LXR qemu/target/i386/tcg/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 2.1 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
  28void 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
  34void 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 */
  44static 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 */
  90static 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
 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, 0);
 118}
 119
 120void 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
 126void 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
 132void QEMU_NORETURN raise_exception(CPUX86State *env, int exception_index)
 133{
 134    raise_interrupt2(env, exception_index, 0, 0, 0, 0);
 135}
 136
 137void 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}
 142