Commit 08673c3e authored by Chuanxiao Dong's avatar Chuanxiao Dong Committed by Zhenyu Wang
Browse files

drm/i915/gvt: Revert "drm/i915/gvt: Fix possible recursive locking issue" 



This reverts commit 62d02fd1.

The rwsem recursive trace should not be fixed from kvmgt side by using
a workqueue and it is an issue should be fixed in VFIO. So this one
should be reverted.

Signed-off-by: default avatarChuanxiao Dong <chuanxiao.dong@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: default avatarZhenyu Wang <zhenyuw@linux.intel.com>
parent 3364bf5f

drivers/gpu/drm/i915/gvt/gvt.h

+0 −3
Original line number Diff line number Diff line
@@ -182,9 +182,6 @@ struct intel_vgpu { 
		struct kvm *kvm;

		struct work_struct release_work;

		atomic_t released;

		struct work_struct unpin_work;

		spinlock_t unpin_lock; /* To protect unpin_list */

		struct list_head unpin_list;

	} vdev;

#endif

};

drivers/gpu/drm/i915/gvt/kvmgt.c

+10 −45
Original line number Diff line number Diff line
@@ -78,7 +78,6 @@ struct gvt_dma { 
	struct rb_node node;

	gfn_t gfn;

	unsigned long iova;

	struct list_head list;

};



static inline bool handle_valid(unsigned long handle)
@@ -167,7 +166,6 @@ static void gvt_cache_add(struct intel_vgpu *vgpu, gfn_t gfn, 


	new->gfn = gfn;

	new->iova = iova;

	INIT_LIST_HEAD(&new->list);



	mutex_lock(&vgpu->vdev.cache_lock);

	while (*link) {
@@ -199,52 +197,26 @@ static void __gvt_cache_remove_entry(struct intel_vgpu *vgpu, 
	kfree(entry);

}



static void intel_vgpu_unpin_work(struct work_struct *work)

static void gvt_cache_remove(struct intel_vgpu *vgpu, gfn_t gfn)

{

	struct intel_vgpu *vgpu = container_of(work, struct intel_vgpu,

					       vdev.unpin_work);

	struct device *dev = mdev_dev(vgpu->vdev.mdev);

	struct gvt_dma *this;

	unsigned long gfn;



	for (;;) {

		spin_lock(&vgpu->vdev.unpin_lock);

		if (list_empty(&vgpu->vdev.unpin_list)) {

			spin_unlock(&vgpu->vdev.unpin_lock);

			break;

		}

		this = list_first_entry(&vgpu->vdev.unpin_list,

					struct gvt_dma, list);

		list_del(&this->list);

		spin_unlock(&vgpu->vdev.unpin_lock);



		gfn = this->gfn;

		vfio_unpin_pages(dev, &gfn, 1);

		kfree(this);

	}

}



static bool gvt_cache_mark_remove(struct intel_vgpu *vgpu, gfn_t gfn)

{

	struct gvt_dma *this;

	unsigned long g1;

	int rc;



	mutex_lock(&vgpu->vdev.cache_lock);

	this  = __gvt_cache_find(vgpu, gfn);

	if (!this) {

		mutex_unlock(&vgpu->vdev.cache_lock);

		return false;

		return;

	}



	g1 = gfn;

	gvt_dma_unmap_iova(vgpu, this->iova);

	/* remove this from rb tree */

	rb_erase(&this->node, &vgpu->vdev.cache);

	rc = vfio_unpin_pages(dev, &g1, 1);

	WARN_ON(rc != 1);

	__gvt_cache_remove_entry(vgpu, this);

	mutex_unlock(&vgpu->vdev.cache_lock);



	/* put this to the unpin_list */

	spin_lock(&vgpu->vdev.unpin_lock);

	list_move_tail(&this->list, &vgpu->vdev.unpin_list);

	spin_unlock(&vgpu->vdev.unpin_lock);



	return true;

}



static void gvt_cache_init(struct intel_vgpu *vgpu)
@@ -485,9 +457,6 @@ static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev) 
	}



	INIT_WORK(&vgpu->vdev.release_work, intel_vgpu_release_work);

	INIT_WORK(&vgpu->vdev.unpin_work, intel_vgpu_unpin_work);

	spin_lock_init(&vgpu->vdev.unpin_lock);

	INIT_LIST_HEAD(&vgpu->vdev.unpin_list);



	vgpu->vdev.mdev = mdev;

	mdev_set_drvdata(mdev, vgpu);
@@ -517,7 +486,6 @@ static int intel_vgpu_iommu_notifier(struct notifier_block *nb, 
	struct intel_vgpu *vgpu = container_of(nb,

					struct intel_vgpu,

					vdev.iommu_notifier);

	bool sched_unmap = false;



	if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {

		struct vfio_iommu_type1_dma_unmap *unmap = data;
@@ -527,10 +495,7 @@ static int intel_vgpu_iommu_notifier(struct notifier_block *nb, 
		end_gfn = gfn + unmap->size / PAGE_SIZE;



		while (gfn < end_gfn)

			sched_unmap |= gvt_cache_mark_remove(vgpu, gfn++);



		if (sched_unmap)

			schedule_work(&vgpu->vdev.unpin_work);

			gvt_cache_remove(vgpu, gfn++);

	}



	return NOTIFY_OK;

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