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