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| author | Borislav Petkov <bp@suse.de> | 2022-05-25 18:12:30 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2022-05-31 09:31:19 +0200 |
| commit | a77a94f86273ce42a39cb479217dd8d68acfe0ff (patch) | |
| tree | c54dd66607fa015e227baa7f9b05cfabc84c7896 /arch/x86/Kconfig | |
| parent | 181b6f40e9ea80c76756d4d0cdeed396016c487e (diff) | |
| download | lwn-a77a94f86273ce42a39cb479217dd8d68acfe0ff.tar.gz lwn-a77a94f86273ce42a39cb479217dd8d68acfe0ff.zip | |
x86/microcode: Default-disable late loading
It is dangerous and it should not be used anyway - there's a nice early
loading already.
Requested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220525161232.14924-3-bp@alien8.de
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index f423a2d87b15..976309d57a58 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1350,6 +1350,17 @@ config MICROCODE_AMD If you select this option, microcode patch loading support for AMD processors will be enabled. +config MICROCODE_LATE_LOADING + bool "Late microcode loading (DANGEROUS)" + default n + depends on MICROCODE + help + Loading microcode late, when the system is up and executing instructions + is a tricky business and should be avoided if possible. Just the sequence + of synchronizing all cores and SMT threads is one fragile dance which does + not guarantee that cores might not softlock after the loading. Therefore, + use this at your own risk. Late loading taints the kernel too. + config X86_MSR tristate "/dev/cpu/*/msr - Model-specific register support" help |