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 * This file and its contents are supplied under the terms of the
30 * Common Development and Distribution License ("CDDL"), version 1.0.
31 * You may only use this file in accordance with the terms of version
32 * 1.0 of the CDDL.
33 *
34 * A full copy of the text of the CDDL should have accompanied this
35 * source. A copy of the CDDL is also available via the Internet at
36 * http://www.illumos.org/license/CDDL.
37 */
38 /* This file is dual-licensed; see usr/src/contrib/bhyve/LICENSE */
39
40 /*
41 * Copyright 2013 Pluribus Networks Inc.
42 */
43
44 #include <sys/cdefs.h>
45
46 #include <sys/param.h>
47 #include <sys/pcpu.h>
48
49 #include <machine/cpufunc.h>
50 #include <machine/segments.h>
51 #include <machine/specialreg.h>
52
53 #include "vmm_host.h"
54
55 static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4,
56 vmm_host_xcr0;
57 static struct xsave_limits vmm_xsave_limits;
58
59 void
vmm_host_state_init(void)60 vmm_host_state_init(void)
61 {
62 unsigned int regs[4];
63
64 vmm_host_efer = rdmsr(MSR_EFER);
65 vmm_host_pat = rdmsr(MSR_PAT);
66
67 /*
68 * We always want CR0.TS to be set when the processor does a VM exit.
69 *
70 * With emulation turned on unconditionally after a VM exit, we are
71 * able to trap inadvertent use of the FPU until the guest FPU state
72 * has been safely squirreled away.
73 */
74 vmm_host_cr0 = rcr0() | CR0_TS;
75
76 /*
77 * On non-PCID or PCID but without INVPCID support machines,
78 * we flush kernel i.e. global TLB entries, by temporary
79 * clearing the CR4.PGE bit, see invltlb_glob(). If
80 * preemption occurs at the wrong time, cached vmm_host_cr4
81 * might store the value with CR4.PGE cleared. Since FreeBSD
82 * requires support for PG_G on amd64, just set it
83 * unconditionally.
84 */
85 vmm_host_cr4 = rcr4() | CR4_PGE;
86
87 /*
88 * Only permit a guest to use XSAVE if the host is using
89 * XSAVE. Only permit a guest to use XSAVE features supported
90 * by the host. This ensures that the FPU state used by the
91 * guest is always a subset of the saved guest FPU state.
92 *
93 * In addition, only permit known XSAVE features where the
94 * rules for which features depend on other features is known
95 * to properly emulate xsetbv.
96 */
97 if (vmm_host_cr4 & CR4_XSAVE) {
98 vmm_xsave_limits.xsave_enabled = 1;
99 vmm_host_xcr0 = rxcr(0);
100 vmm_xsave_limits.xcr0_allowed = vmm_host_xcr0 &
101 (XFEATURE_AVX | XFEATURE_MPX | XFEATURE_AVX512);
102
103 cpuid_count(0xd, 0x0, regs);
104 vmm_xsave_limits.xsave_max_size = regs[1];
105 }
106 }
107
108 uint64_t
vmm_get_host_pat(void)109 vmm_get_host_pat(void)
110 {
111
112 return (vmm_host_pat);
113 }
114
115 uint64_t
vmm_get_host_efer(void)116 vmm_get_host_efer(void)
117 {
118
119 return (vmm_host_efer);
120 }
121
122 uint64_t
vmm_get_host_cr0(void)123 vmm_get_host_cr0(void)
124 {
125
126 return (vmm_host_cr0);
127 }
128
129 uint64_t
vmm_get_host_cr4(void)130 vmm_get_host_cr4(void)
131 {
132
133 return (vmm_host_cr4);
134 }
135
136 uint64_t
vmm_get_host_xcr0(void)137 vmm_get_host_xcr0(void)
138 {
139
140 return (vmm_host_xcr0);
141 }
142
143 uint64_t
vmm_get_host_datasel(void)144 vmm_get_host_datasel(void)
145 {
146 return (SEL_GDT(GDT_KDATA, SEL_KPL));
147 }
148
149 uint64_t
vmm_get_host_codesel(void)150 vmm_get_host_codesel(void)
151 {
152 return (SEL_GDT(GDT_KCODE, SEL_KPL));
153 }
154
155 uint64_t
vmm_get_host_tsssel(void)156 vmm_get_host_tsssel(void)
157 {
158 return (SEL_GDT(GDT_KTSS, SEL_KPL));
159 }
160
161 uint64_t
vmm_get_host_fsbase(void)162 vmm_get_host_fsbase(void)
163 {
164 return (rdmsr(MSR_FSBASE));
165 }
166
167 uint64_t
vmm_get_host_idtrbase(void)168 vmm_get_host_idtrbase(void)
169 {
170 desctbr_t idtr;
171
172 rd_idtr(&idtr);
173 return (idtr.dtr_base);
174 }
175
176 const struct xsave_limits *
vmm_get_xsave_limits(void)177 vmm_get_xsave_limits(void)
178 {
179
180 return (&vmm_xsave_limits);
181 }
182