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 }