text: /******************************************************************************
   * hypervisor.h
   *
   * Linux-specific hypervisor handling.
   *
   * Copyright (c) 2002-2004, K A Fraser
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License version 2
   * as published by the Free Software Foundation; or, when distributed
   * separately from the Linux kernel or incorporated into other
   * software packages, subject to the following license:
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this source file (the "Software"), to deal in the Software without
   * restriction, including without limitation the rights to use, copy, modify,
   * merge, publish, distribute, sublicense, and/or sell copies of the Software,
   * and to permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
   * IN THE SOFTWARE.
   */
  
  #ifndef _ASM_X86_XEN_HYPERVISOR_H
  #define _ASM_X86_XEN_HYPERVISOR_H
  
  /* arch/i386/kernel/setup.c */
  extern struct shared_info *HYPERVISOR_shared_info;
  extern struct start_info *xen_start_info;
  
  #include <asm/processor.h>
  
  static inline uint32_t xen_cpuid_base(void)
  {
  	uint32_t base, eax, ebx, ecx, edx;
  	char signature[13];
  
  	for (base = 0x40000000; base < 0x40010000; base += 0x100) {
  		cpuid(base, &eax, &ebx, &ecx, &edx);
  		*(uint32_t *)(signature + 0) = ebx;
  		*(uint32_t *)(signature + 4) = ecx;
  		*(uint32_t *)(signature + 8) = edx;
  		signature[12] = 0;
  
  		if (!strcmp("XenVMMXenVMM", signature) && ((eax - base) >= 2))
  			return base;
  	}
  
  	return 0;
  }
  
  #ifdef CONFIG_XEN
  extern bool xen_hvm_need_lapic(void);
  
  static inline bool xen_x2apic_para_available(void)
  {
  	return xen_hvm_need_lapic();
  }
  #else
  static inline bool xen_x2apic_para_available(void)
  {
  	return (xen_cpuid_base() != 0);
  }
  #endif
  
  #endif /* _ASM_X86_XEN_HYPERVISOR_H */
  