vfio: Split virqfd into a separate module for vfio bus drivers

An unintended consequence of commit 42ac9bd18d ("vfio: initialize
the virqfd workqueue in VFIO generic code") is that the vfio module
is renamed to vfio_core so that it can include both vfio and virqfd.
That's a user visible change that may break module loading scritps
and it imposes eventfd support as a dependency on the core vfio code,
which it's really not.  virqfd is intended to be provided as a service
to vfio bus drivers, so instead of wrapping it into vfio.ko, we can
make it a stand-alone module toggled by vfio bus drivers.  This has
the additional benefit of removing initialization and exit from the
core vfio code.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Alex Williamson 2015-03-17 08:33:38 -06:00
parent 66fdc052d7
commit 71be3423a6
7 changed files with 25 additions and 14 deletions

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@ -13,6 +13,11 @@ config VFIO_SPAPR_EEH
depends on EEH && VFIO_IOMMU_SPAPR_TCE
default n
config VFIO_VIRQFD
tristate
depends on VFIO && EVENTFD
default n
menuconfig VFIO
tristate "VFIO Non-Privileged userspace driver framework"
depends on IOMMU_API

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@ -1,6 +1,7 @@
vfio_core-y := vfio.o virqfd.o
vfio_virqfd-y := virqfd.o
obj-$(CONFIG_VFIO) += vfio_core.o
obj-$(CONFIG_VFIO) += vfio.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_SPAPR_EEH) += vfio_spapr_eeh.o

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@ -1,6 +1,7 @@
config VFIO_PCI
tristate "VFIO support for PCI devices"
depends on VFIO && PCI && EVENTFD
select VFIO_VIRQFD
help
Support for the PCI VFIO bus driver. This is required to make
use of PCI drivers using the VFIO framework.

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@ -1,6 +1,7 @@
config VFIO_PLATFORM
tristate "VFIO support for platform devices"
depends on VFIO && EVENTFD && ARM
select VFIO_VIRQFD
help
Support for platform devices with VFIO. This is required to make
use of platform devices present on the system using the VFIO

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@ -1552,11 +1552,6 @@ static int __init vfio_init(void)
if (ret)
goto err_cdev_add;
/* Start the virqfd cleanup handler used by some VFIO bus drivers */
ret = vfio_virqfd_init();
if (ret)
goto err_virqfd;
pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
/*
@ -1569,8 +1564,6 @@ static int __init vfio_init(void)
return 0;
err_virqfd:
cdev_del(&vfio.group_cdev);
err_cdev_add:
unregister_chrdev_region(vfio.group_devt, MINORMASK);
err_alloc_chrdev:
@ -1585,7 +1578,6 @@ static void __exit vfio_cleanup(void)
{
WARN_ON(!list_empty(&vfio.group_list));
vfio_virqfd_exit();
idr_destroy(&vfio.group_idr);
cdev_del(&vfio.group_cdev);
unregister_chrdev_region(vfio.group_devt, MINORMASK);

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@ -13,12 +13,17 @@
#include <linux/vfio.h>
#include <linux/eventfd.h>
#include <linux/file.h>
#include <linux/module.h>
#include <linux/slab.h>
#define DRIVER_VERSION "0.1"
#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
#define DRIVER_DESC "IRQFD support for VFIO bus drivers"
static struct workqueue_struct *vfio_irqfd_cleanup_wq;
static DEFINE_SPINLOCK(virqfd_lock);
int __init vfio_virqfd_init(void)
static int __init vfio_virqfd_init(void)
{
vfio_irqfd_cleanup_wq =
create_singlethread_workqueue("vfio-irqfd-cleanup");
@ -28,7 +33,7 @@ int __init vfio_virqfd_init(void)
return 0;
}
void vfio_virqfd_exit(void)
static void __exit vfio_virqfd_exit(void)
{
destroy_workqueue(vfio_irqfd_cleanup_wq);
}
@ -211,3 +216,11 @@ void vfio_virqfd_disable(struct virqfd **pvirqfd)
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);

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@ -142,8 +142,6 @@ struct virqfd {
struct virqfd **pvirqfd;
};
extern int vfio_virqfd_init(void);
extern void vfio_virqfd_exit(void);
extern int vfio_virqfd_enable(void *opaque,
int (*handler)(void *, void *),
void (*thread)(void *, void *),