KVM: arm/arm64: Let the timer expire in hardirq context on RT (9090825f) · Commits · 戴 / test

The timers are canceled from an preempt-notifier which is invoked with disabled preemption which is not allowed on PREEMPT_RT. The timer callback is short so in could be invoked in hard-IRQ context on -RT. Let the timer expire on hard-IRQ context even on -RT. Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Signed-off-by:

Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:

Marc Zyngier <maz@kernel.org> Tested-by:

Julien Grall <julien.grall@arm.com> Acked-by:

Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20191107095424.16647-1-bigeasy@linutronix.de

virt/kvm/arm/arch_timer.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -80,7 +80,7 @@ static inline bool userspace_irqchip(struct kvm *kvm)
		static void soft_timer_start(struct hrtimer *hrt, u64 ns)
		{
		hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns),
		HRTIMER_MODE_ABS);
		HRTIMER_MODE_ABS_HARD);
		}

		static void soft_timer_cancel(struct hrtimer *hrt)
		@@ -697,11 +697,11 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
		update_vtimer_cntvoff(vcpu, kvm_phys_timer_read());
		ptimer->cntvoff = 0;

		hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
		hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
		timer->bg_timer.function = kvm_bg_timer_expire;

		hrtimer_init(&vtimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
		hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
		hrtimer_init(&vtimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
		hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
		vtimer->hrtimer.function = kvm_hrtimer_expire;
		ptimer->hrtimer.function = kvm_hrtimer_expire;

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