vmwgfx_execbuf.c

/**************************************************************************
 *
 * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/

#include "vmwgfx_drv.h"
#include "vmwgfx_reg.h"
#include <drm/ttm/ttm_bo_api.h>
#include <drm/ttm/ttm_placement.h>

#define VMW_RES_HT_ORDER 12

/**
 * struct vmw_resource_relocation - Relocation info for resources
 *
 * @head: List head for the software context's relocation list.
 * @res: Non-ref-counted pointer to the resource.
 * @offset: Offset of 4 byte entries into the command buffer where the
 * id that needs fixup is located.
 */
struct vmw_resource_relocation {
	struct list_head head;
	const struct vmw_resource *res;
	unsigned long offset;
};

/**
 * struct vmw_resource_val_node - Validation info for resources
 *
 * @head: List head for the software context's resource list.
 * @hash: Hash entry for quick resouce to val_node lookup.
 * @res: Ref-counted pointer to the resource.
 * @switch_backup: Boolean whether to switch backup buffer on unreserve.
 * @new_backup: Refcounted pointer to the new backup buffer.
 * @staged_bindings: If @res is a context, tracks bindings set up during
 * the command batch. Otherwise NULL.
 * @new_backup_offset: New backup buffer offset if @new_backup is non-NUll.
 * @first_usage: Set to true the first time the resource is referenced in
 * the command stream.
 * @no_buffer_needed: Resources do not need to allocate buffer backup on
 * reservation. The command stream will provide one.
 */
struct vmw_resource_val_node {
	struct list_head head;
	struct drm_hash_item hash;
	struct vmw_resource *res;
	struct vmw_dma_buffer *new_backup;
	struct vmw_ctx_binding_state *staged_bindings;
	unsigned long new_backup_offset;
	bool first_usage;
	bool no_buffer_needed;
};

/**
 * struct vmw_cmd_entry - Describe a command for the verifier
 *
 * @user_allow: Whether allowed from the execbuf ioctl.
 * @gb_disable: Whether disabled if guest-backed objects are available.
 * @gb_enable: Whether enabled iff guest-backed objects are available.
 */
struct vmw_cmd_entry {
	int (*func) (struct vmw_private *, struct vmw_sw_context *,
		     SVGA3dCmdHeader *);
	bool user_allow;
	bool gb_disable;
	bool gb_enable;
};

#define VMW_CMD_DEF(_cmd, _func, _user_allow, _gb_disable, _gb_enable)	\
	[(_cmd) - SVGA_3D_CMD_BASE] = {(_func), (_user_allow),\
				       (_gb_disable), (_gb_enable)}

/**
 * vmw_resource_unreserve - unreserve resources previously reserved for
 * command submission.
 *
 * @list_head: list of resources to unreserve.
 * @backoff: Whether command submission failed.
 */
static void vmw_resource_list_unreserve(struct list_head *list,
					bool backoff)
{
	struct vmw_resource_val_node *val;

	list_for_each_entry(val, list, head) {
		struct vmw_resource *res = val->res;
		struct vmw_dma_buffer *new_backup =
			backoff ? NULL : val->new_backup;

		/*
		 * Transfer staged context bindings to the
		 * persistent context binding tracker.
		 */
		if (unlikely(val->staged_bindings)) {
			if (!backoff) {
				vmw_context_binding_state_transfer
					(val->res, val->staged_bindings);
			}
			kfree(val->staged_bindings);
			val->staged_bindings = NULL;
		}
		vmw_resource_unreserve(res, new_backup,
			val->new_backup_offset);
		vmw_dmabuf_unreference(&val->new_backup);
	}
}


