Re: [PATCH] x86: Unbreak early processor microcode loading

From: Daniel J Blueman
Date: Thu Mar 19 2015 - 03:30:41 EST


On Thu, Mar 19, 2015 at 2:42 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
On Wed, Mar 18, 2015 at 11:02:27AM +0100, Borislav Petkov wrote:
I don't like the ifdeffery in your solution and would like to try to fix
it in a cleaner way. Unless you come up with a better solution first.

Ok, how about this below? It is more involved but finds and loads the
microcode built-in into the kernel in the early loader which is when
you want to load microcode anyway. Only AMD for now but that should be
enough for testing.
[]

Neat; I added the 'amd-ucode/' directory prefix to the string and adjusted the buffer size, and the microcode is loaded, but we see consistent hangs when onlining core 32 on the first server.

Further investigation shows the BIOS in this platform isn't loading the microcode after the Hypertransport reconfig warm-boot (though other platforms do), so it's a better solution I engage with the vendor to fix their BIOS, rather than working around it in the kernel at this time.

Many thanks!
Daniel

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