x86/cpuid: Provide get_scattered_cpuid_leaf()
Sparse populated CPUID leafs are collected in a software provided leaf to avoid bloat of the x86_capability array, but there is no way to rebuild the real leafs (e.g. for KVM CPUID enumeration) other than rereading the CPUID leaf from the CPU. While this is possible it is problematic as it does not take software disabled features into account. If a feature is disabled on the host it should not be exposed to a guest either. Add get_scattered_cpuid_leaf() which rebuilds the leaf from the scattered cpuid table information and the active CPU features. [ tglx: Rewrote changelog ] Signed-off-by:He Chen <he.chen@linux.intel.com> Reviewed-by:
Borislav Petkov <bp@suse.de> Cc: Luwei Kang <luwei.kang@intel.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Piotr Luc <Piotr.Luc@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Link: http://lkml.kernel.org/r/1478856336-9388-3-git-send-email-he.chen@linux.intel.com Signed-off-by:
Thomas Gleixner <tglx@linutronix.de>
parent
47f10a36
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