text: /*
   * Virtio Support
   *
   * Copyright IBM, Corp. 2007
   *
   * Authors:
   *  Anthony Liguori   <aliguori@us.ibm.com>
   *
   * This work is licensed under the terms of the GNU GPL, version 2.  See
   * the COPYING file in the top-level directory.
   *
   */
  
  #ifndef QEMU_VIRTIO_H
  #define QEMU_VIRTIO_H
  
  #include "exec/memory.h"
  #include "hw/qdev-core.h"
  #include "net/net.h"
  #include "migration/vmstate.h"
  #include "qemu/event_notifier.h"
  #include "standard-headers/linux/virtio_config.h"
  #include "standard-headers/linux/virtio_ring.h"
  #include "qom/object.h"
  
  /* A guest should never accept this.  It implies negotiation is broken. */
  #define VIRTIO_F_BAD_FEATURE		30
  
  #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \
                                  (0x1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \
                                  (0x1ULL << VIRTIO_F_ANY_LAYOUT))
  
  struct VirtQueue;
  
  static inline hwaddr vring_align(hwaddr addr,
                                               unsigned long align)
  {
      return QEMU_ALIGN_UP(addr, align);
  }
  
  typedef struct VirtIOFeature {
      uint64_t flags;
      size_t end;
  } VirtIOFeature;
  
  size_t virtio_feature_get_config_size(VirtIOFeature *features,
                                        uint64_t host_features);
  
  typedef struct VirtQueue VirtQueue;
  
  #define VIRTQUEUE_MAX_SIZE 1024
  
  typedef struct VirtQueueElement
  {
      unsigned int index;
      unsigned int len;
      unsigned int ndescs;
      unsigned int out_num;
      unsigned int in_num;
      hwaddr *in_addr;
      hwaddr *out_addr;
      struct iovec *in_sg;
      struct iovec *out_sg;
  } VirtQueueElement;
  
  #define VIRTIO_QUEUE_MAX 1024
  
  #define VIRTIO_NO_VECTOR 0xffff
  
  #define TYPE_VIRTIO_DEVICE "virtio-device"
  OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE)
  
  enum virtio_device_endian {
      VIRTIO_DEVICE_ENDIAN_UNKNOWN,
      VIRTIO_DEVICE_ENDIAN_LITTLE,
      VIRTIO_DEVICE_ENDIAN_BIG,
  };
  
  struct VirtIODevice
  {
      DeviceState parent_obj;
      const char *name;
      uint8_t status;
      uint8_t isr;
      uint16_t queue_sel;
      uint64_t guest_features;
      uint64_t host_features;
      uint64_t backend_features;
      size_t config_len;
      void *config;
      uint16_t config_vector;
      uint32_t generation;
      int nvectors;
      VirtQueue *vq;
      MemoryListener listener;
      uint16_t device_id;
      bool vm_running;
      bool broken; /* device in invalid state, needs reset */
      bool use_disabled_flag; /* allow use of 'disable' flag when needed */
      bool disabled; /* device in temporarily disabled state */
      bool use_started;
      bool started;
      bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
      bool disable_legacy_check;
      VMChangeStateEntry *vmstate;
      char *bus_name;
      uint8_t device_endian;
      bool use_guest_notifier_mask;
      AddressSpace *dma_as;
      QLIST_HEAD(, VirtQueue) *vector_queues;
  };
  
  struct VirtioDeviceClass {
      /*< private >*/
      DeviceClass parent;
      /*< public >*/
  