/**
 * vmw_resource_val_add - Add a resource to the software context's
 * resource list if it's not already on it.
 *
 * @sw_context: Pointer to the software context.
 * @res: Pointer to the resource.
 * @p_node On successful return points to a valid pointer to a
 * struct vmw_resource_val_node, if non-NULL on entry.
 */
static int vmw_resource_val_add(struct vmw_sw_context *sw_context,
				struct vmw_resource *res,
				struct vmw_resource_val_node **p_node)
{
	struct vmw_resource_val_node *node;
	struct drm_hash_item *hash;
	int ret;

	if (likely(drm_ht_find_item(&sw_context->res_ht, (unsigned long) res,
				    &hash) == 0)) {
		node = container_of(hash, struct vmw_resource_val_node, hash);
		node->first_usage = false;
		if (unlikely(p_node != NULL))
			*p_node = node;
		return 0;
	}

	node = kzalloc(sizeof(*node), GFP_KERNEL);
	if (unlikely(node == NULL)) {
		DRM_ERROR("Failed to allocate a resource validation "
			  "entry.\n");
		return -ENOMEM;
	}

	node->hash.key = (unsigned long) res;
	ret = drm_ht_insert_item(&sw_context->res_ht, &node->hash);
	if (unlikely(ret != 0)) {
		DRM_ERROR("Failed to initialize a resource validation "
			  "entry.\n");
		kfree(node);
		return ret;
	}
	list_add_tail(&node->head, &sw_context->resource_list);
	node->res = vmw_resource_reference(res);
	node->first_usage = true;

	if (unlikely(p_node != NULL))
		*p_node = node;

	return 0;
}

/**
 * vmw_resource_context_res_add - Put resources previously bound to a context on
 * the validation list
 *
 * @dev_priv: Pointer to a device private structure
 * @sw_context: Pointer to a software context used for this command submission
 * @ctx: Pointer to the context resource
 *
 * This function puts all resources that were previously bound to @ctx on
 * the resource validation list. This is part of the context state reemission
 */
static int vmw_resource_context_res_add(struct vmw_private *dev_priv,
					struct vmw_sw_context *sw_context,
					struct vmw_resource *ctx)
{
	struct list_head *binding_list;
	struct vmw_ctx_binding *entry;
	int ret = 0;
	struct vmw_resource *res;

	mutex_lock(&dev_priv->binding_mutex);
	binding_list = vmw_context_binding_list(ctx);

	list_for_each_entry(entry, binding_list, ctx_list) {
		res = vmw_resource_reference_unless_doomed(entry->bi.res);
		if (unlikely(res == NULL))
			continue;

		ret = vmw_resource_val_add(sw_context, entry->bi.res, NULL);
		vmw_resource_unreference(&res);
		if (unlikely(ret != 0))
			break;
	}

	mutex_unlock(&dev_priv->binding_mutex);
	return ret;
}

/**
 * vmw_resource_relocation_add - Add a relocation to the relocation list
 *
 * @list: Pointer to head of relocation list.
 * @res: The resource.
 * @offset: Offset into the command buffer currently being parsed where the
 * id that needs fixup is located. Granularity is 4 bytes.
 */
static int vmw_resource_relocation_add(struct list_head *list,
				       const struct vmw_resource *res,
				       unsigned long offset)
{
	struct vmw_resource_relocation *rel;

	rel = kmalloc(sizeof(*rel), GFP_KERNEL);
	if (unlikely(rel == NULL)) {
		DRM_ERROR("Failed to allocate a resource relocation.\n");
		return -ENOMEM;
	}

	rel->res = res;
	rel->offset = offset;
	list_add_tail(&rel->head, list);

	return 0;
}

/**
 * vmw_resource_relocations_free - Free all relocations on a list
 *
 * @list: Pointer to the head of the relocation list.
 */
static void vmw_resource_relocations_free(struct list_head *list)
{
	struct vmw_resource_relocation *rel, *n;

	list_for_each_entry_safe(rel, n, list, head) {
		list_del(&rel->head);
		kfree(rel);
	}
}

