Commit 8c6f5e73 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio 

Pull VFIO updates from Alex Williamson:

 - Include Intel XXV710 in INTx workaround (Alex Williamson)

 - Make use of ERR_CAST() for error return (Dan Carpenter)

 - Fix vfio_group release deadlock from iommu notifier (Alex Williamson)

 - Unset KVM-VFIO attributes only on group match (Alex Williamson)

 - Fix release path group/file matching with KVM-VFIO (Alex Williamson)

 - Remove unnecessary lock uses triggering lockdep splat (Alex Williamson)

* tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio:
  vfio: Remove unnecessary uses of vfio_container.group_lock
  vfio: New external user group/file match
  kvm-vfio: Decouple only when we match a group
  vfio: Fix group release deadlock
  vfio: Use ERR_CAST() instead of open coding it
  vfio/pci: Add Intel XXV710 to hidden INTx devices
parents 3a00be19 7f56c30b

drivers/vfio/pci/vfio_pci.c

+2 −2
Original line number Diff line number Diff line
@@ -195,11 +195,11 @@ static bool vfio_pci_nointx(struct pci_dev *pdev) 
	switch (pdev->vendor) {

	case PCI_VENDOR_ID_INTEL:

		switch (pdev->device) {

		/* All i40e (XL710/X710) 10/20/40GbE NICs */

		/* All i40e (XL710/X710/XXV710) 10/20/25/40GbE NICs */

		case 0x1572:

		case 0x1574:

		case 0x1580 ... 0x1581:

		case 0x1583 ... 0x1589:

		case 0x1583 ... 0x158b:

		case 0x37d0 ... 0x37d2:

			return true;

		default:

drivers/vfio/vfio.c

+46 −40
Original line number Diff line number Diff line
@@ -382,7 +382,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) 
	if (IS_ERR(dev)) {

		vfio_free_group_minor(minor);

		vfio_group_unlock_and_free(group);

		return (struct vfio_group *)dev; /* ERR_PTR */

		return ERR_CAST(dev);

	}



	group->minor = minor;
@@ -423,6 +423,34 @@ static void vfio_group_put(struct vfio_group *group) 
	kref_put_mutex(&group->kref, vfio_group_release, &vfio.group_lock);

}



struct vfio_group_put_work {

	struct work_struct work;

	struct vfio_group *group;

};



static void vfio_group_put_bg(struct work_struct *work)

{

	struct vfio_group_put_work *do_work;



	do_work = container_of(work, struct vfio_group_put_work, work);



	vfio_group_put(do_work->group);

	kfree(do_work);

}



static void vfio_group_schedule_put(struct vfio_group *group)

{

	struct vfio_group_put_work *do_work;



	do_work = kmalloc(sizeof(*do_work), GFP_KERNEL);

	if (WARN_ON(!do_work))

		return;



	INIT_WORK(&do_work->work, vfio_group_put_bg);

	do_work->group = group;

	schedule_work(&do_work->work);

}



/* Assume group_lock or group reference is held */

static void vfio_group_get(struct vfio_group *group)

{
@@ -762,7 +790,14 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb, 
		break;

	}



	vfio_group_put(group);

	/*

	 * If we're the last reference to the group, the group will be

	 * released, which includes unregistering the iommu group notifier.

	 * We hold a read-lock on that notifier list, unregistering needs

	 * a write-lock... deadlock.  Release our reference asynchronously

	 * to avoid that situation.

	 */

	vfio_group_schedule_put(group);

	return NOTIFY_OK;

}
@@ -1140,15 +1175,11 @@ static long vfio_fops_unl_ioctl(struct file *filep, 
		ret = vfio_ioctl_set_iommu(container, arg);

		break;

	default:

		down_read(&container->group_lock);



		driver = container->iommu_driver;

		data = container->iommu_data;



		if (driver) /* passthrough all unrecognized ioctls */

			ret = driver->ops->ioctl(data, cmd, arg);



		up_read(&container->group_lock);

