arch/x86/kernel/cpu/hypervisor.c

   1 /*
   2  * Common hypervisor code
   3  *
   4  * Copyright (C) 2008, VMware, Inc.
   5  * Author : Alok N Kataria <akataria@vmware.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  15  * NON INFRINGEMENT.  See the GNU General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  21  *
  22  */
  23
  24 #include <linux/module.h>
  25 #include <asm/processor.h>
  26 #include <asm/hypervisor.h>
  27
  28 static const __initconst struct hypervisor_x86 * const hypervisors[] =
  29 {
  30 #ifdef CONFIG_XEN
  31         &x86_hyper_xen,
  32 #endif
  33         &x86_hyper_vmware,
  34         &x86_hyper_ms_hyperv,
  35 #ifdef CONFIG_KVM_GUEST
  36         &x86_hyper_kvm,
  37 #endif
  38 };
  39
  40 const struct hypervisor_x86 *x86_hyper;
  41 EXPORT_SYMBOL(x86_hyper);
  42
  43 static inline void __init
  44 detect_hypervisor_vendor(void)
  45 {
  46         const struct hypervisor_x86 *h, * const *p;
  47         uint32_t pri, max_pri = 0;
  48
  49         for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
  50                 h = *p;
  51                 pri = h->detect();
  52                 if (pri != 0 && pri > max_pri) {
  53                         max_pri = pri;
  54                         x86_hyper = h;
  55                 }
  56         }
  57
  58         if (max_pri)
  59                 pr_info("Hypervisor detected: %s\n", x86_hyper->name);
  60 }
  61
  62 void init_hypervisor(struct cpuinfo_x86 *c)
  63 {
  64         if (x86_hyper && x86_hyper->set_cpu_features)
  65                 x86_hyper->set_cpu_features(c);
  66 }
  67
  68 void __init init_hypervisor_platform(void)
  69 {
  70
  71         detect_hypervisor_vendor();
  72
  73         if (!x86_hyper)
  74                 return;
  75
  76         init_hypervisor(&boot_cpu_data);
  77
  78         if (x86_hyper->init_platform)
  79                 x86_hyper->init_platform();
  80 }
  81
  82 bool __init hypervisor_x2apic_available(void)
  83 {
  84         return x86_hyper                   &&
  85                x86_hyper->x2apic_available &&
  86                x86_hyper->x2apic_available();
  87 }