linux/arch/x86/include/asm/xen/hypervisor.h
Sheng Yang d9b8ca8474 xen: HVM X2APIC support
This patch is similiar to Gleb Natapov's patch for KVM, which enable the
hypervisor to emulate x2apic feature for the guest. By this way, the emulation
of lapic would be simpler with x2apic interface(MSR), and faster.

[v2: Re-organized 'xen_hvm_need_lapic' per Ian Campbell suggestion]

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-01-07 10:03:50 -05:00

76 lines
2.4 KiB
C

/******************************************************************************
* 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
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* and to permit persons to whom the Software is furnished to do so, subject to
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* The above copyright notice and this permission notice shall be included in
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*/
#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 */