Add virtio gpu driver.

This patch adds a kms driver for the virtio gpu.  The xorg modesetting
driver can handle the device just fine, the framebuffer for fbcon is
there too.

Qemu patches for the host side are under review currently.

The pci version of the device comes in two variants: with and without
vga compatibility.  The former has a extra memory bar for the vga
framebuffer, the later is a pure virtio device.  The only concern for
this driver is that in the virtio-vga case we have to kick out the
firmware framebuffer.

Initial revision has only 2d support, 3d (virgl) support requires
some more work on the qemu side and will be added later.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 469 insertions, 0 deletions

diff --git a/drivers/gpu/drm/virtio/virtgpu_ttm.c b/drivers/gpu/drm/virtio/virtgpu_ttm.c
new file mode 100644
index 000000000000..e0e74c6bb959
--- /dev/null
+++ b/drivers/gpu/drm/virtio/virtgpu_ttm.c
@@ -0,0 +1,469 @@
+/*
+ * Copyright (C) 2015 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * Authors:
+ *    Dave Airlie
+ *    Alon Levy
+ *
+ * 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, sublicense,
+ * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) 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 <ttm/ttm_bo_api.h>
+#include <ttm/ttm_bo_driver.h>
+#include <ttm/ttm_placement.h>
+#include <ttm/ttm_page_alloc.h>
+#include <ttm/ttm_module.h>
+#include <drm/drmP.h>
+#include <drm/drm.h>
+#include "virtgpu_drv.h"
+
+#include <linux/delay.h>
+
+#define DRM_FILE_PAGE_OFFSET (0x100000000ULL >> PAGE_SHIFT)
+
+static struct
+virtio_gpu_device *virtio_gpu_get_vgdev(struct ttm_bo_device *bdev)
+{
+	struct virtio_gpu_mman *mman;
+	struct virtio_gpu_device *vgdev;
+
+	mman = container_of(bdev, struct virtio_gpu_mman, bdev);
+	vgdev = container_of(mman, struct virtio_gpu_device, mman);
+	return vgdev;
+}
+
+static int virtio_gpu_ttm_mem_global_init(struct drm_global_reference *ref)
+{
+	return ttm_mem_global_init(ref->object);
+}
+
+static void virtio_gpu_ttm_mem_global_release(struct drm_global_reference *ref)
+{
+	ttm_mem_global_release(ref->object);
+}
+
+static int virtio_gpu_ttm_global_init(struct virtio_gpu_device *vgdev)
+{
+	struct drm_global_reference *global_ref;
+	int r;
+
+	vgdev->mman.mem_global_referenced = false;
+	global_ref = &vgdev->mman.mem_global_ref;
+	global_ref->global_type = DRM_GLOBAL_TTM_MEM;
+	global_ref->size = sizeof(struct ttm_mem_global);
+	global_ref->init = &virtio_gpu_ttm_mem_global_init;
+	global_ref->release = &virtio_gpu_ttm_mem_global_release;
+
+	r = drm_global_item_ref(global_ref);
+	if (r != 0) {
+		DRM_ERROR("Failed setting up TTM memory accounting "
+			  "subsystem.\n");
+		return r;
+	}
+
+	vgdev->mman.bo_global_ref.mem_glob =
+		vgdev->mman.mem_global_ref.object;
+	global_ref = &vgdev->mman.bo_global_ref.ref;
+	global_ref->global_type = DRM_GLOBAL_TTM_BO;
+	global_ref->size = sizeof(struct ttm_bo_global);
+	global_ref->init = &ttm_bo_global_init;
+	global_ref->release = &ttm_bo_global_release;
+	r = drm_global_item_ref(global_ref);
+	if (r != 0) {
+		DRM_ERROR("Failed setting up TTM BO subsystem.\n");
+		drm_global_item_unref(&vgdev->mman.mem_global_ref);
+		return r;
+	}
+
+	vgdev->mman.mem_global_referenced = true;
+	return 0;
+}
+
+static void virtio_gpu_ttm_global_fini(struct virtio_gpu_device *vgdev)
+{
+	if (vgdev->mman.mem_global_referenced) {
+		drm_global_item_unref(&vgdev->mman.bo_global_ref.ref);
+		drm_global_item_unref(&vgdev->mman.mem_global_ref);
+		vgdev->mman.mem_global_referenced = false;
+	}
+}
+
+#if 0
+/*
+ * Hmm, seems to not do anything useful.  Leftover debug hack?
