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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2019-10-23 12:28:57 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-10-28 08:37:00 +0100 |
| commit | 7531a3596e3272d1f6841e0d601a614555dc6b65 (patch) | |
| tree | b58244f08cec9c20ff369094032e2ceea595e335 | |
| parent | e1d38b63acd843cfdd4222bf19a26700fd5c699e (diff) | |
| download | lwn-7531a3596e3272d1f6841e0d601a614555dc6b65.tar.gz lwn-7531a3596e3272d1f6841e0d601a614555dc6b65.zip | |
x86/tsx: Add "auto" option to the tsx= cmdline parameter
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>
| -rw-r--r-- | Documentation/admin-guide/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/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index af4b1d95b08f..6e548cddb6c3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4869,6 +4869,9 @@ 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/admin-guide/hw-vuln/tsx_async_abort.rst diff --git a/arch/x86/kernel/cpu/tsx.c b/arch/x86/kernel/cpu/tsx.c index 04471c4378d8..dda328ec2ba1 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"); |