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