KVM: arm64: GICv4.1: Let doorbells be auto-enabled

As GICv4.1 understands the life cycle of doorbells (instead of
just randomly firing them at the most inconvenient time), just
enable them at irq_request time, and be done with it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200304203330.4967-18-maz@kernel.org

diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 1eb0f8c762191ccb6ae3ce43a2ada94ad9bc45ce..c2fcde104ea25c2ec806c6effe3299162cbfa6e1 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -141,6 +141,7 @@ int vgic_v4_init(struct kvm *kvm)
 
        kvm_for_each_vcpu(i, vcpu, kvm) {
                int irq = dist->its_vm.vpes[i]->irq;
+               unsigned long irq_flags = DB_IRQ_FLAGS;
 
                /*
                 * Don't automatically enable the doorbell, as we're
@@ -148,8 +149,14 @@ int vgic_v4_init(struct kvm *kvm)
                 * blocked. Also disable the lazy disabling, as the
                 * doorbell could kick us out of the guest too
                 * early...
+                *
+                * On GICv4.1, the doorbell is managed in HW and must
+                * be left enabled.
                 */
-               irq_set_status_flags(irq, DB_IRQ_FLAGS);
+               if (kvm_vgic_global_state.has_gicv4_1)
+                       irq_flags &= ~IRQ_NOAUTOEN;
+               irq_set_status_flags(irq, irq_flags);
+
                ret = request_irq(irq, vgic_v4_doorbell_handler,
                                  0, "vcpu", vcpu);
                if (ret) {