[PATCH v5 0/3] Support virtio cross-device resources

[PATCH v5 0/3] Support virtio cross-device resources

[David Stevens]

This patchset implements the current proposal for virtio cross-device
resource sharing [1]. It will be used to import virtio resources into
the virtio-video driver currently under discussion [2]. The patch
under consideration to add support in the virtio-video driver is [3].
It uses the APIs from v3 of this series, but the changes to update it
are relatively minor.

This patchset adds a new flavor of dma-bufs that supports querying the
underlying virtio object UUID, as well as adding support for exporting
resources from virtgpu.

[1] https://markmail.org/thread/2ypjt5cfeu3m6lxu
[2] https://markmail.org/thread/p5d3k566srtdtute
[3] https://markmail.org/thread/j4xlqaaim266qpks

v4 -> v5 changes:
 - Remove virtio_dma_buf_export_info.

David Stevens (3):
  virtio: add dma-buf support for exported objects
  virtio-gpu: add VIRTIO_GPU_F_RESOURCE_UUID feature
  drm/virtio: Support virtgpu exported resources

 drivers/gpu/drm/virtio/virtgpu_drv.c   |  3 +
 drivers/gpu/drm/virtio/virtgpu_drv.h   | 20 ++++++
 drivers/gpu/drm/virtio/virtgpu_kms.c   |  4 ++
 drivers/gpu/drm/virtio/virtgpu_prime.c | 96 +++++++++++++++++++++++++-
 drivers/gpu/drm/virtio/virtgpu_vq.c    | 55 +++++++++++++++
 drivers/virtio/Makefile                |  2 +-
 drivers/virtio/virtio.c                |  6 ++
 drivers/virtio/virtio_dma_buf.c        | 82 ++++++++++++++++++++++
 include/linux/virtio.h                 |  1 +
 include/linux/virtio_dma_buf.h         | 37 ++++++++++
 include/uapi/linux/virtio_gpu.h        | 19 +++++
 11 files changed, 321 insertions(+), 4 deletions(-)
 create mode 100644 drivers/virtio/virtio_dma_buf.c
 create mode 100644 include/linux/virtio_dma_buf.h

-- 
2.27.0.278.ge193c7cf3a9-goog

[PATCH v5 1/3] virtio: add dma-buf support for exported objects

[David Stevens]

This change adds a new flavor of dma-bufs that can be used by virtio
drivers to share exported objects. A virtio dma-buf can be queried by
virtio drivers to obtain the UUID which identifies the underlying
exported object.

Signed-off-by: David Stevens <stevensd@chromium.org>
---
 drivers/virtio/Makefile         |  2 +-
 drivers/virtio/virtio.c         |  6 +++
 drivers/virtio/virtio_dma_buf.c | 82 +++++++++++++++++++++++++++++++++
 include/linux/virtio.h          |  1 +
 include/linux/virtio_dma_buf.h  | 37 +++++++++++++++
 5 files changed, 127 insertions(+), 1 deletion(-)
 create mode 100644 drivers/virtio/virtio_dma_buf.c
 create mode 100644 include/linux/virtio_dma_buf.h

diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 29a1386ecc03..ecdae5b596de 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
+obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o virtio_dma_buf.o
 obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
 obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
 virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index a977e32a88f2..5d46f0ded92d 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -357,6 +357,12 @@ int register_virtio_device(struct virtio_device *dev)
 }
 EXPORT_SYMBOL_GPL(register_virtio_device);
 
