Commit 4ce98bf0 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Wake-up from WFI when iqrchip is in userspace 

It appears that there is nothing in the wake-up path that
evaluates whether the in-kernel interrupts are pending unless
we have a vgic.

This means that the userspace irqchip support has been broken for
about four years, and nobody noticed. It was also broken before
as we wouldn't wake-up on a PMU interrupt, but hey, who cares...

It is probably time to remove the feature altogether, because it
was a terrible idea 10 years ago, and it still is.

Fixes: b57de4ff ("KVM: arm64: Simplify kvm_cpu_has_pending_timer()")
Link: https://patch.msgid.link/20260423163607.486345-1-maz@kernel.org


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
parent 5bb0aed5

arch/arm64/kvm/arm.c

+4 −0
Original line number Diff line number Diff line
@@ -824,6 +824,10 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) 
{

	bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF | HCR_VSE);



	irq_lines |= (!irqchip_in_kernel(v->kvm) &&

		      (kvm_timer_should_notify_user(v) ||

		       kvm_pmu_should_notify_user(v)));



	return ((irq_lines || kvm_vgic_vcpu_pending_irq(v))

		&& !kvm_arm_vcpu_stopped(v) && !v->arch.pause);

}