CPUID leaf CPUID_Fn80000008_ECX provides information about the
number of threads supported by the processor. It was found that
the field ApicIdSize(bits 15-12) was not set correctly.
ApicIdSize is defined as the number of bits required to represent
all the ApicId values within a package.
Valid Values: Value Description
3h-0h Reserved.
4h up to 16 threads.
5h up to 32 threads.
6h up to 64 threads.
7h up to 128 threads.
Fh-8h Reserved.
Fix the bit appropriately.
This came up during following thread.
https://lore.kernel.org/qemu-devel/158643709116.17430.15995069125716778943.malonedeb@wampee.canonical.com/#t
Refer the Processor Programming Reference (PPR) for AMD Family 17h
Model 01h, Revision B1 Processors. The documentation is available
from the bugzilla Link below.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Reported-by: Philipp Eppelt <1871842@bugs.launchpad.net>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Message-Id: <20200417215345.64800.73351.stgit@localhost.localdomain>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>