From: Jason Gunthorpe <jgg@ziepe.ca> To: linux-mm@kvack.org, Jerome Glisse <jglisse@redhat.com>, Ralph Campbell <rcampbell@nvidia.com>, John Hubbard <jhubbard@nvidia.com>, Felix.Kuehling@amd.com Cc: "Juergen Gross" <jgross@suse.com>, "David Zhou" <David1.Zhou@amd.com>, "Mike Marciniszyn" <mike.marciniszyn@intel.com>, "Stefano Stabellini" <sstabellini@kernel.org>, "Oleksandr Andrushchenko" <oleksandr_andrushchenko@epam.com>, linux-rdma@vger.kernel.org, nouveau@lists.freedesktop.org, "Dennis Dalessandro" <dennis.dalessandro@intel.com>, amd-gfx@lists.freedesktop.org, "Christoph Hellwig" <hch@infradead.org>, "Jason Gunthorpe" <jgg@mellanox.com>, dri-devel@lists.freedesktop.org, "Alex Deucher" <alexander.deucher@amd.com>, xen-devel@lists.xenproject.org, "Boris Ostrovsky" <boris.ostrovsky@oracle.com>, "Petr Cvek" <petrcvekcz@gmail.com>, "Christian König" <christian.koenig@amd.com>, "Ben Skeggs" <bskeggs@redhat.com> Subject: [PATCH v3 14/14] xen/gntdev: use mmu_interval_notifier_insert Date: Tue, 12 Nov 2019 16:22:31 -0400 [thread overview] Message-ID: <20191112202231.3856-15-jgg@ziepe.ca> (raw) In-Reply-To: <20191112202231.3856-1-jgg@ziepe.ca> From: Jason Gunthorpe <jgg@mellanox.com> gntdev simply wants to monitor a specific VMA for any notifier events, this can be done straightforwardly using mmu_interval_notifier_insert() over the VMA's VA range. The notifier should be attached until the original VMA is destroyed. It is unclear if any of this is even sane, but at least a lot of duplicate code is removed. Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> --- drivers/xen/gntdev-common.h | 8 +- drivers/xen/gntdev.c | 179 ++++++++++-------------------------- 2 files changed, 49 insertions(+), 138 deletions(-) diff --git a/drivers/xen/gntdev-common.h b/drivers/xen/gntdev-common.h index 2f8b949c3eeb14..91e44c04f7876c 100644 --- a/drivers/xen/gntdev-common.h +++ b/drivers/xen/gntdev-common.h @@ -21,15 +21,8 @@ struct gntdev_dmabuf_priv; struct gntdev_priv { /* Maps with visible offsets in the file descriptor. */ struct list_head maps; - /* - * Maps that are not visible; will be freed on munmap. - * Only populated if populate_freeable_maps == 1 - */ - struct list_head freeable_maps; /* lock protects maps and freeable_maps. */ struct mutex lock; - struct mm_struct *mm; - struct mmu_notifier mn; #ifdef CONFIG_XEN_GRANT_DMA_ALLOC /* Device for which DMA memory is allocated. */ @@ -49,6 +42,7 @@ struct gntdev_unmap_notify { }; struct gntdev_grant_map { + struct mmu_interval_notifier notifier; struct list_head next; struct vm_area_struct *vma; int index; diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 81401f386c9ce0..a04ddf2a68afa5 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -63,7 +63,6 @@ MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " static atomic_t pages_mapped = ATOMIC_INIT(0); static int use_ptemod; -#define populate_freeable_maps use_ptemod static int unmap_grant_pages(struct gntdev_grant_map *map, int offset, int pages); @@ -249,12 +248,6 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map) evtchn_put(map->notify.event); } - if (populate_freeable_maps && priv) { - mutex_lock(&priv->lock); - list_del(&map->next); - mutex_unlock(&priv->lock); - } - if (map->pages && !use_ptemod) unmap_grant_pages(map, 0, map->count); gntdev_free_map(map); @@ -444,16 +437,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma) pr_debug("gntdev_vma_close %p\n", vma); if (use_ptemod) { - /* It is possible that an mmu notifier could be running - * concurrently, so take priv->lock to ensure that the vma won't - * vanishing during the unmap_grant_pages call, since we will - * spin here until that completes. Such a concurrent call will - * not do any unmapping, since that has been done prior to - * closing the vma, but it may still iterate the unmap_ops list. - */ - mutex_lock(&priv->lock); + WARN_ON(map->vma != vma); + mmu_interval_notifier_remove(&map->notifier); map->vma = NULL; - mutex_unlock(&priv->lock); } vma->vm_private_data = NULL; gntdev_put_map(priv, map); @@ -475,109 +461,44 @@ static const struct vm_operations_struct gntdev_vmops = { /* ------------------------------------------------------------------ */ -static bool in_range(struct gntdev_grant_map *map, - unsigned long start, unsigned long end) -{ - if (!map->vma) - return false; - if (map->vma->vm_start >= end) - return false; - if (map->vma->vm_end <= start) - return false; - - return true; -} - -static int unmap_if_in_range(struct gntdev_grant_map *map, - unsigned long start, unsigned long end, - bool blockable) +static bool gntdev_invalidate(struct mmu_interval_notifier *mn, + const struct mmu_notifier_range *range, + unsigned long cur_seq) { + struct gntdev_grant_map *map = + container_of(mn, struct gntdev_grant_map, notifier); unsigned long mstart, mend; int err; - if (!in_range(map, start, end)) - return 0; + if (!mmu_notifier_range_blockable(range)) + return false; - if (!blockable) - return -EAGAIN; + /* + * If the VMA is split or otherwise changed the notifier is not + * updated, but we don't want to process VA's outside the modified + * VMA. FIXME: It would be much more understandable to just prevent + * modifying the VMA in the first place. + */ + if (map->vma->vm_start >= range->end || + map->vma->vm_end <= range->start) + return true; - mstart = max(start, map->vma->vm_start); - mend = min(end, map->vma->vm_end); + mstart = max(range->start, map->vma->vm_start); + mend = min(range->end, map->vma->vm_end); pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", map->index, map->count, map->vma->vm_start, map->vma->vm_end, - start, end, mstart, mend); + range->start, range->end, mstart, mend); err = unmap_grant_pages(map, (mstart - map->vma->vm_start) >> PAGE_SHIFT, (mend - mstart) >> PAGE_SHIFT); WARN_ON(err); - return 0; -} - -static int mn_invl_range_start(struct mmu_notifier *mn, - const struct mmu_notifier_range *range) -{ - struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); - struct gntdev_grant_map *map; - int ret = 0; - - if (mmu_notifier_range_blockable(range)) - mutex_lock(&priv->lock); - else if (!mutex_trylock(&priv->lock)) - return -EAGAIN; - - list_for_each_entry(map, &priv->maps, next) { - ret = unmap_if_in_range(map, range->start, range->end, - mmu_notifier_range_blockable(range)); - if (ret) - goto out_unlock; - } - list_for_each_entry(map, &priv->freeable_maps, next) { - ret = unmap_if_in_range(map, range->start, range->end, - mmu_notifier_range_blockable(range)); - if (ret) - goto out_unlock; - } - -out_unlock: - mutex_unlock(&priv->lock); - - return ret; -} - -static void mn_release(struct mmu_notifier *mn, - struct mm_struct *mm) -{ - struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); - struct gntdev_grant_map *map; - int err; - - mutex_lock(&priv->lock); - list_for_each_entry(map, &priv->maps, next) { - if (!map->vma) - continue; - pr_debug("map %d+%d (%lx %lx)\n", - map->index, map->count, - map->vma->vm_start, map->vma->vm_end); - err = unmap_grant_pages(map, /* offset */ 0, map->count); - WARN_ON(err); - } - list_for_each_entry(map, &priv->freeable_maps, next) { - if (!map->vma) - continue; - pr_debug("map %d+%d (%lx %lx)\n", - map->index, map->count, - map->vma->vm_start, map->vma->vm_end); - err = unmap_grant_pages(map, /* offset */ 0, map->count); - WARN_ON(err); - } - mutex_unlock(&priv->lock); + return true; } -static const struct mmu_notifier_ops gntdev_mmu_ops = { - .release = mn_release, - .invalidate_range_start = mn_invl_range_start, +static const struct mmu_interval_notifier_ops gntdev_mmu_ops = { + .invalidate = gntdev_invalidate, }; /* ------------------------------------------------------------------ */ @@ -592,7 +513,6 @@ static int gntdev_open(struct inode *inode, struct file *flip) return -ENOMEM; INIT_LIST_HEAD(&priv->maps); - INIT_LIST_HEAD(&priv->freeable_maps); mutex_init(&priv->lock); #ifdef CONFIG_XEN_GNTDEV_DMABUF @@ -604,17 +524,6 @@ static int gntdev_open(struct inode *inode, struct file *flip) } #endif - if (use_ptemod) { - priv->mm = get_task_mm(current); - if (!priv->mm) { - kfree(priv); - return -ENOMEM; - } - priv->mn.ops = &gntdev_mmu_ops; - ret = mmu_notifier_register(&priv->mn, priv->mm); - mmput(priv->mm); - } - if (ret) { kfree(priv); return ret; @@ -644,16 +553,12 @@ static int gntdev_release(struct inode *inode, struct file *flip) list_del(&map->next); gntdev_put_map(NULL /* already removed */, map); } - WARN_ON(!list_empty(&priv->freeable_maps)); mutex_unlock(&priv->lock); #ifdef CONFIG_XEN_GNTDEV_DMABUF gntdev_dmabuf_fini(priv->dmabuf_priv); #endif - if (use_ptemod) - mmu_notifier_unregister(&priv->mn, priv->mm); - kfree(priv); return 0; } @@ -714,8 +619,6 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); if (map) { list_del(&map->next); - if (populate_freeable_maps) - list_add_tail(&map->next, &priv->freeable_maps); err = 0; } mutex_unlock(&priv->lock); @@ -1087,11 +990,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) goto unlock_out; if (use_ptemod && map->vma) goto unlock_out; - if (use_ptemod && priv->mm != vma->vm_mm) { - pr_warn("Huh? Other mm?\n"); - goto unlock_out; - } - refcount_inc(&map->users); vma->vm_ops = &gntdev_vmops; @@ -1102,10 +1000,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) vma->vm_flags |= VM_DONTCOPY; vma->vm_private_data = map; - - if (use_ptemod) - map->vma = vma; - if (map->flags) { if ((vma->vm_flags & VM_WRITE) && (map->flags & GNTMAP_readonly)) @@ -1116,8 +1010,28 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) map->flags |= GNTMAP_readonly; } + if (use_ptemod) { + map->vma = vma; + err = mmu_interval_notifier_insert_locked( + &map->notifier, vma->vm_mm, vma->vm_start, + vma->vm_end - vma->vm_start, &gntdev_mmu_ops); + if (err) + goto out_unlock_put; + } mutex_unlock(&priv->lock); + /* + * gntdev takes the address of the PTE in find_grant_ptes() and passes + * it to the hypervisor in gntdev_map_grant_pages(). The purpose of + * the notifier is to prevent the hypervisor pointer to the PTE from + * going stale. + * + * Since this vma's mappings can't be touched without the mmap_sem, + * and we are holding it now, there is no need for the notifier_range + * locking pattern. + */ + mmu_interval_read_begin(&map->notifier); + if (use_ptemod) { map->pages_vm_start = vma->vm_start; err = apply_to_page_range(vma->vm_mm, vma->vm_start, @@ -1166,8 +1080,11 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) mutex_unlock(&priv->lock); out_put_map: if (use_ptemod) { - map->vma = NULL; unmap_grant_pages(map, 0, map->count); + if (map->vma) { + mmu_interval_notifier_remove(&map->notifier); + map->vma = NULL; + } } gntdev_put_map(priv, map); return err; -- 2.24.0 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@ziepe.ca> To: linux-mm@kvack.org, Jerome Glisse <jglisse@redhat.com>, Ralph Campbell <rcampbell@nvidia.com>, John Hubbard <jhubbard@nvidia.com>, Felix.Kuehling@amd.com Cc: "Juergen Gross" <jgross@suse.com>, "David Zhou" <David1.Zhou@amd.com>, "Mike Marciniszyn" <mike.marciniszyn@intel.com>, "Stefano Stabellini" <sstabellini@kernel.org>, "Oleksandr Andrushchenko" <oleksandr_andrushchenko@epam.com>, linux-rdma@vger.kernel.org, nouveau@lists.freedesktop.org, "Dennis Dalessandro" <dennis.dalessandro@intel.com>, amd-gfx@lists.freedesktop.org, "Christoph Hellwig" <hch@infradead.org>, "Jason Gunthorpe" <jgg@mellanox.com>, dri-devel@lists.freedesktop.org, "Alex Deucher" <alexander.deucher@amd.com>, xen-devel@lists.xenproject.org, "Boris Ostrovsky" <boris.ostrovsky@oracle.com>, "Petr Cvek" <petrcvekcz@gmail.com>, "Christian König" <christian.koenig@amd.com>, "Ben Skeggs" <bskeggs@redhat.com> Subject: [PATCH v3 14/14] xen/gntdev: use mmu_interval_notifier_insert Date: Tue, 12 Nov 2019 16:22:31 -0400 [thread overview] Message-ID: <20191112202231.3856-15-jgg@ziepe.ca> (raw) Message-ID: <20191112202231.T7Qs41ZeJNo83W7RcABlq8qwTRBwsvhl8_bs1qpZQl4@z> (raw) In-Reply-To: <20191112202231.3856-1-jgg@ziepe.ca> From: Jason Gunthorpe <jgg@mellanox.com> gntdev simply wants to monitor a specific VMA for any notifier events, this can be done straightforwardly using mmu_interval_notifier_insert() over the VMA's VA range. The notifier should be attached until the original VMA is destroyed. It is unclear if any of this is even sane, but at least a lot of duplicate code is removed. Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> --- drivers/xen/gntdev-common.h | 8 +- drivers/xen/gntdev.c | 179 ++++++++++-------------------------- 2 files changed, 49 insertions(+), 138 deletions(-) diff --git a/drivers/xen/gntdev-common.h b/drivers/xen/gntdev-common.h index 2f8b949c3eeb14..91e44c04f7876c 100644 --- a/drivers/xen/gntdev-common.h +++ b/drivers/xen/gntdev-common.h @@ -21,15 +21,8 @@ struct gntdev_dmabuf_priv; struct gntdev_priv { /* Maps with visible offsets in the file descriptor. */ struct list_head maps; - /* - * Maps that are not visible; will be freed on munmap. - * Only populated if populate_freeable_maps == 1 - */ - struct list_head freeable_maps; /* lock protects maps and freeable_maps. */ struct mutex lock; - struct mm_struct *mm; - struct mmu_notifier mn; #ifdef CONFIG_XEN_GRANT_DMA_ALLOC /* Device for which DMA memory is allocated. */ @@ -49,6 +42,7 @@ struct gntdev_unmap_notify { }; struct gntdev_grant_map { + struct mmu_interval_notifier notifier; struct list_head next; struct vm_area_struct *vma; int index; diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 81401f386c9ce0..a04ddf2a68afa5 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -63,7 +63,6 @@ MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " static atomic_t pages_mapped = ATOMIC_INIT(0); static int use_ptemod; -#define populate_freeable_maps use_ptemod static int unmap_grant_pages(struct gntdev_grant_map *map, int offset, int pages); @@ -249,12 +248,6 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map) evtchn_put(map->notify.event); } - if (populate_freeable_maps && priv) { - mutex_lock(&priv->lock); - list_del(&map->next); - mutex_unlock(&priv->lock); - } - if (map->pages && !use_ptemod) unmap_grant_pages(map, 0, map->count); gntdev_free_map(map); @@ -444,16 +437,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma) pr_debug("gntdev_vma_close %p\n", vma); if (use_ptemod) { - /* It is possible that an mmu notifier could be running - * concurrently, so take priv->lock to ensure that the vma won't - * vanishing during the unmap_grant_pages call, since we will - * spin here until that completes. Such a concurrent call will - * not do any unmapping, since that has been done prior to - * closing the vma, but it may still iterate the unmap_ops list. - */ - mutex_lock(&priv->lock); + WARN_ON(map->vma != vma); + mmu_interval_notifier_remove(&map->notifier); map->vma = NULL; - mutex_unlock(&priv->lock); } vma->vm_private_data = NULL; gntdev_put_map(priv, map); @@ -475,109 +461,44 @@ static const struct vm_operations_struct gntdev_vmops = { /* ------------------------------------------------------------------ */ -static bool in_range(struct gntdev_grant_map *map, - unsigned long start, unsigned long end) -{ - if (!map->vma) - return false; - if (map->vma->vm_start >= end) - return false; - if (map->vma->vm_end <= start) - return false; - - return true; -} - -static int unmap_if_in_range(struct gntdev_grant_map *map, - unsigned long start, unsigned long end, - bool blockable) +static bool gntdev_invalidate(struct mmu_interval_notifier *mn, + const struct mmu_notifier_range *range, + unsigned long cur_seq) { + struct gntdev_grant_map *map = + container_of(mn, struct gntdev_grant_map, notifier); unsigned long mstart, mend; int err; - if (!in_range(map, start, end)) - return 0; + if (!mmu_notifier_range_blockable(range)) + return false; - if (!blockable) - return -EAGAIN; + /* + * If the VMA is split or otherwise changed the notifier is not + * updated, but we don't want to process VA's outside the modified + * VMA. FIXME: It would be much more understandable to just prevent + * modifying the VMA in the first place. + */ + if (map->vma->vm_start >= range->end || + map->vma->vm_end <= range->start) + return true; - mstart = max(start, map->vma->vm_start); - mend = min(end, map->vma->vm_end); + mstart = max(range->start, map->vma->vm_start); + mend = min(range->end, map->vma->vm_end); pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", map->index, map->count, map->vma->vm_start, map->vma->vm_end, - start, end, mstart, mend); + range->start, range->end, mstart, mend); err = unmap_grant_pages(map, (mstart - map->vma->vm_start) >> PAGE_SHIFT, (mend - mstart) >> PAGE_SHIFT); WARN_ON(err); - return 0; -} - -static int mn_invl_range_start(struct mmu_notifier *mn, - const struct mmu_notifier_range *range) -{ - struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); - struct gntdev_grant_map *map; - int ret = 0; - - if (mmu_notifier_range_blockable(range)) - mutex_lock(&priv->lock); - else if (!mutex_trylock(&priv->lock)) - return -EAGAIN; - - list_for_each_entry(map, &priv->maps, next) { - ret = unmap_if_in_range(map, range->start, range->end, - mmu_notifier_range_blockable(range)); - if (ret) - goto out_unlock; - } - list_for_each_entry(map, &priv->freeable_maps, next) { - ret = unmap_if_in_range(map, range->start, range->end, - mmu_notifier_range_blockable(range)); - if (ret) - goto out_unlock; - } - -out_unlock: - mutex_unlock(&priv->lock); - - return ret; -} - -static void mn_release(struct mmu_notifier *mn, - struct mm_struct *mm) -{ - struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); - struct gntdev_grant_map *map; - int err; - - mutex_lock(&priv->lock); - list_for_each_entry(map, &priv->maps, next) { - if (!map->vma) - continue; - pr_debug("map %d+%d (%lx %lx)\n", - map->index, map->count, - map->vma->vm_start, map->vma->vm_end); - err = unmap_grant_pages(map, /* offset */ 0, map->count); - WARN_ON(err); - } - list_for_each_entry(map, &priv->freeable_maps, next) { - if (!map->vma) - continue; - pr_debug("map %d+%d (%lx %lx)\n", - map->index, map->count, - map->vma->vm_start, map->vma->vm_end); - err = unmap_grant_pages(map, /* offset */ 0, map->count); - WARN_ON(err); - } - mutex_unlock(&priv->lock); + return true; } -static const struct mmu_notifier_ops gntdev_mmu_ops = { - .release = mn_release, - .invalidate_range_start = mn_invl_range_start, +static const struct mmu_interval_notifier_ops gntdev_mmu_ops = { + .invalidate = gntdev_invalidate, }; /* ------------------------------------------------------------------ */ @@ -592,7 +513,6 @@ static int gntdev_open(struct inode *inode, struct file *flip) return -ENOMEM; INIT_LIST_HEAD(&priv->maps); - INIT_LIST_HEAD(&priv->freeable_maps); mutex_init(&priv->lock); #ifdef CONFIG_XEN_GNTDEV_DMABUF @@ -604,17 +524,6 @@ static int gntdev_open(struct inode *inode, struct file *flip) } #endif - if (use_ptemod) { - priv->mm = get_task_mm(current); - if (!priv->mm) { - kfree(priv); - return -ENOMEM; - } - priv->mn.ops = &gntdev_mmu_ops; - ret = mmu_notifier_register(&priv->mn, priv->mm); - mmput(priv->mm); - } - if (ret) { kfree(priv); return ret; @@ -644,16 +553,12 @@ static int gntdev_release(struct inode *inode, struct file *flip) list_del(&map->next); gntdev_put_map(NULL /* already removed */, map); } - WARN_ON(!list_empty(&priv->freeable_maps)); mutex_unlock(&priv->lock); #ifdef CONFIG_XEN_GNTDEV_DMABUF gntdev_dmabuf_fini(priv->dmabuf_priv); #endif - if (use_ptemod) - mmu_notifier_unregister(&priv->mn, priv->mm); - kfree(priv); return 0; } @@ -714,8 +619,6 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); if (map) { list_del(&map->next); - if (populate_freeable_maps) - list_add_tail(&map->next, &priv->freeable_maps); err = 0; } mutex_unlock(&priv->lock); @@ -1087,11 +990,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) goto unlock_out; if (use_ptemod && map->vma) goto unlock_out; - if (use_ptemod && priv->mm != vma->vm_mm) { - pr_warn("Huh? Other mm?