/**
 * vmw_resource_relocations_apply - Apply all relocations on a list
 *
 * @cb: Pointer to the start of the command buffer bein patch. This need
 * not be the same buffer as the one being parsed when the relocation
 * list was built, but the contents must be the same modulo the
 * resource ids.
 * @list: Pointer to the head of the relocation list.
 */
static void vmw_resource_relocations_apply(uint32_t *cb,
					   struct list_head *list)
{
	struct vmw_resource_relocation *rel;

	list_for_each_entry(rel, list, head) {
		if (likely(rel->res != NULL))
			cb[rel->offset] = rel->res->id;
		else
			cb[rel->offset] = SVGA_3D_CMD_NOP;
	}
}

static int vmw_cmd_invalid(struct vmw_private *dev_priv,
			   struct vmw_sw_context *sw_context,
			   SVGA3dCmdHeader *header)
{
	return capable(CAP_SYS_ADMIN) ? : -EINVAL;
}

static int vmw_cmd_ok(struct vmw_private *dev_priv,
		      struct vmw_sw_context *sw_context,
		      SVGA3dCmdHeader *header)
{
	return 0;
}

/**
 * vmw_bo_to_validate_list - add a bo to a validate list
 *
 * @sw_context: The software context used for this command submission batch.
 * @bo: The buffer object to add.
 * @validate_as_mob: Validate this buffer as a MOB.
 * @p_val_node: If non-NULL Will be updated with the validate node number
 * on return.
 *
 * Returns -EINVAL if the limit of number of buffer objects per command
 * submission is reached.
 */
static int vmw_bo_to_validate_list(struct vmw_sw_context *sw_context,
				   struct ttm_buffer_object *bo,
				   bool validate_as_mob,
				   uint32_t *p_val_node)
{
	uint32_t val_node;
	struct vmw_validate_buffer *vval_buf;
	struct ttm_validate_buffer *val_buf;
	struct drm_hash_item *hash;
	int ret;

	if (likely(drm_ht_find_item(&sw_context->res_ht, (unsigned long) bo,
				    &hash) == 0)) {
		vval_buf = container_of(hash, struct vmw_validate_buffer,
					hash);
		if (unlikely(vval_buf->validate_as_mob != validate_as_mob)) {
			DRM_ERROR("Inconsistent buffer usage.\n");
			return -EINVAL;
		}
		val_buf = &vval_buf->base;
		val_node = vval_buf - sw_context->val_bufs;
	} else {
		val_node = sw_context->cur_val_buf;
		if (unlikely(val_node >= VMWGFX_MAX_VALIDATIONS)) {
			DRM_ERROR("Max number of DMA buffers per submission "
				  "exceeded.\n");
			return -EINVAL;
		}
		vval_buf = &sw_context->val_bufs[val_node];
		vval_buf->hash.key = (unsigned long) bo;
		ret = drm_ht_insert_item(&sw_context->res_ht, &vval_buf->hash);
		if (unlikely(ret != 0)) {
			DRM_ERROR("Failed to initialize a buffer validation "
				  "entry.\n");
			return ret;
		}
		++sw_context->cur_val_buf;
		val_buf = &vval_buf->base;
		val_buf->bo = ttm_bo_reference(bo);
		val_buf->reserved = false;
		list_add_tail(&val_buf->head, &sw_context->validate_nodes);
		vval_buf->validate_as_mob = validate_as_mob;
	}

	sw_context->fence_flags |= DRM_VMW_FENCE_FLAG_EXEC;

	if (p_val_node)
		*p_val_node = val_node;

	return 0;
}

/**
 * vmw_resources_reserve - Reserve all resources on the sw_context's
 * resource list.
 *
 * @sw_context: Pointer to the software context.
 *
 * Note that since vmware's command submission currently is protected by
 * the cmdbuf mutex, no fancy deadlock avoidance is required for resources,
 * since only a single thread at once will attempt this.
 */
static int vmw_resources_reserve(struct vmw_sw_context *sw_context)
{
	struct vmw_resource_val_node *val;
	int ret;

	list_for_each_entry(val, &sw_context->resource_list, head) {
		struct vmw_resource *res = val->res;

		ret = vmw_resource_reserve(res, val->no_buffer_needed);
		if (unlikely(ret != 0))
			return ret;

		if (res->backup) {
			struct ttm_buffer_object *bo = &res->backup->base;

			ret = vmw_bo_to_validate_list
				(sw_context, bo,
				 vmw_resource_needs_backup(res), NULL);

