drm/vmwgfx: Replace SurfaceDMA usage with SurfaceCopy in 2D VMs

This patch address the following underlying issues with SurfaceDMA

* SurfaceDMA command does not work in a 2D VM, but we can wrap a
  proxy surface around the same DMA buffer and use the SurfaceCopy
  command which does work in a 2D VM.

* Wrapping a DMA buffer with a proxy surface also gives us an
  added optimization path for the case when the DMA buf
  dimensions match the mode.  In this case, the DMA buf can
  be pinned as the display surface, saving an extra copy.
  This only works in a 2D VM because we won't be doing any
  rendering operations directly to the display surface.

v2
* Moved is_dmabuf_proxy field to vmw_framebuffer_surface
* Undone coding style changes
* Addressed other issues from review

Signed-off-by: Sinclair Yeh <syeh@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>

drivers/gpu/drm/vmwgfx/vmwgfx_drv.h

@@ -342,7 +342,8 @@ enum vmw_display_unit_type {
 };
 
 
-#define VMW_QUIRK_SCREENTARGET (1U << 0)
+#define VMW_QUIRK_DST_SID_OK (1U << 0)
+#define VMW_QUIRK_SRC_SID_OK (1U << 1)
 
 struct vmw_sw_context{
 	struct drm_open_hash res_ht;

drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c

@@ -674,13 +674,16 @@ static int vmw_cmd_surface_copy_check(struct vmw_private *dev_priv,
 	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;
 
-	if (sw_context->quirks & VMW_QUIRK_SCREENTARGET)
+	if (!(sw_context->quirks & VMW_QUIRK_SRC_SID_OK)) {
+		ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
+					user_surface_converter,
+					&cmd->body.src.sid, NULL);
+		if (ret != 0)
+			return ret;
+	}
+
+	if (sw_context->quirks & VMW_QUIRK_DST_SID_OK)
 		return 0;
 
 	return vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
@@ -1264,7 +1267,7 @@ static int vmw_cmd_dma(struct vmw_private *dev_priv,
 	if (unlikely(suffix->maximumOffset > bo_size))
 		suffix->maximumOffset = bo_size;
 
-	if (sw_context->quirks & VMW_QUIRK_SCREENTARGET)
+	if (sw_context->quirks & VMW_QUIRK_DST_SID_OK)
 		goto out_no_surface;
 
 	ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
@@ -1505,6 +1508,9 @@ static int vmw_cmd_update_gb_image(struct vmw_private *dev_priv,
 
 	cmd = container_of(header, struct vmw_gb_surface_cmd, header);
 
+	if (sw_context->quirks & VMW_QUIRK_SRC_SID_OK)
+		return 0;
+
 	return vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
 				 user_surface_converter,
 				 &cmd->body.image.sid, NULL);

drivers/gpu/drm/vmwgfx/vmwgfx_kms.c

@@ -487,7 +487,8 @@ static int vmw_kms_new_framebuffer_surface(struct vmw_private *dev_priv,
 					   struct vmw_surface *surface,
 					   struct vmw_framebuffer **out,
 					   const struct drm_mode_fb_cmd
-					   *mode_cmd)
+					   *mode_cmd,
+					   bool is_dmabuf_proxy)
 
 {
 	struct drm_device *dev = dev_priv->dev;
@@ -562,6 +563,7 @@ static int vmw_kms_new_framebuffer_surface(struct vmw_private *dev_priv,
 	vfbs->surface = surface;
 	vfbs->base.user_handle = mode_cmd->handle;
 	vfbs->master = drm_master_get(file_priv->master);
+	vfbs->is_dmabuf_proxy = is_dmabuf_proxy;
 
 	mutex_lock(&vmaster->fb_surf_mutex);
 	list_add_tail(&vfbs->head, &vmaster->fb_surf);
@@ -699,6 +701,82 @@ static int vmw_framebuffer_dmabuf_unpin(struct vmw_framebuffer *vfb)
 	return vmw_dmabuf_unpin(dev_priv, vfbd->buffer, false);
 }
 
