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 "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
  27void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend)
  28{
  29    raise_interrupt(env, intno, 1, 0, next_eip_addend);
  30}
  31
  32void 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 */
  42static 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 */
  87static 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
 111void 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
 117void 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
 123void 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
 129void raise_exception(CPUX86State *env, int exception_index)
 130{
 131    raise_interrupt2(env, exception_index, 0, 0, 0, 0);
 132}
 133
 134void raise_exception_ra(CPUX86State *env, int exception_index, uintptr_t retaddr)
 135{
 136    raise_interrupt2(env, exception_index, 0, 0, 0, retaddr);
 137}
 138