vmsvga: don't process more than 1024 fifo commands at once
[qemu.git] / target-i386 / excp_helper.c
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 "qemu/osdep.h"
21 #include "cpu.h"
22 #include "exec/exec-all.h"
23 #include "qemu/log.h"
24 #include "sysemu/sysemu.h"
25 #include "exec/helper-proto.h"
26
27 void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend)
28 {
29 raise_interrupt(env, intno, 1, 0, next_eip_addend);
30 }
31
32 void helper_raise_exception(CPUX86State *env, int exception_index)
33 {
34 raise_exception(env, exception_index);
35 }
36
37 /*
38 * Check nested exceptions and change to double or triple fault if
39 * needed. It should only be called, if this is not an interrupt.
40 * Returns the new exception number.
41 */
42 static int check_exception(CPUX86State *env, int intno, int *error_code)
43 {
44 int first_contributory = env->old_exception == 0 ||
45 (env->old_exception >= 10 &&
46 env->old_exception <= 13);
47 int second_contributory = intno == 0 ||
48 (intno >= 10 && intno <= 13);
49
50 qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n",
51 env->old_exception, intno);
52
53 #if !defined(CONFIG_USER_ONLY)
54 if (env->old_exception == EXCP08_DBLE) {
55 if (env->hflags & HF_SVMI_MASK) {
56 cpu_vmexit(env, SVM_EXIT_SHUTDOWN, 0); /* does not return */
57 }
58
59 qemu_log_mask(CPU_LOG_RESET, "Triple fault\n");
60
61 qemu_system_reset_request();
62 return EXCP_HLT;
63 }
64 #endif
65
66 if ((first_contributory && second_contributory)
67 || (env->old_exception == EXCP0E_PAGE &&
68 (second_contributory || (intno == EXCP0E_PAGE)))) {
69 intno = EXCP08_DBLE;
70 *error_code = 0;
71 }
72
73 if (second_contributory || (intno == EXCP0E_PAGE) ||
74 (intno == EXCP08_DBLE)) {
75 env->old_exception = intno;
76 }
77
78 return intno;
79 }
80
81 /*
82 * Signal an interruption. It is executed in the main CPU loop.
83 * is_int is TRUE if coming from the int instruction. next_eip is the
84 * env->eip value AFTER the interrupt instruction. It is only relevant if
85 * is_int is TRUE.
86 */
87 static void QEMU_NORETURN raise_interrupt2(CPUX86State *env, int intno,
88 int is_int, int error_code,
89 int next_eip_addend,
90 uintptr_t retaddr)
91 {
92 CPUState *cs = CPU(x86_env_get_cpu(env));
93
94 if (!is_int) {
95 cpu_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno,
96 error_code);
97 intno = check_exception(env, intno, &error_code);
98 } else {
99 cpu_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0);
100 }
101
102 cs->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_restore(cs, retaddr);
107 }
108
109 /* shortcuts to generate exceptions */
110
111 void QEMU_NORETURN raise_interrupt(CPUX86State *env, int intno, int is_int,
112 int error_code, int next_eip_addend)
113 {
114 raise_interrupt2(env, intno, is_int, error_code, next_eip_addend, 0);
115 }
116
117 void raise_exception_err(CPUX86State *env, int exception_index,
118 int error_code)
119 {
120 raise_interrupt2(env, exception_index, 0, error_code, 0, 0);
121 }
122
123 void raise_exception_err_ra(CPUX86State *env, int exception_index,
124 int error_code, uintptr_t retaddr)
125 {
126 raise_interrupt2(env, exception_index, 0, error_code, 0, retaddr);
127 }
128
129 void raise_exception(CPUX86State *env, int exception_index)
130 {
131 raise_interrupt2(env, exception_index, 0, 0, 0, 0);
132 }
133
134 void raise_exception_ra(CPUX86State *env, int exception_index, uintptr_t retaddr)
135 {
136 raise_interrupt2(env, exception_index, 0, 0, 0, retaddr);
137 }