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