On Sat, Jun 01 2024 at 09:06, Linux regression tracking (Thorsten Leemhuis) wrote:
On 31.05.24 10:42, Thomas Gleixner wrote:
On Fri, May 31 2024 at 10:33, Thomas Gleixner wrote:
Subject: x86/topology/intel: Unlock CPUID before evaluating anything From: Thomas Gleixner tglx@linutronix.de Date: Thu, 30 May 2024 17:29:18 +0200
Intel CPUs have a MSR bit to limit CPUID enumeration to leaf two. If this bit is set by the BIOS then CPUID evaluation including topology enumeration does not work correctly as the evaluation code does not try to analyze any leaf greater than two. [...]
TWIMC, I noticed a bug report with a "12 × 12th Gen Intel® Core™ i7-1255U" where the reporter also noticed a lot of messages like these:
archlinux kernel: [Firmware Bug]: CPU4: Topology domain 1 shift 7 != 6 archlinux kernel: [Firmware Bug]: CPU4: Topology domain 2 shift 7 != 6 archlinux kernel: [Firmware Bug]: CPU4: Topology domain 3 shift 7 != 6
Asked the reporter to test this patch. For details see: https://bugzilla.kernel.org/show_bug.cgi?id=218879
Won't help. See: https://lore.kernel.org/all/87plt26m2b.ffs@tglx/
Thanks,
tglx