0f1371724c86b88e9943d07648702f2220f3f98d
[linux-2.6.git] / 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 <asm/processor.h>
15 #include <asm/hypervisor.h>
16 #include <asm/hyperv.h>
17 #include <asm/mshyperv.h>
18
19 struct ms_hyperv_info ms_hyperv;
20
21 static bool __init ms_hyperv_platform(void)
22 {
23         u32 eax;
24         u32 hyp_signature[3];
25
26         if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
27                 return false;
28
29         cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
30               &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
31
32         return eax >= HYPERV_CPUID_MIN &&
33                 eax <= HYPERV_CPUID_MAX &&
34                 !memcmp("Microsoft Hv", hyp_signature, 12);
35 }
36
37 static void __init ms_hyperv_init_platform(void)
38 {
39         /*
40          * Extract the features and hints
41          */
42         ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
43         ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
44
45         printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
46                ms_hyperv.features, ms_hyperv.hints);
47 }
48
49 const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
50         .name                   = "Microsoft HyperV",
51         .detect                 = ms_hyperv_platform,
52         .init_platform          = ms_hyperv_init_platform,
53 };
54 EXPORT_SYMBOL(x86_hyper_ms_hyperv);