2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2012 NetApp, Inc.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
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31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
37 #include <machine/cpufunc.h>
38 #include <machine/segments.h>
39 #include <machine/specialreg.h>
43 static uint64_t vmm_host_efer, vmm_host_pat, vmm_host_cr0, vmm_host_cr4,
45 static struct xsave_limits vmm_xsave_limits;
48 vmm_host_state_init(void)
52 vmm_host_efer = rdmsr(MSR_EFER);
53 vmm_host_pat = rdmsr(MSR_PAT);
56 * We always want CR0.TS to be set when the processor does a VM exit.
58 * With emulation turned on unconditionally after a VM exit, we are
59 * able to trap inadvertent use of the FPU until the guest FPU state
60 * has been safely squirreled away.
62 vmm_host_cr0 = rcr0() | CR0_TS;
64 vmm_host_cr4 = rcr4();
67 * Only permit a guest to use XSAVE if the host is using
68 * XSAVE. Only permit a guest to use XSAVE features supported
69 * by the host. This ensures that the FPU state used by the
70 * guest is always a subset of the saved guest FPU state.
72 * In addition, only permit known XSAVE features where the
73 * rules for which features depend on other features is known
74 * to properly emulate xsetbv.
76 if (vmm_host_cr4 & CR4_XSAVE) {
77 vmm_xsave_limits.xsave_enabled = 1;
78 vmm_host_xcr0 = rxcr(0);
79 vmm_xsave_limits.xcr0_allowed = vmm_host_xcr0 &
80 (XFEATURE_AVX | XFEATURE_MPX | XFEATURE_AVX512);
82 cpuid_count(0xd, 0x0, regs);
83 vmm_xsave_limits.xsave_max_size = regs[1];
88 vmm_get_host_pat(void)
91 return (vmm_host_pat);
95 vmm_get_host_efer(void)
98 return (vmm_host_efer);
102 vmm_get_host_cr0(void)
105 return (vmm_host_cr0);
109 vmm_get_host_cr4(void)
112 return (vmm_host_cr4);
116 vmm_get_host_xcr0(void)
119 return (vmm_host_xcr0);
123 vmm_get_host_datasel(void)
126 return (GSEL(GDATA_SEL, SEL_KPL));
131 vmm_get_host_codesel(void)
134 return (GSEL(GCODE_SEL, SEL_KPL));
138 vmm_get_host_tsssel(void)
141 return (GSEL(GPROC0_SEL, SEL_KPL));
145 vmm_get_host_fsbase(void)
152 vmm_get_host_idtrbase(void)
155 return (r_idt.rd_base);
158 const struct xsave_limits *
159 vmm_get_xsave_limits(void)
162 return (&vmm_xsave_limits);