From da51a1e7e398129d9fddd4b26b8469145dd4fd08 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 11 Aug 2014 12:08:58 +0200 Subject: [PATCH] drm/i915: Fix secure dispatch with full ppgtt Based upon a hunk from a patch from Chris Wilson, but augmented to: - Process the batch in the full ppgtt vm so that self-relocations match again with userspace's expectations.. - Add a comment why plain pin for the global gtt binding is safe at that point. v2: Drop local bind_vm variable (Chris). v3: Explain why this works despite the lack of proper active tracking for the ggtt batch vma. Cc: Chris Wilson Cc: Ben Widawsky Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 48 +++++++++++----------- 1 file changed, 25 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 70946c551e5d..e1eac15b2583 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -95,7 +95,6 @@ eb_lookup_vmas(struct eb_vmas *eb, struct i915_address_space *vm, struct drm_file *file) { - struct drm_i915_private *dev_priv = vm->dev->dev_private; struct drm_i915_gem_object *obj; struct list_head objects; int i, ret; @@ -130,7 +129,6 @@ eb_lookup_vmas(struct eb_vmas *eb, i = 0; while (!list_empty(&objects)) { struct i915_vma *vma; - struct i915_address_space *bind_vm = vm; if (exec[i].flags & EXEC_OBJECT_NEEDS_GTT && USES_FULL_PPGTT(vm->dev)) { @@ -138,13 +136,6 @@ eb_lookup_vmas(struct eb_vmas *eb, goto err; } - /* If we have secure dispatch, or the userspace assures us that - * they know what they're doing, use the GGTT VM. - */ - if (((args->flags & I915_EXEC_SECURE) && - (i == (args->buffer_count - 1)))) - bind_vm = &dev_priv->gtt.base; - obj = list_first_entry(&objects, struct drm_i915_gem_object, obj_exec_link); @@ -157,7 +148,7 @@ eb_lookup_vmas(struct eb_vmas *eb, * from the (obj, vm) we don't run the risk of creating * duplicated vmas for the same vm. */ - vma = i915_gem_obj_lookup_or_create_vma(obj, bind_vm); + vma = i915_gem_obj_lookup_or_create_vma(obj, vm); if (IS_ERR(vma)) { DRM_DEBUG("Failed to lookup VMA\n"); ret = PTR_ERR(vma); @@ -1391,25 +1382,36 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, /* snb/ivb/vlv conflate the "batch in ppgtt" bit with the "non-secure * batch" bit. Hence we need to pin secure batches into the global gtt. * hsw should have this fixed, but bdw mucks it up again. */ - if (flags & I915_DISPATCH_SECURE && - !batch_obj->has_global_gtt_mapping) { - /* When we have multiple VMs, we'll need to make sure that we - * allocate space first */ - struct i915_vma *vma = i915_gem_obj_to_ggtt(batch_obj); - BUG_ON(!vma); - vma->bind_vma(vma, batch_obj->cache_level, GLOBAL_BIND); - } + if (flags & I915_DISPATCH_SECURE) { + /* + * So on first glance it looks freaky that we pin the batch here + * outside of the reservation loop. But: + * - The batch is already pinned into the relevant ppgtt, so we + * already have the backing storage fully allocated. + * - No other BO uses the global gtt (well contexts, but meh), + * so we don't really have issues with mutliple objects not + * fitting due to fragmentation. + * So this is actually safe. + */ + ret = i915_gem_obj_ggtt_pin(batch_obj, 0, 0); + if (ret) + goto err; - if (flags & I915_DISPATCH_SECURE) exec_start += i915_gem_obj_ggtt_offset(batch_obj); - else + } else exec_start += i915_gem_obj_offset(batch_obj, vm); ret = legacy_ringbuffer_submission(dev, file, ring, ctx, - args, &eb->vmas, batch_obj, exec_start, flags); - if (ret) - goto err; + args, &eb->vmas, batch_obj, exec_start, flags); + /* + * FIXME: We crucially rely upon the active tracking for the (ppgtt) + * batch vma for correctness. For less ugly and less fragility this + * needs to be adjusted to also track the ggtt batch vma properly as + * active. + */ + if (flags & I915_DISPATCH_SECURE) + i915_gem_object_ggtt_unpin(batch_obj); err: /* the request owns the ref now */ i915_gem_context_unreference(ctx); -- 2.20.1