diff options
author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2019-10-23 12:28:57 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-16 10:27:51 +0100 |
commit | f6eabafe0fa2a007219af36340414f961bedde9d (patch) | |
tree | 3a3a7521d2d9d72823b2fdfba35904b901f1a151 | |
parent | 5b3b71385e07830aab9ee1c6f03bf140736e1fdc (diff) |
x86/tsx: Add "auto" option to the tsx= cmdline parameter
commit 7531a3596e3272d1f6841e0d601a614555dc6b65 upstream.
Platforms which are not affected by X86_BUG_TAA may want the TSX feature
enabled. Add "auto" option to the TSX cmdline parameter. When tsx=auto
disable TSX when X86_BUG_TAA is present, otherwise enable TSX.
More details on X86_BUG_TAA can be found here:
https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html
[ bp: Extend the arg buffer to accommodate "auto\0". ]
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: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
[bwh: Backported to 4.4: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | Documentation/kernel-parameters.txt | 3 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/tsx.c | 7 |
2 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 58421b7f62b0..49dd31f30022 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -4073,6 +4073,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. update. This new MSR allows for the reliable deactivation of the TSX functionality.) + auto - Disable TSX if X86_BUG_TAA is present, + otherwise enable TSX on the system. + Not specifying this option is equivalent to tsx=off. See Documentation/hw-vuln/tsx_async_abort.rst diff --git a/arch/x86/kernel/cpu/tsx.c b/arch/x86/kernel/cpu/tsx.c index 0f8a60f43206..d73bc1ae932b 100644 --- a/arch/x86/kernel/cpu/tsx.c +++ b/arch/x86/kernel/cpu/tsx.c @@ -75,7 +75,7 @@ static bool __init tsx_ctrl_is_supported(void) void __init tsx_init(void) { - char arg[4] = {}; + char arg[5] = {}; int ret; if (!tsx_ctrl_is_supported()) @@ -87,6 +87,11 @@ void __init tsx_init(void) tsx_ctrl_state = TSX_CTRL_ENABLE; } else if (!strcmp(arg, "off")) { tsx_ctrl_state = TSX_CTRL_DISABLE; + } else if (!strcmp(arg, "auto")) { + if (boot_cpu_has_bug(X86_BUG_TAA)) + tsx_ctrl_state = TSX_CTRL_DISABLE; + else + tsx_ctrl_state = TSX_CTRL_ENABLE; } else { tsx_ctrl_state = TSX_CTRL_DISABLE; pr_err("tsx: invalid option, defaulting to off\n"); |