Package: intel-microcode Version: 3.20160607.1 Severity: important Erratum BDF90 (BDX90?) for the Xeon E7v4 (and maybe Xeon E5v4) may result in a hung system on all affected processors when a microcode update is attempted during boot on a Debian system with the intel-microcode package installed.
If this errata is being triggered on a system and causing boot hangs, please boot the kernel using the "dis_ucode_ldr" parameter to bypass the kernel microcode loader, as described in the intel-microcode package documentation (README.Debian): https://sources.debian.net/src/intel-microcode/3.20161104.1/debian/README.Debian/#L104 Known details about BDF90: Intel® Xeon® Processor E7-8800/4800 v4 Product Family Specification Update, April 2017: BDF90 - Loading Microcode Updates or Executing an Authenticated Code Module May Result in a System Hang Problem: An uncorrectable error (IA32_MC3_STATUS.MCACOD=0400 and IA32_MC3_STATUS.MSCOD=0080) may be logged for processors that have more than 2.5MB last-level-cache per core on attempting to load a microcode update or execute an authenticated code module. This issue does not occur with microcode updates with a signature of 0x0b000021 and greater. Implication: Due to this erratum, the processor may hang when attempting to load a microcode update or execute an authenticated code module. Known-affected processors (list may be incomplete): Xeon E7-8891v4 Xeon E7-8893v4 Other possibily-affected processors (incomplete list): Xeon E5-2667v4 Xeon E5-2643v4 Xeon E5-2637v4 Xeon E5-4655v4 This erratum is worked around by microcode revision 0xb000021, included in the intel-microcode 20170511 release (which will be uploaded soon). -- Henrique Holschuh
