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 extern const struct hypervisor_x86 x86_hyper_vmware;
  30 extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
  31 extern const struct hypervisor_x86 x86_hyper_xen_pv;
  32 extern const struct hypervisor_x86 x86_hyper_xen_hvm;
  33 extern const struct hypervisor_x86 x86_hyper_kvm;
  34 extern const struct hypervisor_x86 x86_hyper_jailhouse;
  35
  36 static const __initconst struct hypervisor_x86 * const hypervisors[] =
  37 {
  38 #ifdef CONFIG_XEN_PV
  39         &x86_hyper_xen_pv,
  40 #endif
  41 #ifdef CONFIG_XEN_PVHVM
  42         &x86_hyper_xen_hvm,
  43 #endif
  44         &x86_hyper_vmware,
  45         &x86_hyper_ms_hyperv,
  46 #ifdef CONFIG_KVM_GUEST
  47         &x86_hyper_kvm,
  48 #endif
  49 #ifdef CONFIG_JAILHOUSE_GUEST
  50         &x86_hyper_jailhouse,
  51 #endif
  52 };
  53
  54 enum x86_hypervisor_type x86_hyper_type;
  55 EXPORT_SYMBOL(x86_hyper_type);
  56
  57 static inline const struct hypervisor_x86 * __init
  58 detect_hypervisor_vendor(void)
  59 {
  60         const struct hypervisor_x86 *h = NULL, * const *p;
  61         uint32_t pri, max_pri = 0;
  62
  63         for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
  64                 pri = (*p)->detect();
  65                 if (pri > max_pri) {
  66                         max_pri = pri;
  67                         h = *p;
  68                 }
  69         }
  70
  71         if (h)
  72                 pr_info("Hypervisor detected: %s\n", h->name);
  73
  74         return h;
  75 }
  76
  77 static void __init copy_array(const void *src, void *target, unsigned int size)
  78 {
  79         unsigned int i, n = size / sizeof(void *);
  80         const void * const *from = (const void * const *)src;
  81         const void **to = (const void **)target;
  82
  83         for (i = 0; i < n; i++)
  84                 if (from[i])
  85                         to[i] = from[i];
  86 }
  87
  88 void __init init_hypervisor_platform(void)
  89 {
  90         const struct hypervisor_x86 *h;
  91
  92         h = detect_hypervisor_vendor();
  93
  94         if (!h)
  95                 return;
  96
  97         copy_array(&h->init, &x86_init.hyper, sizeof(h->init));
  98         copy_array(&h->runtime, &x86_platform.hyper, sizeof(h->runtime));
  99
 100         x86_hyper_type = h->type;
 101         x86_init.hyper.init_platform();
 102 }