[RFC 06/12] KVM: arm/arm64: Helper to detect whether an RDIST is the last one

[Eric Auger]

The TYPER of an redistributor needs to reflect whether the rdist is
the last one of the redistributor region. With a single region we compared
the vcpu id against the number of online vcpus. With multiple regions,
we also need to check the region is not full.

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
---
 virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 +--
 virt/kvm/arm/vgic/vgic.h         | 9 +++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 227b8b6..5768034 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -637,8 +637,7 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
 	}
 
 	rdreg->free_pfn_offset += 2;
-	vgic_cpu->rdist_last =
-		(vcpu->vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1);
+	vgic_cpu->rdist_last = vgic_v3_last_rdist(vcpu, rdreg);
 out:
 	mutex_unlock(&kvm->slots_lock);
 	return ret;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 38b2406..04456d3 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -254,6 +254,15 @@ vgic_v3_redist_region_full(struct vgic_redist_region *region)
 	return (region->free_pfn_offset > region->pfns - 2);
 }
 
+static inline bool
+vgic_v3_last_rdist(struct kvm_vcpu *vcpu, struct vgic_redist_region *region)
+{
+	if (vcpu->vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1)
+		return true;
+
+	return vgic_v3_redist_region_full(region);
+}
+
 struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head *rd_regions,
 						   uint32_t *free_pfn_offset);
 
-- 
2.5.5