Commit-ID: 96e39ac0e9d18020c8c5a41b64b8fe86c26575ab Gitweb: http://git.kernel.org/tip/96e39ac0e9d18020c8c5a41b64b8fe86c26575ab Author: Jason Wang <[email protected]> AuthorDate: Thu, 25 Jul 2013 16:54:32 +0800 Committer: H. Peter Anvin <[email protected]> CommitDate: Mon, 5 Aug 2013 06:33:54 -0700
x86: Introduce hypervisor_cpuid_base() This patch introduce hypervisor_cpuid_base() which loop test the hypervisor existence function until the signature match and check the number of leaves if required. This could be used by Xen/KVM guest to detect the existence of hypervisor. Cc: Paolo Bonzini <[email protected]> Cc: Gleb Natapov <[email protected]> Signed-off-by: Jason Wang <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: H. Peter Anvin <[email protected]> --- arch/x86/include/asm/processor.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 24cf5ae..7763307 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -971,6 +971,21 @@ unsigned long calc_aperfmperf_ratio(struct aperfmperf *old, return ratio; } +static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves) +{ + uint32_t base, eax, signature[3]; + + for (base = 0x40000000; base < 0x40010000; base += 0x100) { + cpuid(base, &eax, &signature[0], &signature[1], &signature[2]); + + if (!memcmp(sig, signature, 12) && + (leaves == 0 || ((eax - base) >= leaves))) + return base; + } + + return 0; +} + extern unsigned long arch_align_stack(unsigned long sp); extern void free_init_pages(char *what, unsigned long begin, unsigned long end); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