      /* This is what a VirtioDevice must implement */
      DeviceRealize realize;
      DeviceUnrealize unrealize;
      uint64_t (*get_features)(VirtIODevice *vdev,
                               uint64_t requested_features,
                               Error **errp);
      uint64_t (*bad_features)(VirtIODevice *vdev);
      void (*set_features)(VirtIODevice *vdev, uint64_t val);
      int (*validate_features)(VirtIODevice *vdev);
      void (*get_config)(VirtIODevice *vdev, uint8_t *config);
      void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
      void (*reset)(VirtIODevice *vdev);
      void (*set_status)(VirtIODevice *vdev, uint8_t val);
      /* For transitional devices, this is a bitmap of features
       * that are only exposed on the legacy interface but not
       * the modern one.
       */
      uint64_t legacy_features;
      /* Test and clear event pending status.
       * Should be called after unmask to avoid losing events.
       * If backend does not support masking,
       * must check in frontend instead.
       */
      bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
      /* Mask/unmask events from this vq. Any events reported
       * while masked will become pending.
       * If backend does not support masking,
       * must mask in frontend instead.
       */
      void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
      int (*start_ioeventfd)(VirtIODevice *vdev);
      void (*stop_ioeventfd)(VirtIODevice *vdev);
      /* Saving and loading of a device; trying to deprecate save/load
       * use vmsd for new devices.
       */
      void (*save)(VirtIODevice *vdev, QEMUFile *f);
      int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
      /* Post load hook in vmsd is called early while device is processed, and
       * when VirtIODevice isn't fully initialized.  Devices should use this instead,
       * unless they specifically want to verify the migration stream as it's
       * processed, e.g. for bounds checking.
       */
      int (*post_load)(VirtIODevice *vdev);
      const VMStateDescription *vmsd;
      bool (*primary_unplug_pending)(void *opaque);
  };
  
  void virtio_instance_init_common(Object *proxy_obj, void *data,
                                   size_t vdev_size, const char *vdev_name);
  
  void virtio_init(VirtIODevice *vdev, const char *name,
                           uint16_t device_id, size_t config_size);
  void virtio_cleanup(VirtIODevice *vdev);
  
  void virtio_error(VirtIODevice *vdev, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
  
  /* Set the child bus name. */
  void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name);
  
  typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
  typedef bool (*VirtIOHandleAIOOutput)(VirtIODevice *, VirtQueue *);
  
  VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
                              VirtIOHandleOutput handle_output);
  
  void virtio_del_queue(VirtIODevice *vdev, int n);
  
  void virtio_delete_queue(VirtQueue *vq);
  
  void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
                      unsigned int len);
  void virtqueue_flush(VirtQueue *vq, unsigned int count);
  void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem,
                                unsigned int len);
  void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem,
                       unsigned int len);
  bool virtqueue_rewind(VirtQueue *vq, unsigned int num);
  void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
                      unsigned int len, unsigned int idx);
  
  void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem);
  void *virtqueue_pop(VirtQueue *vq, size_t sz);
  unsigned int virtqueue_drop_all(VirtQueue *vq);
  void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz);
  void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f,
                                  VirtQueueElement *elem);
  int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
                            unsigned int out_bytes);
  void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
                                 unsigned int *out_bytes,
                                 unsigned max_in_bytes, unsigned max_out_bytes);
  
  void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq);
  void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
  
  int virtio_save(VirtIODevice *vdev, QEMUFile *f);
  
  extern const VMStateInfo virtio_vmstate_info;
  
  #define VMSTATE_VIRTIO_DEVICE \
      {                                         \
          .name = "virtio",                     \
          .info = &virtio_vmstate_info,         \
          .flags = VMS_SINGLE,                  \
      }
  
  int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id);
  
  void virtio_notify_config(VirtIODevice *vdev);
  
  bool virtio_queue_get_notification(VirtQueue *vq);
  void virtio_queue_set_notification(VirtQueue *vq, int enable);
  
  int virtio_queue_ready(VirtQueue *vq);
  
  int virtio_queue_empty(VirtQueue *vq);
  
  /* Host binding interface.  */
  
  uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
  uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
  uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
  void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
  void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
  void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
  uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr);
  uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr);
  uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr);
  void virtio_config_modern_writeb(VirtIODevice *vdev,
                                   uint32_t addr, uint32_t data);
  void virtio_config_modern_writew(VirtIODevice *vdev,
                                   uint32_t addr, uint32_t data);
  void virtio_config_modern_writel(VirtIODevice *vdev,
                                   uint32_t addr, uint32_t data);
  void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
  hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
  void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
  int virtio_queue_get_num(VirtIODevice *vdev, int n);
  int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
  int virtio_get_num_queues(VirtIODevice *vdev);
  void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
                              hwaddr avail, hwaddr used);
  void virtio_queue_update_rings(VirtIODevice *vdev, int n);
  void virtio_queue_set_align(VirtIODevice *vdev, int n, int align);
  void virtio_queue_notify(VirtIODevice *vdev, int n);
  uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
  void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
  int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n,
                                        MemoryRegion *mr, bool assign);
  int virtio_set_status(VirtIODevice *vdev, uint8_t val);
  void virtio_reset(void *opaque);
  void virtio_update_irq(VirtIODevice *vdev);
  int virtio_set_features(VirtIODevice *vdev, uint64_t val);
  
