Messages in this thread Patch in this message | | | From | Jason Wang <> | Subject | [PATCH 1/4] x86: introduce hypervisor_cpuid_base() | Date | Tue, 23 Jul 2013 17:41:02 +0800 |
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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: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Paolo Bonzini" <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: x86@kernel.org Signed-off-by: Jason Wang <jasowang@redhat.com> --- arch/x86/include/asm/processor.h | 20 ++++++++++++++++++++ 1 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 24cf5ae..a8136d0 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -971,6 +971,26 @@ 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, 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(sig, signature) && + (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); -- 1.7.1
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