+/**
+ * vmw_create_dmabuf_proxy - create a proxy surface for the DMA buf
+ *
+ * @dev: DRM device
+ * @mode_cmd: parameters for the new surface
+ * @dmabuf_mob: MOB backing the DMA buf
+ * @srf_out: newly created surface
+ *
+ * When the content FB is a DMA buf, we create a surface as a proxy to the
+ * same buffer.  This way we can do a surface copy rather than a surface DMA.
+ * This is a more efficient approach
+ *
+ * RETURNS:
+ * 0 on success, error code otherwise
+ */
+static int vmw_create_dmabuf_proxy(struct drm_device *dev,
+				   struct drm_mode_fb_cmd *mode_cmd,
+				   struct vmw_dma_buffer *dmabuf_mob,
+				   struct vmw_surface **srf_out)
+{
+	uint32_t format;
+	struct drm_vmw_size content_base_size;
+	int ret;
+
+
+	switch (mode_cmd->depth) {
+	case 32:
+	case 24:
+		format = SVGA3D_X8R8G8B8;
+		break;
+
+	case 16:
+	case 15:
+		format = SVGA3D_R5G6B5;
+		break;
+
+	case 8:
+		format = SVGA3D_P8;
+		break;
+
+	default:
+		DRM_ERROR("Invalid framebuffer format %d\n", mode_cmd->depth);
+		return -EINVAL;
+	}
+
+	content_base_size.width  = mode_cmd->width;
+	content_base_size.height = mode_cmd->height;
+	content_base_size.depth  = 1;
+
+	ret = vmw_surface_gb_priv_define(dev,
+			0, /* kernel visible only */
+			0, /* flags */
+			format,
+			true, /* can be a scanout buffer */
+			1, /* num of mip levels */
+			0,
+			content_base_size,
+			srf_out);
+	if (ret) {
+		DRM_ERROR("Failed to allocate proxy content buffer\n");
+		return ret;
+	}
+
+	/* Use the same MOB backing for surface */
+	vmw_dmabuf_reference(dmabuf_mob);
+
+	(*srf_out)->res.backup = dmabuf_mob;
+
+	/* FIXME:  Waiting for fbdev rework to do a proper reserve/pin */
+	ret = vmw_resource_validate(&(*srf_out)->res);
+
+	return ret;
+}
+
+
+
 static int vmw_kms_new_framebuffer_dmabuf(struct vmw_private *dev_priv,
 					  struct vmw_dma_buffer *dmabuf,
 					  struct vmw_framebuffer **out,
@@ -801,6 +879,7 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,
 	struct vmw_dma_buffer *bo = NULL;
 	struct ttm_base_object *user_obj;
 	struct drm_mode_fb_cmd mode_cmd;
+	bool is_dmabuf_proxy = false;
 	int ret;
 
 	mode_cmd.width = mode_cmd2->width;
@@ -849,13 +928,29 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,
 	if (ret)
 		goto err_out;
 
-	/* Create the new framebuffer depending one what we got back */
-	if (bo)
+	/*
+	 * We cannot use the SurfaceDMA command in an non-accelerated VM,
+	 * therefore, wrap the DMA buf in a surface so we can use the
+	 * SurfaceCopy command.
+	 */
+	if (bo && !(dev_priv->capabilities & SVGA_CAP_3D) &&
+	    dev_priv->active_display_unit == vmw_du_screen_target) {
+		ret = vmw_create_dmabuf_proxy(dev_priv->dev, &mode_cmd, bo,
+			&surface);
+		if (ret)
+			goto err_out;
+
+		is_dmabuf_proxy = true;
+	}
+
+	/* Create the new framebuffer depending one what we have */
+	if (surface)
+		ret = vmw_kms_new_framebuffer_surface(dev_priv, file_priv,
+						      surface, &vfb, &mode_cmd,
+						      is_dmabuf_proxy);
+	else if (bo)
 		ret = vmw_kms_new_framebuffer_dmabuf(dev_priv, bo, &vfb,
 						     &mode_cmd);
-	else if (surface)
-		ret = vmw_kms_new_framebuffer_surface(dev_priv, file_priv,
-						      surface, &vfb, &mode_cmd);
 	else
 		BUG();
 

drivers/gpu/drm/vmwgfx/vmwgfx_kms.h

@@ -72,6 +72,7 @@ struct vmw_framebuffer_surface {
 	struct vmw_dma_buffer *buffer;
 	struct list_head head;
 	struct drm_master *master;
+	bool is_dmabuf_proxy;  /* true if this is proxy surface for DMA buf */
 };
 