+ * Something like printing pagefaults to kernel log?
+ */
+static struct vm_operations_struct virtio_gpu_ttm_vm_ops;
+static const struct vm_operations_struct *ttm_vm_ops;
+
+static int virtio_gpu_ttm_fault(struct vm_area_struct *vma,
+				struct vm_fault *vmf)
+{
+	struct ttm_buffer_object *bo;
+	struct virtio_gpu_device *vgdev;
+	int r;
+
+	bo = (struct ttm_buffer_object *)vma->vm_private_data;
+	if (bo == NULL)
+		return VM_FAULT_NOPAGE;
+	vgdev = virtio_gpu_get_vgdev(bo->bdev);
+	r = ttm_vm_ops->fault(vma, vmf);
+	return r;
+}
+#endif
+
+int virtio_gpu_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct drm_file *file_priv;
+	struct virtio_gpu_device *vgdev;
+	int r;
+
+	file_priv = filp->private_data;
+	vgdev = file_priv->minor->dev->dev_private;
+	if (vgdev == NULL) {
+		DRM_ERROR(
+		 "filp->private_data->minor->dev->dev_private == NULL\n");
+		return -EINVAL;
+	}
+	r = ttm_bo_mmap(filp, vma, &vgdev->mman.bdev);
+#if 0
+	if (unlikely(r != 0))
+		return r;
+	if (unlikely(ttm_vm_ops == NULL)) {
+		ttm_vm_ops = vma->vm_ops;
+		virtio_gpu_ttm_vm_ops = *ttm_vm_ops;
+		virtio_gpu_ttm_vm_ops.fault = &virtio_gpu_ttm_fault;
+	}
+	vma->vm_ops = &virtio_gpu_ttm_vm_ops;
+	return 0;
+#else
+	return r;
+#endif
+}
+
+static int virtio_gpu_invalidate_caches(struct ttm_bo_device *bdev,
+					uint32_t flags)
+{
+	return 0;
+}
+
+static int ttm_bo_man_get_node(struct ttm_mem_type_manager *man,
+			       struct ttm_buffer_object *bo,
+			       const struct ttm_place *place,
+			       struct ttm_mem_reg *mem)
+{
+	mem->mm_node = (void *)1;
+	return 0;
+}
+
+static void ttm_bo_man_put_node(struct ttm_mem_type_manager *man,
+				struct ttm_mem_reg *mem)
+{
+	mem->mm_node = (void *)NULL;
+	return;
+}
+
+static int ttm_bo_man_init(struct ttm_mem_type_manager *man,
+			   unsigned long p_size)
+{
+	return 0;
+}
+
+static int ttm_bo_man_takedown(struct ttm_mem_type_manager *man)
+{
+	return 0;
+}
+
+static void ttm_bo_man_debug(struct ttm_mem_type_manager *man,
+			     const char *prefix)
+{
+}
+
+static const struct ttm_mem_type_manager_func virtio_gpu_bo_manager_func = {
+	ttm_bo_man_init,
+	ttm_bo_man_takedown,
+	ttm_bo_man_get_node,
+	ttm_bo_man_put_node,
+	ttm_bo_man_debug
+};
+
+static int virtio_gpu_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
+				    struct ttm_mem_type_manager *man)
+{
+	struct virtio_gpu_device *vgdev;
+
+	vgdev = virtio_gpu_get_vgdev(bdev);
+
+	switch (type) {
+	case TTM_PL_SYSTEM:
+		/* System memory */
+		man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
+		man->available_caching = TTM_PL_MASK_CACHING;
+		man->default_caching = TTM_PL_FLAG_CACHED;
+		break;
+	case TTM_PL_TT:
+		man->func = &virtio_gpu_bo_manager_func;
+		man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
+		man->available_caching = TTM_PL_MASK_CACHING;
+		man->default_caching = TTM_PL_FLAG_CACHED;
+		break;
+	default:
+		DRM_ERROR("Unsupported memory type %u\n", (unsigned)type);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void virtio_gpu_evict_flags(struct ttm_buffer_object *bo,
+				struct ttm_placement *placement)
+{
+	static struct ttm_place placements = {
+		.fpfn  = 0,
+		.lpfn  = 0,
+		.flags = TTM_PL_MASK_CACHING | TTM_PL_FLAG_SYSTEM,
+	};
+
+	placement->placement = &placements;
+	placement->busy_placement = &placements;
+	placement->num_placement = 1;
+	placement->num_busy_placement = 1;
+	return;
+}
+
+static int virtio_gpu_verify_access(struct ttm_buffer_object *bo,
+				    struct file *filp)
+{
+	return 0;
+}
+
+static int virtio_gpu_ttm_io_mem_reserve(struct ttm_bo_device *bdev,
+					 struct ttm_mem_reg *mem)
+{
+	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
+
+	mem->bus.addr = NULL;
+	mem->bus.offset = 0;
+	mem->bus.size = mem->num_pages << PAGE_SHIFT;
+	mem->bus.base = 0;
+	mem->bus.is_iomem = false;
+	if (!(man->flags & TTM_MEMTYPE_FLAG_MAPPABLE))
+		return -EINVAL;
+	switch (mem->mem_type) {
+	case TTM_PL_SYSTEM:
+	case TTM_PL_TT:
+		/* system memory */
+		return 0;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void virtio_gpu_ttm_io_mem_free(struct ttm_bo_device *bdev,
+				       struct ttm_mem_reg *mem)
+{
+}
+
+/*
+ * TTM backend functions.
