vmm_host.c revision 285830
1/*- 2 * Copyright (c) 2012 NetApp, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: releng/10.2/sys/amd64/vmm/vmm_host.c 267427 2014-06-12 19:58:12Z jhb $ 27 */ 28 29#include <sys/cdefs.h> 30__FBSDID("$FreeBSD: releng/10.2/sys/amd64/vmm/vmm_host.c 267427 2014-06-12 19:58:12Z jhb $"); 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 41static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4, 42 vmm_host_xcr0; 43static struct xsave_limits vmm_xsave_limits; 44 45void 46vmm_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 vmm_host_cr4 = rcr4(); 63 64 /* 65 * Only permit a guest to use XSAVE if the host is using 66 * XSAVE. Only permit a guest to use XSAVE features supported 67 * by the host. This ensures that the FPU state used by the 68 * guest is always a subset of the saved guest FPU state. 69 * 70 * In addition, only permit known XSAVE features where the 71 * rules for which features depend on other features is known 72 * to properly emulate xsetbv. 73 */ 74 if (vmm_host_cr4 & CR4_XSAVE) { 75 vmm_xsave_limits.xsave_enabled = 1; 76 vmm_host_xcr0 = rxcr(0); 77 vmm_xsave_limits.xcr0_allowed = vmm_host_xcr0 & 78 (XFEATURE_AVX | XFEATURE_MPX | XFEATURE_AVX512); 79 80 cpuid_count(0xd, 0x0, regs); 81 vmm_xsave_limits.xsave_max_size = regs[1]; 82 } 83} 84 85uint64_t 86vmm_get_host_pat(void) 87{ 88 89 return (vmm_host_pat); 90} 91 92uint64_t 93vmm_get_host_efer(void) 94{ 95 96 return (vmm_host_efer); 97} 98 99uint64_t 100vmm_get_host_cr0(void) 101{ 102 103 return (vmm_host_cr0); 104} 105 106uint64_t 107vmm_get_host_cr4(void) 108{ 109 110 return (vmm_host_cr4); 111} 112 113uint64_t 114vmm_get_host_xcr0(void) 115{ 116 117 return (vmm_host_xcr0); 118} 119 120uint64_t 121vmm_get_host_datasel(void) 122{ 123 124 return (GSEL(GDATA_SEL, SEL_KPL)); 125 126} 127 128uint64_t 129vmm_get_host_codesel(void) 130{ 131 132 return (GSEL(GCODE_SEL, SEL_KPL)); 133} 134 135uint64_t 136vmm_get_host_tsssel(void) 137{ 138 139 return (GSEL(GPROC0_SEL, SEL_KPL)); 140} 141 142uint64_t 143vmm_get_host_fsbase(void) 144{ 145 146 return (0); 147} 148 149uint64_t 150vmm_get_host_idtrbase(void) 151{ 152 153 return (r_idt.rd_base); 154} 155 156const struct xsave_limits * 157vmm_get_xsave_limits(void) 158{ 159 160 return (&vmm_xsave_limits); 161} 162