[PATCH v2 02/11] KVM: arm64: vgic-its: Treat the collection target address as a vcpu_id

[Marc Zyngier <maz@kernel.org>]

Since our emulated ITS advertises GITS_TYPER.PTA=0, the target
address associated to a collection is a PE number and not
an address. So far, so good. However, the PE number is what userspace
has provided given us (aka the vcpu_id), and not the internal vcpu
index.

Make sure we consistently retrieve the vcpu by ID rather than
by index, adding a helper that deals with most of the cases.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-its.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 5fe2365a629f..4aadcd24f6f6 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -378,6 +378,12 @@ static int update_affinity(struct vgic_irq *irq, struct kvm_vcpu *vcpu)
 	return ret;
 }
 
+static struct kvm_vcpu *collection_to_vcpu(struct kvm *kvm,
+					   struct its_collection *col)
+{
+	return kvm_get_vcpu_by_id(kvm, col->target_addr);
+}
+
 /*
  * Promotes the ITS view of affinity of an ITTE (which redistributor this LPI
  * is targeting) to the VGIC's view, which deals with target VCPUs.
@@ -391,7 +397,7 @@ static void update_affinity_ite(struct kvm *kvm, struct its_ite *ite)
 	if (!its_is_collection_mapped(ite->collection))
 		return;
 
-	vcpu = kvm_get_vcpu(kvm, ite->collection->target_addr);
+	vcpu = collection_to_vcpu(kvm, ite->collection);
 	update_affinity(ite->irq, vcpu);
 }
 
@@ -679,7 +685,7 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 	if (!ite || !its_is_collection_mapped(ite->collection))
 		return E_ITS_INT_UNMAPPED_INTERRUPT;
 
-	vcpu = kvm_get_vcpu(kvm, ite->collection->target_addr);
+	vcpu = collection_to_vcpu(kvm, ite->collection);
 	if (!vcpu)
 		return E_ITS_INT_UNMAPPED_INTERRUPT;
 
@@ -887,7 +893,7 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
 		return E_ITS_MOVI_UNMAPPED_COLLECTION;
 
 	ite->collection = collection;
-	vcpu = kvm_get_vcpu(kvm, collection->target_addr);
+	vcpu = collection_to_vcpu(kvm, collection);
 
 	vgic_its_invalidate_cache(kvm);
 
@@ -1121,7 +1127,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
 	}
 
 	if (its_is_collection_mapped(collection))
-		vcpu = kvm_get_vcpu(kvm, collection->target_addr);
+		vcpu = collection_to_vcpu(kvm, collection);
 
 	irq = vgic_add_lpi(kvm, lpi_nr, vcpu);
 	if (IS_ERR(irq)) {
@@ -1382,7 +1388,7 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
 	if (!its_is_collection_mapped(collection))
 		return E_ITS_INVALL_UNMAPPED_COLLECTION;
 
-	vcpu = kvm_get_vcpu(kvm, collection->target_addr);
+	vcpu = collection_to_vcpu(kvm, collection);
 	vgic_its_invall(vcpu);
 
 	return 0;
@@ -1413,8 +1419,9 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
 	if (target1_addr == target2_addr)
 		return 0;
 
-	vcpu1 = kvm_get_vcpu(kvm, target1_addr);
-	vcpu2 = kvm_get_vcpu(kvm, target2_addr);
+	/* We advertise GITS_TYPER.PTA==0, making the address the vcpu ID */
+	vcpu1 = kvm_get_vcpu_by_id(kvm, target1_addr);
+	vcpu2 = kvm_get_vcpu_by_id(kvm, target2_addr);
 
 	irq_count = vgic_copy_lpi_list(kvm, vcpu1, &intids);
 	if (irq_count < 0)
-- 
2.34.1