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 QEMU_NORETURN helper_raise_interrupt(CPUX86State *env, int intno,
  29                                           int next_eip_addend)
  30 {
  31     raise_interrupt(env, intno, 1, 0, next_eip_addend);
  32 }
  33
  34 void QEMU_NORETURN helper_raise_exception(CPUX86State *env, int exception_index)
  35 {
  36     raise_exception(env, exception_index);
  37 }
  38
  39 /*
  40  * Check nested exceptions and change to double or triple fault if
  41  * needed. It should only be called, if this is not an interrupt.
  42  * Returns the new exception number.
  43  */
  44 static int check_exception(CPUX86State *env, int intno, int *error_code,
  45                            uintptr_t retaddr)
  46 {
  47     int first_contributory = env->old_exception == 0 ||
  48                               (env->old_exception >= 10 &&
  49                                env->old_exception <= 13);
  50     int second_contributory = intno == 0 ||
  51                                (intno >= 10 && intno <= 13);
  52
  53     qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n",
  54                 env->old_exception, intno);
  55
  56 #if !defined(CONFIG_USER_ONLY)
  57     if (env->old_exception == EXCP08_DBLE) {
  58         if (env->hflags & HF_GUEST_MASK) {
  59             cpu_vmexit(env, SVM_EXIT_SHUTDOWN, 0, retaddr); /* does not return */
  60         }
  61
  62         qemu_log_mask(CPU_LOG_RESET, "Triple fault\n");
  63
  64         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
  65         return EXCP_HLT;
  66     }
  67 #endif
  68
  69     if ((first_contributory && second_contributory)
  70         || (env->old_exception == EXCP0E_PAGE &&
  71             (second_contributory || (intno == EXCP0E_PAGE)))) {
  72         intno = EXCP08_DBLE;
  73         *error_code = 0;
  74     }
  75
  76     if (second_contributory || (intno == EXCP0E_PAGE) ||
  77         (intno == EXCP08_DBLE)) {
  78         env->old_exception = intno;
  79     }
  80
  81     return intno;
  82 }
  83
  84 /*
  85  * Signal an interruption. It is executed in the main CPU loop.
  86  * is_int is TRUE if coming from the int instruction. next_eip is the
  87  * env->eip value AFTER the interrupt instruction. It is only relevant if
  88  * is_int is TRUE.
  89  */
  90 static void QEMU_NORETURN raise_interrupt2(CPUX86State *env, int intno,
  91                                            int is_int, int error_code,
  92                                            int next_eip_addend,
  93                                            uintptr_t retaddr)
  94 {
  95     CPUState *cs = env_cpu(env);
  96
  97     if (!is_int) {
  98         cpu_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno,
  99                                       error_code, retaddr);
 100         intno = check_exception(env, intno, &error_code, retaddr);
 101     } else {
 102         cpu_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0, retaddr);
 103     }
 104
 105     cs->exception_index = intno;
 106     env->error_code = error_code;
 107     env->exception_is_int = is_int;
 108     env->exception_next_eip = env->eip + next_eip_addend;
 109     cpu_loop_exit_restore(cs, retaddr);
 110 }
 111
 112 /* shortcuts to generate exceptions */
 113
 114 void QEMU_NORETURN raise_interrupt(CPUX86State *env, int intno, int is_int,
 115                                    int error_code, int next_eip_addend)
 116 {
 117     raise_interrupt2(env, intno, is_int, error_code, next_eip_addend, 0);
 118 }
 119
 120 void QEMU_NORETURN raise_exception_err(CPUX86State *env, int exception_index,
 121                                        int error_code)
 122 {
 123     raise_interrupt2(env, exception_index, 0, error_code, 0, 0);
 124 }
 125
 126 void QEMU_NORETURN raise_exception_err_ra(CPUX86State *env, int exception_index,
 127                                           int error_code, uintptr_t retaddr)
 128 {
 129     raise_interrupt2(env, exception_index, 0, error_code, 0, retaddr);
 130 }
 131
 132 void QEMU_NORETURN raise_exception(CPUX86State *env, int exception_index)
 133 {
 134     raise_interrupt2(env, exception_index, 0, 0, 0, 0);
 135 }
 136
 137 void QEMU_NORETURN raise_exception_ra(CPUX86State *env, int exception_index,
 138                                       uintptr_t retaddr)
 139 {
 140     raise_interrupt2(env, exception_index, 0, 0, 0, retaddr);
 141 }