xref: /freebsd/sys/x86/include/kvm.h (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2014 Bryan Venteicher <bryanv@FreeBSD.org>
5  * Copyright (c) 2021 Mathieu Chouquet-Stringer
6  * Copyright (c) 2021 Juniper Networks, Inc.
7  * Copyright (c) 2021 Klara, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * Linux KVM paravirtualization: common definitions
33  *
34  * References:
35  *     - [1] https://www.kernel.org/doc/html/latest/virt/kvm/cpuid.html
36  *     - [2] https://www.kernel.org/doc/html/latest/virt/kvm/msr.html
37  */
38 
39 #ifndef _X86_KVM_H_
40 #define	_X86_KVM_H_
41 
42 #include <sys/types.h>
43 #include <sys/systm.h>
44 
45 #include <machine/md_var.h>
46 
47 #define	KVM_CPUID_SIGNATURE			0x40000000
48 #define	KVM_CPUID_FEATURES_LEAF			0x40000001
49 
50 #define	KVM_FEATURE_CLOCKSOURCE			0x00000001
51 #define	KVM_FEATURE_CLOCKSOURCE2		0x00000008
52 #define	KVM_FEATURE_CLOCKSOURCE_STABLE_BIT	0x01000000
53 
54 /* Deprecated: for the CLOCKSOURCE feature. */
55 #define	KVM_MSR_WALL_CLOCK			0x11
56 #define	KVM_MSR_SYSTEM_TIME			0x12
57 
58 #define	KVM_MSR_WALL_CLOCK_NEW			0x4b564d00
59 #define	KVM_MSR_SYSTEM_TIME_NEW			0x4b564d01
60 
61 static inline bool
62 kvm_cpuid_features_leaf_supported(void)
63 {
64 	return (vm_guest == VM_GUEST_KVM &&
65 	    KVM_CPUID_FEATURES_LEAF > hv_base &&
66 	    KVM_CPUID_FEATURES_LEAF <= hv_high);
67 }
68 
69 static inline void
70 kvm_cpuid_get_features(u_int *regs)
71 {
72 	if (!kvm_cpuid_features_leaf_supported())
73 		regs[0] = regs[1] = regs[2] = regs[3] = 0;
74 	else
75 		do_cpuid(KVM_CPUID_FEATURES_LEAF, regs);
76 }
77 
78 #endif /* !_X86_KVM_H_ */
79