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 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/pcpu.h> 36 37 #include <machine/cpufunc.h> 38 #include <machine/segments.h> 39 #include <machine/specialreg.h> 40 41 #include "vmm_host.h" 42 43 static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4, 44 vmm_host_xcr0; 45 static struct xsave_limits vmm_xsave_limits; 46 47 void 48 vmm_host_state_init(void) 49 { 50 int regs[4]; 51 52 vmm_host_efer = rdmsr(MSR_EFER); 53 vmm_host_pat = rdmsr(MSR_PAT); 54 55 /* 56 * We always want CR0.TS to be set when the processor does a VM exit. 57 * 58 * With emulation turned on unconditionally after a VM exit, we are 59 * able to trap inadvertent use of the FPU until the guest FPU state 60 * has been safely squirreled away. 61 */ 62 vmm_host_cr0 = rcr0() | CR0_TS; 63 64 /* 65 * On non-PCID or PCID but without INVPCID support machines, 66 * we flush kernel i.e. global TLB entries, by temporary 67 * clearing the CR4.PGE bit, see invltlb_glob(). If 68 * preemption occurs at the wrong time, cached vmm_host_cr4 69 * might store the value with CR4.PGE cleared. Since FreeBSD 70 * requires support for PG_G on amd64, just set it 71 * unconditionally. 72 */ 73 vmm_host_cr4 = rcr4() | CR4_PGE; 74 75 /* 76 * Only permit a guest to use XSAVE if the host is using 77 * XSAVE. Only permit a guest to use XSAVE features supported 78 * by the host. This ensures that the FPU state used by the 79 * guest is always a subset of the saved guest FPU state. 80 * 81 * In addition, only permit known XSAVE features where the 82 * rules for which features depend on other features is known 83 * to properly emulate xsetbv. 84 */ 85 if (vmm_host_cr4 & CR4_XSAVE) { 86 vmm_xsave_limits.xsave_enabled = 1; 87 vmm_host_xcr0 = rxcr(0); 88 vmm_xsave_limits.xcr0_allowed = vmm_host_xcr0 & 89 (XFEATURE_AVX | XFEATURE_MPX | XFEATURE_AVX512); 90 91 cpuid_count(0xd, 0x0, regs); 92 vmm_xsave_limits.xsave_max_size = regs[1]; 93 } 94 } 95 96 uint64_t 97 vmm_get_host_pat(void) 98 { 99 100 return (vmm_host_pat); 101 } 102 103 uint64_t 104 vmm_get_host_efer(void) 105 { 106 107 return (vmm_host_efer); 108 } 109 110 uint64_t 111 vmm_get_host_cr0(void) 112 { 113 114 return (vmm_host_cr0); 115 } 116 117 uint64_t 118 vmm_get_host_cr4(void) 119 { 120 121 return (vmm_host_cr4); 122 } 123 124 uint64_t 125 vmm_get_host_xcr0(void) 126 { 127 128 return (vmm_host_xcr0); 129 } 130 131 uint64_t 132 vmm_get_host_datasel(void) 133 { 134 135 return (GSEL(GDATA_SEL, SEL_KPL)); 136 137 } 138 139 uint64_t 140 vmm_get_host_codesel(void) 141 { 142 143 return (GSEL(GCODE_SEL, SEL_KPL)); 144 } 145 146 uint64_t 147 vmm_get_host_tsssel(void) 148 { 149 150 return (GSEL(GPROC0_SEL, SEL_KPL)); 151 } 152 153 uint64_t 154 vmm_get_host_fsbase(void) 155 { 156 157 return (0); 158 } 159 160 uint64_t 161 vmm_get_host_idtrbase(void) 162 { 163 164 return (r_idt.rd_base); 165 } 166 167 const struct xsave_limits * 168 vmm_get_xsave_limits(void) 169 { 170 171 return (&vmm_xsave_limits); 172 } 173