			if (unlikely(ret != 0))
				return ret;
		}
	}
	return 0;
}

/**
 * vmw_resources_validate - Validate all resources on the sw_context's
 * resource list.
 *
 * @sw_context: Pointer to the software context.
 *
 * Before this function is called, all resource backup buffers must have
 * been validated.
 */
static int vmw_resources_validate(struct vmw_sw_context *sw_context)
{
	struct vmw_resource_val_node *val;
	int ret;

	list_for_each_entry(val, &sw_context->resource_list, head) {
		struct vmw_resource *res = val->res;

		ret = vmw_resource_validate(res);
		if (unlikely(ret != 0)) {
			if (ret != -ERESTARTSYS)
				DRM_ERROR("Failed to validate resource.\n");
			return ret;
		}
	}
	return 0;
}

/**
 * vmw_cmd_compat_res_check - Check that a resource is present and if so, put it
 * on the resource validate list unless it's already there.
 *
 * @dev_priv: Pointer to a device private structure.
 * @sw_context: Pointer to the software context.
 * @res_type: Resource type.
 * @converter: User-space visisble type specific information.
 * @id: user-space resource id handle.
 * @id_loc: Pointer to the location in the command buffer currently being
 * parsed from where the user-space resource id handle is located.
 * @p_val: Pointer to pointer to resource validalidation node. Populated
 * on exit.
 */
static int
vmw_cmd_compat_res_check(struct vmw_private *dev_priv,
			 struct vmw_sw_context *sw_context,
			 enum vmw_res_type res_type,
			 const struct vmw_user_resource_conv *converter,
			 uint32_t id,
			 uint32_t *id_loc,
			 struct vmw_resource_val_node **p_val)
{
	struct vmw_res_cache_entry *rcache =
		&sw_context->res_cache[res_type];
	struct vmw_resource *res;
	struct vmw_resource_val_node *node;
	int ret;

	if (id == SVGA3D_INVALID_ID) {
		if (p_val)
			*p_val = NULL;
		if (res_type == vmw_res_context) {
			DRM_ERROR("Illegal context invalid id.\n");
			return -EINVAL;
		}
		return 0;
	}

	/*
	 * Fastpath in case of repeated commands referencing the same
	 * resource
	 */

	if (likely(rcache->valid && id == rcache->handle)) {
		const struct vmw_resource *res = rcache->res;

		rcache->node->first_usage = false;
		if (p_val)
			*p_val = rcache->node;

		return vmw_resource_relocation_add
			(&sw_context->res_relocations, res,
			 id_loc - sw_context->buf_start);
	}

	ret = vmw_user_resource_lookup_handle(dev_priv,
					      sw_context->fp->tfile,
					      id,
					      converter,
					      &res);
	if (unlikely(ret != 0)) {
		DRM_ERROR("Could not find or use resource 0x%08x.\n",
			  (unsigned) id);
		dump_stack();
		return ret;
	}

	rcache->valid = true;
	rcache->res = res;
	rcache->handle = id;

	ret = vmw_resource_relocation_add(&sw_context->res_relocations,
					  res,
					  id_loc - sw_context->buf_start);
	if (unlikely(ret != 0))
		goto out_no_reloc;

	ret = vmw_resource_val_add(sw_context, res, &node);
	if (unlikely(ret != 0))
		goto out_no_reloc;

	rcache->node = node;
	if (p_val)
		*p_val = node;

	if (dev_priv->has_mob && node->first_usage &&
	    res_type == vmw_res_context) {
		ret = vmw_resource_context_res_add(dev_priv, sw_context, res);
		if (unlikely(ret != 0))
			goto out_no_reloc;
		node->staged_bindings =
			kzalloc(sizeof(*node->staged_bindings), GFP_KERNEL);
		if (node->staged_bindings == NULL) {
			DRM_ERROR("Failed to allocate context binding "
				  "information.\n");
			goto out_no_reloc;
		}
		INIT_LIST_HEAD(&node->staged_bindings->list);
	}

	vmw_resource_unreference(&res);
	return 0;

out_no_reloc:
	BUG_ON(sw_context->error_resource != NULL);
	sw_context->error_resource = res;

