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 2.1 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/runstate.h" 25 #include "exec/helper-proto.h" 26 #include "helper-tcg.h" 27 28 void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend) 29 { 30 raise_interrupt(env, intno, 1, 0, next_eip_addend); 31 } 32 33 void helper_raise_exception(CPUX86State *env, int exception_index) 34 { 35 raise_exception(env, exception_index); 36 } 37 38 /* 39 * Check nested exceptions and change to double or triple fault if 40 * needed. It should only be called, if this is not an interrupt. 41 * Returns the new exception number. 42 */ 43 static int check_exception(CPUX86State *env, int intno, int *error_code, 44 uintptr_t retaddr) 45 { 46 int first_contributory = env->old_exception == 0 || 47 (env->old_exception >= 10 && 48 env->old_exception <= 13); 49 int second_contributory = intno == 0 || 50 (intno >= 10 && intno <= 13); 51 52 qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n", 53 env->old_exception, intno); 54 55 #if !defined(CONFIG_USER_ONLY) 56 if (env->old_exception == EXCP08_DBLE) { 57 if (env->hflags & HF_GUEST_MASK) { 58 cpu_vmexit(env, SVM_EXIT_SHUTDOWN, 0, retaddr); /* does not return */ 59 } 60 61 qemu_log_mask(CPU_LOG_RESET, "Triple fault\n"); 62 63 qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET); 64 return EXCP_HLT; 65 } 66 #endif 67 68 if ((first_contributory && second_contributory) 69 || (env->old_exception == EXCP0E_PAGE && 70 (second_contributory || (intno == EXCP0E_PAGE)))) { 71 intno = EXCP08_DBLE; 72 *error_code = 0; 73 } 74 75 if (second_contributory || (intno == EXCP0E_PAGE) || 76 (intno == EXCP08_DBLE)) { 77 env->old_exception = intno; 78 } 79 80 return intno; 81 } 82 83 /* 84 * Signal an interruption. It is executed in the main CPU loop. 85 * is_int is TRUE if coming from the int instruction. next_eip is the 86 * env->eip value AFTER the interrupt instruction. It is only relevant if 87 * is_int is TRUE. 88 */ 89 static void QEMU_NORETURN raise_interrupt2(CPUX86State *env, int intno, 90 int is_int, int error_code, 91 int next_eip_addend, 92 uintptr_t retaddr) 93 { 94 CPUState *cs = env_cpu(env); 95 96 if (!is_int) { 97 cpu_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno, 98 error_code, retaddr); 99 intno = check_exception(env, intno, &error_code, retaddr); 100 } else { 101 cpu_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0, retaddr); 102 } 103 104 cs->exception_index = intno; 105 env->error_code = error_code; 106 env->exception_is_int = is_int; 107 env->exception_next_eip = env->eip + next_eip_addend; 108 cpu_loop_exit_restore(cs, retaddr); 109 } 110 111 /* shortcuts to generate exceptions */ 112 113 void QEMU_NORETURN raise_interrupt(CPUX86State *env, int intno, int is_int, 114 int error_code, int next_eip_addend) 115 { 116 raise_interrupt2(env, intno, is_int, error_code, next_eip_addend, 0); 117 } 118 119 void raise_exception_err(CPUX86State *env, int exception_index, 120 int error_code) 121 { 122 raise_interrupt2(env, exception_index, 0, error_code, 0, 0); 123 } 124 125 void raise_exception_err_ra(CPUX86State *env, int exception_index, 126 int error_code, uintptr_t retaddr) 127 { 128 raise_interrupt2(env, exception_index, 0, error_code, 0, retaddr); 129 } 130 131 void raise_exception(CPUX86State *env, int exception_index) 132 { 133 raise_interrupt2(env, exception_index, 0, 0, 0, 0); 134 } 135 136 void raise_exception_ra(CPUX86State *env, int exception_index, uintptr_t retaddr) 137 { 138 raise_interrupt2(env, exception_index, 0, 0, 0, retaddr); 139 } 140