Hi Andre,
On 03/21/2018 04:32 PM, Andre Przywara wrote:
Tell Xen whether a particular VCPU has an IRQ that needs handling
in the guest. This is used to decide whether a VCPU is runnable or
if a hypercall should be preempted to let the guest handle the IRQ.
This is based on Linux commit 90eee56c5f90, written by Eric Auger.
Signed-off-by: Andre Przywara <andre.przyw...@linaro.org>
---
Changelog v2 ... v3:
- adjust vgic_vcpu_pending_irq() to return integers, not false/true
I would have preferred to have the return switch to bool instead. I
guess this can be done on a follow-up. With one comment below:
Reviewed-by: Julien Grall <julien.gr...@arm.com>
Changelog v1 ... v2:
- adjust to new vgic_vcpu_pending_irq() prototype, drop wrapper
xen/arch/arm/vgic/vgic.c | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/xen/arch/arm/vgic/vgic.c b/xen/arch/arm/vgic/vgic.c
index 2fa595f4f7..925cda4580 100644
--- a/xen/arch/arm/vgic/vgic.c
+++ b/xen/arch/arm/vgic/vgic.c
@@ -647,6 +647,43 @@ void vgic_sync_to_lrs(void)
gic_hw_ops->update_hcr_status(GICH_HCR_EN, 1);
}
+/**
+ * vgic_vcpu_pending_irq() - determine if interrupts need to be injected
+ * @vcpu: The vCPU on which to check for interrupts.
+ *
+ * Checks whether there is an interrupt on the given VCPU which needs
+ * handling in the guest. This requires at least one IRQ to be pending
+ * and enabled.
+ *
+ * Returns: 1 if the guest should run to handle interrupts, 0 otherwise.
NIT: Because of "ret = irq_is_pending(irq) && irq->enabled", you will
return a non-zero value if the guest should run to handle interrupts.
+ */
+int vgic_vcpu_pending_irq(struct vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic;
+ struct vgic_irq *irq;
+ unsigned long flags;
+ int ret = 0;
+
+ if ( !vcpu->domain->arch.vgic.enabled )
+ return 0;
+
+ spin_lock_irqsave(&vgic_cpu->ap_list_lock, flags);
+
+ list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list)
+ {
+ spin_lock(&irq->irq_lock);
+ ret = irq_is_pending(irq) && irq->enabled;
+ spin_unlock(&irq->irq_lock);
+
+ if ( ret )
+ break;
+ }
+
+ spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags);
+
+ return ret;
+}
+
/*
* Local variables:
* mode: C
Cheers,
--
Julien Grall
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
