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 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 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 */ 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 */ 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 */ 110 111 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 } 116 117 void raise_exception(CPUX86State *env, int exception_index) 118 { 119 raise_interrupt(env, exception_index, 0, 0, 0); 120 } 121
