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Commit 066941bd authored by H. Peter Anvin's avatar H. Peter Anvin Committed by Ingo Molnar
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x86: unmask CPUID levels on Intel CPUs



Impact: Fixes crashes with misconfigured BIOSes on XSAVE hardware

Avuton Olrich reported early boot crashes with v2.6.28 and
bisected it down to dc1e35c6
("x86, xsave: enable xsave/xrstor on cpus with xsave support").

If the CPUID limit bit in MSR_IA32_MISC_ENABLE is set, clear it to
make all CPUID information available.  This is required for some
features to work, in particular XSAVE.

Reported-and-bisected-by: default avatarAvuton Olrich <avuton@gmail.com>
Tested-by: default avatarAvuton Olrich <avuton@gmail.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent bdf21a49
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