xref: /linux/arch/x86/kernel/cpu/hypervisor.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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/module.h>
25 #include <asm/processor.h>
26 #include <asm/hypervisor.h>
27 
28 static const __initconst struct hypervisor_x86 * const hypervisors[] =
29 {
30 #ifdef CONFIG_XEN_PVHVM
31 	&x86_hyper_xen_hvm,
32 #endif
33 	&x86_hyper_vmware,
34 	&x86_hyper_ms_hyperv,
35 #ifdef CONFIG_KVM_GUEST
36 	&x86_hyper_kvm,
37 #endif
38 };
39 
40 const struct hypervisor_x86 *x86_hyper;
41 EXPORT_SYMBOL(x86_hyper);
42 
43 static inline void __init
44 detect_hypervisor_vendor(void)
45 {
46 	const struct hypervisor_x86 *h, * const *p;
47 	uint32_t pri, max_pri = 0;
48 
49 	for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
50 		h = *p;
51 		pri = h->detect();
52 		if (pri != 0 && pri > max_pri) {
53 			max_pri = pri;
54 			x86_hyper = h;
55 		}
56 	}
57 
58 	if (max_pri)
59 		printk(KERN_INFO "Hypervisor detected: %s\n", x86_hyper->name);
60 }
61 
62 void init_hypervisor(struct cpuinfo_x86 *c)
63 {
64 	if (x86_hyper && x86_hyper->set_cpu_features)
65 		x86_hyper->set_cpu_features(c);
66 }
67 
68 void __init init_hypervisor_platform(void)
69 {
70 
71 	detect_hypervisor_vendor();
72 
73 	if (!x86_hyper)
74 		return;
75 
76 	init_hypervisor(&boot_cpu_data);
77 
78 	if (x86_hyper->init_platform)
79 		x86_hyper->init_platform();
80 }
81 
82 bool __init hypervisor_x2apic_available(void)
83 {
84 	return x86_hyper                   &&
85 	       x86_hyper->x2apic_available &&
86 	       x86_hyper->x2apic_available();
87 }
88