Archipelago » qemu

/*

 *  x86 exception helpers

 *

 *  Copyright (c) 2003 Fabrice Bellard

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include "cpu.h"

#include "qemu-log.h"

#include "sysemu.h"

#include "helper.h"

#if 0

#define raise_exception_err(env, a, b)                                  \

    do {                                                                \

        qemu_log("raise_exception line=%d\n", __LINE__);                \

        (raise_exception_err)(env, a, b);                               \

    } while (0)

#endif

void helper_raise_interrupt(CPUX86State *env, int intno, int next_eip_addend)

{

    raise_interrupt(env, intno, 1, 0, next_eip_addend);

}

void helper_raise_exception(CPUX86State *env, int exception_index)

{

    raise_exception(env, exception_index);

}

/*

 * Check nested exceptions and change to double or triple fault if

 * needed. It should only be called, if this is not an interrupt.

 * Returns the new exception number.

 */

static int check_exception(CPUX86State *env, int intno, int *error_code)

{

    int first_contributory = env->old_exception == 0 ||

                              (env->old_exception >= 10 &&

                               env->old_exception <= 13);

    int second_contributory = intno == 0 ||

                               (intno >= 10 && intno <= 13);

    qemu_log_mask(CPU_LOG_INT, "check_exception old: 0x%x new 0x%x\n",

                env->old_exception, intno);

#if !defined(CONFIG_USER_ONLY)

    if (env->old_exception == EXCP08_DBLE) {

        if (env->hflags & HF_SVMI_MASK) {

            cpu_vmexit(env, SVM_EXIT_SHUTDOWN, 0); /* does not return */

        }

        qemu_log_mask(CPU_LOG_RESET, "Triple fault\n");

        qemu_system_reset_request();

        return EXCP_HLT;

    }

#endif

    if ((first_contributory && second_contributory)

        || (env->old_exception == EXCP0E_PAGE &&

            (second_contributory || (intno == EXCP0E_PAGE)))) {

        intno = EXCP08_DBLE;

        *error_code = 0;

    }

    if (second_contributory || (intno == EXCP0E_PAGE) ||

        (intno == EXCP08_DBLE)) {

        env->old_exception = intno;

    }

    return intno;

}

/*

 * Signal an interruption. It is executed in the main CPU loop.

 * is_int is TRUE if coming from the int instruction. next_eip is the

 * EIP value AFTER the interrupt instruction. It is only relevant if

 * is_int is TRUE.

 */

static void QEMU_NORETURN raise_interrupt2(CPUX86State *env, int intno,

                                           int is_int, int error_code,

                                           int next_eip_addend)

{

    if (!is_int) {

        cpu_svm_check_intercept_param(env, SVM_EXIT_EXCP_BASE + intno,

                                      error_code);

        intno = check_exception(env, intno, &error_code);

    } else {

        cpu_svm_check_intercept_param(env, SVM_EXIT_SWINT, 0);

    }

    env->exception_index = intno;

    env->error_code = error_code;

    env->exception_is_int = is_int;

    env->exception_next_eip = env->eip + next_eip_addend;

    cpu_loop_exit(env);

}

/* shortcuts to generate exceptions */

void QEMU_NORETURN raise_interrupt(CPUX86State *env, int intno, int is_int,

                                   int error_code, int next_eip_addend)

{

    raise_interrupt2(env, intno, is_int, error_code, next_eip_addend);

}

void raise_exception_err(CPUX86State *env, int exception_index,

                         int error_code)

{

    raise_interrupt2(env, exception_index, 0, error_code, 0);

}

void raise_exception(CPUX86State *env, int exception_index)

{

    raise_interrupt2(env, exception_index, 0, 0, 0);

}