+bool is_virtio_device(struct device *dev)
+{
+	return dev->bus == &virtio_bus;
+}
+EXPORT_SYMBOL_GPL(is_virtio_device);
+
 void unregister_virtio_device(struct virtio_device *dev)
 {
 	int index = dev->index; /* save for after device release */
diff --git a/drivers/virtio/virtio_dma_buf.c b/drivers/virtio/virtio_dma_buf.c
new file mode 100644
index 000000000000..fa0d3a668f53
--- /dev/null
+++ b/drivers/virtio/virtio_dma_buf.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * dma-bufs for virtio exported objects
+ *
+ * Copyright (C) 2020 Google, Inc.
+ */
+
+#include <linux/virtio_dma_buf.h>
+
+/**
+ * virtio_dma_buf_export - Creates a new dma-buf for a virtio exported object
+ * @exp_info: [in] see dma_buf_export(). ops MUST refer to a dma_buf_ops
+ *	struct embedded in a virtio_dma_buf_ops.
+ *
+ * This wraps dma_buf_export() to allow virtio drivers to create a dma-buf
+ * for an virtio exported object that can be queried by other virtio drivers
+ * for the object's UUID.
+ */
+struct dma_buf *virtio_dma_buf_export(
+		const struct dma_buf_export_info *exp_info)
+{
+	const struct virtio_dma_buf_ops *virtio_ops = container_of(
+			exp_info->ops, const struct virtio_dma_buf_ops, ops);
+
+	if (!exp_info->ops
+		|| exp_info->ops->attach != &virtio_dma_buf_attach
+		|| !virtio_ops->get_uuid) {
+		return ERR_PTR(-EINVAL);
+	}
+
+	return dma_buf_export(exp_info);
+}
+EXPORT_SYMBOL(virtio_dma_buf_export);
+
+/**
+ * virtio_dma_buf_attach - mandatory attach callback for virtio dma-bufs
+ */
+int virtio_dma_buf_attach(struct dma_buf *dma_buf,
+			  struct dma_buf_attachment *attach)
+{
+	int ret;
+	const struct virtio_dma_buf_ops *ops = container_of(
+			dma_buf->ops, const struct virtio_dma_buf_ops, ops);
+
+	if (ops->device_attach) {
+		ret = ops->device_attach(dma_buf, attach);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(virtio_dma_buf_attach);
+
+/**
+ * is_virtio_dma_buf - returns true if the given dma-buf is a virtio dma-buf
+ * @dma_buf: buffer to query
+ */
+bool is_virtio_dma_buf(struct dma_buf *dma_buf)
+{
+	return dma_buf->ops->attach == &virtio_dma_buf_attach;
+}
+EXPORT_SYMBOL(is_virtio_dma_buf);
+
+/**
+ * virtio_dma_buf_get_uuid - gets the uuid of the virtio dma-buf's exported object
+ * @dma_buf: [in] buffer to query
+ * @uuid: [out] the uuid
+ *
+ * Returns: 0 on success, negative on failure.
+ */
+int virtio_dma_buf_get_uuid(struct dma_buf *dma_buf,
+			    uuid_t *uuid)
+{
+	const struct virtio_dma_buf_ops *ops = container_of(
+			dma_buf->ops, const struct virtio_dma_buf_ops, ops);
+
+	if (!is_virtio_dma_buf(dma_buf))
+		return -EINVAL;
+
+	return ops->get_uuid(dma_buf, uuid);
+}
+EXPORT_SYMBOL(virtio_dma_buf_get_uuid);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 15f906e4a748..9397e25616c4 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -128,6 +128,7 @@ static inline struct virtio_device *dev_to_virtio(struct device *_dev)
 void virtio_add_status(struct virtio_device *dev, unsigned int status);
 int register_virtio_device(struct virtio_device *dev);
 void unregister_virtio_device(struct virtio_device *dev);
+bool is_virtio_device(struct device *dev);
 
 void virtio_break_device(struct virtio_device *dev);
 
