target/i386/tcg/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 2.1 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 }