xref: /openbmc/linux/arch/x86/kernel/cpu/hypervisor.c (revision d3964221)
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 
35 static const __initconst struct hypervisor_x86 * const hypervisors[] =
36 {
37 #ifdef CONFIG_XEN_PV
38 	&x86_hyper_xen_pv,
39 #endif
40 #ifdef CONFIG_XEN_PVHVM
41 	&x86_hyper_xen_hvm,
42 #endif
43 	&x86_hyper_vmware,
44 	&x86_hyper_ms_hyperv,
45 #ifdef CONFIG_KVM_GUEST
46 	&x86_hyper_kvm,
47 #endif
48 };
49 
50 enum x86_hypervisor_type x86_hyper_type;
51 EXPORT_SYMBOL(x86_hyper_type);
52 
53 static inline const struct hypervisor_x86 * __init
54 detect_hypervisor_vendor(void)
55 {
56 	const struct hypervisor_x86 *h = NULL, * const *p;
57 	uint32_t pri, max_pri = 0;
58 
59 	for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) {
60 		pri = (*p)->detect();
61 		if (pri > max_pri) {
62 			max_pri = pri;
63 			h = *p;
64 		}
65 	}
66 
67 	if (h)
68 		pr_info("Hypervisor detected: %s\n", h->name);
69 
70 	return h;
71 }
72 
73 static void __init copy_array(const void *src, void *target, unsigned int size)
74 {
75 	unsigned int i, n = size / sizeof(void *);
76 	const void * const *from = (const void * const *)src;
77 	const void **to = (const void **)target;
78 
79 	for (i = 0; i < n; i++)
80 		if (from[i])
81 			to[i] = from[i];
82 }
83 
84 void __init init_hypervisor_platform(void)
85 {
86 	const struct hypervisor_x86 *h;
87 
88 	h = detect_hypervisor_vendor();
89 
90 	if (!h)
91 		return;
92 
93 	copy_array(&h->init, &x86_init.hyper, sizeof(h->init));
94 	copy_array(&h->runtime, &x86_platform.hyper, sizeof(h->runtime));
95 
96 	x86_hyper_type = h->type;
97 	x86_init.hyper.init_platform();
98 }
99