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>
*eax = cpu->phys_bits;
}
*ebx = env->features[FEAT_8000_0008_EBX];
- *ecx = 0;
- *edx = 0;
if (cs->nr_cores * cs->nr_threads > 1) {
- *ecx |= (cs->nr_cores * cs->nr_threads) - 1;
+ /*
+ * Bits 15:12 is "The number of bits in the initial
+ * Core::X86::Apic::ApicId[ApicId] value that indicate
+ * thread ID within a package". This is already stored at
+ * CPUX86State::pkg_offset.
+ * Bits 7:0 is "The number of threads in the package is NC+1"
+ */
+ *ecx = (env->pkg_offset << 12) |
+ ((cs->nr_cores * cs->nr_threads) - 1);
+ } else {
+ *ecx = 0;
}
+ *edx = 0;
break;
case 0x8000000A:
if (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_SVM) {