1 /******************************************************************************
2 * hypervisor.h
3 *
4 * Linux-specific hypervisor handling.
5 *
6 * Copyright (c) 2002-2004, K A Fraser
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version 2
10 * as published by the Free Software Foundation; or, when distributed
11 * separately from the Linux kernel or incorporated into other
12 * software packages, subject to the following license:
13 *
14 * Permission is hereby granted, free of charge, to any person obtaining a copy
15 * of this source file (the "Software"), to deal in the Software without
16 * restriction, including without limitation the rights to use, copy, modify,
17 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
18 * and to permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be included in
22 * all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
27 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
28 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
29 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
30 * IN THE SOFTWARE.
31 */
32
33 #ifndef _ASM_X86_XEN_HYPERVISOR_H
34 #define _ASM_X86_XEN_HYPERVISOR_H
35
36 /* arch/i386/kernel/setup.c */
37 extern struct shared_info *HYPERVISOR_shared_info;
38 extern struct start_info *xen_start_info;
39
40 #include <asm/processor.h>
41
xen_cpuid_base(void)42 static inline uint32_t xen_cpuid_base(void)
43 {
44 uint32_t base, eax, ebx, ecx, edx;
45 char signature[13];
46
47 for (base = 0x40000000; base < 0x40010000; base += 0x100) {
48 cpuid(base, &eax, &ebx, &ecx, &edx);
49 *(uint32_t *)(signature + 0) = ebx;
50 *(uint32_t *)(signature + 4) = ecx;
51 *(uint32_t *)(signature + 8) = edx;
52 signature[12] = 0;
53
54 if (!strcmp("XenVMMXenVMM", signature) && ((eax - base) >= 2))
55 return base;
56 }
57
58 return 0;
59 }
60
61 #ifdef CONFIG_XEN
62 extern bool xen_hvm_need_lapic(void);
63
xen_x2apic_para_available(void)64 static inline bool xen_x2apic_para_available(void)
65 {
66 return xen_hvm_need_lapic();
67 }
68 #else
xen_x2apic_para_available(void)69 static inline bool xen_x2apic_para_available(void)
70 {
71 return (xen_cpuid_base() != 0);
72 }
73 #endif
74
75 #endif /* _ASM_X86_XEN_HYPERVISOR_H */
76