Commit 3c443ec7 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Alex Williamson
Browse files

vfio: remove dead notifier code 



group->notifier is dead code. VFIO initializes it and checks it for
emptiness on teardown, but nobody ever registers on it or triggers it.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Acked-by: default avatarAnthony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20260407175934.1602711-1-pbonzini@redhat.com


Signed-off-by: default avatarAlex Williamson <alex@shazbot.org>
parent 7487d8db

Documentation/arch/s390/vfio-ap.rst

+8 −12
Original line number Diff line number Diff line
@@ -431,17 +431,14 @@ matrix device. 
* callback interfaces



  open_device:

    The vfio_ap driver uses this callback to register a

    VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the matrix mdev

    devices. The open_device callback is invoked by userspace to connect the

    VFIO iommu group for the matrix mdev device to the MDEV bus. Access to the

    KVM structure used to configure the KVM guest is provided via this callback.

    The KVM structure, is used to configure the guest's access to the AP matrix

    defined via the vfio_ap mediated device's sysfs attribute files.

    the open_device callback is invoked by userspace to connect the

    VFIO iommu group for the matrix mdev device to the MDEV bus.  The

    callback retrieves the KVM structure used to configure the KVM guest

    and configures the guest's access to the AP matrix defined via the

    vfio_ap mediated device's sysfs attribute files.



  close_device:

    unregisters the VFIO_GROUP_NOTIFY_SET_KVM notifier callback function for the

    matrix mdev device and deconfigures the guest's AP matrix.

    this callback deconfigures the guest's AP matrix.



  ioctl:

    this callback handles the VFIO_DEVICE_GET_INFO and VFIO_DEVICE_RESET ioctls
@@ -449,9 +446,8 @@ matrix device. 


Configure the guest's AP resources

----------------------------------

Configuring the AP resources for a KVM guest will be performed when the

VFIO_GROUP_NOTIFY_SET_KVM notifier callback is invoked. The notifier

function is called when userspace connects to KVM. The guest's AP resources are

Configuring the AP resources for a KVM guest will be performed at the

time of ``open_device`` and ``close_device``. The guest's AP resources are

configured via its APCB by:



* Setting the bits in the APM corresponding to the APIDs assigned to the

drivers/vfio/group.c

+0 −3
Original line number Diff line number Diff line
@@ -461,7 +461,6 @@ static int vfio_group_fops_release(struct inode *inode, struct file *filep) 
	 * Device FDs hold a group file reference, therefore the group release

	 * is only called when there are no open devices.

	 */

	WARN_ON(group->notifier.head);

	if (group->container)

		vfio_group_detach_container(group);

	if (group->iommufd) {
@@ -546,7 +545,6 @@ static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, 
	/* put in vfio_group_release() */

	iommu_group_ref_get(iommu_group);

	group->type = type;

	BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);



	return group;

}
@@ -725,7 +723,6 @@ void vfio_device_remove_group(struct vfio_device *device) 
	 * properly hold the group reference.

	 */

	WARN_ON(!list_empty(&group->device_list));

	WARN_ON(group->notifier.head);



	/*

	 * Revoke all users of group->iommu_group. At this point we know there

drivers/vfio/vfio.h

+0 −1
Original line number Diff line number Diff line
@@ -90,7 +90,6 @@ struct vfio_group { 
	struct mutex			group_lock;

	struct kvm			*kvm;

	struct file			*opened_file;

	struct blocking_notifier_head	notifier;

	struct iommufd_ctx		*iommufd;

	spinlock_t			kvm_ref_lock;

	unsigned int			cdev_device_open_cnt;

drivers/vfio/vfio_iommu_type1.c

+0 −1
Original line number Diff line number Diff line
@@ -36,7 +36,6 @@ 
#include <linux/uaccess.h>

#include <linux/vfio.h>

#include <linux/workqueue.h>

#include <linux/notifier.h>

#include <linux/mm_inline.h>

#include <linux/overflow.h>

#include "vfio.h"