contrib: add vhost-user-gpu

Add a vhost-user gpu backend, based on virtio-gpu/3d device. It is
associated with a vhost-user-gpu device.

Various TODO and nice to have items:
- multi-head support
- crash & resume handling
- accelerated rendering/display that avoids the waiting round trips
- edid support

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20190524130946.31736-6-marcandre.lureau@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

contrib/vhost-user-gpu/vugbm.h

@@ -0,0 +1,67 @@
+/*
+ * Virtio vhost-user GPU Device
+ *
+ * GBM helpers
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#ifndef VHOST_USER_GPU_GBM_H
+#define VHOST_USER_GPU_GBM_H
+
+#include "qemu/osdep.h"
+
+#ifdef CONFIG_MEMFD
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#endif
+
+#ifdef CONFIG_GBM
+#include <gbm.h>
+#endif
+
+struct vugbm_buffer;
+
+struct vugbm_device {
+    bool inited;
+    int fd;
+#ifdef CONFIG_GBM
+    struct gbm_device *dev;
+#endif
+
+    bool (*alloc_bo)(struct vugbm_buffer *buf);
+    void (*free_bo)(struct vugbm_buffer *buf);
+    bool (*get_fd)(struct vugbm_buffer *buf, int *fd);
+    bool (*map_bo)(struct vugbm_buffer *buf);
+    void (*unmap_bo)(struct vugbm_buffer *buf);
+    void (*device_destroy)(struct vugbm_device *dev);
+};
+
+struct vugbm_buffer {
+    struct vugbm_device *dev;
+
+#ifdef CONFIG_MEMFD
+    int memfd;
+#endif
+#ifdef CONFIG_GBM
+    struct gbm_bo *bo;
+    void *mmap_data;
+#endif
+
+    uint8_t *mmap;
+    uint32_t width;
+    uint32_t height;
+    uint32_t stride;
+    uint32_t format;
+};
+
+bool vugbm_device_init(struct vugbm_device *dev, int fd);
+void vugbm_device_destroy(struct vugbm_device *dev);
+
+bool vugbm_buffer_create(struct vugbm_buffer *buffer, struct vugbm_device *dev,
+                         uint32_t width, uint32_t height);
+bool vugbm_buffer_can_get_dmabuf_fd(struct vugbm_buffer *buffer);
+bool vugbm_buffer_get_dmabuf_fd(struct vugbm_buffer *buffer, int *fd);
+void vugbm_buffer_destroy(struct vugbm_buffer *buffer);
+
+#endif