diff --git a/include/linux/virtio_dma_buf.h b/include/linux/virtio_dma_buf.h
new file mode 100644
index 000000000000..394bf04362d7
--- /dev/null
+++ b/include/linux/virtio_dma_buf.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * dma-bufs for virtio exported objects
+ *
+ * Copyright (C) 2020 Google, Inc.
+ */
+
+#ifndef _LINUX_VIRTIO_DMA_BUF_H
+#define _LINUX_VIRTIO_DMA_BUF_H
+
+#include <linux/dma-buf.h>
+#include <linux/uuid.h>
+#include <linux/virtio.h>
+
+/**
+ * struct virtio_dma_buf_ops - operations possible on exported object dma-buf
+ * @ops: the base dma_buf_ops. ops.attach MUST be virtio_dma_buf_attach.
+ * @device_attach: [optional] callback invoked by virtio_dma_buf_attach during
+ *		   all attach operations.
+ * @get_uid: [required] callback to get the uuid of the exported object.
+ */
+struct virtio_dma_buf_ops {
+	struct dma_buf_ops ops;
+	int (*device_attach)(struct dma_buf *dma_buf,
+			     struct dma_buf_attachment *attach);
+	int (*get_uuid)(struct dma_buf *dma_buf, uuid_t *uuid);
+};
+
+int virtio_dma_buf_attach(struct dma_buf *dma_buf,
+			  struct dma_buf_attachment *attach);
+
+struct dma_buf *virtio_dma_buf_export(
+		const struct dma_buf_export_info *exp_info);
+bool is_virtio_dma_buf(struct dma_buf *dma_buf);
+int virtio_dma_buf_get_uuid(struct dma_buf *dma_buf, uuid_t *uuid);
+
+#endif /* _LINUX_VIRTIO_DMA_BUF_H */
-- 
2.27.0.278.ge193c7cf3a9-goog

[PATCH v5 2/3] virtio-gpu: add VIRTIO_GPU_F_RESOURCE_UUID feature

[David Stevens]

This feature allows the guest to request a UUID from the host for a
particular virtio_gpu resource. The UUID can then be shared with other
virtio devices, to allow the other host devices to access the
virtio_gpu's corresponding host resource.

Signed-off-by: David Stevens <stevensd@chromium.org>
---
 include/uapi/linux/virtio_gpu.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
index 0c85914d9369..9721d58b4d58 100644
--- a/include/uapi/linux/virtio_gpu.h
+++ b/include/uapi/linux/virtio_gpu.h
@@ -50,6 +50,10 @@
  * VIRTIO_GPU_CMD_GET_EDID
  */
 #define VIRTIO_GPU_F_EDID                1
+/*
+ * VIRTIO_GPU_CMD_RESOURCE_ASSIGN_UUID
+ */
+#define VIRTIO_GPU_F_RESOURCE_UUID       2
 
 enum virtio_gpu_ctrl_type {
 	VIRTIO_GPU_UNDEFINED = 0,
@@ -66,6 +70,7 @@ enum virtio_gpu_ctrl_type {
 	VIRTIO_GPU_CMD_GET_CAPSET_INFO,
 	VIRTIO_GPU_CMD_GET_CAPSET,
 	VIRTIO_GPU_CMD_GET_EDID,
+	VIRTIO_GPU_CMD_RESOURCE_ASSIGN_UUID,
 
 	/* 3d commands */
 	VIRTIO_GPU_CMD_CTX_CREATE = 0x0200,
@@ -87,6 +92,7 @@ enum virtio_gpu_ctrl_type {
 	VIRTIO_GPU_RESP_OK_CAPSET_INFO,
 	VIRTIO_GPU_RESP_OK_CAPSET,
 	VIRTIO_GPU_RESP_OK_EDID,
+	VIRTIO_GPU_RESP_OK_RESOURCE_UUID,
 
 	/* error responses */
 	VIRTIO_GPU_RESP_ERR_UNSPEC = 0x1200,
@@ -340,4 +346,17 @@ enum virtio_gpu_formats {
 	VIRTIO_GPU_FORMAT_R8G8B8X8_UNORM  = 134,
 };
 
+/* VIRTIO_GPU_CMD_RESOURCE_ASSIGN_UUID */
+struct virtio_gpu_resource_assign_uuid {
+	struct virtio_gpu_ctrl_hdr hdr;
+	__le32 resource_id;
+	__le32 padding;
+};
+
+/* VIRTIO_GPU_RESP_OK_RESOURCE_UUID */
+struct virtio_gpu_resp_resource_uuid {
+	struct virtio_gpu_ctrl_hdr hdr;
+	__u8 uuid[16];
+};
+
 #endif
-- 
2.27.0.278.ge193c7cf3a9-goog

[PATCH v5 3/3] drm/virtio: Support virtgpu exported resources

[David Stevens]

Add support for UUID-based resource sharing mechanism to virtgpu. This
implements the new virtgpu commands and hooks them up to dma-buf's
get_uuid callback.

