Messages in this thread | | | Date | Tue, 2 Apr 2019 17:35:24 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86/microcode: Remove useless code after early microcode support added |
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On Mon, Apr 01, 2019 at 04:46:52PM +0800, Zhenzhong Duan wrote: > After early microcode update was added, microcode couldn't be configured
No, early loading doesn't have anything to do with it - the driver was made built-in only.
> as a module, microcode update happens at early bootup and cpu hotplug > stage. This made the microcode update code in module loading stage > useless. > > This patch
Avoid having "This patch" or "This commit" in the commit message. It is tautologically useless.
Also, do
$ git grep 'This patch' Documentation/process
for more details.
> remove the useless code.
Well, not useless.
1. Apply your patch, boot kernel without an initrd so that it doesn't apply early microcode.
2. Load late microcode:
# echo 1 > /sys/devices/system/cpu/microcode/reload [ 66.430052] microcode: CPU0: new patch_level=0x05000029 [ 66.430352] x86/CPU: CPU features have changed after loading microcode, but might not take effect. [ 66.430620] microcode: Reload completed, microcode revision: 0x5000029
3. # grep microcode /proc/cpuinfo microcode : 0x5000029 microcode : 0x5000028 <--- !!!
Whoops. CPU1 didn't get updated.
So I'd suggest leaving this code alone and concentrating on fixing real bugs. Unless it is causing other issues.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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