[v1,4/7] drm/virtio: implement userptr: add userptr obj

Commit Message

Honglei Huang Feb. 28, 2025, 5:36 a.m. UTC

From: Honglei Huang <[e-mail]>

Add implement for virtio gpu userptr. Current solution is pinning
all the user space memory. The UMD needs manage all the userptrs.

Signed-off-by: Honglei Huang <[e-mail]>
---
 drivers/gpu/drm/virtio/Makefile          |   3 +-
 drivers/gpu/drm/virtio/virtgpu_drv.h     |  33 ++++
 drivers/gpu/drm/virtio/virtgpu_object.c  |   5 +
 drivers/gpu/drm/virtio/virtgpu_userptr.c | 230 +++++++++++++++++++++++
 4 files changed, 270 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/virtio/virtgpu_userptr.c

Patch

diff --git a/drivers/gpu/drm/virtio/Makefile b/drivers/gpu/drm/virtio/Makefile
index d2e1788a8227..fe7332a621aa 100644
--- a/drivers/gpu/drm/virtio/Makefile
+++ b/drivers/gpu/drm/virtio/Makefile
@@ -6,6 +6,7 @@ 
 virtio-gpu-y := virtgpu_drv.o virtgpu_kms.o virtgpu_gem.o virtgpu_vram.o \
 	virtgpu_display.o virtgpu_vq.o \
 	virtgpu_fence.o virtgpu_object.o virtgpu_debugfs.o virtgpu_plane.o \
-	virtgpu_ioctl.o virtgpu_prime.o virtgpu_trace_points.o virtgpu_submit.o
+	virtgpu_ioctl.o virtgpu_prime.o virtgpu_trace_points.o virtgpu_submit.o \
+	virtgpu_userptr.o
 
 obj-$(CONFIG_DRM_VIRTIO_GPU) += virtio-gpu.o
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 7bdcbaa20ef1..f3dcbd241f5a 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -85,6 +85,7 @@  struct virtio_gpu_object_params {
 	uint32_t blob_mem;
 	uint32_t blob_flags;
 	uint64_t blob_id;
+	uint64_t userptr;
 };
 
 struct virtio_gpu_object {
@@ -112,12 +113,38 @@  struct virtio_gpu_object_vram {
 	struct drm_mm_node vram_node;
 };
 
+struct virtio_gpu_object_userptr;
+
+struct virtio_gpu_object_userptr_ops {
+	int (*get_pages)(struct virtio_gpu_object_userptr *userptr);
+	void (*put_pages)(struct virtio_gpu_object_userptr *userptr);
+	void (*release)(struct virtio_gpu_object_userptr *userptr);
+};
+struct virtio_gpu_object_userptr {
+	struct virtio_gpu_object base;
+	const struct virtio_gpu_object_userptr_ops *ops;
+	struct mutex lock;
+
+	uint64_t start;
+	uint32_t npages;
+	uint32_t bo_handle;
+	uint32_t flags;
+
+	struct virtio_gpu_device *vgdev;
+	struct drm_file *file;
+	struct page **pages;
+	struct sg_table *sgt;
+};
+
 #define to_virtio_gpu_shmem(virtio_gpu_object) \
 	container_of((virtio_gpu_object), struct virtio_gpu_object_shmem, base)
 
 #define to_virtio_gpu_vram(virtio_gpu_object) \
 	container_of((virtio_gpu_object), struct virtio_gpu_object_vram, base)
 
+#define to_virtio_gpu_userptr(virtio_gpu_object) \
+	container_of((virtio_gpu_object), struct virtio_gpu_object_userptr, base)
+
 struct virtio_gpu_object_array {
 	struct ww_acquire_ctx ticket;
 	struct list_head next;
@@ -489,4 +516,10 @@  void virtio_gpu_vram_unmap_dma_buf(struct device *dev,
 int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
 				struct drm_file *file);
 