Signed-off-by: David Stevens <stevensd@chromium.org>
---
 drivers/gpu/drm/virtio/virtgpu_drv.c   |  3 +
 drivers/gpu/drm/virtio/virtgpu_drv.h   | 20 ++++++
 drivers/gpu/drm/virtio/virtgpu_kms.c   |  4 ++
 drivers/gpu/drm/virtio/virtgpu_prime.c | 96 +++++++++++++++++++++++++-
 drivers/gpu/drm/virtio/virtgpu_vq.c    | 55 +++++++++++++++
 5 files changed, 175 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index ab4bed78e656..b039f493bda9 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -165,6 +165,7 @@ static unsigned int features[] = {
 	VIRTIO_GPU_F_VIRGL,
 #endif
 	VIRTIO_GPU_F_EDID,
+	VIRTIO_GPU_F_RESOURCE_UUID,
 };
 static struct virtio_driver virtio_gpu_driver = {
 	.feature_table = features,
@@ -202,6 +203,8 @@ static struct drm_driver driver = {
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_mmap = drm_gem_prime_mmap,
+	.gem_prime_export = virtgpu_gem_prime_export,
+	.gem_prime_import = virtgpu_gem_prime_import,
 	.gem_prime_import_sg_table = virtgpu_gem_prime_import_sg_table,
 
 	.gem_create_object = virtio_gpu_create_object,
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 49bebdee6d91..39dc907aa805 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -49,6 +49,10 @@
 #define DRIVER_MINOR 1
 #define DRIVER_PATCHLEVEL 0
 
+#define UUID_INITIALIZING 0
+#define UUID_INITIALIZED 1
+#define UUID_INITIALIZATION_FAILED 2
+
 struct virtio_gpu_object_params {
 	uint32_t format;
 	uint32_t width;
@@ -71,6 +75,9 @@ struct virtio_gpu_object {
 	uint32_t hw_res_handle;
 	bool dumb;
 	bool created;
+
+	int uuid_state;
+	uuid_t uuid;
 };
 #define gem_to_virtio_gpu_obj(gobj) \
 	container_of((gobj), struct virtio_gpu_object, base.base)
@@ -200,6 +207,7 @@ struct virtio_gpu_device {
 	bool has_virgl_3d;
 	bool has_edid;
 	bool has_indirect;
+	bool has_resource_assign_uuid;
 
 	struct work_struct config_changed_work;
 
@@ -210,6 +218,8 @@ struct virtio_gpu_device {
 	struct virtio_gpu_drv_capset *capsets;
 	uint32_t num_capsets;
 	struct list_head cap_cache;
+
+	spinlock_t resource_export_lock;
 };
 
 struct virtio_gpu_fpriv {
@@ -335,6 +345,10 @@ void virtio_gpu_dequeue_fence_func(struct work_struct *work);
 
 void virtio_gpu_notify(struct virtio_gpu_device *vgdev);
 
+int
+virtio_gpu_cmd_resource_assign_uuid(struct virtio_gpu_device *vgdev,
+				    struct virtio_gpu_object_array *objs);
+
 /* virtgpu_display.c */
 void virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev);
 void virtio_gpu_modeset_fini(struct virtio_gpu_device *vgdev);
@@ -366,6 +380,12 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 bool virtio_gpu_is_shmem(struct virtio_gpu_object *bo);
 
