[MODERATED] [PATCH v6 7/9] TAAv6 7
Pawan Gupta <[email protected]>
| Newsgroups | org.kernel.lore.historical-speck |
|---|---|
| Message-ID | <0103f2d9adfd78341de3cf2cd261bbeb50b607f1.157065 [email protected]> |
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 Signed-off-by: Pawan Gupta <[email protected]> Reviewed-by: Tony Luck <[email protected]> Tested-by: Neelima Krishnan <[email protected]> --- Documentation/admin-guide/kernel-parameters.txt | 5 +++++ arch/x86/kernel/cpu/tsx.c | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 832537d59562..d7b48c38c6e5 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4821,6 +4821,11 @@ on - Enable TSX on the system. off - Disable TSX on the system. + auto - Disable TSX if X86_BUG_TAA is present, + otherwise enable TSX on the system. + + More details on X86_BUG_TAA are here: + Documentation/admin-guide/hw-vuln/tsx_async_abort.rst Not specifying this option is equivalent to tsx=off. diff --git a/arch/x86/kernel/cpu/tsx.c b/arch/x86/kernel/cpu/tsx.c index e39b33b7cef8..e93abe6f0bb9 100644 --- a/arch/x86/kernel/cpu/tsx.c +++ b/arch/x86/kernel/cpu/tsx.c @@ -80,6 +80,11 @@ 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_info("tsx: invalid option, defaulting to off\n"); -- 2.20.1