xref: /linux/arch/x86/kernel/cpu/hypervisor.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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_PV
32 	&x86_hyper_xen_pv,
33 #endif
34 #ifdef CONFIG_XEN_PVHVM
35 	&x86_hyper_xen_hvm,
36 #endif
37 	&x86_hyper_vmware,
38 	&x86_hyper_ms_hyperv,
39 #ifdef CONFIG_KVM_GUEST
40 	&x86_hyper_kvm,
41 #endif
42 };
43 
44 const struct hypervisor_x86 *x86_hyper;
45 EXPORT_SYMBOL(x86_hyper);
46 
47 static inline void __init
48 detect_hypervisor_vendor(void)
49 {
50 	const struct hypervisor_x86 *h, * const *p;
51 	uint32_t pri, max_pri = 0;
52 
53 	for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
54 		h = *p;
55 		pri = h->detect();
56 		if (pri != 0 && pri > max_pri) {
57 			max_pri = pri;
58 			x86_hyper = h;
59 		}
60 	}
61 
62 	if (max_pri)
63 		pr_info("Hypervisor detected: %s\n", x86_hyper->name);
64 }
65 
66 void __init init_hypervisor_platform(void)
67 {
68 
69 	detect_hypervisor_vendor();
70 
71 	if (!x86_hyper)
72 		return;
73 
74 	if (x86_hyper->init_platform)
75 		x86_hyper->init_platform();
76 }
77 
78 bool __init hypervisor_x2apic_available(void)
79 {
80 	return x86_hyper                   &&
81 	       x86_hyper->x2apic_available &&
82 	       x86_hyper->x2apic_available();
83 }
84 
85 void hypervisor_pin_vcpu(int cpu)
86 {
87 	if (!x86_hyper)
88 		return;
89 
90 	if (x86_hyper->pin_vcpu)
91 		x86_hyper->pin_vcpu(cpu);
92 	else
93 		WARN_ONCE(1, "vcpu pinning requested but not supported!\n");
94 }
95