 /* virtgpu_prime.c */
+struct dma_buf *virtgpu_gem_prime_export(struct drm_gem_object *obj,
+					 int flags);
+struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev,
+						struct dma_buf *buf);
+int virtgpu_gem_prime_get_uuid(struct drm_gem_object *obj,
+			       uuid_t *uuid);
 struct drm_gem_object *virtgpu_gem_prime_import_sg_table(
 	struct drm_device *dev, struct dma_buf_attachment *attach,
 	struct sg_table *sgt);
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index 023a030ca7b9..7bcd0c75effa 100644
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -125,6 +125,7 @@ int virtio_gpu_init(struct drm_device *dev)
 	vgdev->dev = dev->dev;
 
 	spin_lock_init(&vgdev->display_info_lock);
+	spin_lock_init(&vgdev->resource_export_lock);
 	ida_init(&vgdev->ctx_id_ida);
 	ida_init(&vgdev->resource_ida);
 	init_waitqueue_head(&vgdev->resp_wq);
@@ -153,6 +154,9 @@ int virtio_gpu_init(struct drm_device *dev)
 	if (virtio_has_feature(vgdev->vdev, VIRTIO_RING_F_INDIRECT_DESC)) {
 		vgdev->has_indirect = true;
 	}
+	if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_RESOURCE_UUID)) {
+		vgdev->has_resource_assign_uuid = true;
+	}
 
 	DRM_INFO("features: %cvirgl %cedid\n",
 		 vgdev->has_virgl_3d ? '+' : '-',
diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c
index 050d24c39a8f..acd14ef73d56 100644
--- a/drivers/gpu/drm/virtio/virtgpu_prime.c
+++ b/drivers/gpu/drm/virtio/virtgpu_prime.c
@@ -23,12 +23,102 @@
  */
 
 #include <drm/drm_prime.h>
+#include <linux/virtio_dma_buf.h>
 
 #include "virtgpu_drv.h"
 
-/* Empty Implementations as there should not be any other driver for a virtual
- * device that might share buffers with virtgpu
- */
+static int virtgpu_virtio_get_uuid(struct dma_buf *buf,
+				   uuid_t *uuid)
+{
+	struct drm_gem_object *obj = buf->priv;
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
+
+	wait_event(vgdev->resp_wq, bo->uuid_state != UUID_INITIALIZING);
+	if (bo->uuid_state != UUID_INITIALIZED)
+		return -ENODEV;
+
+	uuid_copy(uuid, &bo->uuid);
+
+	return 0;
+}
+
+const struct virtio_dma_buf_ops virtgpu_dmabuf_ops =  {
+	.ops = {
+		.cache_sgt_mapping = true,
+		.attach = virtio_dma_buf_attach,
+		.detach = drm_gem_map_detach,
+		.map_dma_buf = drm_gem_map_dma_buf,
+		.unmap_dma_buf = drm_gem_unmap_dma_buf,
+		.release = drm_gem_dmabuf_release,
+		.mmap = drm_gem_dmabuf_mmap,
+		.vmap = drm_gem_dmabuf_vmap,
+		.vunmap = drm_gem_dmabuf_vunmap,
+	},
+	.device_attach = drm_gem_map_attach,
+	.get_uuid = virtgpu_virtio_get_uuid,
+};
+
+struct dma_buf *virtgpu_gem_prime_export(struct drm_gem_object *obj,
+					 int flags)
+{
+	struct dma_buf *buf;
+	struct drm_device *dev = obj->dev;
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+	struct virtio_gpu_object_array *objs;
+	int ret = 0;
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+	if (vgdev->has_resource_assign_uuid) {
+		objs = virtio_gpu_array_alloc(1);
+		if (!objs)
+			return ERR_PTR(-ENOMEM);
+		virtio_gpu_array_add_obj(objs, &bo->base.base);
+
+		ret = virtio_gpu_cmd_resource_assign_uuid(vgdev, objs);
+		if (ret)
+			return ERR_PTR(ret);
+		virtio_gpu_notify(vgdev);
+	} else {
+		bo->uuid_state = UUID_INITIALIZATION_FAILED;
+	}
+
+	exp_info.ops = &virtgpu_dmabuf_ops.ops;
+	exp_info.size = obj->size;
+	exp_info.flags = flags;
+	exp_info.priv = obj;
+	exp_info.resv = obj->resv;
+
+	buf = virtio_dma_buf_export(&exp_info);
+	if (IS_ERR(buf))
+		return buf;
+
+	drm_dev_get(dev);
+	drm_gem_object_get(obj);
+
+	return buf;
+}
+
+struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev,
+						struct dma_buf *buf)
+{
+	struct drm_gem_object *obj;
+
+	if (buf->ops == &virtgpu_dmabuf_ops.ops) {
+		obj = buf->priv;
+		if (obj->dev == dev) {
+			/*
+			 * Importing dmabuf exported from our own gem increases
+			 * refcount on gem itself instead of f_count of dmabuf.
+			 */
+			drm_gem_object_get(obj);
+			return obj;
+		}
+	}
+
+	return drm_gem_prime_import(dev, buf);
+}
 
