include/hw/virtio/virtio-bus.h

   1 /*
   2  * VirtioBus
   3  *
   4  *  Copyright (C) 2012 : GreenSocs Ltd
   5  *      http://www.greensocs.com/ , email: info@greensocs.com
   6  *
   7  *  Developed by :
   8  *  Frederic Konrad   <fred.konrad@greensocs.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation, either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, see <http://www.gnu.org/licenses/>.
  22  *
  23  */
  24
  25 #ifndef VIRTIO_BUS_H
  26 #define VIRTIO_BUS_H
  27
  28 #include "hw/qdev-core.h"
  29 #include "hw/virtio/virtio.h"
  30
  31 #define TYPE_VIRTIO_BUS "virtio-bus"
  32 #define VIRTIO_BUS_GET_CLASS(obj) \
  33         OBJECT_GET_CLASS(VirtioBusClass, obj, TYPE_VIRTIO_BUS)
  34 #define VIRTIO_BUS_CLASS(klass) \
  35         OBJECT_CLASS_CHECK(VirtioBusClass, klass, TYPE_VIRTIO_BUS)
  36 #define VIRTIO_BUS(obj) OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_BUS)
  37
  38 typedef struct VirtioBusState VirtioBusState;
  39
  40 typedef struct VirtioBusClass {
  41     /* This is what a VirtioBus must implement */
  42     BusClass parent;
  43     void (*notify)(DeviceState *d, uint16_t vector);
  44     void (*save_config)(DeviceState *d, QEMUFile *f);
  45     void (*save_queue)(DeviceState *d, int n, QEMUFile *f);
  46     void (*save_extra_state)(DeviceState *d, QEMUFile *f);
  47     int (*load_config)(DeviceState *d, QEMUFile *f);
  48     int (*load_queue)(DeviceState *d, int n, QEMUFile *f);
  49     int (*load_done)(DeviceState *d, QEMUFile *f);
  50     int (*load_extra_state)(DeviceState *d, QEMUFile *f);
  51     bool (*has_extra_state)(DeviceState *d);
  52     bool (*query_guest_notifiers)(DeviceState *d);
  53     int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign);
  54     int (*set_host_notifier_mr)(DeviceState *d, int n,
  55                                 MemoryRegion *mr, bool assign);
  56     void (*vmstate_change)(DeviceState *d, bool running);
  57     /*
  58      * Expose the features the transport layer supports before
  59      * the negotiation takes place.
  60      */
  61     void (*pre_plugged)(DeviceState *d, Error **errp);
  62     /*
  63      * transport independent init function.
  64      * This is called by virtio-bus just after the device is plugged.
  65      */
  66     void (*device_plugged)(DeviceState *d, Error **errp);
  67     /*
  68      * transport independent exit function.
  69      * This is called by virtio-bus just before the device is unplugged.
  70      */
  71     void (*device_unplugged)(DeviceState *d);
  72     int (*query_nvectors)(DeviceState *d);
  73     /*
  74      * ioeventfd handling: if the transport implements ioeventfd_assign,
  75      * it must implement ioeventfd_enabled as well.
  76      */
  77     /* Returns true if the ioeventfd is enabled for the device. */
  78     bool (*ioeventfd_enabled)(DeviceState *d);
  79     /*
  80      * Assigns/deassigns the ioeventfd backing for the transport on
  81      * the device for queue number n. Returns an error value on
  82      * failure.
  83      */
  84     int (*ioeventfd_assign)(DeviceState *d, EventNotifier *notifier,
  85                             int n, bool assign);
  86     /*
  87      * Does the transport have variable vring alignment?
  88      * (ie can it ever call virtio_queue_set_align()?)
  89      * Note that changing this will break migration for this transport.
  90      */
  91     bool has_variable_vring_alignment;
  92     AddressSpace *(*get_dma_as)(DeviceState *d);
  93 } VirtioBusClass;
  94
  95 struct VirtioBusState {
  96     BusState parent_obj;
  97
  98     /*
  99      * Set if ioeventfd has been started.
 100      */
 101     bool ioeventfd_started;
 102
 103     /*
 104      * Set if ioeventfd has been grabbed by vhost.  When ioeventfd
 105      * is grabbed by vhost, we track its started/stopped state (which
 106      * depends in turn on the virtio status register), but do not
 107      * register a handler for the ioeventfd.  When ioeventfd is
 108      * released, if ioeventfd_started is true we finally register
 109      * the handler so that QEMU's device model can use ioeventfd.
 110      */
 111     int ioeventfd_grabbed;
 112 };
 113
 114 void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp);
 115 void virtio_bus_reset(VirtioBusState *bus);
 116 void virtio_bus_device_unplugged(VirtIODevice *bus);
 117 /* Get the device id of the plugged device. */
 118 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus);
 119 /* Get the config_len field of the plugged device. */
 120 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus);
 121 /* Get bad features of the plugged device. */
 122 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus);
 123 /* Get config of the plugged device. */
 124 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config);
 125 /* Set config of the plugged device. */
 126 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config);
 127
 128 static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus)
 129 {
 130     BusState *qbus = &bus->parent_obj;
 131     BusChild *kid = QTAILQ_FIRST(&qbus->children);
 132     DeviceState *qdev = kid ? kid->child : NULL;
 133
 134     /* This is used on the data path, the cast is guaranteed
 135      * to succeed by the qdev machinery.
 136      */
 137     return (VirtIODevice *)qdev;
 138 }
 139
 140 /* Return whether the proxy allows ioeventfd.  */
 141 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus);
 142 /* Start the ioeventfd. */
 143 int virtio_bus_start_ioeventfd(VirtioBusState *bus);
 144 /* Stop the ioeventfd. */
 145 void virtio_bus_stop_ioeventfd(VirtioBusState *bus);
 146 /* Tell the bus that vhost is grabbing the ioeventfd. */
 147 int virtio_bus_grab_ioeventfd(VirtioBusState *bus);
 148 /* bus that vhost is not using the ioeventfd anymore. */
 149 void virtio_bus_release_ioeventfd(VirtioBusState *bus);
 150 /* Switch from/to the generic ioeventfd handler */
 151 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign);
 152 /* Tell the bus that the ioeventfd handler is no longer required. */
 153 void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n);
 154
 155 #endif /* VIRTIO_BUS_H */