KVM: selftests: Add IRQ GSI routing library functions

Add an architecture independent wrapper function for creating and
writing IRQ GSI routing tables. Also add a function to add irqchip
entries.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
Acked-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211109023906.1091208-15-ricarkol@google.com

tools/testing/selftests/kvm/include/kvm_util.h

@@ -252,6 +252,14 @@ int _vcpu_access_device_attr(struct kvm_vm *vm, uint32_t vcpuid, uint32_t group,
 int vcpu_access_device_attr(struct kvm_vm *vm, uint32_t vcpuid, uint32_t group,
 			 uint64_t attr, void *val, bool write);
 
+#define KVM_MAX_IRQ_ROUTES		4096
+
+struct kvm_irq_routing *kvm_gsi_routing_create(void);
+void kvm_gsi_routing_irqchip_add(struct kvm_irq_routing *routing,
+		uint32_t gsi, uint32_t pin);
+int _kvm_gsi_routing_write(struct kvm_vm *vm, struct kvm_irq_routing *routing);
+void kvm_gsi_routing_write(struct kvm_vm *vm, struct kvm_irq_routing *routing);
+
 const char *exit_reason_str(unsigned int exit_reason);
 
 void virt_pgd_alloc(struct kvm_vm *vm);

tools/testing/selftests/kvm/lib/kvm_util.c

@@ -2107,6 +2107,57 @@ void kvm_irq_line(struct kvm_vm *vm, uint32_t irq, int level)
 	TEST_ASSERT(ret >= 0, "KVM_IRQ_LINE failed, rc: %i errno: %i", ret, errno);
 }
 
+struct kvm_irq_routing *kvm_gsi_routing_create(void)
+{
+	struct kvm_irq_routing *routing;
+	size_t size;
+
+	size = sizeof(struct kvm_irq_routing);
+	/* Allocate space for the max number of entries: this wastes 196 KBs. */
+	size += KVM_MAX_IRQ_ROUTES * sizeof(struct kvm_irq_routing_entry);
+	routing = calloc(1, size);
+	assert(routing);
+
+	return routing;
+}
+
+void kvm_gsi_routing_irqchip_add(struct kvm_irq_routing *routing,
+		uint32_t gsi, uint32_t pin)
+{
+	int i;
+
+	assert(routing);
+	assert(routing->nr < KVM_MAX_IRQ_ROUTES);
+
+	i = routing->nr;
+	routing->entries[i].gsi = gsi;
+	routing->entries[i].type = KVM_IRQ_ROUTING_IRQCHIP;
+	routing->entries[i].flags = 0;
+	routing->entries[i].u.irqchip.irqchip = 0;
+	routing->entries[i].u.irqchip.pin = pin;
+	routing->nr++;
+}
+
+int _kvm_gsi_routing_write(struct kvm_vm *vm, struct kvm_irq_routing *routing)
+{
+	int ret;
+
+	assert(routing);
+	ret = ioctl(vm_get_fd(vm), KVM_SET_GSI_ROUTING, routing);
+	free(routing);
+
+	return ret;
+}
+
+void kvm_gsi_routing_write(struct kvm_vm *vm, struct kvm_irq_routing *routing)
+{
+	int ret;
+
+	ret = _kvm_gsi_routing_write(vm, routing);
+	TEST_ASSERT(ret == 0, "KVM_SET_GSI_ROUTING failed, rc: %i errno: %i",
+				ret, errno);
+}
+
 /*
  * VM Dump
  *