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| author | Jason Wang <jasowang@redhat.com> | 2013-07-25 16:54:32 +0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-08-05 06:33:54 -0700 |
| commit | 96e39ac0e9d18020c8c5a41b64b8fe86c26575ab (patch) | |
| tree | 0f1256c242ac8d57c92b03dae6b619ca12f46c07 | |
| parent | c095ba7224d8edc71dcef0d655911399a8bd4a3f (diff) | |
| download | talos-op-linux-96e39ac0e9d18020c8c5a41b64b8fe86c26575ab.tar.gz talos-op-linux-96e39ac0e9d18020c8c5a41b64b8fe86c26575ab.zip | |
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 <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: http://lkml.kernel.org/r/1374742475-2485-1-git-send-email-jasowang@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| -rw-r--r-- | arch/x86/include/asm/processor.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 24cf5aefb704..7763307b4137 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); |
