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authorMarc Zyngier <marc.zyngier@arm.com>2016-08-16 15:03:02 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2016-08-17 12:23:47 +0200
commitcabdc5c59ab46a1ec5ea98c5ac4022111fbfd63a (patch)
tree42a9e42c4682c9c98131ad7ef61dfc9081db0664 /virt
parent674e70127069f3fd3c58fb0f94c60eb0f6567d78 (diff)
downloadlinux-stericsson-cabdc5c59ab46a1ec5ea98c5ac4022111fbfd63a.tar.gz
KVM: arm/arm64: timer: Workaround misconfigured timer interrupt
Similarily to f005bd7e3b84 ("clocksource/arm_arch_timer: Force per-CPU interrupt to be level-triggered"), make sure we can survive an interrupt that has been misconfigured as edge-triggered by forcing it to be level-triggered (active low is assumed, but the GIC doesn't really care whether this is high or low). Hopefully, the amount of shouting in the kernel log will convince the user to do something about their firmware. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/arch_timer.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 4fde8c7dfcfe..77e6ccf14901 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -33,6 +33,7 @@
static struct timecounter *timecounter;
static struct workqueue_struct *wqueue;
static unsigned int host_vtimer_irq;
+static u32 host_vtimer_irq_flags;
void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
{
@@ -365,7 +366,7 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
static void kvm_timer_init_interrupt(void *info)
{
- enable_percpu_irq(host_vtimer_irq, 0);
+ enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
}
int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
@@ -432,6 +433,14 @@ int kvm_timer_hyp_init(void)
}
host_vtimer_irq = info->virtual_irq;
+ host_vtimer_irq_flags = irq_get_trigger_type(host_vtimer_irq);
+ if (host_vtimer_irq_flags != IRQF_TRIGGER_HIGH &&
+ host_vtimer_irq_flags != IRQF_TRIGGER_LOW) {
+ kvm_err("Invalid trigger for IRQ%d, assuming level low\n",
+ host_vtimer_irq);
+ host_vtimer_irq_flags = IRQF_TRIGGER_LOW;
+ }
+
err = request_percpu_irq(host_vtimer_irq, kvm_arch_timer_handler,
"kvm guest timer", kvm_get_running_vcpus());
if (err) {