kernel-rt/SOURCES/1017-x86-microcode-Deprecate-MICROCODE_OLD_INTERFACE.patch

52 lines
1.9 KiB
Diff

From b31d4c149df44c050b12b7aca2c535e06f1b1237 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@suse.de>
Date: Fri, 5 Apr 2019 06:28:11 +0200
Subject: [PATCH 03/36] 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
(cherry picked from commit c02f48e070bde326f55bd94544ca82291f7396e3)
Signed-off-by: Mridula Shastry <mridula.c.shastry@oracle.com>
Reviewed-by: Todd Vierling <todd.vierling@oracle.com>
---
arch/x86/Kconfig | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f26d1d596e9a..4f762b807bd4 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1361,8 +1361,16 @@ 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"
--
2.39.3