usr/src/uts/intel/io/vmm/vmm_host.c

root/usr/src/uts/intel/io/vmm/vmm_host.c
/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2012 NetApp, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */
/* This file is dual-licensed; see usr/src/contrib/bhyve/LICENSE */

/*
 * Copyright 2013 Pluribus Networks Inc.
 */

#include <sys/cdefs.h>

#include <sys/param.h>
#include <sys/pcpu.h>

#include <machine/cpufunc.h>
#include <machine/segments.h>
#include <machine/specialreg.h>

#include "vmm_host.h"

static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4,
        vmm_host_xcr0;
static struct xsave_limits vmm_xsave_limits;

void
vmm_host_state_init(void)
{
        unsigned int regs[4];

        vmm_host_efer = rdmsr(MSR_EFER);
        vmm_host_pat = rdmsr(MSR_PAT);

        /*
         * We always want CR0.TS to be set when the processor does a VM exit.
         *
         * With emulation turned on unconditionally after a VM exit, we are
         * able to trap inadvertent use of the FPU until the guest FPU state
         * has been safely squirreled away.
         */
        vmm_host_cr0 = rcr0() | CR0_TS;

        /*
         * On non-PCID or PCID but without INVPCID support machines,
         * we flush kernel i.e. global TLB entries, by temporary
         * clearing the CR4.PGE bit, see invltlb_glob().  If
         * preemption occurs at the wrong time, cached vmm_host_cr4
         * might store the value with CR4.PGE cleared.  Since FreeBSD
         * requires support for PG_G on amd64, just set it
         * unconditionally.
         */
        vmm_host_cr4 = rcr4() | CR4_PGE;

        /*
         * Only permit a guest to use XSAVE if the host is using
         * XSAVE.  Only permit a guest to use XSAVE features supported
         * by the host.  This ensures that the FPU state used by the
         * guest is always a subset of the saved guest FPU state.
         *
         * In addition, only permit known XSAVE features where the
         * rules for which features depend on other features is known
         * to properly emulate xsetbv.
         */
        if (vmm_host_cr4 & CR4_XSAVE) {
                vmm_xsave_limits.xsave_enabled = 1;
                vmm_host_xcr0 = rxcr(0);
                vmm_xsave_limits.xcr0_allowed = vmm_host_xcr0 &
                    (XFEATURE_AVX | XFEATURE_MPX | XFEATURE_AVX512);

                cpuid_count(0xd, 0x0, regs);
                vmm_xsave_limits.xsave_max_size = regs[1];
        }
}

uint64_t
vmm_get_host_pat(void)
{

        return (vmm_host_pat);
}

uint64_t
vmm_get_host_efer(void)
{

        return (vmm_host_efer);
}

uint64_t
vmm_get_host_cr0(void)
{

        return (vmm_host_cr0);
}

uint64_t
vmm_get_host_cr4(void)
{

        return (vmm_host_cr4);
}

uint64_t
vmm_get_host_xcr0(void)
{

        return (vmm_host_xcr0);
}

uint64_t
vmm_get_host_datasel(void)
{
        return (SEL_GDT(GDT_KDATA, SEL_KPL));
}

uint64_t
vmm_get_host_codesel(void)
{
        return (SEL_GDT(GDT_KCODE, SEL_KPL));
}

uint64_t
vmm_get_host_tsssel(void)
{
        return (SEL_GDT(GDT_KTSS, SEL_KPL));
}

uint64_t
vmm_get_host_fsbase(void)
{
        return (rdmsr(MSR_FSBASE));
}

uint64_t
vmm_get_host_idtrbase(void)
{
        desctbr_t idtr;

        rd_idtr(&idtr);
        return (idtr.dtr_base);
}

const struct xsave_limits *
vmm_get_xsave_limits(void)
{

        return (&vmm_xsave_limits);
}
Illumos
