vfio: Fold vfio_virqfd.ko into vfio.ko

This is only 1.8k, putting it in its own module is not really
necessary. The kconfig infrastructure is still there to completely remove
it for systems that are trying for small footprint.

Put it in the main vfio.ko module now that kbuild can support multiple .c
files.

Signed-off-by: Jason Gunthorpe <[e-mail]>
Reviewed-by: Cornelia Huck <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alex Williamson <[e-mail]>

drivers/vfio/Kconfig

···
 	default VFIO
 
 config VFIO_VIRQFD
-	tristate
+	bool
 	select EVENTFD
 	default n
 

drivers/vfio/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
-vfio_virqfd-y := virqfd.o
-
 obj-$(CONFIG_VFIO) += vfio.o
 
 vfio-y += vfio_main.o \
 	  iova_bitmap.o \
 	  container.o
+vfio-$(CONFIG_VFIO_VIRQFD) += virqfd.o
 
-obj-$(CONFIG_VFIO_VIRQFD) += vfio_virqfd.o
 obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o
 obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o
 obj-$(CONFIG_VFIO_PCI) += pci/

drivers/vfio/vfio.h

···
 int __init vfio_container_init(void);
 void vfio_container_cleanup(void);
 
+#if IS_ENABLED(CONFIG_VFIO_VIRQFD)
+int __init vfio_virqfd_init(void);
+void vfio_virqfd_exit(void);
+#else
+static inline int __init vfio_virqfd_init(void)
+{
+	return 0;
+}
+static inline void vfio_virqfd_exit(void)
+{
+}
+#endif
+
 #ifdef CONFIG_VFIO_NOIOMMU
 extern bool vfio_noiommu __read_mostly;
 #else

drivers/vfio/vfio_main.c

···
 	if (ret)
 		return ret;
 
+	ret = vfio_virqfd_init();
+	if (ret)
+		goto err_virqfd;
+
 	/* /dev/vfio/$GROUP */
 	vfio.class = class_create(THIS_MODULE, "vfio");
 	if (IS_ERR(vfio.class)) {
···
 	class_destroy(vfio.class);
 	vfio.class = NULL;
 err_group_class:
+	vfio_virqfd_exit();
+err_virqfd:
 	vfio_container_cleanup();
 	return ret;
 }
···
 	class_destroy(vfio.device_class);
 	vfio.device_class = NULL;
 	class_destroy(vfio.class);
+	vfio_virqfd_exit();
 	vfio_container_cleanup();
 	vfio.class = NULL;
 	xa_destroy(&vfio_device_set_xa);

drivers/vfio/virqfd.c

···
 #include <linux/file.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-
-#define DRIVER_VERSION  "0.1"
-#define DRIVER_AUTHOR   "Alex Williamson <[e-mail]>"
-#define DRIVER_DESC     "IRQFD support for VFIO bus drivers"
+#include "vfio.h"
 
 static struct workqueue_struct *vfio_irqfd_cleanup_wq;
 static DEFINE_SPINLOCK(virqfd_lock);
 
-static int __init vfio_virqfd_init(void)
+int __init vfio_virqfd_init(void)
 {
 	vfio_irqfd_cleanup_wq =
 		create_singlethread_workqueue("vfio-irqfd-cleanup");
···
 	return 0;
 }
 
-static void __exit vfio_virqfd_exit(void)
+void vfio_virqfd_exit(void)
 {
 	destroy_workqueue(vfio_irqfd_cleanup_wq);
 }
···
 	flush_workqueue(vfio_irqfd_cleanup_wq);
 }
 EXPORT_SYMBOL_GPL(vfio_virqfd_disable);
-
-module_init(vfio_virqfd_init);
-module_exit(vfio_virqfd_exit);
-
-MODULE_VERSION(DRIVER_VERSION);
-MODULE_LICENSE("GPL v2");
-MODULE_AUTHOR(DRIVER_AUTHOR);
-MODULE_DESCRIPTION(DRIVER_DESC);