i, p) {
37 if (p == 0xf2 || p == 0xf3)
38 return true;
39 }
40
41 return false;
42 }
43
vc_decode_insn(struct es_em_ctxt * ctxt)44 enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
45 {
46 char buffer[MAX_INSN_SIZE];
47 int ret;
48
49 memcpy(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
50
51 ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64);
52 if (ret < 0)
53 return ES_DECODE_FAILED;
54
55 return ES_OK;
56 }
57
58 extern void sev_insn_decode_init(void) __alias(inat_init_tables);
59
60 /*
61 * Only a dummy for insn_get_seg_base() - Early boot-code is 64bit only and
62 * doesn't use segments.
63 */
insn_get_seg_base(struct pt_regs * regs,int seg_reg_idx)64 static unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx)
65 {
66 return 0UL;
67 }
68
vc_write_mem(struct es_em_ctxt * ctxt,void * dst,char * buf,size_t size)69 static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
70 void *dst, char *buf, size_t size)
71 {
72 memcpy(dst, buf, size);
73
74 return ES_OK;
75 }
76
vc_read_mem(struct es_em_ctxt * ctxt,void * src,char * buf,size_t size)77 static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
78 void *src, char *buf, size_t size)
79 {
80 memcpy(buf, src, size);
81
82 return ES_OK;
83 }
84
vc_ioio_check(struct es_em_ctxt * ctxt,u16 port,size_t size)85 static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size)
86 {
87 return ES_OK;
88 }
89
fault_in_kernel_space(unsigned long address)90 static bool fault_in_kernel_space(unsigned long address)
91 {
92 return false;
93 }
94
95 #define sev_printk(fmt, ...)
96
97 #include "../../coco/sev/vc-shared.c"
98
do_boot_stage2_vc(struct pt_regs * regs,unsigned long exit_code)99 void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
100 {
101 struct es_em_ctxt ctxt;
102 enum es_result result;
103
104 if (!boot_ghcb && !early_setup_ghcb())
105 sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
106
107 vc_ghcb_invalidate(boot_ghcb);
108 result = vc_init_em_ctxt(&ctxt, regs, exit_code);
109 if (result != ES_OK)
110 goto finish;
111
112 result = vc_check_opcode_bytes(&ctxt, exit_code);
113 if (result != ES_OK)
114 goto finish;
115
116 switch (exit_code) {
117 case SVM_EXIT_RDTSC:
118 case SVM_EXIT_RDTSCP:
119 result = vc_handle_rdtsc(boot_ghcb, &ctxt, exit_code);
120 break;
121 case SVM_EXIT_IOIO:
122 result = vc_handle_ioio(boot_ghcb, &ctxt);
123 break;
124 case SVM_EXIT_CPUID:
125 result = vc_handle_cpuid(boot_ghcb, &ctxt);
126 break;
127 default:
128 result = ES_UNSUPPORTED;
129 break;
130 }
131
132 finish:
133 if (result == ES_OK)
134 vc_finish_insn(&ctxt);
135 else if (result != ES_RETRY)
136 sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
137 }
138