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/init.h>
  25 #include <linux/export.h>
  26 #include <asm/processor.h>
  27 #include <asm/hypervisor.h>
  28
  29 static const __initconst struct hypervisor_x86 * const hypervisors[] =
  30 {
  31 #ifdef CONFIG_XEN_PV
  32         &x86_hyper_xen_pv,
  33 #endif
  34 #ifdef CONFIG_XEN_PVHVM
  35         &x86_hyper_xen_hvm,
  36 #endif
  37         &x86_hyper_vmware,
  38         &x86_hyper_ms_hyperv,
  39 #ifdef CONFIG_KVM_GUEST
  40         &x86_hyper_kvm,
  41 #endif
  42 };
  43
  44 const struct hypervisor_x86 *x86_hyper;
  45 EXPORT_SYMBOL(x86_hyper);
  46
  47 static inline void __init
  48 detect_hypervisor_vendor(void)
  49 {
  50         const struct hypervisor_x86 *h, * const *p;
  51         uint32_t pri, max_pri = 0;
  52
  53         for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
  54                 h = *p;
  55                 pri = h->detect();
  56                 if (pri != 0 && pri > max_pri) {
  57                         max_pri = pri;
  58                         x86_hyper = h;
  59                 }
  60         }
  61
  62         if (max_pri)
  63                 pr_info("Hypervisor detected: %s\n", x86_hyper->name);
  64 }
  65
  66 void __init init_hypervisor_platform(void)
  67 {
  68
  69         detect_hypervisor_vendor();
  70
  71         if (!x86_hyper)
  72                 return;
  73
  74         if (x86_hyper->init_platform)
  75                 x86_hyper->init_platform();
  76 }
  77
  78 bool __init hypervisor_x2apic_available(void)
  79 {
  80         return x86_hyper                   &&
  81                x86_hyper->x2apic_available &&
  82                x86_hyper->x2apic_available();
  83 }
  84
  85 void hypervisor_pin_vcpu(int cpu)
  86 {
  87         if (!x86_hyper)
  88                 return;
  89
  90         if (x86_hyper->pin_vcpu)
  91                 x86_hyper->pin_vcpu(cpu);
  92         else
  93                 WARN_ONCE(1, "vcpu pinning requested but not supported!\n");
  94 }