LXR qemu/target-i386/excp

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