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 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 64 static inline bool xen_x2apic_para_available(void) 65 { 66 return xen_hvm_need_lapic(); 67 } 68 #else 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