	return ret;
}

/**
 * vmw_cmd_res_check - Check that a resource is present and if so, put it
 * on the resource validate list unless it's already there.
 *
 * @dev_priv: Pointer to a device private structure.
 * @sw_context: Pointer to the software context.
 * @res_type: Resource type.
 * @converter: User-space visisble type specific information.
 * @id_loc: Pointer to the location in the command buffer currently being
 * parsed from where the user-space resource id handle is located.
 * @p_val: Pointer to pointer to resource validalidation node. Populated
 * on exit.
 */
static int
vmw_cmd_res_check(struct vmw_private *dev_priv,
		  struct vmw_sw_context *sw_context,
		  enum vmw_res_type res_type,
		  const struct vmw_user_resource_conv *converter,
		  uint32_t *id_loc,
		  struct vmw_resource_val_node **p_val)
{
	return vmw_cmd_compat_res_check(dev_priv, sw_context, res_type,
					converter, *id_loc, id_loc, p_val);
}

/**
 * vmw_rebind_contexts - Rebind all resources previously bound to
 * referenced contexts.
 *
 * @sw_context: Pointer to the software context.
 *
 * Rebind context binding points that have been scrubbed because of eviction.
 */
static int vmw_rebind_contexts(struct vmw_sw_context *sw_context)
{
	struct vmw_resource_val_node *val;
	int ret;

	list_for_each_entry(val, &sw_context->resource_list, head) {
		if (likely(!val->staged_bindings))
			continue;

		ret = vmw_context_rebind_all(val->res);
		if (unlikely(ret != 0)) {
			if (ret != -ERESTARTSYS)
				DRM_ERROR("Failed to rebind context.\n");
			return ret;
		}
	}

	return 0;
}

/**
 * vmw_cmd_cid_check - Check a command header for valid context information.
 *
 * @dev_priv: Pointer to a device private structure.
 * @sw_context: Pointer to the software context.
 * @header: A command header with an embedded user-space context handle.
 *
 * Convenience function: Call vmw_cmd_res_check with the user-space context
 * handle embedded in @header.
 */
static int vmw_cmd_cid_check(struct vmw_private *dev_priv,
			     struct vmw_sw_context *sw_context,
			     SVGA3dCmdHeader *header)
{
	struct vmw_cid_cmd {
		SVGA3dCmdHeader header;
		uint32_t cid;
	} *cmd;

	cmd = container_of(header, struct vmw_cid_cmd, header);
	return vmw_cmd_res_check(dev_priv, sw_context, vmw_res_context,
				 user_context_converter, &cmd->cid, NULL);
}

static int vmw_cmd_set_render_target_check(struct vmw_private *dev_priv,
					   struct vmw_sw_context *sw_context,
					   SVGA3dCmdHeader *header)
{
	struct vmw_sid_cmd {
		SVGA3dCmdHeader header;
		SVGA3dCmdSetRenderTarget body;
	} *cmd;
	struct vmw_resource_val_node *ctx_node;
	struct vmw_resource_val_node *res_node;
	int ret;

	cmd = container_of(header, struct vmw_sid_cmd, header);

	ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_context,
				user_context_converter, &cmd->body.cid,
				&ctx_node);
	if (unlikely(ret != 0))
		return ret;

	ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
				user_surface_converter,
				&cmd->body.target.sid, &res_node);
	if (unlikely(ret != 0))
		return ret;

	if (dev_priv->has_mob) {
		struct vmw_ctx_bindinfo bi;

		bi.ctx = ctx_node->res;
		bi.res = res_node ? res_node->res : NULL;
		bi.bt = vmw_ctx_binding_rt;
		bi.i1.rt_type = cmd->body.type;
		return vmw_context_binding_add(ctx_node->staged_bindings, &bi);
	}

	return 0;
}

static int vmw_cmd_surface_copy_check(struct vmw_private *dev_priv,
				      struct vmw_sw_context *sw_context,
				      SVGA3dCmdHeader *header)
{
	struct vmw_sid_cmd {
		SVGA3dCmdHeader header;
		SVGA3dCmdSurfaceCopy body;
	} *cmd;
	int ret;