 struct drm_gem_object *virtgpu_gem_prime_import_sg_table(
 	struct drm_device *dev, struct dma_buf_attachment *attach,
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 9e663a5d9952..55af6fc7bc7c 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -1107,3 +1107,58 @@ void virtio_gpu_cursor_ping(struct virtio_gpu_device *vgdev,
 	memcpy(cur_p, &output->cursor, sizeof(output->cursor));
 	virtio_gpu_queue_cursor(vgdev, vbuf);
 }
+
+static void virtio_gpu_cmd_resource_uuid_cb(struct virtio_gpu_device *vgdev,
+					    struct virtio_gpu_vbuffer *vbuf)
+{
+	struct virtio_gpu_object *obj =
+		gem_to_virtio_gpu_obj(vbuf->objs->objs[0]);
+	struct virtio_gpu_resp_resource_uuid *resp =
+		(struct virtio_gpu_resp_resource_uuid *)vbuf->resp_buf;
+	uint32_t resp_type = le32_to_cpu(resp->hdr.type);
+
+	spin_lock(&vgdev->resource_export_lock);
+	WARN_ON(obj->uuid_state != UUID_INITIALIZING);
+
+	if (resp_type == VIRTIO_GPU_RESP_OK_RESOURCE_UUID &&
+			obj->uuid_state == UUID_INITIALIZING) {
+		memcpy(&obj->uuid.b, resp->uuid, sizeof(obj->uuid.b));
+		obj->uuid_state = UUID_INITIALIZED;
+	} else {
+		obj->uuid_state = UUID_INITIALIZATION_FAILED;
+	}
+	spin_unlock(&vgdev->resource_export_lock);
+
+	wake_up_all(&vgdev->resp_wq);
+}
+
+int
+virtio_gpu_cmd_resource_assign_uuid(struct virtio_gpu_device *vgdev,
+				    struct virtio_gpu_object_array *objs)
+{
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(objs->objs[0]);
+	struct virtio_gpu_resource_assign_uuid *cmd_p;
+	struct virtio_gpu_vbuffer *vbuf;
+	struct virtio_gpu_resp_resource_uuid *resp_buf;
+
+	resp_buf = kzalloc(sizeof(*resp_buf), GFP_KERNEL);
+	if (!resp_buf) {
+		spin_lock(&vgdev->resource_export_lock);
+		bo->uuid_state = UUID_INITIALIZATION_FAILED;
+		spin_unlock(&vgdev->resource_export_lock);
+		virtio_gpu_array_put_free(objs);
+		return -ENOMEM;
+	}
+
+	cmd_p = virtio_gpu_alloc_cmd_resp(vgdev,
+		virtio_gpu_cmd_resource_uuid_cb, &vbuf, sizeof(*cmd_p),
+		sizeof(struct virtio_gpu_resp_resource_uuid), resp_buf);
+	memset(cmd_p, 0, sizeof(*cmd_p));
+
+	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_ASSIGN_UUID);
+	cmd_p->resource_id = cpu_to_le32(bo->hw_res_handle);
+
+	vbuf->objs = objs;
+	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+	return 0;
+}
-- 
2.27.0.278.ge193c7cf3a9-goog

Re: [PATCH v5 0/3] Support virtio cross-device resources

[Michael S. Tsirkin]

On Tue, Jun 09, 2020 at 10:25:15AM +0900, David Stevens wrote:
> This patchset implements the current proposal for virtio cross-device
> resource sharing [1]. It will be used to import virtio resources into
> the virtio-video driver currently under discussion [2]. The patch
> under consideration to add support in the virtio-video driver is [3].
> It uses the APIs from v3 of this series, but the changes to update it
> are relatively minor.
> 
> This patchset adds a new flavor of dma-bufs that supports querying the
> underlying virtio object UUID, as well as adding support for exporting
> resources from virtgpu.

