KVM ARM Archive on lore.kernel.org
 help / color / Atom feed
* [PATCH] KVM: arm/arm64: Let the timer expire in hardirq context on RT
@ 2019-11-07  9:54 Sebastian Andrzej Siewior
  0 siblings, 0 replies; only message in thread
From: Sebastian Andrzej Siewior @ 2019-11-07  9:54 UTC (permalink / raw)
  To: kvmarm
  Cc: Marc Zyngier, Sebastian Andrzej Siewior, Julien Grall,
	Thomas Gleixner, linux-arm-kernel

From: Thomas Gleixner <tglx@linutronix.de>

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>
Acked-by: Marc Zyngier <maz@kernel.org>
Tested-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 virt/kvm/arm/arch_timer.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index e2bb5bd602270..f182b23803457 100644
--- 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),
 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;

kvmarm mailing list

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, back to index

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-11-07  9:54 [PATCH] KVM: arm/arm64: Let the timer expire in hardirq context on RT Sebastian Andrzej Siewior

KVM ARM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/kvmarm/0 kvmarm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 kvmarm kvmarm/ https://lore.kernel.org/kvmarm \
	public-inbox-index kvmarm

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git