+/* virtgpu_userptr.c */
+int virtio_gpu_userptr_create(struct virtio_gpu_device *vgdev,
+			      struct drm_file *file,
+			      struct virtio_gpu_object_params *params,
+			      struct virtio_gpu_object **bo_ptr);
+bool virtio_gpu_is_userptr(struct virtio_gpu_object *bo);
 #endif
diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index c7e74cf13022..31659b0a028d 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -80,6 +80,11 @@  void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo)
 		drm_gem_free_mmap_offset(&vram->base.base.base);
 		drm_gem_object_release(&vram->base.base.base);
 		kfree(vram);
+	} else if (virtio_gpu_is_userptr(bo)) {
+		struct virtio_gpu_object_userptr *userptr = to_virtio_gpu_userptr(bo);
+
+		drm_gem_object_release(&userptr->base.base.base);
+		kfree(userptr);
 	}
 }
 
diff --git a/drivers/gpu/drm/virtio/virtgpu_userptr.c b/drivers/gpu/drm/virtio/virtgpu_userptr.c
new file mode 100644
index 000000000000..b4a08811d345
--- /dev/null
+++ b/drivers/gpu/drm/virtio/virtgpu_userptr.c
@@ -0,0 +1,230 @@ 
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/dma-mapping.h>
+#include <linux/mm.h>
+#include <linux/pid.h>
+#include <linux/vmalloc.h>
+
+#include "virtgpu_drv.h"
+#include "drm/drm_gem.h"
+
+static struct sg_table *
+virtio_gpu_userptr_get_sg_table(struct drm_gem_object *obj);
+
+static void virtio_gpu_userptr_free(struct drm_gem_object *obj)
+{
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
+	struct virtio_gpu_object_userptr *userptr = to_virtio_gpu_userptr(bo);
+
+	if (bo->created) {
+		userptr->ops->release(userptr);
+
+		virtio_gpu_cmd_unref_resource(vgdev, bo);
+		virtio_gpu_notify(vgdev);
+	}
+}
+
+static void virtio_gpu_userptr_object_close(struct drm_gem_object *obj,
+					    struct drm_file *file)
+{
+	virtio_gpu_gem_object_close(obj, file);
+}
+
+static const struct drm_gem_object_funcs virtio_gpu_userptr_funcs = {
+	.open = virtio_gpu_gem_object_open,
+	.close = virtio_gpu_userptr_object_close,
+	.free = virtio_gpu_userptr_free,
+	.get_sg_table = virtio_gpu_userptr_get_sg_table,
+};
+
+bool virtio_gpu_is_userptr(struct virtio_gpu_object *bo)
+{
+	return bo->base.base.funcs == &virtio_gpu_userptr_funcs;
+}
+
+static int
+virtio_gpu_userptr_get_pages(struct virtio_gpu_object_userptr *userptr)
+{
+	unsigned int flag = FOLL_LONGTERM;
+	unsigned int num_pages, pinned = 0;
+	int ret = 0;
+
+	if (userptr->pages)
+		return 0;
+
+	userptr->pages = kvmalloc_array(userptr->npages, sizeof(struct page *),
+					GFP_KERNEL);
+	if (!userptr->pages)
+		return -ENOMEM;
+
+	if (!(userptr->flags & VIRTGPU_BLOB_FLAG_USERPTR_RDONLY))
+		flag |= FOLL_WRITE;
+
+	do {
+		num_pages = userptr->npages - pinned;
+
+		ret = pin_user_pages_fast(userptr->start + pinned * PAGE_SIZE,
+					  num_pages, flag,
+					  userptr->pages + pinned);
+
+		if (ret < 0) {
+			if (pinned)
+				unpin_user_pages(userptr->pages, pinned);
+			kvfree(userptr->pages);
+			return ret;
+		}
+
+		pinned += ret;
+
+	} while (pinned < userptr->npages);
+
+	return 0;
+}
+
+static void
+virtio_gpu_userptr_put_pages(struct virtio_gpu_object_userptr *userptr)
+{
+	if (userptr->pages) {
+		unpin_user_pages(userptr->pages, userptr->npages);
+		kvfree(userptr->pages);
+		userptr->pages = NULL;
+	}
+
+	if (userptr->sgt) {
+		sg_free_table(userptr->sgt);
+		kfree(userptr->sgt);
+		userptr->sgt = NULL;
