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.h"
  29 #include "sysemu/sysemu.h"
  30 #include "hw/virtio/virtio.h"
  31
  32 #define TYPE_VIRTIO_BUS "virtio-bus"
  33 #define VIRTIO_BUS_GET_CLASS(obj) \
  34         OBJECT_GET_CLASS(VirtioBusClass, obj, TYPE_VIRTIO_BUS)
  35 #define VIRTIO_BUS_CLASS(klass) \
  36         OBJECT_CLASS_CHECK(VirtioBusClass, klass, TYPE_VIRTIO_BUS)
  37 #define VIRTIO_BUS(obj) OBJECT_CHECK(VirtioBusState, (obj), TYPE_VIRTIO_BUS)
  38
  39 typedef struct VirtioBusState VirtioBusState;
  40
  41 typedef struct VirtioBusClass {
  42     /* This is what a VirtioBus must implement */
  43     BusClass parent;
  44     void (*notify)(DeviceState *d, uint16_t vector);
  45     void (*save_config)(DeviceState *d, QEMUFile *f);
  46     void (*save_queue)(DeviceState *d, int n, QEMUFile *f);
  47     void (*save_extra_state)(DeviceState *d, QEMUFile *f);
  48     int (*load_config)(DeviceState *d, QEMUFile *f);
  49     int (*load_queue)(DeviceState *d, int n, QEMUFile *f);
  50     int (*load_done)(DeviceState *d, QEMUFile *f);
  51     int (*load_extra_state)(DeviceState *d, QEMUFile *f);
  52     bool (*has_extra_state)(DeviceState *d);
  53     bool (*query_guest_notifiers)(DeviceState *d);
  54     int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign);
  55     int (*set_host_notifier_mr)(DeviceState *d, int n,
  56                                 MemoryRegion *mr, bool assign);
  57     void (*vmstate_change)(DeviceState *d, bool running);
  58     /*
  59      * Expose the features the transport layer supports before
  60      * the negotiation takes place.
  61      */
  62     void (*pre_plugged)(DeviceState *d, Error **errp);
  63     /*
  64      * transport independent init function.
  65      * This is called by virtio-bus just after the device is plugged.
  66      */
  67     void (*device_plugged)(DeviceState *d, Error **errp);
  68     /*
  69      * transport independent exit function.
  70      * This is called by virtio-bus just before the device is unplugged.
  71      */
  72     void (*device_unplugged)(DeviceState *d);
  73     int (*query_nvectors)(DeviceState *d);
  74     /*
  75      * ioeventfd handling: if the transport implements ioeventfd_assign,
  76      * it must implement ioeventfd_enabled as well.
  77      */
  78     /* Returns true if the ioeventfd is enabled for the device. */
  79     bool (*ioeventfd_enabled)(DeviceState *d);
  80     /*
  81      * Assigns/deassigns the ioeventfd backing for the transport on
  82      * the device for queue number n. Returns an error value on
  83      * failure.
  84      */
  85     int (*ioeventfd_assign)(DeviceState *d, EventNotifier *notifier,
  86                             int n, bool assign);
  87     /*
  88      * Does the transport have variable vring alignment?
  89      * (ie can it ever call virtio_queue_set_align()?)
  90      * Note that changing this will break migration for this transport.
  91      */
  92     bool has_variable_vring_alignment;
  93     AddressSpace *(*get_dma_as)(DeviceState *d);
  94 } VirtioBusClass;
  95
  96 struct VirtioBusState {
  97     BusState parent_obj;
  98
  99     /*
 100      * Set if ioeventfd has been started.
 101      */
 102     bool ioeventfd_started;
 103
 104     /*
 105      * Set if ioeventfd has been grabbed by vhost.  When ioeventfd
 106      * is grabbed by vhost, we track its started/stopped state (which
 107      * depends in turn on the virtio status register), but do not
 108      * register a handler for the ioeventfd.  When ioeventfd is
 109      * released, if ioeventfd_started is true we finally register
 110      * the handler so that QEMU's device model can use ioeventfd.
 111      */
 112     int ioeventfd_grabbed;
 113 };
 114
 115 void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp);
 116 void virtio_bus_reset(VirtioBusState *bus);
 117 void virtio_bus_device_unplugged(VirtIODevice *bus);
 118 /* Get the device id of the plugged device. */
 119 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus);
 120 /* Get the config_len field of the plugged device. */
 121 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus);
 122 /* Get bad features of the plugged device. */
 123 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus);
 124 /* Get config of the plugged device. */
 125 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config);
 126 /* Set config of the plugged device. */
 127 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config);
 128
 129 static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus)
 130 {
 131     BusState *qbus = &bus->parent_obj;
 132     BusChild *kid = QTAILQ_FIRST(&qbus->children);
 133     DeviceState *qdev = kid ? kid->child : NULL;
 134
 135     /* This is used on the data path, the cast is guaranteed
 136      * to succeed by the qdev machinery.
 137      */
 138     return (VirtIODevice *)qdev;
 139 }
 140
 141 /* Return whether the proxy allows ioeventfd.  */
 142 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus);
 143 /* Start the ioeventfd. */
 144 int virtio_bus_start_ioeventfd(VirtioBusState *bus);
 145 /* Stop the ioeventfd. */
 146 void virtio_bus_stop_ioeventfd(VirtioBusState *bus);
 147 /* Tell the bus that vhost is grabbing the ioeventfd. */
 148 int virtio_bus_grab_ioeventfd(VirtioBusState *bus);
 149 /* bus that vhost is not using the ioeventfd anymore. */
 150 void virtio_bus_release_ioeventfd(VirtioBusState *bus);
 151 /* Switch from/to the generic ioeventfd handler */
 152 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign);
 153 /* Tell the bus that the ioeventfd handler is no longer required. */
 154 void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n);
 155
 156 #endif /* VIRTIO_BUS_H */