arch/x86/kernel/cpu/mshyperv.c

   1 /*
   2  * HyperV  Detection code.
   3  *
   4  * Copyright (C) 2010, Novell, Inc.
   5  * Author : K. Y. Srinivasan <ksrinivasan@novell.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; version 2 of the License.
  10  *
  11  */
  12
  13 #include <linux/types.h>
  14 #include <linux/module.h>
  15 #include <asm/processor.h>
  16 #include <asm/hypervisor.h>
  17 #include <asm/hyperv.h>
  18 #include <asm/mshyperv.h>
  19
  20 struct ms_hyperv_info ms_hyperv;
  21 EXPORT_SYMBOL_GPL(ms_hyperv);
  22
  23 static bool __init ms_hyperv_platform(void)
  24 {
  25         u32 eax;
  26         u32 hyp_signature[3];
  27
  28         if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
  29                 return false;
  30
  31         cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
  32               &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
  33
  34         return eax >= HYPERV_CPUID_MIN &&
  35                 eax <= HYPERV_CPUID_MAX &&
  36                 !memcmp("Microsoft Hv", hyp_signature, 12);
  37 }
  38
  39 static void __init ms_hyperv_init_platform(void)
  40 {
  41         /*
  42          * Extract the features and hints
  43          */
  44         ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
  45         ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
  46
  47         printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
  48                ms_hyperv.features, ms_hyperv.hints);
  49 }
  50
  51 const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
  52         .name                   = "Microsoft HyperV",
  53         .detect                 = ms_hyperv_platform,
  54         .init_platform          = ms_hyperv_init_platform,
  55 };
  56 EXPORT_SYMBOL(x86_hyper_ms_hyperv);