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 #ifdef CONFIG_JAILHOUSE_GUEST
  43         &x86_hyper_jailhouse,
  44 #endif
  45 #ifdef CONFIG_ACRN_GUEST
  46         &x86_hyper_acrn,
  47 #endif
  48 };
  49
  50 enum x86_hypervisor_type x86_hyper_type;
  51 EXPORT_SYMBOL(x86_hyper_type);
  52
  53 bool __initdata nopv;
  54 static __init int parse_nopv(char *arg)
  55 {
  56         nopv = true;
  57         return 0;
  58 }
  59 early_param("nopv", parse_nopv);
  60
  61 static inline const struct hypervisor_x86 * __init
  62 detect_hypervisor_vendor(void)
  63 {
  64         const struct hypervisor_x86 *h = NULL, * const *p;
  65         uint32_t pri, max_pri = 0;
  66
  67         for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
  68                 if (unlikely(nopv) && !(*p)->ignore_nopv)
  69                         continue;
  70
  71                 pri = (*p)->detect();
  72                 if (pri > max_pri) {
  73                         max_pri = pri;
  74                         h = *p;
  75                 }
  76         }
  77
  78         if (h)
  79                 pr_info("Hypervisor detected: %s\n", h->name);
  80
  81         return h;
  82 }
  83
  84 static void __init copy_array(const void *src, void *target, unsigned int size)
  85 {
  86         unsigned int i, n = size / sizeof(void *);
  87         const void * const *from = (const void * const *)src;
  88         const void **to = (const void **)target;
  89
  90         for (i = 0; i < n; i++)
  91                 if (from[i])
  92                         to[i] = from[i];
  93 }
  94
  95 void __init init_hypervisor_platform(void)
  96 {
  97         const struct hypervisor_x86 *h;
  98
  99         h = detect_hypervisor_vendor();
 100
 101         if (!h)
 102                 return;
 103
 104         copy_array(&h->init, &x86_init.hyper, sizeof(h->init));
 105         copy_array(&h->runtime, &x86_platform.hyper, sizeof(h->runtime));
 106
 107         x86_hyper_type = h->type;
 108         x86_init.hyper.init_platform();
 109 }