1 /*
2 * x86 exception helpers
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "cpu.h"
21 #include "qemu/log.h"
22 #include "sysemu/sysemu.h"
23 #include "exec/helper-proto.h"
24
25 #include "uc_priv.h"
26
27 #if 0
28 #define raise_exception_err(env, a, b) \
29 do { \
30 qemu_log("raise_exception line=%d\n", __LINE__); \
31 (raise_exception_err)(env, a, b); \
32 } while (0)
33 #endif
34
helper_raise_interrupt(CPUX86State * env,int intno,int next_eip_addend)35 void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend)
36 {
37 raise_interrupt(env, intno, 1, 0, next_eip_addend);
38 }
39
helper_raise_exception(CPUX86State * env,int exception_index)40 void helper_raise_exception(CPUX86State *env, int exception_index)
41 {
42 raise_exception(env, exception_index);
43 }
44
45 /*
46 * Check nested exceptions and change to double or triple fault if
47 * needed. It should only be called, if this is not an interrupt.
48 * Returns the new exception number.
49 */
check_exception(CPUX86State * env,int intno,int * error_code)50 static int check_exception(CPUX86State *env, int intno, int *error_code)
51 {
52 int first_contributory = env->old_exception == 0 ||
53 (env->old_exception >= 10 &&
54 env->old_exception <= 13);
55 int second_contributory = intno == 0 ||
56 (intno >= 10 && intno <= 13);
57
58 qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n",
59 env->old_exception, intno);
60
61 #if !defined(CONFIG_USER_ONLY)
62 if (env->old_exception == EXCP08_DBLE) {
63 if (env->hflags & HF_SVMI_MASK) {
64 cpu_vmexit(env, SVM_EXIT_SHUTDOWN, 0); /* does not return */
65 }
66
67 qemu_log_mask(CPU_LOG_RESET, "Triple fault\n");
68
69 qemu_system_reset_request(env->uc);
70 return EXCP_HLT;
71 }
72 #endif
73
74 if ((first_contributory && second_contributory)
75 || (env->old_exception == EXCP0E_PAGE &&
76 (second_contributory || (intno == EXCP0E_PAGE)))) {
77 intno = EXCP08_DBLE;
78 *error_code = 0;
79 }
80
81 if (second_contributory || (intno == EXCP0E_PAGE) ||
82 (intno == EXCP08_DBLE)) {
83 env->old_exception = intno;
84 }
85
86 return intno;
87 }
88
89 /*
90 * Signal an interruption. It is executed in the main CPU loop.
91 * is_int is TRUE if coming from the int instruction. next_eip is the
92 * env->eip value AFTER the interrupt instruction. It is only relevant if
93 * is_int is TRUE.
94 */
raise_interrupt2(CPUX86State * env,int intno,int is_int,int error_code,int next_eip_addend)95 static void QEMU_NORETURN raise_interrupt2(CPUX86State *env, int intno,
96 int is_int, int error_code,
97 int next_eip_addend)
98 {
99 CPUState *cs = CPU(x86_env_get_cpu(env));
100
101 if (!is_int) {
102 cpu_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno,
103 error_code);
104 intno = check_exception(env, intno, &error_code);
105 } else {
106 cpu_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0);
107 }
108
109 cs->exception_index = intno; // qq
110 env->error_code = error_code;
111 env->exception_is_int = is_int;
112 env->exception_next_eip = env->eip + next_eip_addend;
113 cpu_loop_exit(cs);
114 }
115
116 /* shortcuts to generate exceptions */
117
raise_interrupt(CPUX86State * env,int intno,int is_int,int error_code,int next_eip_addend)118 void QEMU_NORETURN raise_interrupt(CPUX86State *env, int intno, int is_int,
119 int error_code, int next_eip_addend)
120 {
121 raise_interrupt2(env, intno, is_int, error_code, next_eip_addend);
122 }
123
raise_exception_err(CPUX86State * env,int exception_index,int error_code)124 void raise_exception_err(CPUX86State *env, int exception_index,
125 int error_code)
126 {
127 raise_interrupt2(env, exception_index, 0, error_code, 0);
128 }
129
raise_exception(CPUX86State * env,int exception_index)130 void raise_exception(CPUX86State *env, int exception_index)
131 {
132 raise_interrupt2(env, exception_index, 0, 0, 0);
133 }
134