+	}
+}
+
+static void
+virtio_gpu_userptr_release(struct virtio_gpu_object_userptr *userptr)
+{
+	mutex_lock(&userptr->lock);
+	userptr->ops->put_pages(userptr);
+	mutex_unlock(&userptr->lock);
+}
+
+static struct sg_table *
+virtio_gpu_userptr_get_sg_table(struct drm_gem_object *obj)
+{
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+	struct virtio_gpu_object_userptr *userptr = to_virtio_gpu_userptr(bo);
+
+	mutex_lock(&userptr->lock);
+	if (!userptr->pages) {
+		if (userptr->ops->get_pages(userptr)) {
+			mutex_unlock(&userptr->lock);
+			return ERR_PTR(-ENOMEM);
+		}
+	}
+
+	if (!userptr->sgt)
+		userptr->sgt = drm_prime_pages_to_sg(NULL, userptr->pages,
+						     userptr->npages);
+	mutex_unlock(&userptr->lock);
+
+	return userptr->sgt;
+}
+
+static int
+virtio_gpu_userptr_init(struct drm_device *dev, struct drm_file *file,
+			struct virtio_gpu_object_userptr *userptr,
+			struct virtio_gpu_object_params *params,
+			const struct virtio_gpu_object_userptr_ops *ops)
+{
+	uint32_t page_offset;
+	uint64_t aligned_size;
+	uint64_t aligned_addr;
+	int ret;
+	struct drm_gem_object *obj;
+
+	page_offset = params->userptr & (PAGE_SIZE - 1UL);
+	aligned_addr = params->userptr - page_offset;
+	aligned_size = roundup(page_offset + params->size, PAGE_SIZE);
+
+	userptr->start = aligned_addr;
+	userptr->npages = aligned_size >> PAGE_SHIFT;
+	userptr->flags = params->blob_flags;
+
+	mutex_init(&userptr->lock);
+	userptr->vgdev = dev->dev_private;
+	userptr->file = file;
+	userptr->ops = ops;
+
+	obj = &userptr->base.base.base;
+	obj->funcs = &virtio_gpu_userptr_funcs;
+
+	drm_gem_private_object_init(dev, obj, aligned_size);
+
+	ret = virtio_gpu_resource_id_get(userptr->vgdev,
+					 &userptr->base.hw_res_handle);
+
+	return ret;
+}
+
+static const struct virtio_gpu_object_userptr_ops virtio_gpu_userptr_ops = {
+	.get_pages = virtio_gpu_userptr_get_pages,
+	.put_pages = virtio_gpu_userptr_put_pages,
+	.release = virtio_gpu_userptr_release,
+};
+
+int virtio_gpu_userptr_create(struct virtio_gpu_device *vgdev,
+			      struct drm_file *file,
+			      struct virtio_gpu_object_params *params,
+			      struct virtio_gpu_object **bo_ptr)
+{
+	struct virtio_gpu_object_userptr *userptr;
+	int ret, si;
+	struct sg_table *sgt;
+	struct scatterlist *sg;
+	struct virtio_gpu_mem_entry *ents;
+
+	if (!params->size)
+		return -EINVAL;
+
+	if (!access_ok((char __user *)(unsigned long)params->userptr,
+		       params->size))
+		return -EFAULT;
+
+	userptr = kzalloc(sizeof(*userptr), GFP_KERNEL);
+	if (!userptr)
+		return -ENOMEM;
+
+	ret = virtio_gpu_userptr_init(vgdev->ddev, file, userptr, params,
+				      &virtio_gpu_userptr_ops);
+
+	if (ret)
+		goto failed_free;
+
+	sgt = virtio_gpu_userptr_get_sg_table(&userptr->base.base.base);
+
+	if (IS_ERR(sgt)) {
+		ret = PTR_ERR(sgt);
+		goto failed_free;
+	}
+
+	ents = kvmalloc_array(sgt->nents, sizeof(struct virtio_gpu_mem_entry),
+			      GFP_KERNEL);
+
+	if (!ents) {
+		ret = -ENOMEM;
+		goto failed_free;
+	}
+
+	for_each_sgtable_sg(sgt, sg, si) {
+		(ents)[si].addr = cpu_to_le64(sg_phys(sg));
+		(ents)[si].length = cpu_to_le32(sg->length);
+		(ents)[si].padding = 0;
+	}
+
+	virtio_gpu_cmd_resource_create_blob(vgdev, &userptr->base, params, ents,
+					    sgt->nents);
+
+	*bo_ptr = &userptr->base;
+	return 0;
+
+failed_free:
+	kfree(userptr);
+	return ret;
+}