diff --git a/README.caveats b/README.caveats index b15642b..9529de3 100644 --- a/README.caveats +++ b/README.caveats @@ -10,8 +10,8 @@ behaviour. General behaviour ================= -In RHEL 8 (as well as RHEL 7 before it), there are currently two main handlers -for CPU microcode update: +In RHEL 9 (as well as in RHEL 7 and RHEL 8 before it), there are currently +two main handlers for CPU microcode update: * Early microcode update. It uses GenuineIntel.bin or AuthenticAMD.bin file placed at the beginning of an initramfs image (/boot/initramfs-KERNEL_VERSION.img, where "KERNEL_VERSION" is a kernel @@ -45,10 +45,10 @@ zero-filled. The early microcode is placed into initramfs image by the "dracut" script, which scans the aforementioned subdirectories of the configured list of firmware -directories (by default, the list consists of two directories in RHEL 8, +directories (by default, the list consists of two directories in RHEL 9, "/lib/firmware/updates" and "/lib/firmware"). -In RHEL 8, AMD CPU microcode is shipped as a part of the linux-firmware package, +In RHEL 9, AMD CPU microcode is shipped as a part of the linux-firmware package, and Intel microcode is shipped as a part of the microcode_ctl package. The microcode_ctl package currently includes the following: @@ -613,7 +613,7 @@ Mitigation: microcode loading is disabled for the affected CPU model. Minimum versions of the kernel package that contain the aforementioned patch series: - - Upstream/RHEL 8: 4.17.0 + - Upstream/RHEL 8/RHEL 9: 4.17.0 - RHEL 7.6 onwards: 3.10.0-894 - RHEL 7.5: 3.10.0-862.6.1 - RHEL 7.4: 3.10.0-693.35.1 @@ -628,7 +628,7 @@ series: Early microcode load inside a virtual machine --------------------------------------------- -RHEL 8 kernel supports performing microcode update during early boot stage +RHEL 9 kernel supports performing microcode update during early boot stage from a cpio archive placed at the beginning of the initramfs image. However, when an early microcode update is attempted inside some virtualised environments, that may result in unexpected system behaviour. @@ -643,7 +643,7 @@ Mitigation: early microcode loading is disabled for all CPU models on kernels without the fix. Minimum versions of the kernel package that contain the fix: - - Upstream/RHEL 8: 4.10.0 + - Upstream/RHEL 8/RHEL 9: 4.10.0 - RHEL 7.6 onwards: 3.10.0-930 - RHEL 7.5: 3.10.0-862.14.1 - RHEL 7.4: 3.10.0-693.38.1