From a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656 Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Wed, 5 Aug 2026 07:52:36 -0700 Subject: workqueue: skip the node_nr_active update for non-unbound workqueues apply_wqattrs_commit() updates node_nr_active->max unconditionally. wq->node_nr_active[] is only allocated for unbound workqueues, so guard the call before per-cpu workqueues start using this path. No functional change: only unbound workqueues reach apply_wqattrs_*() today. Signed-off-by: Breno Leitao Signed-off-by: Tejun Heo --- arch/x86/entry/common.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 arch/x86/entry/common.c (limited to 'arch/x86/entry/common.c') diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c new file mode 100644 index 000000000..14cd43d4d --- /dev/null +++ b/arch/x86/entry/common.c @@ -0,0 +1,61 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include +#include +#include +#include +#include + +#if IS_ENABLED(CONFIG_KVM_INTEL) +/* + * On VMX, NMIs and IRQs (as configured by KVM) are acknowledged by hardware as + * part of the VM-Exit, i.e. the event itself is consumed as part the VM-Exit. + * x86_entry_from_kvm() is invoked by KVM to effectively forward NMIs and IRQs + * to the kernel for servicing. On SVM, a.k.a. AMD, the NMI/IRQ VM-Exit is + * purely a signal that an NMI/IRQ is pending, i.e. the event that triggered + * the VM-Exit is held pending until it's unblocked in the host. + */ +noinstr void x86_entry_from_kvm(unsigned int event_type, unsigned int vector) +{ + if (event_type == EVENT_TYPE_EXTINT) { +#ifdef CONFIG_X86_64 + /* + * Use FRED dispatch, even when running IDT. The dispatch + * tables are kept in sync between FRED and IDT, and the FRED + * dispatch works well with CFI. + */ + fred_entry_from_kvm(event_type, vector); +#else + idt_entry_from_kvm(vector); +#endif + /* + * Strictly speaking, only the NMI path requires noinstr. + */ + instrumentation_begin(); + /* + * KVM/VMX will dispatch from IRQ-disabled but for a context + * that will have IRQs-enabled. This confuses the entry code + * and it will not have reprogrammed the timer. Do so now. + */ + hrtimer_rearm_deferred(); + instrumentation_end(); + + return; + } + + WARN_ON_ONCE(event_type != EVENT_TYPE_NMI); + +#ifdef CONFIG_X86_64 + if (cpu_feature_enabled(X86_FEATURE_FRED)) + return fred_entry_from_kvm(event_type, vector); +#endif + + /* + * Notably, we must use IDT dispatch for NMI when running in IDT mode. + * The FRED NMI context is significantly different and will not work + * right (specifically FRED fixed the NMI recursion issue). + */ + idt_do_nmi_irqoff(); +} +EXPORT_SYMBOL_FOR_KVM(x86_entry_from_kvm); +#endif -- cgit v1.3.1