diff options
| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2019-10-23 11:01:53 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-16 10:27:50 +0100 |
| commit | ab7b39b99f030a15f4f398ea6c2fbe9600e4818c (patch) | |
| tree | 0076e30323bf74e8ad600eb0afd1b583f0e72ed8 /arch/x86/kernel/cpu/intel.c | |
| parent | 725afc0d60cf8b9e3bf023920c881f4a4261dc49 (diff) | |
x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default
commit 95c5824f75f3ba4c9e8e5a4b1a623c95390ac266 upstream.
Add a kernel cmdline parameter "tsx" to control the Transactional
Synchronization Extensions (TSX) feature. On CPUs that support TSX
control, use "tsx=on|off" to enable or disable TSX. Not specifying this
option is equivalent to "tsx=off". This is because on certain processors
TSX may be used as a part of a speculative side channel attack.
Carve out the TSX controlling functionality into a separate compilation
unit because TSX is a CPU feature while the TSX async abort control
machinery will go to cpu/bugs.c.
[ bp: - Massage, shorten and clear the arg buffer.
- Clarifications of the tsx= possible options - Josh.
- Expand on TSX_CTRL availability - Pawan. ]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
[bwh: Backported to 4.4:
- Drop __ro_after_init attribute
- Adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index b0e0c7a12e61..7beef3da5904 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -582,6 +582,11 @@ static void init_intel(struct cpuinfo_x86 *c) detect_vmx_virtcap(c); init_intel_energy_perf(c); + + if (tsx_ctrl_state == TSX_CTRL_ENABLE) + tsx_enable(); + if (tsx_ctrl_state == TSX_CTRL_DISABLE) + tsx_disable(); } #ifdef CONFIG_X86_32 |