  /* Base devices.  */
  typedef struct VirtIOBlkConf VirtIOBlkConf;
  struct virtio_net_conf;
  typedef struct virtio_serial_conf virtio_serial_conf;
  typedef struct virtio_input_conf virtio_input_conf;
  typedef struct VirtIOSCSIConf VirtIOSCSIConf;
  typedef struct VirtIORNGConf VirtIORNGConf;
  
  #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
      DEFINE_PROP_BIT64("indirect_desc", _state, _field,    \
                        VIRTIO_RING_F_INDIRECT_DESC, true), \
      DEFINE_PROP_BIT64("event_idx", _state, _field,        \
                        VIRTIO_RING_F_EVENT_IDX, true),     \
      DEFINE_PROP_BIT64("notify_on_empty", _state, _field,  \
                        VIRTIO_F_NOTIFY_ON_EMPTY, true), \
      DEFINE_PROP_BIT64("any_layout", _state, _field, \
                        VIRTIO_F_ANY_LAYOUT, true), \
      DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
                        VIRTIO_F_IOMMU_PLATFORM, false), \
      DEFINE_PROP_BIT64("packed", _state, _field, \
                        VIRTIO_F_RING_PACKED, false)
  
  hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
  bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n);
  bool virtio_queue_enabled(VirtIODevice *vdev, int n);
  hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
  hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
  hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
  hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
  hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
  unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
  void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
                                       unsigned int idx);
  void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
  void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
  void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
  VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
  uint16_t virtio_get_queue_index(VirtQueue *vq);
  EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
  void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                  bool with_irqfd);
  int virtio_device_start_ioeventfd(VirtIODevice *vdev);
  int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
  void virtio_device_release_ioeventfd(VirtIODevice *vdev);
  bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev);
  EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
  void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled);
  void virtio_queue_host_notifier_read(EventNotifier *n);
  void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
                                                  VirtIOHandleAIOOutput handle_output);
  VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
  VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
  
  static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
  {
      assert(fbit < 64);
      *features |= (1ULL << fbit);
  }
  
  static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit)
  {
      assert(fbit < 64);
      *features &= ~(1ULL << fbit);
  }
  
  static inline bool virtio_has_feature(uint64_t features, unsigned int fbit)
  {
      assert(fbit < 64);
      return !!(features & (1ULL << fbit));
  }
  
  static inline bool virtio_vdev_has_feature(VirtIODevice *vdev,
                                             unsigned int fbit)
  {
      return virtio_has_feature(vdev->guest_features, fbit);
  }
  
  static inline bool virtio_host_has_feature(VirtIODevice *vdev,
                                             unsigned int fbit)
  {
      return virtio_has_feature(vdev->host_features, fbit);
  }
  
  static inline bool virtio_is_big_endian(VirtIODevice *vdev)
  {
      if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
          assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN);
          return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
      }
      /* Devices conforming to VIRTIO 1.0 or later are always LE. */
      return false;
  }
  
  static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
  {
      if (vdev->use_started) {
          return vdev->started;
      }
  
      return status & VIRTIO_CONFIG_S_DRIVER_OK;
  }
  
  static inline void virtio_set_started(VirtIODevice *vdev, bool started)
  {
      if (started) {
          vdev->start_on_kick = false;
      }
  
      if (vdev->use_started) {
          vdev->started = started;
      }
  }
  
  static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable)
  {
      if (vdev->use_disabled_flag) {
          vdev->disabled = disable;
      }
  }
  
  static inline bool virtio_device_disabled(VirtIODevice *vdev)
  {
      return unlikely(vdev->disabled || vdev->broken);
  }
  
  bool virtio_legacy_allowed(VirtIODevice *vdev);
  bool virtio_legacy_check_disabled(VirtIODevice *vdev);
  
  #endif
  