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