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 */
37extern struct shared_info *HYPERVISOR_shared_info;
38extern struct start_info *xen_start_info;
39
40#include <asm/processor.h>
41
42static 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
62extern bool xen_hvm_need_lapic(void);
63
64static inline bool xen_x2apic_para_available(void)
65{
66	return xen_hvm_need_lapic();
67}
68#else
69static 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 */