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/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/pcpu.h> 34 35 #include <machine/cpufunc.h> 36 #include <machine/segments.h> 37 #include <machine/specialreg.h> 38 39 #include "vmm_host.h" 40 41 static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4, 42 vmm_host_xcr0; 43 static struct xsave_limits vmm_xsave_limits; 44 45 void 46 vmm_host_state_init(void) 47 { 48 int regs[4]; 49 50 vmm_host_efer = rdmsr(MSR_EFER); 51 vmm_host_pat = rdmsr(MSR_PAT); 52 53 /* 54 * We always want CR0.TS to be set when the processor does a VM exit. 55 * 56 * With emulation turned on unconditionally after a VM exit, we are 57 * able to trap inadvertent use of the FPU until the guest FPU state 58 * has been safely squirreled away. 59 */ 60 vmm_host_cr0 = rcr0() | CR0_TS; 61 62 /* 63 * On non-PCID or PCID but without INVPCID support machines, 64 * we flush kernel i.e. global TLB entries, by temporary 65 * clearing the CR4.PGE bit, see invltlb_glob(). If 66 * preemption occurs at the wrong time, cached vmm_host_cr4 67 * might store the value with CR4.PGE cleared. Since FreeBSD 68 * requires support for PG_G on amd64, just set it 69 * unconditionally. 70 */ 71 vmm_host_cr4 = rcr4() | CR4_PGE; 72 73 /* 74 * Only permit a guest to use XSAVE if the host is using 75 * XSAVE. Only permit a guest to use XSAVE features supported 76 * by the host. This ensures that the FPU state used by the 77 * guest is always a subset of the saved guest FPU state. 78 * 79 * In addition, only permit known XSAVE features where the 80 * rules for which features depend on other features is known 81 * to properly emulate xsetbv. 82 */ 83 if (vmm_host_cr4 & CR4_XSAVE) { 84 vmm_xsave_limits.xsave_enabled = 1; 85 vmm_host_xcr0 = rxcr(0); 86 vmm_xsave_limits.xcr0_allowed = vmm_host_xcr0 & 87 (XFEATURE_AVX | XFEATURE_MPX | XFEATURE_AVX512); 88 89 cpuid_count(0xd, 0x0, regs); 90 vmm_xsave_limits.xsave_max_size = regs[1]; 91 } 92 } 93 94 uint64_t 95 vmm_get_host_pat(void) 96 { 97 98 return (vmm_host_pat); 99 } 100 101 uint64_t 102 vmm_get_host_efer(void) 103 { 104 105 return (vmm_host_efer); 106 } 107 108 uint64_t 109 vmm_get_host_cr0(void) 110 { 111 112 return (vmm_host_cr0); 113 } 114 115 uint64_t 116 vmm_get_host_cr4(void) 117 { 118 119 return (vmm_host_cr4); 120 } 121 122 uint64_t 123 vmm_get_host_xcr0(void) 124 { 125 126 return (vmm_host_xcr0); 127 } 128 129 uint64_t 130 vmm_get_host_datasel(void) 131 { 132 133 return (GSEL(GDATA_SEL, SEL_KPL)); 134 135 } 136 137 uint64_t 138 vmm_get_host_codesel(void) 139 { 140 141 return (GSEL(GCODE_SEL, SEL_KPL)); 142 } 143 144 uint64_t 145 vmm_get_host_tsssel(void) 146 { 147 148 return (GSEL(GPROC0_SEL, SEL_KPL)); 149 } 150 151 uint64_t 152 vmm_get_host_fsbase(void) 153 { 154 155 return (0); 156 } 157 158 uint64_t 159 vmm_get_host_idtrbase(void) 160 { 161 162 return (r_idt.rd_base); 163 } 164 165 const struct xsave_limits * 166 vmm_get_xsave_limits(void) 167 { 168 169 return (&vmm_xsave_limits); 170 } 171