x86/apic: Introduce apic_extnmi command line parameter

This patch introduces a command line parameter apic_extnmi:

 apic_extnmi=( bsp|all|none )

The default value is "bsp" and this is the current behavior: only the
Boot-Strapping Processor receives an external NMI.

"all" allows external NMIs to be broadcast to all CPUs. This would
raise the success rate of panic on NMI when BSP hangs in NMI context
or the external NMI is swallowed by other NMI handlers on the BSP.

If you specify "none", no CPUs receive external NMIs. This is useful for
the dump capture kernel so that it cannot be shot down by accidentally
pressing the external NMI button (on platforms which have it) while
saving a crash dump.

Signed-off-by: Hidehiro Kawai <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Bandan Das <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: "Maciej W. Rozycki" <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ricardo Ribalda Delgado <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Viresh Kumar <[email protected]>
Cc: Vivek Goyal <[email protected]>
Cc: x86-ml <[email protected]>
Link: http://lkml.kernel.org/r/20151210014632.25437.43778.stgit@softrs
Signed-off-by: Borislav Petkov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>

0 files changed, 0 insertions, 0 deletions