	cmd = container_of(header, struct vmw_sid_cmd, header);
	ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
				user_surface_converter,
				&cmd->body.src.sid, NULL);
	if (unlikely(ret != 0))
		return ret;
	return vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
				 user_surface_converter,
				 &cmd->body.dest.sid, NULL);
}

static int vmw_cmd_stretch_blt_check(struct vmw_private *dev_priv,
				     struct vmw_sw_context *sw_context,
				     SVGA3dCmdHeader *header)
{
	struct vmw_sid_cmd {
		SVGA3dCmdHeader header;
		SVGA3dCmdSurfaceStretchBlt body;
	} *cmd;
	int ret;

	cmd = container_of(header, struct vmw_sid_cmd, header);
	ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
				user_surface_converter,
				&cmd->body.src.sid, NULL);
	if (unlikely(ret != 0))
		return ret;
	return vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
				 user_surface_converter,
				 &cmd->body.dest.sid, NULL);
}

static int vmw_cmd_blt_surf_screen_check(struct vmw_private *dev_priv,
					 struct vmw_sw_context *sw_context,
					 SVGA3dCmdHeader *header)
{
	struct vmw_sid_cmd {
		SVGA3dCmdHeader header;
		SVGA3dCmdBlitSurfaceToScreen body;
	} *cmd;

	cmd = container_of(header, struct vmw_sid_cmd, header);

	return vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
				 user_surface_converter,
				 &cmd->body.srcImage.sid, NULL);
}

static int vmw_cmd_present_check(struct vmw_private *dev_priv,
				 struct vmw_sw_context *sw_context,
				 SVGA3dCmdHeader *header)
{
	struct vmw_sid_cmd {
		SVGA3dCmdHeader header;
		SVGA3dCmdPresent body;
	} *cmd;


	cmd = container_of(header, struct vmw_sid_cmd, header);

	return vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
				 user_surface_converter, &cmd->body.sid,
				 NULL);
}

/**
 * vmw_query_bo_switch_prepare - Prepare to switch pinned buffer for queries.
 *
 * @dev_priv: The device private structure.
 * @new_query_bo: The new buffer holding query results.
 * @sw_context: The software context used for this command submission.
 *
 * This function checks whether @new_query_bo is suitable for holding
 * query results, and if another buffer currently is pinned for query
 * results. If so, the function prepares the state of @sw_context for
 * switching pinned buffers after successful submission of the current
 * command batch.
 */
static int vmw_query_bo_switch_prepare(struct vmw_private *dev_priv,
				       struct ttm_buffer_object *new_query_bo,
				       struct vmw_sw_context *sw_context)
{
	struct vmw_res_cache_entry *ctx_entry =
		&sw_context->res_cache[vmw_res_context];
	int ret;

	BUG_ON(!ctx_entry->valid);
	sw_context->last_query_ctx = ctx_entry->res;

	if (unlikely(new_query_bo != sw_context->cur_query_bo)) {

		if (unlikely(new_query_bo->num_pages > 4)) {
			DRM_ERROR("Query buffer too large.\n");
			return -EINVAL;
		}

		if (unlikely(sw_context->cur_query_bo != NULL)) {
			sw_context->needs_post_query_barrier = true;
			ret = vmw_bo_to_validate_list(sw_context,
						      sw_context->cur_query_bo,
						      dev_priv->has_mob, NULL);
			if (unlikely(ret != 0))
				return ret;
		}
		sw_context->cur_query_bo = new_query_bo;

		ret = vmw_bo_to_validate_list(sw_context,
					      dev_priv->dummy_query_bo,
					      dev_priv->has_mob, NULL);
		if (unlikely(ret != 0))
			return ret;

