1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2012 NetApp, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 /* 31 * This file and its contents are supplied under the terms of the 32 * Common Development and Distribution License ("CDDL"), version 1.0. 33 * You may only use this file in accordance with the terms of version 34 * 1.0 of the CDDL. 35 * 36 * A full copy of the text of the CDDL should have accompanied this 37 * source. A copy of the CDDL is also available via the Internet at 38 * http://www.illumos.org/license/CDDL. 39 * 40 * Copyright 2013 Pluribus Networks Inc. 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include <sys/param.h> 47 #include <sys/pcpu.h> 48 49 #include <machine/cpufunc.h> 50 #include <machine/segments.h> 51 #include <machine/specialreg.h> 52 53 #include "vmm_host.h" 54 55 static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4, 56 vmm_host_xcr0; 57 static struct xsave_limits vmm_xsave_limits; 58 59 void 60 vmm_host_state_init(void) 61 { 62 unsigned int regs[4]; 63 64 vmm_host_efer = rdmsr(MSR_EFER); 65 vmm_host_pat = rdmsr(MSR_PAT); 66 67 /* 68 * We always want CR0.TS to be set when the processor does a VM exit. 69 * 70 * With emulation turned on unconditionally after a VM exit, we are 71 * able to trap inadvertent use of the FPU until the guest FPU state 72 * has been safely squirreled away. 73 */ 74 vmm_host_cr0 = rcr0() | CR0_TS; 75 76 /* 77 * On non-PCID or PCID but without INVPCID support machines, 78 * we flush kernel i.e. global TLB entries, by temporary 79 * clearing the CR4.PGE bit, see invltlb_glob(). If 80 * preemption occurs at the wrong time, cached vmm_host_cr4 81 * might store the value with CR4.PGE cleared. Since FreeBSD 82 * requires support for PG_G on amd64, just set it 83 * unconditionally. 84 */ 85 vmm_host_cr4 = rcr4() | CR4_PGE; 86 87 /* 88 * Only permit a guest to use XSAVE if the host is using 89 * XSAVE. Only permit a guest to use XSAVE features supported 90 * by the host. This ensures that the FPU state used by the 91 * guest is always a subset of the saved guest FPU state. 92 * 93 * In addition, only permit known XSAVE features where the 94 * rules for which features depend on other features is known 95 * to properly emulate xsetbv. 96 */ 97 if (vmm_host_cr4 & CR4_XSAVE) { 98 vmm_xsave_limits.xsave_enabled = 1; 99 vmm_host_xcr0 = rxcr(0); 100 vmm_xsave_limits.xcr0_allowed = vmm_host_xcr0 & 101 (XFEATURE_AVX | XFEATURE_MPX | XFEATURE_AVX512); 102 103 cpuid_count(0xd, 0x0, regs); 104 vmm_xsave_limits.xsave_max_size = regs[1]; 105 } 106 } 107 108 uint64_t 109 vmm_get_host_pat(void) 110 { 111 112 return (vmm_host_pat); 113 } 114 115 uint64_t 116 vmm_get_host_efer(void) 117 { 118 119 return (vmm_host_efer); 120 } 121 122 uint64_t 123 vmm_get_host_cr0(void) 124 { 125 126 return (vmm_host_cr0); 127 } 128 129 uint64_t 130 vmm_get_host_cr4(void) 131 { 132 133 return (vmm_host_cr4); 134 } 135 136 uint64_t 137 vmm_get_host_xcr0(void) 138 { 139 140 return (vmm_host_xcr0); 141 } 142 143 uint64_t 144 vmm_get_host_datasel(void) 145 { 146 return (SEL_GDT(GDT_KDATA, SEL_KPL)); 147 } 148 149 uint64_t 150 vmm_get_host_codesel(void) 151 { 152 return (SEL_GDT(GDT_KCODE, SEL_KPL)); 153 } 154 155 uint64_t 156 vmm_get_host_tsssel(void) 157 { 158 return (SEL_GDT(GDT_KTSS, SEL_KPL)); 159 } 160 161 uint64_t 162 vmm_get_host_fsbase(void) 163 { 164 return (rdmsr(MSR_FSBASE)); 165 } 166 167 uint64_t 168 vmm_get_host_idtrbase(void) 169 { 170 desctbr_t idtr; 171 172 rd_idtr(&idtr); 173 return (idtr.dtr_base); 174 } 175 176 const struct xsave_limits * 177 vmm_get_xsave_limits(void) 178 { 179 180 return (&vmm_xsave_limits); 181 } 182