+ */
+struct virtio_gpu_ttm_tt {
+	struct ttm_dma_tt		ttm;
+	struct virtio_gpu_device	*vgdev;
+	u64				offset;
+};
+
+static int virtio_gpu_ttm_backend_bind(struct ttm_tt *ttm,
+				       struct ttm_mem_reg *bo_mem)
+{
+	struct virtio_gpu_ttm_tt *gtt = (void *)ttm;
+
+	gtt->offset = (unsigned long)(bo_mem->start << PAGE_SHIFT);
+	if (!ttm->num_pages)
+		WARN(1, "nothing to bind %lu pages for mreg %p back %p!\n",
+		     ttm->num_pages, bo_mem, ttm);
+
+	/* Not implemented */
+	return 0;
+}
+
+static int virtio_gpu_ttm_backend_unbind(struct ttm_tt *ttm)
+{
+	/* Not implemented */
+	return 0;
+}
+
+static void virtio_gpu_ttm_backend_destroy(struct ttm_tt *ttm)
+{
+	struct virtio_gpu_ttm_tt *gtt = (void *)ttm;
+
+	ttm_dma_tt_fini(&gtt->ttm);
+	kfree(gtt);
+}
+
+static struct ttm_backend_func virtio_gpu_backend_func = {
+	.bind = &virtio_gpu_ttm_backend_bind,
+	.unbind = &virtio_gpu_ttm_backend_unbind,
+	.destroy = &virtio_gpu_ttm_backend_destroy,
+};
+
+static int virtio_gpu_ttm_tt_populate(struct ttm_tt *ttm)
+{
+	if (ttm->state != tt_unpopulated)
+		return 0;
+
+	return ttm_pool_populate(ttm);
+}
+
+static void virtio_gpu_ttm_tt_unpopulate(struct ttm_tt *ttm)
+{
+	ttm_pool_unpopulate(ttm);
+}
+
+static struct ttm_tt *virtio_gpu_ttm_tt_create(struct ttm_bo_device *bdev,
+					       unsigned long size,
+					       uint32_t page_flags,
+					       struct page *dummy_read_page)
+{
+	struct virtio_gpu_device *vgdev;
+	struct virtio_gpu_ttm_tt *gtt;
+
+	vgdev = virtio_gpu_get_vgdev(bdev);
+	gtt = kzalloc(sizeof(struct virtio_gpu_ttm_tt), GFP_KERNEL);
+	if (gtt == NULL)
+		return NULL;
+	gtt->ttm.ttm.func = &virtio_gpu_backend_func;
+	gtt->vgdev = vgdev;
+	if (ttm_dma_tt_init(&gtt->ttm, bdev, size, page_flags,
+			    dummy_read_page)) {
+		kfree(gtt);
+		return NULL;
+	}
+	return &gtt->ttm.ttm;
+}
+
+static void virtio_gpu_move_null(struct ttm_buffer_object *bo,
+				 struct ttm_mem_reg *new_mem)
+{
+	struct ttm_mem_reg *old_mem = &bo->mem;
+
+	BUG_ON(old_mem->mm_node != NULL);
+	*old_mem = *new_mem;
+	new_mem->mm_node = NULL;
+}
+
+static int virtio_gpu_bo_move(struct ttm_buffer_object *bo,
+			      bool evict, bool interruptible,
+			      bool no_wait_gpu,
+			      struct ttm_mem_reg *new_mem)
+{
+	virtio_gpu_move_null(bo, new_mem);
+	return 0;
+}
+
+static void virtio_gpu_bo_move_notify(struct ttm_buffer_object *tbo,
+				      struct ttm_mem_reg *new_mem)
+{
+	struct virtio_gpu_object *bo;