Gerd, David, if possible, please test this in configuration with
virtual VTD enabled but with iommu_platform=off
to make sure we didn't break this config.


Besides that, for virtio parts:

Acked-by: Michael S. Tsirkin <mst@redhat.com>


> [1] https://markmail.org/thread/2ypjt5cfeu3m6lxu
> [2] https://markmail.org/thread/p5d3k566srtdtute
> [3] https://markmail.org/thread/j4xlqaaim266qpks
> 
> v4 -> v5 changes:
>  - Remove virtio_dma_buf_export_info.
> 
> David Stevens (3):
>   virtio: add dma-buf support for exported objects
>   virtio-gpu: add VIRTIO_GPU_F_RESOURCE_UUID feature
>   drm/virtio: Support virtgpu exported resources
> 
>  drivers/gpu/drm/virtio/virtgpu_drv.c   |  3 +
>  drivers/gpu/drm/virtio/virtgpu_drv.h   | 20 ++++++
>  drivers/gpu/drm/virtio/virtgpu_kms.c   |  4 ++
>  drivers/gpu/drm/virtio/virtgpu_prime.c | 96 +++++++++++++++++++++++++-
>  drivers/gpu/drm/virtio/virtgpu_vq.c    | 55 +++++++++++++++
>  drivers/virtio/Makefile                |  2 +-
>  drivers/virtio/virtio.c                |  6 ++
>  drivers/virtio/virtio_dma_buf.c        | 82 ++++++++++++++++++++++
>  include/linux/virtio.h                 |  1 +
>  include/linux/virtio_dma_buf.h         | 37 ++++++++++
>  include/uapi/linux/virtio_gpu.h        | 19 +++++
>  11 files changed, 321 insertions(+), 4 deletions(-)
>  create mode 100644 drivers/virtio/virtio_dma_buf.c
>  create mode 100644 include/linux/virtio_dma_buf.h
> 
> -- 
> 2.27.0.278.ge193c7cf3a9-goog

Re: [virtio-dev] Re: [PATCH v5 0/3] Support virtio cross-device resources

[David Stevens]

Unless there are any remaining objections to these patches, what are
the next steps towards getting these merged? Sorry, I'm not familiar
with the workflow for contributing patches to Linux.

Thanks,
David

On Tue, Jun 9, 2020 at 6:53 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Tue, Jun 09, 2020 at 10:25:15AM +0900, David Stevens wrote:
> > This patchset implements the current proposal for virtio cross-device
> > resource sharing [1]. It will be used to import virtio resources into
> > the virtio-video driver currently under discussion [2]. The patch
> > under consideration to add support in the virtio-video driver is [3].
> > It uses the APIs from v3 of this series, but the changes to update it
> > are relatively minor.
> >
> > This patchset adds a new flavor of dma-bufs that supports querying the
> > underlying virtio object UUID, as well as adding support for exporting
> > resources from virtgpu.
>
> Gerd, David, if possible, please test this in configuration with
> virtual VTD enabled but with iommu_platform=off
> to make sure we didn't break this config.
>
>
> Besides that, for virtio parts:
>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
>
>
> > [1] https://markmail.org/thread/2ypjt5cfeu3m6lxu
> > [2] https://markmail.org/thread/p5d3k566srtdtute
> > [3] https://markmail.org/thread/j4xlqaaim266qpks
> >
> > v4 -> v5 changes:
> >  - Remove virtio_dma_buf_export_info.
> >
> > David Stevens (3):
> >   virtio: add dma-buf support for exported objects
> >   virtio-gpu: add VIRTIO_GPU_F_RESOURCE_UUID feature
> >   drm/virtio: Support virtgpu exported resources
> >
> >  drivers/gpu/drm/virtio/virtgpu_drv.c   |  3 +
> >  drivers/gpu/drm/virtio/virtgpu_drv.h   | 20 ++++++
> >  drivers/gpu/drm/virtio/virtgpu_kms.c   |  4 ++
> >  drivers/gpu/drm/virtio/virtgpu_prime.c | 96 +++++++++++++++++++++++++-
> >  drivers/gpu/drm/virtio/virtgpu_vq.c    | 55 +++++++++++++++
> >  drivers/virtio/Makefile                |  2 +-
> >  drivers/virtio/virtio.c                |  6 ++
> >  drivers/virtio/virtio_dma_buf.c        | 82 ++++++++++++++++++++++
> >  include/linux/virtio.h                 |  1 +
> >  include/linux/virtio_dma_buf.h         | 37 ++++++++++
> >  include/uapi/linux/virtio_gpu.h        | 19 +++++
> >  11 files changed, 321 insertions(+), 4 deletions(-)
> >  create mode 100644 drivers/virtio/virtio_dma_buf.c
> >  create mode 100644 include/linux/virtio_dma_buf.h
> >
> > --
> > 2.27.0.278.ge193c7cf3a9-goog
>
>
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>

