Hi Niranjana,
On Tue, Jan 17, 2023 at 11:16:09PM -0800, Niranjana Vishwanathapura wrote:
> Support dump capture of persistent mappings upon user request.
>
> Capture of a mapping is requested with the VM_BIND ioctl and
> processed during the GPU error handling. They are synchronously
> unbound during eviction so that no additional vma resource
> reference taking is required in the submission path. Thus, a
> list of persistent vmas requiring capture is maintained instead
> of a list of vma resources.
>
> v2: enable with CONFIG_DRM_I915_CAPTURE_ERROR, remove gfp
> overwrite, add kernel-doc and expand commit message
> v3: Ensure vma->resource is valid during capture
>
> Signed-off-by: Brian Welty <brian.welty@xxxxxxxxx>
> Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
> ---
> .../drm/i915/gem/i915_gem_vm_bind_object.c | 13 +++++
> drivers/gpu/drm/i915/gt/intel_gtt.c | 5 ++
> drivers/gpu/drm/i915/gt/intel_gtt.h | 7 +++
> drivers/gpu/drm/i915/i915_gem.c | 14 ++++-
> drivers/gpu/drm/i915/i915_gpu_error.c | 52 ++++++++++++++++++-
> drivers/gpu/drm/i915/i915_vma.c | 4 ++
> drivers/gpu/drm/i915/i915_vma_types.h | 4 ++
> include/uapi/drm/i915_drm.h | 9 +++-
> 8 files changed, 104 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
> index 78e7c0642c5f..562a67a988f2 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
> @@ -88,6 +88,12 @@ static void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
> {
> lockdep_assert_held(&vma->vm->vm_bind_lock);
>
> +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
> + mutex_lock(&vma->vm->vm_capture_lock);
> + if (!list_empty(&vma->vm_capture_link))
> + list_del_init(&vma->vm_capture_link);
> + mutex_unlock(&vma->vm->vm_capture_lock);
> +#endif
> spin_lock(&vma->vm->vm_rebind_lock);
> if (!list_empty(&vma->vm_rebind_link))
> list_del_init(&vma->vm_rebind_link);
> @@ -357,6 +363,13 @@ static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
> continue;
> }
>
> +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
> + if (va->flags & I915_GEM_VM_BIND_CAPTURE) {
> + mutex_lock(&vm->vm_capture_lock);
> + list_add_tail(&vma->vm_capture_link, &vm->vm_capture_list);
> + mutex_unlock(&vm->vm_capture_lock);
> + }
> +#endif
> list_add_tail(&vma->vm_bind_link, &vm->vm_bound_list);
> i915_vm_bind_it_insert(vma, &vm->va);
> if (!obj->priv_root)
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
> index 2e4c9fabf3b8..103ca55222be 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
> @@ -297,6 +297,11 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
> spin_lock_init(&vm->vm_rebind_lock);
> spin_lock_init(&vm->userptr_invalidated_lock);
> INIT_LIST_HEAD(&vm->userptr_invalidated_list);
> +
> +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
> + INIT_LIST_HEAD(&vm->vm_capture_list);
> + mutex_init(&vm->vm_capture_lock);
> +#endif
can we have all these, init/add/remove inside a single
CONFIG_RM_I915_CAPTURE_ERROR?
> }
>
> void *__px_vaddr(struct drm_i915_gem_object *p)
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
> index 620b4e020a9f..7f69e1d4fb5e 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
> @@ -281,6 +281,13 @@ struct i915_address_space {
> /** @root_obj: root object for dma-resv sharing by private objects */
> struct drm_i915_gem_object *root_obj;
>
> +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
> + /* @vm_capture_list: list of vm captures */
> + struct list_head vm_capture_list;
> + /* @vm_capture_lock: protects vm_capture_list */
> + struct mutex vm_capture_lock;
> +#endif
> +
> /* Global GTT */
> bool is_ggtt:1;
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 969581e7106f..d97822f203fc 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -143,6 +143,8 @@ int i915_gem_object_unbind(struct drm_i915_gem_object *obj,
> while (!ret && (vma = list_first_entry_or_null(&obj->vma.list,
> struct i915_vma,
> obj_link))) {
> + bool sync_unbind = true;
> +
> list_move_tail(&vma->obj_link, &still_in_list);
> if (!i915_vma_is_bound(vma, I915_VMA_BIND_MASK))
> continue;
> @@ -171,8 +173,18 @@ int i915_gem_object_unbind(struct drm_i915_gem_object *obj,
> * and destroy the vma from under us.
> */
>
> + /*
> + * Synchronously unbind persistent mappings with capture
> + * request so that vma->resource is valid in the error capture
> + * path without needing extra reference taking in execbuf path.
> + */
> + if (!mutex_lock_interruptible(&vma->vm->vm_capture_lock)) {
> + sync_unbind = !list_empty(&vma->vm_capture_link);
> + mutex_unlock(&vma->vm->vm_capture_lock);
> + }
this, as well?
> +
> ret = -EBUSY;
> - if (flags & I915_GEM_OBJECT_UNBIND_ASYNC) {
> + if (!sync_unbind && (flags & I915_GEM_OBJECT_UNBIND_ASYNC)) {
> assert_object_held(vma->obj);
> ret = i915_vma_unbind_async(vma, vm_trylock);
> }
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 9d5d5a397b64..5ccd1eaea2a5 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -1460,6 +1460,49 @@ capture_vma(struct intel_engine_capture_vma *next,
> return next;
> }
>
> +static struct intel_engine_capture_vma *
> +capture_user_vm(struct intel_engine_capture_vma *capture,
> + struct i915_address_space *vm, gfp_t gfp)
> +{
> + struct list_head vm_capture_list;
> + struct i915_vma *vma, *vn;
> + int err;
> +
> + INIT_LIST_HEAD(&vm_capture_list);
> +
> + err = mutex_lock_interruptible(&vm->vm_capture_lock);
> + if (err)
> + return capture;
> +
> + /* vma->resource should be checked with vm->mutex held */
> + err = mutex_lock_interruptible(&vm->mutex);
> + if (err)
> + goto skip_user_vm_capture;
> +
> + list_for_each_entry_safe(vma, vn, &vm->vm_capture_list,
> + vm_capture_link) {
> + if (drm_WARN_ONCE(&vm->i915->drm, !vma->resource,
> + "vma->resource expected!\n"))
> + continue;
> +
> + i915_vma_resource_get(vma->resource);
> + list_move_tail(&vma->vm_capture_link, &vm_capture_list);
> + }
> + mutex_unlock(&vm->mutex);
> +
> + list_for_each_entry(vma, &vm_capture_list, vm_capture_link) {
> + capture = capture_vma_snapshot(capture, vma->resource,
> + gfp, "user");
> + i915_vma_resource_put(vma->resource);
> + }
> + list_splice_tail(&vm_capture_list, &vm->vm_capture_list);
> +
> +skip_user_vm_capture:
> + mutex_unlock(&vm->vm_capture_lock);
> +
> + return capture;
> +}
By any chance we want to have them all here in i915_gpu_error.c?
Does it look ugly?
Andi
> +
> static struct intel_engine_capture_vma *
> capture_user(struct intel_engine_capture_vma *capture,
> const struct i915_request *rq,
