From c02f48e070bde326f55bd94544ca82291f7396e3 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 5 Apr 2019 06:28:11 +0200 Subject: [PATCH] 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 Reviewed-by: Thomas Gleixner Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20190405133010.24249-4-bp@alien8.de --- arch/x86/Kconfig | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5ad9241..5a0a752 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -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" -- 2.7.4