KVM: arm/arm64: vgic: Move redistributor kvm_io_devices

Logically a GICv3 redistributor is assigned to a (v)CPU, so we should
aim to keep redistributor related variables out of our struct vgic_dist.

Let's start by replacing the redistributor related kvm_io_device array
with two members in our existing struct vgic_cpu, which are naturally
per-VCPU and thus don't require any allocation / freeing.
So apart from the better fit with the redistributor design this saves
some code as well.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

include/kvm/arm_vgic.h

@@ -145,7 +145,6 @@ struct vgic_dist {
 	struct vgic_irq		*spis;
 
 	struct vgic_io_device	dist_iodev;
-	struct vgic_io_device	*redist_iodevs;
 };
 
 struct vgic_v2_cpu_if {
@@ -193,6 +192,13 @@ struct vgic_cpu {
 	struct list_head ap_list_head;
 
 	u64 live_lrs;
+
+	/*
+	 * Members below are used with GICv3 emulation only and represent
+	 * parts of the redistributor.
+	 */
+	struct vgic_io_device	rd_iodev;
+	struct vgic_io_device	sgi_iodev;
 };
 
 int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);

virt/kvm/arm/vgic/vgic-init.c

@@ -271,7 +271,6 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
 	dist->initialized = false;
 
 	kfree(dist->spis);
-	kfree(dist->redist_iodevs);
 	dist->nr_spis = 0;
 
 	mutex_unlock(&kvm->lock);

virt/kvm/arm/vgic/vgic-mmio-v3.c

@@ -285,21 +285,14 @@ unsigned int vgic_v3_init_dist_iodev(struct vgic_io_device *dev)
 
 int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t redist_base_address)
 {
-	int nr_vcpus = atomic_read(&kvm->online_vcpus);
 	struct kvm_vcpu *vcpu;
-	struct vgic_io_device *devices;
 	int c, ret = 0;
 
-	devices = kmalloc(sizeof(struct vgic_io_device) * nr_vcpus * 2,
-			  GFP_KERNEL);
-	if (!devices)
-		return -ENOMEM;
-
 	kvm_for_each_vcpu(c, vcpu, kvm) {
 		gpa_t rd_base = redist_base_address + c * SZ_64K * 2;
 		gpa_t sgi_base = rd_base + SZ_64K;
-		struct vgic_io_device *rd_dev = &devices[c * 2];
-		struct vgic_io_device *sgi_dev = &devices[c * 2 + 1];
+		struct vgic_io_device *rd_dev = &vcpu->arch.vgic_cpu.rd_iodev;
+		struct vgic_io_device *sgi_dev = &vcpu->arch.vgic_cpu.sgi_iodev;
 
 		kvm_iodevice_init(&rd_dev->dev, &kvm_io_gic_ops);
 		rd_dev->base_addr = rd_base;
@@ -335,14 +328,15 @@ int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t redist_base_address)
 	if (ret) {
 		/* The current c failed, so we start with the previous one. */
 		for (c--; c >= 0; c--) {
+			struct vgic_cpu *vgic_cpu;
+
+			vcpu = kvm_get_vcpu(kvm, c);
+			vgic_cpu = &vcpu->arch.vgic_cpu;
 			kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
-						  &devices[c * 2].dev);
+						  &vgic_cpu->rd_iodev.dev);
 			kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
-						  &devices[c * 2 + 1].dev);
+						  &vgic_cpu->sgi_iodev.dev);
 		}
-		kfree(devices);
-	} else {
-		kvm->arch.vgic.redist_iodevs = devices;
 	}
 
 	return ret;