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 "helper.h"
24
25 #if 0
26 #define raise_exception_err(a, b)\
27 do {\
28 qemu_log("raise_exception line=%d\n", __LINE__);\
29 (raise_exception_err)(a, b);\
30 } while (0)
31 #endif
32
helper_raise_interrupt(CPUX86State * env,int intno,int next_eip_addend)33 void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend)
34 {
35 raise_interrupt(env, intno, 1, 0, next_eip_addend);
36 }
37
helper_raise_exception(CPUX86State * env,int exception_index)38 void helper_raise_exception(CPUX86State *env, int exception_index)
39 {
40 raise_exception(env, exception_index);
41 }
42
43 /*
44 * Check nested exceptions and change to double or triple fault if
45 * needed. It should only be called, if this is not an interrupt.
46 * Returns the new exception number.
47 */
check_exception(CPUX86State * env,int intno,int * error_code)48 static int check_exception(CPUX86State *env, int intno, int *error_code)
49 {
50 int first_contributory = env->old_exception == 0 ||
51 (env->old_exception >= 10 &&
52 env->old_exception <= 13);
53 int second_contributory = intno == 0 ||
54 (intno >= 10 && intno <= 13);
55
56 qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n",
57 env->old_exception, intno);
58
59 #if !defined(CONFIG_USER_ONLY)
60 if (env->old_exception == EXCP08_DBLE) {
61 if (env->hflags & HF_SVMI_MASK)
62 helper_vmexit(env, SVM_EXIT_SHUTDOWN, 0); /* does not return */
63
64 qemu_log_mask(CPU_LOG_RESET, "Triple fault\n");
65
66 qemu_system_reset_request();
67 return EXCP_HLT;
68 }
69 #endif
70
71 if ((first_contributory && second_contributory)
72 || (env->old_exception == EXCP0E_PAGE &&
73 (second_contributory || (intno == EXCP0E_PAGE)))) {
74 intno = EXCP08_DBLE;
75 *error_code = 0;
76 }
77
78 if (second_contributory || (intno == EXCP0E_PAGE) ||
79 (intno == EXCP08_DBLE))
80 env->old_exception = intno;
81
82 return intno;
83 }
84
85 /*
86 * Signal an interruption. It is executed in the main CPU loop.
87 * is_int is TRUE if coming from the int instruction. next_eip is the
88 * EIP value AFTER the interrupt instruction. It is only relevant if
89 * is_int is TRUE.
90 */
raise_interrupt(CPUX86State * env,int intno,int is_int,int error_code,int next_eip_addend)91 void QEMU_NORETURN raise_interrupt(CPUX86State *env,
92 int intno, int is_int, int error_code,
93 int next_eip_addend)
94 {
95 if (!is_int) {
96 helper_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno, error_code);
97 intno = check_exception(env, intno, &error_code);
98 } else {
99 helper_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0);
100 }
101
102 env->exception_index = intno;
103 env->error_code = error_code;
104 env->exception_is_int = is_int;
105 env->exception_next_eip = env->eip + next_eip_addend;
106 cpu_loop_exit(env);
107 }
108
109 /* shortcuts to generate exceptions */
110
raise_exception_err(CPUX86State * env,int exception_index,int error_code)111 void raise_exception_err(CPUX86State *env,
112 int exception_index, int error_code)
113 {
114 raise_interrupt(env, exception_index, 0, error_code, 0);
115 }
116
raise_exception(CPUX86State * env,int exception_index)117 void raise_exception(CPUX86State *env, int exception_index)
118 {
119 raise_interrupt(env, exception_index, 0, 0, 0);
120 }
121