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
vmm_host_state_init(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
vmm_get_host_pat(void)93 vmm_get_host_pat(void)
94 {
95
96 return (vmm_host_pat);
97 }
98
99 uint64_t
vmm_get_host_efer(void)100 vmm_get_host_efer(void)
101 {
102
103 return (vmm_host_efer);
104 }
105
106 uint64_t
vmm_get_host_cr0(void)107 vmm_get_host_cr0(void)
108 {
109
110 return (vmm_host_cr0);
111 }
112
113 uint64_t
vmm_get_host_cr4(void)114 vmm_get_host_cr4(void)
115 {
116
117 return (vmm_host_cr4);
118 }
119
120 uint64_t
vmm_get_host_xcr0(void)121 vmm_get_host_xcr0(void)
122 {
123
124 return (vmm_host_xcr0);
125 }
126
127 uint64_t
vmm_get_host_datasel(void)128 vmm_get_host_datasel(void)
129 {
130
131 return (GSEL(GDATA_SEL, SEL_KPL));
132
133 }
134
135 uint64_t
vmm_get_host_codesel(void)136 vmm_get_host_codesel(void)
137 {
138
139 return (GSEL(GCODE_SEL, SEL_KPL));
140 }
141
142 uint64_t
vmm_get_host_tsssel(void)143 vmm_get_host_tsssel(void)
144 {
145
146 return (GSEL(GPROC0_SEL, SEL_KPL));
147 }
148
149 uint64_t
vmm_get_host_fsbase(void)150 vmm_get_host_fsbase(void)
151 {
152
153 return (0);
154 }
155
156 uint64_t
vmm_get_host_idtrbase(void)157 vmm_get_host_idtrbase(void)
158 {
159
160 return (r_idt.rd_base);
161 }
162
163 const struct xsave_limits *
vmm_get_xsave_limits(void)164 vmm_get_xsave_limits(void)
165 {
166
167 return (&vmm_xsave_limits);
168 }
169