[PATCH 1/2] drm/virtio: introduce the HOST_PAGE_SIZE feature

[Sergio Lopez <slp@xxxxxxxxxx>]

Introduce a new feature, HOST_PAGE_SIZE, that indicates the host
provides its page size as a value in virtio_gpu_config.

Signed-off-by: Sergio Lopez <slp@xxxxxxxxxx>
---
 drivers/gpu/drm/virtio/virtgpu_drv.c |  1 +
 drivers/gpu/drm/virtio/virtgpu_drv.h |  2 ++
 drivers/gpu/drm/virtio/virtgpu_kms.c | 13 ++++++++++---
 include/uapi/linux/virtio_gpu.h      |  5 +++++
 4 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index 188e126383c2..026fc061db6d 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -149,6 +149,7 @@ static unsigned int features[] = {
 	VIRTIO_GPU_F_RESOURCE_UUID,
 	VIRTIO_GPU_F_RESOURCE_BLOB,
 	VIRTIO_GPU_F_CONTEXT_INIT,
+	VIRTIO_GPU_F_HOST_PAGE_SIZE,
 };
 static struct virtio_driver virtio_gpu_driver = {
 	.feature_table = features,
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index bb7d86a0c6a1..5ce795deb1eb 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -249,6 +249,7 @@ struct virtio_gpu_device {
 	bool has_resource_blob;
 	bool has_host_visible;
 	bool has_context_init;
+	bool has_host_page_size;
 	struct virtio_shm_region host_visible_region;
 	struct drm_mm host_visible_mm;
 
@@ -262,6 +263,7 @@ struct virtio_gpu_device {
 	uint32_t num_capsets;
 	uint64_t capset_id_mask;
 	struct list_head cap_cache;
+	uint32_t host_page_size;
 
 	/* protects uuid state when exporting */
 	spinlock_t resource_export_lock;
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index 5a3b5aaed1f3..11cccc3ca560 100644
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -124,7 +124,7 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
 	struct virtio_gpu_device *vgdev;
 	/* this will expand later */
 	struct virtqueue *vqs[2];
-	u32 num_scanouts, num_capsets;
+	u32 num_scanouts, num_capsets, host_page_size;
 	int ret = 0;
 
 	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
@@ -197,6 +197,12 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
 	if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_CONTEXT_INIT)) {
 		vgdev->has_context_init = true;
 	}
+	if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_HOST_PAGE_SIZE)) {
+		vgdev->has_host_page_size = true;
+		virtio_cread_le(vgdev->vdev, struct virtio_gpu_config,
+				host_page_size, &host_page_size);
+		vgdev->host_page_size = host_page_size;
+	}
 
 	DRM_INFO("features: %cvirgl %cedid %cresource_blob %chost_visible",
 		 vgdev->has_virgl_3d    ? '+' : '-',
@@ -204,8 +210,9 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
 		 vgdev->has_resource_blob ? '+' : '-',
 		 vgdev->has_host_visible ? '+' : '-');
 
-	DRM_INFO("features: %ccontext_init\n",
-		 vgdev->has_context_init ? '+' : '-');
+	DRM_INFO("features: %ccontext_init %chost_page_size\n",
+		 vgdev->has_context_init ? '+' : '-',
+		 vgdev->has_host_page_size ? '+' : '-');
 
 	ret = virtio_find_vqs(vgdev->vdev, 2, vqs, callbacks, names, NULL);
 	if (ret) {
diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h
index 0e21f3998108..120e41bf83a5 100644
--- a/include/uapi/linux/virtio_gpu.h
+++ b/include/uapi/linux/virtio_gpu.h
@@ -64,6 +64,10 @@
  * context_init and multiple timelines
  */
 #define VIRTIO_GPU_F_CONTEXT_INIT        4
+/*
+ * Config struct contains host page size
+ */
+#define VIRTIO_GPU_F_HOST_PAGE_SIZE      5
 
 enum virtio_gpu_ctrl_type {
 	VIRTIO_GPU_UNDEFINED = 0,
@@ -363,6 +367,7 @@ struct virtio_gpu_config {
 	__le32 events_clear;
 	__le32 num_scanouts;
 	__le32 num_capsets;
+	__le32 host_page_size;
 };
 
 /* simple formats for fbcon/X use */
-- 
2.45.2