Re: [virtio-dev] Re: [PATCH v5 0/3] Support virtio cross-device resources

[Gerd Hoffmann]

On Tue, Jun 23, 2020 at 10:31:28AM +0900, David Stevens wrote:
> Unless there are any remaining objections to these patches, what are
> the next steps towards getting these merged? Sorry, I'm not familiar
> with the workflow for contributing patches to Linux.

Sorry, just have been busy and not paying as much attention to drm
patches as usual.  Playing catch-up now.  Queued for drm-misc-next,
unless something goes wrong in my testing the patches should land
in linux-next soon and be merged upstream in the next merge window.

take care,
  Gerd

Re: [virtio-dev] Re: [PATCH v5 0/3] Support virtio cross-device resources

[Gerd Hoffmann]

On Mon, Aug 17, 2020 at 12:50:08PM +0200, Gerd Hoffmann wrote:
> On Tue, Jun 23, 2020 at 10:31:28AM +0900, David Stevens wrote:
> > Unless there are any remaining objections to these patches, what are
> > the next steps towards getting these merged? Sorry, I'm not familiar
> > with the workflow for contributing patches to Linux.
> 
> Sorry, just have been busy and not paying as much attention to drm
> patches as usual.  Playing catch-up now.  Queued for drm-misc-next,
> unless something goes wrong in my testing the patches should land
> in linux-next soon and be merged upstream in the next merge window.

Oh, spoke too soon.  scripts/checkpatch.pl has a bunch of codestyle
warnings.  Can you fix them and resend?

thanks,
  Gerd

Re: [virtio-dev] Re: [PATCH v5 0/3] Support virtio cross-device resources

[David Stevens]

On Mon, Aug 17, 2020 at 4:12 AM Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> On Mon, Aug 17, 2020 at 12:50:08PM +0200, Gerd Hoffmann wrote:
> > On Tue, Jun 23, 2020 at 10:31:28AM +0900, David Stevens wrote:
> > > Unless there are any remaining objections to these patches, what are
> > > the next steps towards getting these merged? Sorry, I'm not familiar
> > > with the workflow for contributing patches to Linux.
> >
> > Sorry, just have been busy and not paying as much attention to drm
> > patches as usual.  Playing catch-up now.  Queued for drm-misc-next,
> > unless something goes wrong in my testing the patches should land
> > in linux-next soon and be merged upstream in the next merge window.
>
> Oh, spoke too soon.  scripts/checkpatch.pl has a bunch of codestyle
> warnings.  Can you fix them and resend?

Sent a new version to fix the line length warning. There's still a
MAINTAINER warning, but I think the new virtio_dma_buf file can fall
under virtio core (and the existing wildcards do match it), rather
than get its own MAINTAINER entry. I can break it out into its own
thing if that's better, though.

-David