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target/i386: Fix the CPUID leaf CPUID_Fn80000008

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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>
This commit is contained in:
Babu Moger 2020-04-17 16:55:13 -05:00 committed by Paolo Bonzini
parent 4dd8a7064b
commit cac9edfc4d
1 changed files with 12 additions and 3 deletions
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15
target/i386/cpu.c
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@ -5837,11 +5837,20 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
*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) {