Later commits will cause objtool to warn about static keys being used in .noinstr sections in order to safely defer instruction patching IPIs targeted at NOHZ_FULL CPUs. These keys are used in .noinstr code, and can be modified at runtime (/proc/kernel/vmx* write). However it is not expected that they will be flipped during latency-sensitive operations, and thus shouldn't be a source of interference wrt the text patching IPI. Mark it to let objtool know not to warn about it. Reported-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: Valentin Schneider <vschneid@xxxxxxxxxx> --- arch/x86/kvm/vmx/vmx.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 893366e537322..a028c38f44e02 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -225,8 +225,15 @@ module_param(pt_mode, int, S_IRUGO); struct x86_pmu_lbr __ro_after_init vmx_lbr_caps; -static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush); -static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_cond); +/* + * Both of these static keys end up being used in .noinstr sections, however + * they are only modified: + * - at init + * - from a /proc/kernel/vmx* write + * thus during latency-sensitive operations they should remain stable. + */ +static DEFINE_STATIC_KEY_FALSE_NOINSTR(vmx_l1d_should_flush); +static DEFINE_STATIC_KEY_FALSE_NOINSTR(vmx_l1d_flush_cond); static DEFINE_MUTEX(vmx_l1d_flush_mutex); /* Storage for pre module init parameter parsing */ -- 2.43.0
