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