	}

	return 0;
}


/**
 * vmw_query_bo_switch_commit - Finalize switching pinned query buffer
 *
 * @dev_priv: The device private structure.
 * @sw_context: The software context used for this command submission batch.
 *
 * This function will check if we're switching query buffers, and will then,
 * issue a dummy occlusion query wait used as a query barrier. When the fence
 * object following that query wait has signaled, we are sure that all
 * preceding queries have finished, and the old query buffer can be unpinned.
 * However, since both the new query buffer and the old one are fenced with
 * that fence, we can do an asynchronus unpin now, and be sure that the
 * old query buffer won't be moved until the fence has signaled.
 *
 * As mentioned above, both the new - and old query buffers need to be fenced
 * using a sequence emitted *after* calling this function.
 */
static void vmw_query_bo_switch_commit(struct vmw_private *dev_priv,
				     struct vmw_sw_context *sw_context)
{
	/*
	 * The validate list should still hold references to all
	 * contexts here.
	 */

	if (sw_context->needs_post_query_barrier) {
		struct vmw_res_cache_entry *ctx_entry =
			&sw_context->res_cache[vmw_res_context];
		struct vmw_resource *ctx;
		int ret;

		BUG_ON(!ctx_entry->valid);
		ctx = ctx_entry->res;

		ret = vmw_fifo_emit_dummy_query(dev_priv, ctx->id);

		if (unlikely(ret != 0))
			DRM_ERROR("Out of fifo space for dummy query.\n");
	}

	if (dev_priv->pinned_bo != sw_context->cur_query_bo) {
		if (dev_priv->pinned_bo) {
			vmw_bo_pin(dev_priv->pinned_bo, false);
			ttm_bo_unref(&dev_priv->pinned_bo);
		}

		if (!sw_context->needs_post_query_barrier) {
			vmw_bo_pin(sw_context->cur_query_bo, true);

			/*
			 * We pin also the dummy_query_bo buffer so that we
			 * don't need to validate it when emitting
			 * dummy queries in context destroy paths.
			 */

			vmw_bo_pin(dev_priv->dummy_query_bo, true);
			dev_priv->dummy_query_bo_pinned = true;

			BUG_ON(sw_context->last_query_ctx == NULL);
			dev_priv->query_cid = sw_context->last_query_ctx->id;
			dev_priv->query_cid_valid = true;
			dev_priv->pinned_bo =
				ttm_bo_reference(sw_context->cur_query_bo);
		}
	}
}

/**
 * vmw_translate_mob_pointer - Prepare to translate a user-space buffer
 * handle to a MOB id.
 *
 * @dev_priv: Pointer to a device private structure.
 * @sw_context: The software context used for this command batch validation.
 * @id: Pointer to the user-space handle to be translated.
 * @vmw_bo_p: Points to a location that, on successful return will carry
 * a reference-counted pointer to the DMA buffer identified by the
 * user-space handle in @id.
 *
 * This function saves information needed to translate a user-space buffer
 * handle to a MOB id. The translation does not take place immediately, but
 * during a call to vmw_apply_relocations(). This function builds a relocation
 * list and a list of buffers to validate. The former needs to be freed using
 * either vmw_apply_relocations() or vmw_free_relocations(). The latter
 * needs to be freed using vmw_clear_validations.
 */
static int vmw_translate_mob_ptr(struct vmw_private *dev_priv,
				 struct vmw_sw_context *sw_context,
				 SVGAMobId *id,
				 struct vmw_dma_buffer **vmw_bo_p)
{
	struct vmw_dma_buffer *vmw_bo = NULL;
	struct ttm_buffer_object *bo;
	uint32_t handle = *id;
	struct vmw_relocation *reloc;
	int ret;

	ret = vmw_user_dmabuf_lookup(sw_context->fp->tfile, handle, &vmw_bo);
	if (unlikely(ret != 0)) {
		DRM_ERROR("Could not find or use MOB buffer.\n");
		return -EINVAL;
	}
	bo = &vmw_bo->base;

	if (unlikely(sw_context->cur_reloc >= VMWGFX_MAX_RELOCATIONS)) {
		DRM_ERROR("Max number relocations per submission"
			  " exceeded\n");
		ret = -EINVAL;
		goto out_no_reloc;
	}

	reloc = &sw_context->relocs[sw_context->cur_reloc++];
	reloc->mob_loc = id;
	reloc->location = NULL;

	ret = vmw_bo_to_validate_list(sw_context, bo, true, &reloc->index);
	if (unlikely(ret != 0))
		goto out_no_reloc;

