Commit c02f48e0 authored Apr 05, 2019 by Borislav Petkov

x86/microcode: Deprecate MICROCODE_OLD_INTERFACE



This is the ancient loading interface which requires special tools to be
used. The bigger problem with it is that it is as inadequate for proper
loading of microcode as the late microcode loading interface is because
it happens just as late.

iucode_tool's manpage already warns people that it is deprecated.

Deprecate it and turn it off by default along with a big fat warning in
the Kconfig help. It will go away sometime in the future.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20190405133010.24249-4-bp@alien8.de

parent 24613a04

arch/x86/Kconfig

+9 −1

Original line number	Diff line number	Diff line
		@@ -1330,8 +1330,16 @@ config MICROCODE_AMD
		processors will be enabled.

		config MICROCODE_OLD_INTERFACE
		def_bool y
		bool "Ancient loading interface (DEPRECATED)"
		default n
		depends on MICROCODE
		---help---
		DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
		which was used by userspace tools like iucode_tool and microcode.ctl.
		It is inadequate because it runs too late to be able to properly
		load microcode on a machine and it needs special tools. Instead, you
		should've switched to the early loading method with the initrd or
		builtin microcode by now: Documentation/x86/microcode.txt

		config X86_MSR
		tristate "/dev/cpu/*/msr - Model-specific register support"

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