\n"); - goto unlock_out; - } - refcount_inc(&map->users); vma->vm_ops = &gntdev_vmops; @@ -1102,10 +1000,6 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) vma->vm_flags |= VM_DONTCOPY; vma->vm_private_data = map; - - if (use_ptemod) - map->vma = vma; - if (map->flags) { if ((vma->vm_flags & VM_WRITE) && (map->flags & GNTMAP_readonly)) @@ -1116,8 +1010,28 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) map->flags |= GNTMAP_readonly; } + if (use_ptemod) { + map->vma = vma; + err = mmu_interval_notifier_insert_locked( + &map->notifier, vma->vm_mm, vma->vm_start, + vma->vm_end - vma->vm_start, &gntdev_mmu_ops); + if (err) + goto out_unlock_put; + } mutex_unlock(&priv->lock); + /* + * gntdev takes the address of the PTE in find_grant_ptes() and passes + * it to the hypervisor in gntdev_map_grant_pages(). The purpose of + * the notifier is to prevent the hypervisor pointer to the PTE from + * going stale. + * + * Since this vma's mappings can't be touched without the mmap_sem, + * and we are holding it now, there is no need for the notifier_range + * locking pattern. + */ + mmu_interval_read_begin(&map->notifier); + if (use_ptemod) { map->pages_vm_start = vma->vm_start; err = apply_to_page_range(vma->vm_mm, vma->vm_start, @@ -1166,8 +1080,11 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) mutex_unlock(&priv->lock); out_put_map: if (use_ptemod) { - map->vma = NULL; unmap_grant_pages(map, 0, map->count); + if (map->vma) { + mmu_interval_notifier_remove(&map->notifier); + map->vma = NULL; + } } gntdev_put_map(priv, map); return err; -- 2.24.0 _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
next prev parent reply other threads:[~2019-11-12 20:22 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-12 20:22 [PATCH hmm v3 00/14] Consolidate the mmu notifier interval_tree and locking Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 01/14] mm/mmu_notifier: define the header pre-processor parts even if disabled Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-13 13:52 ` Christoph Hellwig 2019-11-13 13:52 ` Christoph Hellwig 2019-11-12 20:22 ` [PATCH v3 02/14] mm/mmu_notifier: add an interval tree notifier Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-13 13:59 ` Christoph Hellwig 2019-11-13 13:59 ` Christoph Hellwig 2019-11-13 16:46 ` Jason Gunthorpe 2019-11-13 16:46 ` Jason Gunthorpe 2019-11-23 0:54 ` Ralph Campbell 2019-11-23 0:54 ` Ralph Campbell 2019-11-23 23:59 ` Jason Gunthorpe 2019-11-23 23:59 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 03/14] mm/hmm: allow hmm_range to be used with a mmu_interval_notifier or hmm_mirror Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-13 14:00 ` Christoph Hellwig 2019-11-13 14:00 ` Christoph Hellwig 2019-11-12 20:22 ` [PATCH v3 04/14] mm/hmm: define the pre-processor related parts of hmm.h even if disabled Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-13 14:01 ` Christoph Hellwig 2019-11-13 14:01 ` Christoph Hellwig 2019-11-12 20:22 ` [PATCH v3 05/14] RDMA/odp: Use mmu_interval_notifier_insert() Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 06/14] RDMA/hfi1: Use mmu_interval_notifier_insert for user_exp_rcv Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 07/14] drm/radeon: use mmu_interval_notifier_insert Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 08/14] nouveau: use mmu_notifier directly for invalidate_range_start Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 09/14] nouveau: use mmu_interval_notifier instead of hmm_mirror Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 10/14] drm/amdgpu: Call find_vma under mmap_sem Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 11/14] drm/amdgpu: Use mmu_interval_insert instead of hmm_mirror Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-12 20:22 ` [PATCH v3 12/14] drm/amdgpu: Use mmu_interval_notifier " Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-19 19:59 ` Philip Yang 2019-11-19 19:59 ` Philip Yang 2019-11-12 20:22 ` [PATCH v3 13/14] mm/hmm: remove hmm_mirror and related Jason Gunthorpe 2019-11-12 20:22 ` Jason Gunthorpe 2019-11-13 14:02 ` Christoph Hellwig 2019-11-13 14:02 ` Christoph Hellwig 2019-11-12 20:22 ` Jason Gunthorpe [this message] 2019-11-12 20:22 ` [PATCH v3 14/14] xen/gntdev: use mmu_interval_notifier_insert Jason Gunthorpe
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