	*vmw_bo_p = vmw_bo;
	return 0;

out_no_reloc:
	vmw_dmabuf_unreference(&vmw_bo);
	vmw_bo_p = NULL;
	return ret;
}

/**
 * vmw_translate_guest_pointer - Prepare to translate a user-space buffer
 * handle to a valid SVGAGuestPtr
 *
 * @dev_priv: Pointer to a device private structure.
 * @sw_context: The software context used for this command batch validation.
 * @ptr: Pointer to the user-space handle to be translated.
 * @vmw_bo_p: Points to a location that, on successful return will carry
 * a reference-counted pointer to the DMA buffer identified by the
 * user-space handle in @id.
 *
 * This function saves information needed to translate a user-space buffer
 * handle to a valid SVGAGuestPtr. The translation does not take place
 * immediately, but during a call to vmw_apply_relocations().
 * This function builds a relocation list and a list of buffers to validate.
 * The former needs to be freed using either vmw_apply_relocations() or
 * vmw_free_relocations(). The latter needs to be freed using
 * vmw_clear_validations.
 */
static int vmw_translate_guest_ptr(struct vmw_private *dev_priv,
				   struct vmw_sw_context *sw_context,
				   SVGAGuestPtr *ptr,
				   struct vmw_dma_buffer **vmw_bo_p)
{
	struct vmw_dma_buffer *vmw_bo = NULL;
	struct ttm_buffer_object *bo;
	uint32_t handle = ptr->gmrId;
	struct vmw_relocation *reloc;
	int ret;

	ret = vmw_user_dmabuf_lookup(sw_context->fp->tfile, handle, &vmw_bo);
	if (unlikely(ret != 0)) {
		DRM_ERROR("Could not find or use GMR region.\n");
		return -EINVAL;
	}
	bo = &vmw_bo->base;

	if (unlikely(sw_context->cur_reloc >= VMWGFX_MAX_RELOCATIONS)) {
		DRM_ERROR("Max number relocations per submission"
			  " exceeded\n");
		ret = -EINVAL;
		goto out_no_reloc;
	}

	reloc = &sw_context->relocs[sw_context->cur_reloc++];
	reloc->location = ptr;

	ret = vmw_bo_to_validate_list(sw_context, bo, false, &reloc->index);
	if (unlikely(ret != 0))
		goto out_no_reloc;

	*vmw_bo_p = vmw_bo;
	return 0;

out_no_reloc:
	vmw_dmabuf_unreference(&vmw_bo);
	vmw_bo_p = NULL;
	return ret;
}

/**
 * vmw_cmd_begin_gb_query - validate a  SVGA_3D_CMD_BEGIN_GB_QUERY command.
 *
 * @dev_priv: Pointer to a device private struct.
 * @sw_context: The software context used for this command submission.
 * @header: Pointer to the command header in the command stream.
 */
static int vmw_cmd_begin_gb_query(struct vmw_private *dev_priv,
				  struct vmw_sw_context *sw_context,
				  SVGA3dCmdHeader *header)
{
	struct vmw_begin_gb_query_cmd {
		SVGA3dCmdHeader header;
		SVGA3dCmdBeginGBQuery q;
	} *cmd;

	cmd = container_of(header, struct vmw_begin_gb_query_cmd,
			   header);

	return vmw_cmd_res_check(dev_priv, sw_context, vmw_res_context,
				 user_context_converter, &cmd->q.cid,
				 NULL);
}

/**
 * vmw_cmd_begin_query - validate a  SVGA_3D_CMD_BEGIN_QUERY command.
 *
 * @dev_priv: Pointer to a device private struct.
 * @sw_context: The software context used for this command submission.
 * @header: Pointer to the command header in the command stream.
 */
static int vmw_cmd_begin_query(struct vmw_private *dev_priv,
			       struct vmw_sw_context *sw_context,
			       SVGA3dCmdHeader *header)