+	struct virtio_gpu_device *vgdev;
+
+	bo = container_of(tbo, struct virtio_gpu_object, tbo);
+	vgdev = (struct virtio_gpu_device *)bo->gem_base.dev->dev_private;
+
+	if (!new_mem || (new_mem->placement & TTM_PL_FLAG_SYSTEM)) {
+		if (bo->hw_res_handle)
+			virtio_gpu_cmd_resource_inval_backing(vgdev,
+							   bo->hw_res_handle);
+
+	} else if (new_mem->placement & TTM_PL_FLAG_TT) {
+		if (bo->hw_res_handle) {
+			virtio_gpu_object_attach(vgdev, bo, bo->hw_res_handle,
+						 NULL);
+		}
+	}
+}
+
+static void virtio_gpu_bo_swap_notify(struct ttm_buffer_object *tbo)
+{
+	struct virtio_gpu_object *bo;
+	struct virtio_gpu_device *vgdev;
+
+	bo = container_of(tbo, struct virtio_gpu_object, tbo);
+	vgdev = (struct virtio_gpu_device *)bo->gem_base.dev->dev_private;
+
+	if (bo->pages)
+		virtio_gpu_object_free_sg_table(bo);
+}
+
+static struct ttm_bo_driver virtio_gpu_bo_driver = {
+	.ttm_tt_create = &virtio_gpu_ttm_tt_create,
+	.ttm_tt_populate = &virtio_gpu_ttm_tt_populate,
+	.ttm_tt_unpopulate = &virtio_gpu_ttm_tt_unpopulate,
+	.invalidate_caches = &virtio_gpu_invalidate_caches,
+	.init_mem_type = &virtio_gpu_init_mem_type,
+	.evict_flags = &virtio_gpu_evict_flags,
+	.move = &virtio_gpu_bo_move,
+	.verify_access = &virtio_gpu_verify_access,
+	.io_mem_reserve = &virtio_gpu_ttm_io_mem_reserve,
+	.io_mem_free = &virtio_gpu_ttm_io_mem_free,
+	.move_notify = &virtio_gpu_bo_move_notify,
+	.swap_notify = &virtio_gpu_bo_swap_notify,
+};
+
+int virtio_gpu_ttm_init(struct virtio_gpu_device *vgdev)
+{
+	int r;
+
+	r = virtio_gpu_ttm_global_init(vgdev);
+	if (r)
+		return r;
+	/* No others user of address space so set it to 0 */
+	r = ttm_bo_device_init(&vgdev->mman.bdev,
+			       vgdev->mman.bo_global_ref.ref.object,
+			       &virtio_gpu_bo_driver,
+			       vgdev->ddev->anon_inode->i_mapping,
+			       DRM_FILE_PAGE_OFFSET, 0);
+	if (r) {
+		DRM_ERROR("failed initializing buffer object driver(%d).\n", r);
+		goto err_dev_init;
+		return r;
+	}
+
+	r = ttm_bo_init_mm(&vgdev->mman.bdev, TTM_PL_TT, 0);
+	if (r) {
+		DRM_ERROR("Failed initializing GTT heap.\n");
+		goto err_mm_init;
+		return r;
+	}
+	return 0;
+
+err_mm_init:
+	ttm_bo_device_release(&vgdev->mman.bdev);
+err_dev_init:
+	virtio_gpu_ttm_global_fini(vgdev);
+	return r;
+}
+
+void virtio_gpu_ttm_fini(struct virtio_gpu_device *vgdev)
+{
+	ttm_bo_device_release(&vgdev->mman.bdev);
+	virtio_gpu_ttm_global_fini(vgdev);
+	DRM_INFO("virtio_gpu: ttm finalized\n");
+}