x86/tsx: Add "auto" option to the tsx= cmdline parameter (7531a359) · Commits · 戴 / test

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>

Documentation/admin-guide/kernel-parameters.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -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

arch/x86/kernel/cpu/tsx.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -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");

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