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| author | Thomas Gleixner <tglx@linutronix.de> | 2023-10-02 14:00:08 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-10-24 15:05:55 +0200 |
| commit | 8f849ff63bcbc77670da03cb8f2b78b06257f455 (patch) | |
| tree | d53d92a3ca79ec251c1edaa3d046f6e15e3cfb1b /arch/x86/include/asm/microcode.h | |
| parent | 9cab5fb776d4367e26950cf759211e948335288e (diff) | |
| download | linux-8f849ff63bcbc77670da03cb8f2b78b06257f455.tar.gz linux-8f849ff63bcbc77670da03cb8f2b78b06257f455.tar.bz2 linux-8f849ff63bcbc77670da03cb8f2b78b06257f455.zip | |
x86/microcode: Handle "offline" CPUs correctly
Offline CPUs need to be parked in a safe loop when microcode update is
in progress on the primary CPU. Currently, offline CPUs are parked in
mwait_play_dead(), and for Intel CPUs, its not a safe instruction,
because the MWAIT instruction can be patched in the new microcode update
that can cause instability.
- Add a new microcode state 'UCODE_OFFLINE' to report status on per-CPU
basis.
- Force NMI on the offline CPUs.
Wake up offline CPUs while the update is in progress and then return
them back to mwait_play_dead() after microcode update is complete.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231002115903.660850472@linutronix.de
Diffstat (limited to 'arch/x86/include/asm/microcode.h')
| -rw-r--r-- | arch/x86/include/asm/microcode.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h index 82924828a94b..0ee6ed0ff2bf 100644 --- a/arch/x86/include/asm/microcode.h +++ b/arch/x86/include/asm/microcode.h @@ -73,6 +73,7 @@ static inline u32 intel_get_microcode_revision(void) #endif /* !CONFIG_CPU_SUP_INTEL */ bool microcode_nmi_handler(void); +void microcode_offline_nmi_handler(void); #ifdef CONFIG_MICROCODE_LATE_LOADING DECLARE_STATIC_KEY_FALSE(microcode_nmi_handler_enable); |