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 "qemu/log.h"
  23 #include "sysemu/sysemu.h"
  24 #include "exec/helper-proto.h"
  25
  26 void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend)
  27 {
  28     raise_interrupt(env, intno, 1, 0, next_eip_addend);
  29 }
  30
  31 void helper_raise_exception(CPUX86State *env, int exception_index)
  32 {
  33     raise_exception(env, exception_index);
  34 }
  35
  36 /*
  37  * Check nested exceptions and change to double or triple fault if
  38  * needed. It should only be called, if this is not an interrupt.
  39  * Returns the new exception number.
  40  */
  41 static int check_exception(CPUX86State *env, int intno, int *error_code)
  42 {
  43     int first_contributory = env->old_exception == 0 ||
  44                               (env->old_exception >= 10 &&
  45                                env->old_exception <= 13);
  46     int second_contributory = intno == 0 ||
  47                                (intno >= 10 && intno <= 13);
  48
  49     qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n",
  50                 env->old_exception, intno);
  51
  52 #if !defined(CONFIG_USER_ONLY)
  53     if (env->old_exception == EXCP08_DBLE) {
  54         if (env->hflags & HF_SVMI_MASK) {
  55             cpu_vmexit(env, SVM_EXIT_SHUTDOWN, 0); /* does not return */
  56         }
  57
  58         qemu_log_mask(CPU_LOG_RESET, "Triple fault\n");
  59
  60         qemu_system_reset_request();
  61         return EXCP_HLT;
  62     }
  63 #endif
  64
  65     if ((first_contributory && second_contributory)
  66         || (env->old_exception == EXCP0E_PAGE &&
  67             (second_contributory || (intno == EXCP0E_PAGE)))) {
  68         intno = EXCP08_DBLE;
  69         *error_code = 0;
  70     }
  71
  72     if (second_contributory || (intno == EXCP0E_PAGE) ||
  73         (intno == EXCP08_DBLE)) {
  74         env->old_exception = intno;
  75     }
  76
  77     return intno;
  78 }
  79
  80 /*
  81  * Signal an interruption. It is executed in the main CPU loop.
  82  * is_int is TRUE if coming from the int instruction. next_eip is the
  83  * env->eip value AFTER the interrupt instruction. It is only relevant if
  84  * is_int is TRUE.
  85  */
  86 static void QEMU_NORETURN raise_interrupt2(CPUX86State *env, int intno,
  87                                            int is_int, int error_code,
  88                                            int next_eip_addend,
  89                                            uintptr_t retaddr)
  90 {
  91     CPUState *cs = CPU(x86_env_get_cpu(env));
  92
  93     if (!is_int) {
  94         cpu_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno,
  95                                       error_code);
  96         intno = check_exception(env, intno, &error_code);
  97     } else {
  98         cpu_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0);
  99     }
 100
 101     cs->exception_index = intno;
 102     env->error_code = error_code;
 103     env->exception_is_int = is_int;
 104     env->exception_next_eip = env->eip + next_eip_addend;
 105     cpu_loop_exit_restore(cs, retaddr);
 106 }
 107
 108 /* shortcuts to generate exceptions */
 109
 110 void QEMU_NORETURN raise_interrupt(CPUX86State *env, int intno, int is_int,
 111                                    int error_code, int next_eip_addend)
 112 {
 113     raise_interrupt2(env, intno, is_int, error_code, next_eip_addend, 0);
 114 }
 115
 116 void raise_exception_err(CPUX86State *env, int exception_index,
 117                          int error_code)
 118 {
 119     raise_interrupt2(env, exception_index, 0, error_code, 0, 0);
 120 }
 121
 122 void raise_exception_err_ra(CPUX86State *env, int exception_index,
 123                             int error_code, uintptr_t retaddr)
 124 {
 125     raise_interrupt2(env, exception_index, 0, error_code, 0, retaddr);
 126 }
 127
 128 void raise_exception(CPUX86State *env, int exception_index)
 129 {
 130     raise_interrupt2(env, exception_index, 0, 0, 0, 0);
 131 }
 132
 133 void raise_exception_ra(CPUX86State *env, int exception_index, uintptr_t retaddr)
 134 {
 135     raise_interrupt2(env, exception_index, 0, 0, 0, retaddr);
 136 }