Linux 7.4 corrects AMD Zen 5 TLB size reporting in /proc/cpuinfo

Linux 7.4 corrects how the kernel reports Translation Lookaside Buffer sizes for AMD Zen 5 Ryzen and EPYC processors, which had been under-reported because the kernel did not account for a change to 32-entry multiples. The fix ensures /proc/cpuinfo and similar interfaces show accurate values. The release also adds SEV improvements including RMPOPT optimization for confidential VMs and a new sysfs interface for SEV status reporting.

What changed in CPU reporting

• AMD shifted TLB size reporting to multiples of 32 entries starting with Zen 5, but Linux continued using the old format
• This caused the kernel to under-report actual TLB sizes on Zen 5 Ryzen and EPYC chips
• Fix merged via the x86/cpu pull request for Linux 7.4
• Also included: RMPOPT optimization for SEV-protected confidential VMs on lightly-loaded EPYC Zen 6 servers
• New sysfs interface added for reporting AMD SEV status, merged via x86/sev pull

Why it matters

Accurate TLB reporting matters for performance tuning and benchmarking tools that rely on /proc/cpuinfo to make scheduling or optimization decisions. The SEV additions continue AMD's push for confidential computing adoption in data centers.