	}



	return ret;
@@ -1202,15 +1233,11 @@ static ssize_t vfio_fops_read(struct file *filep, char __user *buf, 
	struct vfio_iommu_driver *driver;

	ssize_t ret = -EINVAL;



	down_read(&container->group_lock);



	driver = container->iommu_driver;

	if (likely(driver && driver->ops->read))

		ret = driver->ops->read(container->iommu_data,

					buf, count, ppos);



	up_read(&container->group_lock);



	return ret;

}
@@ -1221,15 +1248,11 @@ static ssize_t vfio_fops_write(struct file *filep, const char __user *buf, 
	struct vfio_iommu_driver *driver;

	ssize_t ret = -EINVAL;



	down_read(&container->group_lock);



	driver = container->iommu_driver;

	if (likely(driver && driver->ops->write))

		ret = driver->ops->write(container->iommu_data,

					 buf, count, ppos);



	up_read(&container->group_lock);



	return ret;

}
@@ -1239,14 +1262,10 @@ static int vfio_fops_mmap(struct file *filep, struct vm_area_struct *vma) 
	struct vfio_iommu_driver *driver;

	int ret = -EINVAL;



	down_read(&container->group_lock);



	driver = container->iommu_driver;

	if (likely(driver && driver->ops->mmap))

		ret = driver->ops->mmap(container->iommu_data, vma);



	up_read(&container->group_lock);



	return ret;

}
@@ -1741,6 +1760,15 @@ void vfio_group_put_external_user(struct vfio_group *group) 
}

EXPORT_SYMBOL_GPL(vfio_group_put_external_user);



bool vfio_external_group_match_file(struct vfio_group *test_group,

				    struct file *filep)

{

	struct vfio_group *group = filep->private_data;



	return (filep->f_op == &vfio_group_fops) && (group == test_group);

}

EXPORT_SYMBOL_GPL(vfio_external_group_match_file);



int vfio_external_user_iommu_id(struct vfio_group *group)

{

	return iommu_group_id(group->iommu_group);
@@ -1949,8 +1977,6 @@ int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage, 
		goto err_pin_pages;



	container = group->container;

	down_read(&container->group_lock);



	driver = container->iommu_driver;

	if (likely(driver && driver->ops->pin_pages))

		ret = driver->ops->pin_pages(container->iommu_data, user_pfn,
@@ -1958,7 +1984,6 @@ int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage, 
	else

		ret = -ENOTTY;



	up_read(&container->group_lock);

	vfio_group_try_dissolve_container(group);



err_pin_pages:
@@ -1998,8 +2023,6 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage) 
		goto err_unpin_pages;



	container = group->container;

	down_read(&container->group_lock);



	driver = container->iommu_driver;

	if (likely(driver && driver->ops->unpin_pages))

		ret = driver->ops->unpin_pages(container->iommu_data, user_pfn,
@@ -2007,7 +2030,6 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage) 
	else

		ret = -ENOTTY;



	up_read(&container->group_lock);

	vfio_group_try_dissolve_container(group);



err_unpin_pages:
@@ -2029,8 +2051,6 @@ static int vfio_register_iommu_notifier(struct vfio_group *group, 
		return -EINVAL;



	container = group->container;

	down_read(&container->group_lock);



	driver = container->iommu_driver;

	if (likely(driver && driver->ops->register_notifier))

		ret = driver->ops->register_notifier(container->iommu_data,
@@ -2038,7 +2058,6 @@ static int vfio_register_iommu_notifier(struct vfio_group *group, 
	else

		ret = -ENOTTY;



	up_read(&container->group_lock);

	vfio_group_try_dissolve_container(group);



	return ret;
@@ -2056,8 +2075,6 @@ static int vfio_unregister_iommu_notifier(struct vfio_group *group, 
		return -EINVAL;



	container = group->container;

	down_read(&container->group_lock);



	driver = container->iommu_driver;

	if (likely(driver && driver->ops->unregister_notifier))

		ret = driver->ops->unregister_notifier(container->iommu_data,
@@ -2065,7 +2082,6 @@ static int vfio_unregister_iommu_notifier(struct vfio_group *group, 
	else

		ret = -ENOTTY;



	up_read(&container->group_lock);

	vfio_group_try_dissolve_container(group);



	return ret;
@@ -2083,7 +2099,6 @@ static int vfio_register_group_notifier(struct vfio_group *group, 
					unsigned long *events,

					struct notifier_block *nb)

