a77f18d139c0e18d7824a960705777c23796daae
[muen/linux.git] / arch / x86 / kernel / cpu / hypervisor.c
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_pv,
33         &x86_hyper_xen_hvm,
34 #endif
35         &x86_hyper_vmware,
36         &x86_hyper_ms_hyperv,
37 #ifdef CONFIG_KVM_GUEST
38         &x86_hyper_kvm,
39 #endif
40 };
41
42 const struct hypervisor_x86 *x86_hyper;
43 EXPORT_SYMBOL(x86_hyper);
44
45 static inline void __init
46 detect_hypervisor_vendor(void)
47 {
48         const struct hypervisor_x86 *h, * const *p;
49         uint32_t pri, max_pri = 0;
50
51         for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
52                 h = *p;
53                 pri = h->detect();
54                 if (pri != 0 && pri > max_pri) {
55                         max_pri = pri;
56                         x86_hyper = h;
57                 }
58         }
59
60         if (max_pri)
61                 pr_info("Hypervisor detected: %s\n", x86_hyper->name);
62 }
63
64 void init_hypervisor(struct cpuinfo_x86 *c)
65 {
66         if (x86_hyper && x86_hyper->set_cpu_features)
67                 x86_hyper->set_cpu_features(c);
68 }
69
70 void __init init_hypervisor_platform(void)
71 {
72
73         detect_hypervisor_vendor();
74
75         if (!x86_hyper)
76                 return;
77
78         init_hypervisor(&boot_cpu_data);
79
80         if (x86_hyper->init_platform)
81                 x86_hyper->init_platform();
82 }
83
84 bool __init hypervisor_x2apic_available(void)
85 {
86         return x86_hyper                   &&
87                x86_hyper->x2apic_available &&
88                x86_hyper->x2apic_available();
89 }
90
91 void hypervisor_pin_vcpu(int cpu)
92 {
93         if (!x86_hyper)
94                 return;
95
96         if (x86_hyper->pin_vcpu)
97                 x86_hyper->pin_vcpu(cpu);
98         else
99                 WARN_ONCE(1, "vcpu pinning requested but not supported!\n");
100 }