Updating Intel microcode on Solaris 11.3 with ucodeadm

So it's seems Intel finally released a working microcode update for the Spectre CPU flaw. You can download it at https://downloadcenter.intel.com/download/27591/Linux-Processor-Microcode-Data-File.

Done that? Good, let's apply it.

# gzcat microcode-20180312.tgz | tar xf -
# ln -s microcode.dat intel-ucode.txt
# ucodeadm -u intel-ucode.txt
# ucodeadm -v
CPU     Microcode Version
0       0x24
1       0x24
2       0x24
3       0x24
# dmesg | tail
...
Mar 16 10:06:36 solaris unix: [ID 518058 kern.info] cpu0: microcode has been updated from version 0x1c to 0x24
Mar 16 10:06:36 solaris unix: [ID 518058 kern.info] cpu1: microcode has been updated from version 0x1c to 0x24
Mar 16 10:06:36 solaris unix: [ID 518058 kern.info] cpu2: microcode has been updated from version 0x1c to 0x24
Mar 16 10:06:36 solaris unix: [ID 518058 kern.info] cpu3: microcode has been updated from version 0x1c to 0x24

You could copy intel-ucode.txt to /platform/i86pc/ucode/intel-ucode.txt to make this permanent. This will break pkg verify system/kernel/platform though.

Links

• Intel has released new CPU microcode for download
• ucodeadm(1M)