{

	struct vfio_container *container;

	int ret;

	bool set_kvm = false;
@@ -2101,9 +2116,6 @@ static int vfio_register_group_notifier(struct vfio_group *group, 
	if (ret)

		return -EINVAL;



	container = group->container;

	down_read(&container->group_lock);



	ret = blocking_notifier_chain_register(&group->notifier, nb);



	/*
@@ -2114,7 +2126,6 @@ static int vfio_register_group_notifier(struct vfio_group *group, 
		blocking_notifier_call_chain(&group->notifier,

					VFIO_GROUP_NOTIFY_SET_KVM, group->kvm);



	up_read(&container->group_lock);

	vfio_group_try_dissolve_container(group);



	return ret;
@@ -2123,19 +2134,14 @@ static int vfio_register_group_notifier(struct vfio_group *group, 
static int vfio_unregister_group_notifier(struct vfio_group *group,

					 struct notifier_block *nb)

{

	struct vfio_container *container;

	int ret;



	ret = vfio_group_add_container_user(group);

	if (ret)

		return -EINVAL;



	container = group->container;

	down_read(&container->group_lock);



	ret = blocking_notifier_chain_unregister(&group->notifier, nb);



	up_read(&container->group_lock);

	vfio_group_try_dissolve_container(group);



	return ret;

include/linux/vfio.h

+2 −0
Original line number Diff line number Diff line
@@ -97,6 +97,8 @@ extern void vfio_unregister_iommu_driver( 
 */

extern struct vfio_group *vfio_group_get_external_user(struct file *filep);

extern void vfio_group_put_external_user(struct vfio_group *group);

extern bool vfio_external_group_match_file(struct vfio_group *group,

					   struct file *filep);

extern int vfio_external_user_iommu_id(struct vfio_group *group);

extern long vfio_external_check_extension(struct vfio_group *group,

					  unsigned long arg);

virt/kvm/vfio.c

+25 −15
Original line number Diff line number Diff line
@@ -51,6 +51,22 @@ static struct vfio_group *kvm_vfio_group_get_external_user(struct file *filep) 
	return vfio_group;

}



static bool kvm_vfio_external_group_match_file(struct vfio_group *group,

					       struct file *filep)

{

	bool ret, (*fn)(struct vfio_group *, struct file *);



	fn = symbol_get(vfio_external_group_match_file);

	if (!fn)

		return false;



	ret = fn(group, filep);



	symbol_put(vfio_external_group_match_file);



	return ret;

}



static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group)

{

	void (*fn)(struct vfio_group *);
@@ -231,37 +247,31 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) 
		if (!f.file)

			return -EBADF;



		vfio_group = kvm_vfio_group_get_external_user(f.file);

		fdput(f);



		if (IS_ERR(vfio_group))

			return PTR_ERR(vfio_group);



		ret = -ENOENT;



		mutex_lock(&kv->lock);



		list_for_each_entry(kvg, &kv->group_list, node) {

			if (kvg->vfio_group != vfio_group)

			if (!kvm_vfio_external_group_match_file(kvg->vfio_group,

								f.file))

				continue;



			list_del(&kvg->node);

			kvm_arch_end_assignment(dev->kvm);

#ifdef CONFIG_SPAPR_TCE_IOMMU

			kvm_spapr_tce_release_vfio_group(dev->kvm,

							 kvg->vfio_group);

#endif

			kvm_vfio_group_set_kvm(kvg->vfio_group, NULL);

			kvm_vfio_group_put_external_user(kvg->vfio_group);

			kfree(kvg);

			ret = 0;

			break;

		}



		kvm_arch_end_assignment(dev->kvm);



		mutex_unlock(&kv->lock);



#ifdef CONFIG_SPAPR_TCE_IOMMU

		kvm_spapr_tce_release_vfio_group(dev->kvm, vfio_group);

#endif

		kvm_vfio_group_set_kvm(vfio_group, NULL);



		kvm_vfio_group_put_external_user(vfio_group);

		fdput(f);



		kvm_vfio_update_coherency(dev);

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