xref: /openbmc/linux/arch/x86/kernel/cpu/hypervisor.c (revision a2818ee4)
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 extern const struct hypervisor_x86 x86_hyper_vmware;
30 extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
31 extern const struct hypervisor_x86 x86_hyper_xen_pv;
32 extern const struct hypervisor_x86 x86_hyper_xen_hvm;
33 extern const struct hypervisor_x86 x86_hyper_kvm;
34 extern const struct hypervisor_x86 x86_hyper_jailhouse;
35 
36 static const __initconst struct hypervisor_x86 * const hypervisors[] =
37 {
38 #ifdef CONFIG_XEN_PV
39 	&x86_hyper_xen_pv,
40 #endif
41 #ifdef CONFIG_XEN_PVHVM
42 	&x86_hyper_xen_hvm,
43 #endif
44 	&x86_hyper_vmware,
45 	&x86_hyper_ms_hyperv,
46 #ifdef CONFIG_KVM_GUEST
47 	&x86_hyper_kvm,
48 #endif
49 #ifdef CONFIG_JAILHOUSE_GUEST
50 	&x86_hyper_jailhouse,
51 #endif
52 };
53 
54 enum x86_hypervisor_type x86_hyper_type;
55 EXPORT_SYMBOL(x86_hyper_type);
56 
57 static inline const struct hypervisor_x86 * __init
58 detect_hypervisor_vendor(void)
59 {
60 	const struct hypervisor_x86 *h = NULL, * const *p;
61 	uint32_t pri, max_pri = 0;
62 
63 	for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
64 		pri = (*p)->detect();
65 		if (pri > max_pri) {
66 			max_pri = pri;
67 			h = *p;
68 		}
69 	}
70 
71 	if (h)
72 		pr_info("Hypervisor detected: %s\n", h->name);
73 
74 	return h;
75 }
76 
77 static void __init copy_array(const void *src, void *target, unsigned int size)
78 {
79 	unsigned int i, n = size / sizeof(void *);
80 	const void * const *from = (const void * const *)src;
81 	const void **to = (const void **)target;
82 
83 	for (i = 0; i < n; i++)
84 		if (from[i])
85 			to[i] = from[i];
86 }
87 
88 void __init init_hypervisor_platform(void)
89 {
90 	const struct hypervisor_x86 *h;
91 
92 	h = detect_hypervisor_vendor();
93 
94 	if (!h)
95 		return;
96 
97 	copy_array(&h->init, &x86_init.hyper, sizeof(h->init));
98 	copy_array(&h->runtime, &x86_platform.hyper, sizeof(h->runtime));
99 
100 	x86_hyper_type = h->type;
101 	x86_init.hyper.init_platform();
102 }
103