 

drivers/gpu/drm/vmwgfx/vmwgfx_mob.c

@@ -31,8 +31,7 @@
  * If we set up the screen target otable, screen objects stop working.
  */
 
-#define VMW_OTABLE_SETUP_SUB ((VMWGFX_ENABLE_SCREEN_TARGET_OTABLE &&	\
-			       (dev_priv->capabilities & SVGA_CAP_3D)) ? 0 : 1)
+#define VMW_OTABLE_SETUP_SUB ((VMWGFX_ENABLE_SCREEN_TARGET_OTABLE ? 0 : 1))
 
 #ifdef CONFIG_64BIT
 #define VMW_PPN_SIZE 8

drivers/gpu/drm/vmwgfx/vmwgfx_resource.c

@@ -497,7 +497,7 @@ int vmw_user_dmabuf_alloc(struct vmw_private *dev_priv,
 
 	ret = vmw_dmabuf_init(dev_priv, &user_bo->dma, size,
 			      (dev_priv->has_mob) ?
-			      &vmw_sys_placement :
+			      &vmw_mob_placement :
 			      &vmw_vram_sys_placement, true,
 			      &vmw_user_dmabuf_destroy);
 	if (unlikely(ret != 0))

drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c

@@ -141,6 +141,63 @@ static void vmw_stdu_crtc_destroy(struct drm_crtc *crtc)
 
 
 
+/**
+ * vmw_stdu_dma_update - Update DMA buf dirty region on the SVGA device
+ *
+ * @dev_priv:  VMW DRM device
+ * @file_priv: Pointer to a drm file private structure
+ * @vfbs: VMW framebuffer surface that may need a DMA buf update
+ * @x: top/left corner of the content area to blit from
+ * @y: top/left corner of the content area to blit from
+ * @width: width of the blit area
+ * @height: height of the blit area
+ *
+ * The SVGA device may have the DMA buf cached, so before letting the
+ * device use it as the source image for a subsequent operation, we
+ * update the cached copy.
+ *
+ * RETURNs:
+ * 0 on success, error code on failure
+ */
+static int vmw_stdu_dma_update(struct vmw_private *dev_priv,
+			       struct drm_file *file_priv,
+			       struct vmw_framebuffer_surface *vfbs,
+			       uint32_t x, uint32_t y,
+			       uint32_t width, uint32_t height)
+{
+	size_t fifo_size;
+	struct {
+		SVGA3dCmdHeader header;
+		SVGA3dCmdUpdateGBImage body;
+	} img_update_cmd;
+
+
+	/* Only need to do this if the surface is a DMA buf proxy */
+	if (!vfbs->is_dmabuf_proxy)
+		return 0;
+
+	fifo_size = sizeof(img_update_cmd);
+
+	memset(&img_update_cmd, 0, fifo_size);
+	img_update_cmd.header.id   = SVGA_3D_CMD_UPDATE_GB_IMAGE;
+	img_update_cmd.header.size = sizeof(img_update_cmd.body);
+
+	img_update_cmd.body.image.sid = vfbs->surface->res.id;
+
+	img_update_cmd.body.box.x = x;
+	img_update_cmd.body.box.y = y;
+	img_update_cmd.body.box.w = width;
+	img_update_cmd.body.box.h = height;
+	img_update_cmd.body.box.d = 1;
+
+	return vmw_execbuf_process(file_priv, dev_priv, NULL,
+				   (void *) &img_update_cmd,
+				   fifo_size, 0, VMW_QUIRK_SRC_SID_OK,
+				   NULL, NULL);
+}
+
+
+
 /**
  * vmw_stdu_content_copy - copies an area from the content to display surface
  *
@@ -166,11 +223,13 @@ static int vmw_stdu_content_copy(struct vmw_private *dev_priv,
 				 uint32_t width, uint32_t height,
 				 uint32_t display_x, uint32_t display_y)
 {
-	size_t fifo_size;
+	struct vmw_framebuffer_surface *content_vfbs;
+	size_t fifo_size;	
 	int ret;
 	void *cmd;
+	u32 quirks = VMW_QUIRK_DST_SID_OK;
 
