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 "qemu/log.h"
  23#include "sysemu/sysemu.h"
  24#include "exec/helper-proto.h"
  25
  26void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend)
  27{
  28    raise_interrupt(env, intno, 1, 0, next_eip_addend);
  29}
  30
  31void helper_raise_exception(CPUX86State *env, int exception_index)
  32{
  33    raise_exception(env, exception_index);
  34}
  35
  36/*
  37 * Check nested exceptions and change to double or triple fault if
  38 * needed. It should only be called, if this is not an interrupt.
  39 * Returns the new exception number.
  40 */
  41static int check_exception(CPUX86State *env, int intno, int *error_code)
  42{
  43    int first_contributory = env->old_exception == 0 ||
  44                              (env->old_exception >= 10 &&
  45                               env->old_exception <= 13);
  46    int second_contributory = intno == 0 ||
  47                               (intno >= 10 && intno <= 13);
  48
  49    qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n",
  50                env->old_exception, intno);
  51
  52#if !defined(CONFIG_USER_ONLY)
  53    if (env->old_exception == EXCP08_DBLE) {
  54        if (env->hflags & HF_SVMI_MASK) {
  55            cpu_vmexit(env, SVM_EXIT_SHUTDOWN, 0); /* does not return */
  56        }
  57
  58        qemu_log_mask(CPU_LOG_RESET, "Triple fault\n");
  59
  60        qemu_system_reset_request();
  61        return EXCP_HLT;
  62    }
  63#endif
  64
  65    if ((first_contributory && second_contributory)
  66        || (env->old_exception == EXCP0E_PAGE &&
  67            (second_contributory || (intno == EXCP0E_PAGE)))) {
  68        intno = EXCP08_DBLE;
  69        *error_code = 0;
  70    }
  71
  72    if (second_contributory || (intno == EXCP0E_PAGE) ||
  73        (intno == EXCP08_DBLE)) {
  74        env->old_exception = intno;
  75    }
  76
  77    return intno;
  78}
  79
  80/*
  81 * Signal an interruption. It is executed in the main CPU loop.
  82 * is_int is TRUE if coming from the int instruction. next_eip is the
  83 * env->eip value AFTER the interrupt instruction. It is only relevant if
  84 * is_int is TRUE.
  85 */
  86static void QEMU_NORETURN raise_interrupt2(CPUX86State *env, int intno,
  87                                           int is_int, int error_code,
  88                                           int next_eip_addend,
  89                                           uintptr_t retaddr)
  90{
  91    CPUState *cs = CPU(x86_env_get_cpu(env));
  92
  93    if (!is_int) {
  94        cpu_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno,
  95                                      error_code);
  96        intno = check_exception(env, intno, &error_code);
  97    } else {
  98        cpu_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0);
  99    }
 100
 101    cs->exception_index = intno;
 102    env->error_code = error_code;
 103    env->exception_is_int = is_int;
 104    env->exception_next_eip = env->eip + next_eip_addend;
 105    cpu_loop_exit_restore(cs, retaddr);
 106}
 107
 108/* shortcuts to generate exceptions */
 109
 110void QEMU_NORETURN raise_interrupt(CPUX86State *env, int intno, int is_int,
 111                                   int error_code, int next_eip_addend)
 112{
 113    raise_interrupt2(env, intno, is_int, error_code, next_eip_addend, 0);
 114}
 115
 116void raise_exception_err(CPUX86State *env, int exception_index,
 117                         int error_code)
 118{
 119    raise_interrupt2(env, exception_index, 0, error_code, 0, 0);
 120}
 121
 122void raise_exception_err_ra(CPUX86State *env, int exception_index,
 123                            int error_code, uintptr_t retaddr)
 124{
 125    raise_interrupt2(env, exception_index, 0, error_code, 0, retaddr);
 126}
 127
 128void raise_exception(CPUX86State *env, int exception_index)
 129{
 130    raise_interrupt2(env, exception_index, 0, 0, 0, 0);
 131}
 132
 133void raise_exception_ra(CPUX86State *env, int exception_index, uintptr_t retaddr)
 134{
 135    raise_interrupt2(env, exception_index, 0, 0, 0, retaddr);
 136}
 137