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arch: fix extended topology enumeration subleafs

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When booting a Linux guest in SMP configuration, on sapphire rapids
and granite rapids the following kernel warning can be observed:

[Firmware Bug]: CPUID leaf 0x1f subleaf 1 APIC ID mismatch 1 != 0
[Firmware Bug]: CPUID leaf 0x1f subleaf 2 APIC ID mismatch 1 != 0

The reason is that we announce the presence of the extended topology
leaf, but fail to announce the x2apic ID in EDX for each subleaf.

Signed-off-by: Thomas Prescher <thomas.prescher@cyberus-technology.de>
On-behalf-of: SAP thomas.prescher@sap.com
This commit is contained in:
Thomas Prescher 2025-11-21 14:44:09 +01:00 • committed by Bo Chen
parent 95b8c6afdd
commit b6032bc492
1 changed files with 3 additions and 0 deletions
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3
arch/src/x86_64/mod.rs
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@ -1347,6 +1347,7 @@ fn update_cpuid_topology(
u32::from(threads_per_core),
);
CpuidPatch::set_cpuid_reg(cpuid, 0x1f, Some(0), CpuidReg::ECX, 1 << 8);
CpuidPatch::set_cpuid_reg(cpuid, 0x1f, Some(0), CpuidReg::EDX, x2apic_id);
CpuidPatch::set_cpuid_reg(cpuid, 0x1f, Some(1), CpuidReg::EAX, core_width);
CpuidPatch::set_cpuid_reg(
@ -1357,6 +1358,7 @@ fn update_cpuid_topology(
u32::from(cores_per_die * threads_per_core),
);
CpuidPatch::set_cpuid_reg(cpuid, 0x1f, Some(1), CpuidReg::ECX, 2 << 8);
CpuidPatch::set_cpuid_reg(cpuid, 0x1f, Some(1), CpuidReg::EDX, x2apic_id);
CpuidPatch::set_cpuid_reg(cpuid, 0x1f, Some(2), CpuidReg::EAX, die_width);
CpuidPatch::set_cpuid_reg(
@ -1367,6 +1369,7 @@ fn update_cpuid_topology(
u32::from(dies_per_package * cores_per_die * threads_per_core),
);
CpuidPatch::set_cpuid_reg(cpuid, 0x1f, Some(2), CpuidReg::ECX, 5 << 8);
CpuidPatch::set_cpuid_reg(cpuid, 0x1f, Some(2), CpuidReg::EDX, x2apic_id);
if matches!(cpu_vendor, CpuVendor::AMD) {
CpuidPatch::set_cpuid_reg(