LXR linux/arch/x86/include/asm/xen/hypervisor.h

   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 */
  76