xref: /linux/arch/x86/kernel/cpu/mshyperv.c (revision a5c4300389bb33ade2515c082709217f0614cf15)
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 
22 static bool __init ms_hyperv_platform(void)
23 {
24 	u32 eax;
25 	u32 hyp_signature[3];
26 
27 	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
28 		return false;
29 
30 	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
31 	      &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
32 
33 	return eax >= HYPERV_CPUID_MIN &&
34 		eax <= HYPERV_CPUID_MAX &&
35 		!memcmp("Microsoft Hv", hyp_signature, 12);
36 }
37 
38 static void __init ms_hyperv_init_platform(void)
39 {
40 	/*
41 	 * Extract the features and hints
42 	 */
43 	ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
44 	ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
45 
46 	printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
47 	       ms_hyperv.features, ms_hyperv.hints);
48 }
49 
50 const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
51 	.name			= "Microsoft HyperV",
52 	.detect			= ms_hyperv_platform,
53 	.init_platform		= ms_hyperv_init_platform,
54 };
55 EXPORT_SYMBOL(x86_hyper_ms_hyperv);
56