include/hw/virtio/virtio-dmabuf.h

   1 /*
   2  * Virtio Shared dma-buf
   3  *
   4  * Copyright Red Hat, Inc. 2023
   5  *
   6  * Authors:
   7  *     Albert Esteve <aesteve@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.
  10  * See the COPYING file in the top-level directory.
  11  */
  12
  13 #ifndef VIRTIO_DMABUF_H
  14 #define VIRTIO_DMABUF_H
  15
  16 #include "qemu/uuid.h"
  17 #include "vhost.h"
  18
  19 typedef enum SharedObjectType {
  20     TYPE_INVALID = 0,
  21     TYPE_DMABUF,
  22     TYPE_VHOST_DEV,
  23 } SharedObjectType;
  24
  25 typedef struct VirtioSharedObject {
  26     SharedObjectType type;
  27     gpointer value;
  28 } VirtioSharedObject;
  29
  30 /**
  31  * virtio_add_dmabuf() - Add a new dma-buf resource to the lookup table
  32  * @uuid: new resource's UUID
  33  * @dmabuf_fd: the dma-buf descriptor that will be stored and shared with
  34  *             other virtio devices. The caller retains ownership over the
  35  *             descriptor and its lifecycle.
  36  *
  37  * Note: @dmabuf_fd must be a valid (non-negative) file descriptor.
  38  *
  39  * Return: true if the UUID did not exist and the resource has been added,
  40  * false if another resource with the same UUID already existed.
  41  * Note that if it finds a repeated UUID, the resource is not inserted in
  42  * the lookup table.
  43  */
  44 bool virtio_add_dmabuf(QemuUUID *uuid, int dmabuf_fd);
  45
  46 /**
  47  * virtio_add_vhost_device() - Add a new exporter vhost device that holds the
  48  * resource with the associated UUID
  49  * @uuid: new resource's UUID
  50  * @dev: the pointer to the vhost device that holds the resource. The caller
  51  *       retains ownership over the device struct and its lifecycle.
  52  *
  53  * Return: true if the UUID did not exist and the device has been tracked,
  54  * false if another resource with the same UUID already existed.
  55  * Note that if it finds a repeated UUID, the resource is not inserted in
  56  * the lookup table.
  57  */
  58 bool virtio_add_vhost_device(QemuUUID *uuid, struct vhost_dev *dev);
  59
  60 /**
  61  * virtio_remove_resource() - Removes a resource from the lookup table
  62  * @uuid: resource's UUID
  63  *
  64  * Return: true if the UUID has been found and removed from the lookup table.
  65  */
  66 bool virtio_remove_resource(const QemuUUID *uuid);
  67
  68 /**
  69  * virtio_lookup_dmabuf() - Looks for a dma-buf resource in the lookup table
  70  * @uuid: resource's UUID
  71  *
  72  * Return: the dma-buf file descriptor integer, or -1 if the key is not found.
  73  */
  74 int virtio_lookup_dmabuf(const QemuUUID *uuid);
  75
  76 /**
  77  * virtio_lookup_vhost_device() - Looks for an exporter vhost device in the
  78  * lookup table
  79  * @uuid: resource's UUID
  80  *
  81  * Return: pointer to the vhost_dev struct, or NULL if the key is not found.
  82  */
  83 struct vhost_dev *virtio_lookup_vhost_device(const QemuUUID *uuid);
  84
  85 /**
  86  * virtio_object_type() - Looks for the type of resource in the lookup table
  87  * @uuid: resource's UUID
  88  *
  89  * Return: the type of resource associated with the UUID, or TYPE_INVALID if
  90  * the key is not found.
  91  */
  92 SharedObjectType virtio_object_type(const QemuUUID *uuid);
  93
  94 /**
  95  * virtio_free_resources() - Destroys all keys and values of the shared
  96  * resources lookup table, and frees them
  97  */
  98 void virtio_free_resources(void);
  99
 100 #endif /* VIRTIO_DMABUF_H */