xref: /openbmc/linux/arch/x86/kernel/cpu/mshyperv.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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);
57