(arm-land adventures 1/3 take2 will have to wait, my cup runeth over) v4.14..v4.15 timer handling changes including calling kvm_timer_vcpu_load() during kvm_preempt_ops.sched_in and taking vgic_dist.lpi_list_lock in the timer interrupt handler required locks for which locking rules/context had been changed be converted to raw_spinlock_t... Quoting virt/kvm/arm/vgic/vgic.c: * Locking order is always: * kvm->lock (mutex) * its->cmd_lock (mutex) * its->its_lock (mutex) * vgic_cpu->ap_list_lock must be taken with IRQs disabled * kvm->lpi_list_lock must be taken with IRQs disabled * vgic_irq->irq_lock must be taken with IRQs disabled * * As the ap_list_lock might be taken from the timer interrupt handler, * we have to disable IRQs before taking this lock and everything lower * than it. ...and fixed the obvious bricking consequence of those changes for RT, but left an RT specific kvm unit test timer failure in its wake. Handling phys_timer in hard interrupt context as expected cures that failure. Pre: PASS selftest-setup (2 tests) PASS selftest-vectors-kernel (2 tests) PASS selftest-vectors-user (2 tests) PASS selftest-smp (65 tests) PASS pci-test (1 tests) PASS pmu (3 tests) PASS gicv2-ipi (3 tests) PASS gicv3-ipi (3 tests) PASS gicv2-active (1 tests) PASS gicv3-active (1 tests) PASS psci (4 tests) FAIL timer (8 tests, 1 unexpected failures) Post: PASS selftest-setup (2 tests) PASS selftest-vectors-kernel (2 tests) PASS selftest-vectors-user (2 tests) PASS selftest-smp (65 tests) PASS pci-test (1 tests) PASS pmu (3 tests) PASS gicv2-ipi (3 tests) PASS gicv3-ipi (3 tests) PASS gicv2-active (1 tests) PASS gicv3-active (1 tests) PASS psci (4 tests) PASS timer (8 tests) Signed-off-by: Mike Galbraith <efault@xxxxxx> --- virt/kvm/arm/arch_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -634,7 +634,7 @@ void kvm_timer_vcpu_init(struct kvm_vcpu hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); timer->bg_timer.function = kvm_bg_timer_expire; - hrtimer_init(&timer->phys_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + hrtimer_init(&timer->phys_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); timer->phys_timer.function = kvm_phys_timer_expire; vtimer->irq.irq = default_vtimer_irq.irq; -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
