static int
xenoprof_is_xen_mode(struct vcpu *v, struct pt_regs *regs)
{
    if (VMX_DOMAIN(v))
        return !vmx_user_mode(regs);
    return ring_0(regs);
}
Exemple #2
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static int nmi_callback(const struct cpu_user_regs *regs, int cpu)
{
	int xen_mode, ovf;

	ovf = model->check_ctrs(cpu, &cpu_msrs[cpu], regs);
	xen_mode = ring_0(regs);
	if ( ovf && is_active(current->domain) && !xen_mode )
		send_guest_vcpu_virq(current, VIRQ_XENOPROF);

	if ( ovf == 2 )
                current->nmi_pending = 1;
	return 1;
}
Exemple #3
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unsigned int compat_iret(void)
{
    struct cpu_user_regs *regs = guest_cpu_user_regs();
    struct vcpu *v = current;
    u32 eflags;

    /* Trim stack pointer to 32 bits. */
    regs->rsp = (u32)regs->rsp;

    /* Restore EAX (clobbered by hypercall). */
    if ( unlikely(__get_user(regs->eax, (u32 *)regs->rsp)) )
    {
        domain_crash(v->domain);
        return 0;
    }

    /* Restore CS and EIP. */
    if ( unlikely(__get_user(regs->eip, (u32 *)regs->rsp + 1)) ||
        unlikely(__get_user(regs->cs, (u32 *)regs->rsp + 2)) )
    {
        domain_crash(v->domain);
        return 0;
    }

    /*
     * Fix up and restore EFLAGS. We fix up in a local staging area
     * to avoid firing the BUG_ON(IOPL) check in arch_get_info_guest.
     */
    if ( unlikely(__get_user(eflags, (u32 *)regs->rsp + 3)) )
    {
        domain_crash(v->domain);
        return 0;
    }

    if ( VM_ASSIST(v->domain, architectural_iopl) )
        v->arch.pv_vcpu.iopl = eflags & X86_EFLAGS_IOPL;

    regs->eflags = (eflags & ~X86_EFLAGS_IOPL) | X86_EFLAGS_IF;

    if ( unlikely(eflags & X86_EFLAGS_VM) )
    {
        /*
         * Cannot return to VM86 mode: inject a GP fault instead. Note that
         * the GP fault is reported on the first VM86 mode instruction, not on
         * the IRET (which is why we can simply leave the stack frame as-is
         * (except for perhaps having to copy it), which in turn seems better
         * than teaching create_bounce_frame() to needlessly deal with vm86
         * mode frames).
         */
        const struct trap_info *ti;
        u32 x, ksp = v->arch.pv_vcpu.kernel_sp - 40;
        unsigned int i;
        int rc = 0;

        gdprintk(XENLOG_ERR, "VM86 mode unavailable (ksp:%08X->%08X)\n",
                 regs->esp, ksp);
        if ( ksp < regs->esp )
        {
            for (i = 1; i < 10; ++i)
            {
                rc |= __get_user(x, (u32 *)regs->rsp + i);
                rc |= __put_user(x, (u32 *)(unsigned long)ksp + i);
            }
        }
        else if ( ksp > regs->esp )
        {
            for ( i = 9; i > 0; --i )
            {
                rc |= __get_user(x, (u32 *)regs->rsp + i);
                rc |= __put_user(x, (u32 *)(unsigned long)ksp + i);
            }
        }
        if ( rc )
        {
            domain_crash(v->domain);
            return 0;
        }
        regs->esp = ksp;
        regs->ss = v->arch.pv_vcpu.kernel_ss;

        ti = &v->arch.pv_vcpu.trap_ctxt[TRAP_gp_fault];
        if ( TI_GET_IF(ti) )
            eflags &= ~X86_EFLAGS_IF;
        regs->eflags &= ~(X86_EFLAGS_VM|X86_EFLAGS_RF|
                          X86_EFLAGS_NT|X86_EFLAGS_TF);
        if ( unlikely(__put_user(0, (u32 *)regs->rsp)) )
        {
            domain_crash(v->domain);
            return 0;
        }
        regs->eip = ti->address;
        regs->cs = ti->cs;
    }
    else if ( unlikely(ring_0(regs)) )
    {
        domain_crash(v->domain);
        return 0;
    }
    else if ( ring_1(regs) )
        regs->esp += 16;
    /* Return to ring 2/3: restore ESP and SS. */
    else if ( __get_user(regs->ss, (u32 *)regs->rsp + 5) ||
              __get_user(regs->esp, (u32 *)regs->rsp + 4) )
    {
        domain_crash(v->domain);
        return 0;
    }

    /* Restore upcall mask from supplied EFLAGS.IF. */
    vcpu_info(v, evtchn_upcall_mask) = !(eflags & X86_EFLAGS_IF);

    async_exception_cleanup(v);

    /*
     * The hypercall exit path will overwrite EAX with this return
     * value.
     */
    return regs->eax;
}