Intel APX Ready With Linux 6.16, Outdated Intel CPU Microcode Reporting Merged
Merged for the Linux 6.16 kernel are all of the x86 core enhancements that provide a variety of benefits to Intel as well as AMD processors.
Preparations for Intel Advanced Performance Extensions (APX) support have made it into the Linux 6.16 kernel. The X86_FEATURE_APX feature flag is added, APX state support is now handled, and various other changes around Intel APX. Intel APX isn't intended to be used by kernel code but rather user-space. Various changes though to the Linux kernel were needed for properly managing APX state and being able to report the capability to user-space. Intel APX will be found with future processors as a very exciting addition to the x86_64 world.
This pull also reports to users when running known outdated Intel CPU microcode. With this code in Linux 6.16, via the existing CPU security vulnerabilities/mitigation reporting it is now noted if the Intel CPU is running an oudated microcode version, a.k.a. what was previously covered on Phoronix within Intel Linux Patch Would Report Outdated CPU Microcode As A Security Vulnerability. The information is reported via the /sys/devices/system/cpu/vulnerabilities/old_microcode sysfs file. This outdated CPU microcode reporting will also taint the kernel with "TAINT_CPU_OUT_OF_SPEC" for mkaing it clear to kernel developers the out-of-date CPU microcode.
Also added as part of this merge is the AMD Zen debugging document. More details on that AMD Zen debugging documentation within New Documentation Aims To Help Improve AMD Zen System Debugging On Linux.
Some of the other x86 core changes for Linux 6.16 include improved code-patching scalability, simplifying the 32-bit PAE page table handling, making 5-level paging support on x86_64 unconditional, a fix for the Intel Spectre V2 mitigation handling by default on Intel CPUs, and a lot of other Intel/AMD CPU code refactoring.
More details on these x86 core changes in Linux 6.16 via this pull request that already has been merged to Linux Git.
Preparations for Intel Advanced Performance Extensions (APX) support have made it into the Linux 6.16 kernel. The X86_FEATURE_APX feature flag is added, APX state support is now handled, and various other changes around Intel APX. Intel APX isn't intended to be used by kernel code but rather user-space. Various changes though to the Linux kernel were needed for properly managing APX state and being able to report the capability to user-space. Intel APX will be found with future processors as a very exciting addition to the x86_64 world.
This pull also reports to users when running known outdated Intel CPU microcode. With this code in Linux 6.16, via the existing CPU security vulnerabilities/mitigation reporting it is now noted if the Intel CPU is running an oudated microcode version, a.k.a. what was previously covered on Phoronix within Intel Linux Patch Would Report Outdated CPU Microcode As A Security Vulnerability. The information is reported via the /sys/devices/system/cpu/vulnerabilities/old_microcode sysfs file. This outdated CPU microcode reporting will also taint the kernel with "TAINT_CPU_OUT_OF_SPEC" for mkaing it clear to kernel developers the out-of-date CPU microcode.
Also added as part of this merge is the AMD Zen debugging document. More details on that AMD Zen debugging documentation within New Documentation Aims To Help Improve AMD Zen System Debugging On Linux.
Some of the other x86 core changes for Linux 6.16 include improved code-patching scalability, simplifying the 32-bit PAE page table handling, making 5-level paging support on x86_64 unconditional, a fix for the Intel Spectre V2 mitigation handling by default on Intel CPUs, and a lot of other Intel/AMD CPU code refactoring.
More details on these x86 core changes in Linux 6.16 via this pull request that already has been merged to Linux Git.