-	struct vmw_surface_dma {
+	struct {
 		SVGA3dCmdHeader     header;
 		SVGA3dCmdSurfaceDMA body;
 		SVGA3dCopyBox       area;
@@ -193,24 +252,43 @@ static int vmw_stdu_content_copy(struct vmw_private *dev_priv,
 		return -EINVAL;
 	}
 
+
 	if (stdu->content_fb_type == SEPARATE_DMA) {
 		struct vmw_framebuffer *content_vfb;
-		struct vmw_framebuffer_dmabuf *content_vfbd;
-		struct vmw_framebuffer_surface *content_vfbs;
 		struct drm_vmw_size cur_size = {0};
 		const struct svga3d_surface_desc *desc;
+		enum SVGA3dSurfaceFormat format;
 		SVGA3dCmdSurfaceDMASuffix *suffix;
 		SVGAGuestPtr ptr;
 
+
 		content_vfb  = vmw_framebuffer_to_vfb(stdu->content_fb);
-		content_vfbd = vmw_framebuffer_to_vfbd(stdu->content_fb);
-		content_vfbs = vmw_framebuffer_to_vfbs(stdu->content_fb);
 
 		cur_size.width  = width;
 		cur_size.height = height;
 		cur_size.depth  = 1;
 
-		desc = svga3dsurface_get_desc(content_vfbs->surface->format);
+		/* Derive a SVGA3dSurfaceFormat for the DMA buf */
+		switch (content_vfb->base.bits_per_pixel) {
+		case 32:
+			format = SVGA3D_A8R8G8B8;
+			break;
+		case 24:
+			format = SVGA3D_X8R8G8B8;
+			break;
+		case 16:
+			format = SVGA3D_R5G6B5;
+			break;
+		case 15:
+			format = SVGA3D_A1R5G5B5;
+			break;
+		default:
+			DRM_ERROR("Invalid color depth: %d\n",
+					content_vfb->base.depth);
+			return -EINVAL;
+		}
+
+		desc = svga3dsurface_get_desc(format);
 
 
 		fifo_size = sizeof(surface_dma_cmd);
@@ -250,19 +328,40 @@ static int vmw_stdu_content_copy(struct vmw_private *dev_priv,
 
 		cmd = (void *) &surface_dma_cmd;
 	} else {
-		struct vmw_framebuffer *content_vfb;
+		u32 src_id;
+
+
+		content_vfbs = vmw_framebuffer_to_vfbs(stdu->content_fb);
+
+		if (content_vfbs->is_dmabuf_proxy) {
+			ret = vmw_stdu_dma_update(dev_priv, file_priv,
+						  content_vfbs,
+						  content_x, content_y,
+						  width, height);
+
+			if (ret != 0) {
+				DRM_ERROR("Failed to update cached DMA buf\n");
+				return ret;
+			}
 
-		content_vfb = vmw_framebuffer_to_vfb(stdu->content_fb);
+			quirks |= VMW_QUIRK_SRC_SID_OK;
+			src_id = content_vfbs->surface->res.id;
+		} else {
+			struct vmw_framebuffer *content_vfb;
 
+			content_vfb = vmw_framebuffer_to_vfb(stdu->content_fb);
+			src_id = content_vfb->user_handle;
+		}
+ 
 		fifo_size = sizeof(surface_cpy_cmd);
 
-		memset(&surface_cpy_cmd, 0, sizeof(surface_cpy_cmd));
+		memset(&surface_cpy_cmd, 0, fifo_size);
 
 		surface_cpy_cmd.header.id   = SVGA_3D_CMD_SURFACE_COPY;
 		surface_cpy_cmd.header.size = sizeof(surface_cpy_cmd.body) +
 					      sizeof(surface_cpy_cmd.area);
 
-		surface_cpy_cmd.body.src.sid  = content_vfb->user_handle;
+		surface_cpy_cmd.body.src.sid  = src_id;
 		surface_cpy_cmd.body.dest.sid = stdu->display_srf->res.id;
 
 		surface_cpy_cmd.area.srcx = content_x;
@@ -276,8 +375,11 @@ static int vmw_stdu_content_copy(struct vmw_private *dev_priv,
 		cmd = (void *) &surface_cpy_cmd;
 	}
 
