sys/x86/include/kvm.h

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   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  * $FreeBSD$
  31  */
  32
  33 /*
  34  * Linux KVM paravirtualization: common definitions
  35  *
  36  * References:
  37  *     - [1] https://www.kernel.org/doc/html/latest/virt/kvm/cpuid.html
  38  *     - [2] https://www.kernel.org/doc/html/latest/virt/kvm/msr.html
  39  */
  40
  41 #ifndef _X86_KVM_H_
  42 #define _X86_KVM_H_
  43
  44 #include <sys/types.h>
  45 #include <sys/systm.h>
  46
  47 #include <machine/md_var.h>
  48
  49 #define KVM_CPUID_SIGNATURE                     0x40000000
  50 #define KVM_CPUID_FEATURES_LEAF                 0x40000001
  51
  52 #define KVM_FEATURE_CLOCKSOURCE                 0x00000001
  53 #define KVM_FEATURE_CLOCKSOURCE2                0x00000008
  54 #define KVM_FEATURE_CLOCKSOURCE_STABLE_BIT      0x01000000
  55
  56 /* Deprecated: for the CLOCKSOURCE feature. */
  57 #define KVM_MSR_WALL_CLOCK                      0x11
  58 #define KVM_MSR_SYSTEM_TIME                     0x12
  59
  60 #define KVM_MSR_WALL_CLOCK_NEW                  0x4b564d00
  61 #define KVM_MSR_SYSTEM_TIME_NEW                 0x4b564d01
  62
  63 static inline bool
  64 kvm_cpuid_features_leaf_supported(void)
  65 {
  66         return (vm_guest == VM_GUEST_KVM &&
  67             KVM_CPUID_FEATURES_LEAF > hv_base &&
  68             KVM_CPUID_FEATURES_LEAF <= hv_high);
  69 }
  70
  71 static inline void
  72 kvm_cpuid_get_features(u_int *regs)
  73 {
  74         if (!kvm_cpuid_features_leaf_supported())
  75                 regs[0] = regs[1] = regs[2] = regs[3] = 0;
  76         else
  77                 do_cpuid(KVM_CPUID_FEATURES_LEAF, regs);
  78 }
  79
  80 #endif /* !_X86_KVM_H_ */