xref: /openbmc/linux/arch/x86/kernel/cpu/hypervisor.c (revision 293d5b43)
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/init.h>
25 #include <linux/export.h>
26 #include <asm/processor.h>
27 #include <asm/hypervisor.h>
28 
29 static const __initconst struct hypervisor_x86 * const hypervisors[] =
30 {
31 #ifdef CONFIG_XEN
32 	&x86_hyper_xen,
33 #endif
34 	&x86_hyper_vmware,
35 	&x86_hyper_ms_hyperv,
36 #ifdef CONFIG_KVM_GUEST
37 	&x86_hyper_kvm,
38 #endif
39 };
40 
41 const struct hypervisor_x86 *x86_hyper;
42 EXPORT_SYMBOL(x86_hyper);
43 
44 static inline void __init
45 detect_hypervisor_vendor(void)
46 {
47 	const struct hypervisor_x86 *h, * const *p;
48 	uint32_t pri, max_pri = 0;
49 
50 	for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
51 		h = *p;
52 		pri = h->detect();
53 		if (pri != 0 && pri > max_pri) {
54 			max_pri = pri;
55 			x86_hyper = h;
56 		}
57 	}
58 
59 	if (max_pri)
60 		pr_info("Hypervisor detected: %s\n", x86_hyper->name);
61 }
62 
63 void init_hypervisor(struct cpuinfo_x86 *c)
64 {
65 	if (x86_hyper && x86_hyper->set_cpu_features)
66 		x86_hyper->set_cpu_features(c);
67 }
68 
69 void __init init_hypervisor_platform(void)
70 {
71 
72 	detect_hypervisor_vendor();
73 
74 	if (!x86_hyper)
75 		return;
76 
77 	init_hypervisor(&boot_cpu_data);
78 
79 	if (x86_hyper->init_platform)
80 		x86_hyper->init_platform();
81 }
82 
83 bool __init hypervisor_x2apic_available(void)
84 {
85 	return x86_hyper                   &&
86 	       x86_hyper->x2apic_available &&
87 	       x86_hyper->x2apic_available();
88 }
89