KVM: arm/arm64: Let the timer expire in hardirq context on RT

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

diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index e2bb5bd602270cace47548f9efe56c9f2331e48d..f182b2380345712d320e299f28b4306c9f5456ff 100644 (file)
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -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;