From 08673c3e27aa4407899e4fbb4738dac25370f706 Mon Sep 17 00:00:00 2001 From: Chuanxiao Dong Date: Fri, 7 Jul 2017 13:21:52 +0800 Subject: [PATCH] drm/i915/gvt: Revert "drm/i915/gvt: Fix possible recursive locking issue" This reverts commit 62d02fd1f807bf5a259a242c483c9fb98a242630. 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: Chuanxiao Dong Cc: Zhenyu Wang Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Zhenyu Wang --- drivers/gpu/drm/i915/gvt/gvt.h | 3 -- drivers/gpu/drm/i915/gvt/kvmgt.c | 55 ++++++-------------------------- 2 files changed, 10 insertions(+), 48 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h index 28d817e96e58..3a74e79eac2f 100644 --- a/drivers/gpu/drm/i915/gvt/gvt.h +++ b/drivers/gpu/drm/i915/gvt/gvt.h @@ -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 }; diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index 75a6e1d8af0d..fd0c85f9ef3c 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -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; -- 2.20.1