/******************************************************************************

 * arch/x86/pv/emul-inv-op.c

 *

 * Emulate invalid op for PV guests

 *

 * Modifications to Linux original are copyright (c) 2002-2004, K A Fraser

 *

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

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

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

 * along with this program; If not, see <http://www.gnu.org/licenses/>.

 */

#include <xen/errno.h>

#include <xen/event.h>

#include <xen/guest_access.h>

#include <xen/iocap.h>

#include <xen/spinlock.h>

#include <xen/trace.h>

#include <asm/apic.h>

#include <asm/debugreg.h>

#include <asm/hpet.h>

#include <asm/hypercall.h>

#include <asm/mc146818rtc.h>

#include <asm/p2m.h>

#include <asm/pv/traps.h>

#include <asm/shared.h>

#include <asm/traps.h>

#include <asm/x86_emulate.h>

#include <xsm/xsm.h>

#include "emulate.h"

static int emulate_invalid_rdtscp(struct cpu_user_regs *regs)

{

    char opcode[3];

    unsigned long eip, rc;

    struct vcpu *v = current;

    eip = regs->rip;

    if ( (rc = copy_from_user(opcode, (char *)eip, sizeof(opcode))) != 0 )

    {

        pv_inject_page_fault(0, eip + sizeof(opcode) - rc);

        return EXCRET_fault_fixed;

    }

    if ( memcmp(opcode, "\xf\x1\xf9", sizeof(opcode)) )

        return 0;

    eip += sizeof(opcode);

    pv_soft_rdtsc(v, regs, 1);

    pv_emul_instruction_done(regs, eip);

    return EXCRET_fault_fixed;

}

static int emulate_forced_invalid_op(struct cpu_user_regs *regs)

{

    char sig[5], instr[2];

    unsigned long eip, rc;

    struct cpuid_leaf res;

    const struct msr_vcpu_policy *vp = current->arch.msr;

    eip = regs->rip;

    /* Check for forced emulation signature: ud2 ; .ascii "xen". */

    if ( (rc = copy_from_user(sig, (char *)eip, sizeof(sig))) != 0 )

    {

        pv_inject_page_fault(0, eip + sizeof(sig) - rc);

        return EXCRET_fault_fixed;

    }

    if ( memcmp(sig, "\xf\xbxen", sizeof(sig)) )

        return 0;

    eip += sizeof(sig);

    /* We only emulate CPUID. */

    if ( ( rc = copy_from_user(instr, (char *)eip, sizeof(instr))) != 0 )

    {

        pv_inject_page_fault(0, eip + sizeof(instr) - rc);

        return EXCRET_fault_fixed;

    }

    if ( memcmp(instr, "\xf\xa2", sizeof(instr)) )

        return 0;

    /* If cpuid faulting is enabled and CPL>0 inject a #GP in place of #UD. */

    if ( vp->misc_features_enables.cpuid_faulting &&

         !guest_kernel_mode(current, regs) )

    {

        regs->rip = eip;

        pv_inject_hw_exception(TRAP_gp_fault, regs->error_code);

        return EXCRET_fault_fixed;

    }

    eip += sizeof(instr);

    guest_cpuid(current, regs->eax, regs->ecx, &res);

    regs->rax = res.a;

    regs->rbx = res.b;

    regs->rcx = res.c;

    regs->rdx = res.d;

    pv_emul_instruction_done(regs, eip);

    trace_trap_one_addr(TRC_PV_FORCED_INVALID_OP, regs->rip);

    return EXCRET_fault_fixed;

}

bool pv_emulate_invalid_op(struct cpu_user_regs *regs)

{

    return !emulate_invalid_rdtscp(regs) && !emulate_forced_invalid_op(regs);

}

/*

 * Local variables:

 * mode: C

 * c-file-style: "BSD"

 * c-basic-offset: 4

 * tab-width: 4

 * indent-tabs-mode: nil

 * End:

 */