-	ret = vmw_execbuf_process(file_priv, dev_priv, NULL, cmd,
-				  fifo_size, 0, VMW_QUIRK_SCREENTARGET,
+
+
+	ret = vmw_execbuf_process(file_priv, dev_priv, NULL,
+				  (void *) cmd,
+				  fifo_size, 0, quirks,
 				  NULL, NULL);
 
 	return ret;
@@ -391,7 +493,8 @@ static int vmw_stdu_bind_st(struct vmw_private *dev_priv,
  * vmw_stdu_update_st - Updates a Screen Target
  *
  * @dev_priv: VMW DRM device
- * @file_priv: Pointer to a drm file private structure
+ * @file_priv: Pointer to DRM file private structure.  Set to NULL when
+ *             we want to blank display.
  * @stdu: display unit affected
  * @update_area: area that needs to be updated
  *
@@ -412,6 +515,7 @@ static int vmw_stdu_update_st(struct vmw_private *dev_priv,
 	u32 width, height;
 	u32 display_update_x, display_update_y;
 	unsigned short display_x1, display_y1, display_x2, display_y2;
+	int ret;
 
 	struct {
 		SVGA3dCmdHeader header;
@@ -444,8 +548,11 @@ static int vmw_stdu_update_st(struct vmw_private *dev_priv,
 	height = min(update_area->y2, display_y2) -
 		 max(update_area->y1, display_y1);
 
+	/*
+	 * If content is on a separate surface, then copy the dirty area to
+	 * the display surface
+	 */
 	if (file_priv && stdu->content_fb_type != SAME_AS_DISPLAY) {
-		int ret;
 
 		ret = vmw_stdu_content_copy(dev_priv, file_priv,
 					    stdu,
@@ -459,6 +566,29 @@ static int vmw_stdu_update_st(struct vmw_private *dev_priv,
 		}
 	}
 
+
+	/*
+	 * If the display surface is the same as the content surface, then
+	 * it may be backed by a DMA buf.  If it is then we need to update
+	 * the device's cached copy of the DMA buf before issuing the screen
+	 * target update.
+	 */
+	if (file_priv && stdu->content_fb_type == SAME_AS_DISPLAY) {
+		struct vmw_framebuffer_surface *vfbs;
+
+		vfbs = vmw_framebuffer_to_vfbs(stdu->content_fb);
+		ret = vmw_stdu_dma_update(dev_priv, file_priv,
+					  vfbs,
+					  max(update_area->x1, display_x1),
+					  max(update_area->y1, display_y1),
+					  width, height);
+
+		if (ret != 0) {
+			DRM_ERROR("Failed to update cached DMA buffer\n");
+			return ret;
+		}
+	}
+
 	cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));
 
 	if (unlikely(cmd == NULL)) {
@@ -1066,8 +1196,7 @@ int vmw_kms_stdu_init_display(struct vmw_private *dev_priv)
 	if (!VMWGFX_ENABLE_SCREEN_TARGET_OTABLE)
 		return -ENOSYS;
 
-	if (!(dev_priv->capabilities & SVGA_CAP_GBOBJECTS) ||
-	    !(dev_priv->capabilities & SVGA_CAP_3D))
+	if (!(dev_priv->capabilities & SVGA_CAP_GBOBJECTS))
 		return -ENOSYS;
 
 	ret = drm_vblank_init(dev, VMWGFX_NUM_DISPLAY_UNITS);
@@ -1333,7 +1462,7 @@ int vmw_kms_stdu_present(struct vmw_private *dev_priv,
 		cmd->body.dest.sid = stdu[cur_du]->display_srf->res.id;
 
 		ret = vmw_execbuf_process(file_priv, dev_priv, NULL, cmd,
-					  fifo_size, 0, VMW_QUIRK_SCREENTARGET,
+					  fifo_size, 0, VMW_QUIRK_DST_SID_OK,
 					  NULL, NULL);
 
 		if (unlikely(ret != 0))