[PATCH v4] drm/virtio: Track total GPU memory for virtio driver

[Yiwei Zhang]

On the success of virtio_gpu_object_create, add size of newly allocated
bo to the tracked total_mem. In drm_gem_object_funcs.free, after the gem
bo loses its last refcount, subtract the bo size from the tracked
total_mem if the original underlying memory allocation is successful.

It's more accurate to do this in device driver layer to best match when
the underlying resource gets allocated and destroyed during tracing.

Signed-off-by: Yiwei Zhang <zzyiwei at android.com>
---
 drivers/gpu/drm/virtio/Kconfig          |  1 +
 drivers/gpu/drm/virtio/virtgpu_drv.h    |  2 ++
 drivers/gpu/drm/virtio/virtgpu_object.c | 11 +++++++++++
 3 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/virtio/Kconfig b/drivers/gpu/drm/virtio/Kconfig
index b925b8b1da16..e103b7e883b1 100644
--- a/drivers/gpu/drm/virtio/Kconfig
+++ b/drivers/gpu/drm/virtio/Kconfig
@@ -5,6 +5,7 @@ config DRM_VIRTIO_GPU
 	select DRM_KMS_HELPER
 	select DRM_GEM_SHMEM_HELPER
 	select VIRTIO_DMA_SHARED_BUFFER
+	select TRACE_GPU_MEM
 	help
 	   This is the virtual GPU driver for virtio.  It can be used with
 	   QEMU based VMMs (like KVM or Xen).
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 6a232553c99b..c5622f9b591f 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -249,6 +249,8 @@ struct virtio_gpu_device {
 	spinlock_t resource_export_lock;
 	/* protects map state and host_visible_mm */
 	spinlock_t host_visible_lock;
+
+	atomic64_t total_mem;
 };
 
 struct virtio_gpu_fpriv {
diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index d69a5b6da553..e2251fc41509 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -25,12 +25,21 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/moduleparam.h>
+#include <trace/events/gpu_mem.h>
 
 #include "virtgpu_drv.h"
 
 static int virtio_gpu_virglrenderer_workaround = 1;
 module_param_named(virglhack, virtio_gpu_virglrenderer_workaround, int, 0400);
 
+static inline void virtio_gpu_trace_total_mem(struct virtio_gpu_device *vgdev,
+					      s64 delta)
+{
+	u64 total_mem = atomic64_add_return(delta, &vgdev->total_mem);
+
+	trace_gpu_mem_total(vgdev->ddev->primary->index, 0, total_mem);
+}
+
 int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev, uint32_t *resid)
 {
 	if (virtio_gpu_virglrenderer_workaround) {
@@ -104,6 +113,7 @@ static void virtio_gpu_free_object(struct drm_gem_object *obj)
 	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
 
 	if (bo->created) {
+		virtio_gpu_trace_total_mem(vgdev, -(obj->size));
 		virtio_gpu_cmd_unref_resource(vgdev, bo);
 		virtio_gpu_notify(vgdev);
 		/* completion handler calls virtio_gpu_cleanup_object() */
@@ -265,6 +275,7 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 		virtio_gpu_object_attach(vgdev, bo, ents, nents);
 	}
 
+	virtio_gpu_trace_total_mem(vgdev, shmem_obj->base.size);
 	*bo_ptr = bo;
 	return 0;
 
-- 
2.30.0.280.ga3ce27912f-goog