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/11.0/sys/amd64/vmm/vmm_host.c 266765 2014-05-27 19:04:38Z jhb $
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/11.0/sys/amd64/vmm/vmm_host.c 266765 2014-05-27 19:04:38Z 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
41 static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4,
42 vmm_host_xcr0;
43 static struct xsave_limits vmm_xsave_limits;
44
45 void
46 vmm_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
85 uint64_t
86 vmm_get_host_pat(void)
87 {
88
89 return (vmm_host_pat);
90 }
91
92 uint64_t
93 vmm_get_host_efer(void)
94 {
95
96 return (vmm_host_efer);
97 }
98
99 uint64_t
100 vmm_get_host_cr0(void)
101 {
102
103 return (vmm_host_cr0);
104 }
105
106 uint64_t
107 vmm_get_host_cr4(void)
108 {
109
110 return (vmm_host_cr4);
111 }
112
113 uint64_t
114 vmm_get_host_xcr0(void)
115 {
116
117 return (vmm_host_xcr0);
118 }
119
120 uint64_t
121 vmm_get_host_datasel(void)
122 {
123
124 return (GSEL(GDATA_SEL, SEL_KPL));
125
126 }
127
128 uint64_t
129 vmm_get_host_codesel(void)
130 {
131
132 return (GSEL(GCODE_SEL, SEL_KPL));
133 }
134
135 uint64_t
136 vmm_get_host_tsssel(void)
137 {
138
139 return (GSEL(GPROC0_SEL, SEL_KPL));
140 }
141
142 uint64_t
143 vmm_get_host_fsbase(void)
144 {
145
146 return (0);
147 }
148
149 uint64_t
150 vmm_get_host_idtrbase(void)
151 {
152
153 return (r_idt.rd_base);
154 }
155
156 const struct xsave_limits *
157 vmm_get_xsave_limits(void)
158 {
159
160 return (&vmm_xsave_limits);
161 }
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