1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 29 #include <sys/param.h> 30 #include <sys/pcpu.h> 31 32 #include <machine/cpufunc.h> 33 #include <machine/segments.h> 34 #include <machine/specialreg.h> 35 36 #include "vmm_host.h" 37 38 static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4, 39 vmm_host_xcr0; 40 static struct xsave_limits vmm_xsave_limits; 41 42 void 43 vmm_host_state_init(void) 44 { 45 int regs[4]; 46 47 vmm_host_efer = rdmsr(MSR_EFER); 48 vmm_host_pat = rdmsr(MSR_PAT); 49 50 /* 51 * We always want CR0.TS to be set when the processor does a VM exit. 52 * 53 * With emulation turned on unconditionally after a VM exit, we are 54 * able to trap inadvertent use of the FPU until the guest FPU state 55 * has been safely squirreled away. 56 */ 57 vmm_host_cr0 = rcr0() | CR0_TS; 58 59 /* 60 * On non-PCID or PCID but without INVPCID support machines, 61 * we flush kernel i.e. global TLB entries, by temporary 62 * clearing the CR4.PGE bit, see invltlb_glob(). If 63 * preemption occurs at the wrong time, cached vmm_host_cr4 64 * might store the value with CR4.PGE cleared. Since FreeBSD 65 * requires support for PG_G on amd64, just set it 66 * unconditionally. 67 */ 68 vmm_host_cr4 = rcr4() | CR4_PGE; 69 70 /* 71 * Only permit a guest to use XSAVE if the host is using 72 * XSAVE. Only permit a guest to use XSAVE features supported 73 * by the host. This ensures that the FPU state used by the 74 * guest is always a subset of the saved guest FPU state. 75 * 76 * In addition, only permit known XSAVE features where the 77 * rules for which features depend on other features is known 78 * to properly emulate xsetbv. 79 */ 80 if (vmm_host_cr4 & CR4_XSAVE) { 81 vmm_xsave_limits.xsave_enabled = 1; 82 vmm_host_xcr0 = rxcr(0); 83 vmm_xsave_limits.xcr0_allowed = vmm_host_xcr0 & 84 (XFEATURE_AVX | XFEATURE_MPX | XFEATURE_AVX512); 85 86 cpuid_count(0xd, 0x0, regs); 87 vmm_xsave_limits.xsave_max_size = regs[1]; 88 } 89 } 90 91 uint64_t 92 vmm_get_host_pat(void) 93 { 94 95 return (vmm_host_pat); 96 } 97 98 uint64_t 99 vmm_get_host_efer(void) 100 { 101 102 return (vmm_host_efer); 103 } 104 105 uint64_t 106 vmm_get_host_cr0(void) 107 { 108 109 return (vmm_host_cr0); 110 } 111 112 uint64_t 113 vmm_get_host_cr4(void) 114 { 115 116 return (vmm_host_cr4); 117 } 118 119 uint64_t 120 vmm_get_host_xcr0(void) 121 { 122 123 return (vmm_host_xcr0); 124 } 125 126 uint64_t 127 vmm_get_host_datasel(void) 128 { 129 130 return (GSEL(GDATA_SEL, SEL_KPL)); 131 132 } 133 134 uint64_t 135 vmm_get_host_codesel(void) 136 { 137 138 return (GSEL(GCODE_SEL, SEL_KPL)); 139 } 140 141 uint64_t 142 vmm_get_host_tsssel(void) 143 { 144 145 return (GSEL(GPROC0_SEL, SEL_KPL)); 146 } 147 148 uint64_t 149 vmm_get_host_fsbase(void) 150 { 151 152 return (0); 153 } 154 155 uint64_t 156 vmm_get_host_idtrbase(void) 157 { 158 159 return (r_idt.rd_base); 160 } 161 162 const struct xsave_limits * 163 vmm_get_xsave_limits(void) 164 { 165 166 return (&vmm_xsave_limits); 167 } 168