[PATCH 1/2] KVM: x86: Convert WARN_ON(preemptible()) to lockdep assertion

From: Sean Christopherson

Date: Thu Oct 22 2026 - 17:57:06 EST


Use lockdep_assert_preemption_disabled() in the local APIC code instead of
open-coding a rough equivalent that would likely do more harm than good if
it were to ever fire (the non-ONCE WARN_ON() would likely spam the kernel
log and hang the host).

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index ecf611845fb1..61bf09badb5a 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2270,7 +2270,8 @@ bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu)

static void cancel_hv_timer(struct kvm_lapic *apic)
{
- WARN_ON(preemptible());
+ lockdep_assert_preemption_disabled();
+
WARN_ON(!apic->lapic_timer.hv_timer_in_use);
kvm_x86_call(cancel_hv_timer)(apic->vcpu);
apic->lapic_timer.hv_timer_in_use = false;
@@ -2282,7 +2283,8 @@ static bool start_hv_timer(struct kvm_lapic *apic)
struct kvm_vcpu *vcpu = apic->vcpu;
bool expired;

- WARN_ON(preemptible());
+ lockdep_assert_preemption_disabled();
+
if (!kvm_can_use_hv_timer(vcpu))
return false;

@@ -2322,7 +2324,8 @@ static void start_sw_timer(struct kvm_lapic *apic)
{
struct kvm_timer *ktimer = &apic->lapic_timer;

- WARN_ON(preemptible());
+ lockdep_assert_preemption_disabled();
+
if (apic->lapic_timer.hv_timer_in_use)
cancel_hv_timer(apic);
if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
--
2.56.0.257.gf7497c7d27-goog