block/export: Add query-block-exports
[qemu.git] / 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 #include "qom/object.h"
31
32 #define TYPE_VIRTIO_BUS "virtio-bus"
33 typedef struct VirtioBusClass VirtioBusClass;
34 typedef struct VirtioBusState VirtioBusState;
35 DECLARE_OBJ_CHECKERS(VirtioBusState, VirtioBusClass,
36 VIRTIO_BUS, TYPE_VIRTIO_BUS)
37
38
39 struct VirtioBusClass {
40 /* This is what a VirtioBus must implement */
41 BusClass parent;
42 void (*notify)(DeviceState *d, uint16_t vector);
43 void (*save_config)(DeviceState *d, QEMUFile *f);
44 void (*save_queue)(DeviceState *d, int n, QEMUFile *f);
45 void (*save_extra_state)(DeviceState *d, QEMUFile *f);
46 int (*load_config)(DeviceState *d, QEMUFile *f);
47 int (*load_queue)(DeviceState *d, int n, QEMUFile *f);
48 int (*load_done)(DeviceState *d, QEMUFile *f);
49 int (*load_extra_state)(DeviceState *d, QEMUFile *f);
50 bool (*has_extra_state)(DeviceState *d);
51 bool (*query_guest_notifiers)(DeviceState *d);
52 int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign);
53 int (*set_host_notifier_mr)(DeviceState *d, int n,
54 MemoryRegion *mr, bool assign);
55 void (*vmstate_change)(DeviceState *d, bool running);
56 /*
57 * Expose the features the transport layer supports before
58 * the negotiation takes place.
59 */
60 void (*pre_plugged)(DeviceState *d, Error **errp);
61 /*
62 * transport independent init function.
63 * This is called by virtio-bus just after the device is plugged.
64 */
65 void (*device_plugged)(DeviceState *d, Error **errp);
66 /*
67 * transport independent exit function.
68 * This is called by virtio-bus just before the device is unplugged.
69 */
70 void (*device_unplugged)(DeviceState *d);
71 int (*query_nvectors)(DeviceState *d);
72 /*
73 * ioeventfd handling: if the transport implements ioeventfd_assign,
74 * it must implement ioeventfd_enabled as well.
75 */
76 /* Returns true if the ioeventfd is enabled for the device. */
77 bool (*ioeventfd_enabled)(DeviceState *d);
78 /*
79 * Assigns/deassigns the ioeventfd backing for the transport on
80 * the device for queue number n. Returns an error value on
81 * failure.
82 */
83 int (*ioeventfd_assign)(DeviceState *d, EventNotifier *notifier,
84 int n, bool assign);
85 /*
86 * Whether queue number n is enabled.
87 */
88 bool (*queue_enabled)(DeviceState *d, int n);
89 /*
90 * Does the transport have variable vring alignment?
91 * (ie can it ever call virtio_queue_set_align()?)
92 * Note that changing this will break migration for this transport.
93 */
94 bool has_variable_vring_alignment;
95 AddressSpace *(*get_dma_as)(DeviceState *d);
96 };
97
98 struct VirtioBusState {
99 BusState parent_obj;
100
101 /*
102 * Set if ioeventfd has been started.
103 */
104 bool ioeventfd_started;
105
106 /*
107 * Set if ioeventfd has been grabbed by vhost. When ioeventfd
108 * is grabbed by vhost, we track its started/stopped state (which
109 * depends in turn on the virtio status register), but do not
110 * register a handler for the ioeventfd. When ioeventfd is
111 * released, if ioeventfd_started is true we finally register
112 * the handler so that QEMU's device model can use ioeventfd.
113 */
114 int ioeventfd_grabbed;
115 };
116
117 void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp);
118 void virtio_bus_reset(VirtioBusState *bus);
119 void virtio_bus_device_unplugged(VirtIODevice *bus);
120 /* Get the device id of the plugged device. */
121 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus);
122 /* Get the config_len field of the plugged device. */
123 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus);
124 /* Get bad features of the plugged device. */
125 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus);
126 /* Get config of the plugged device. */
127 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config);
128 /* Set config of the plugged device. */
129 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config);
130
131 static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus)
132 {
133 BusState *qbus = &bus->parent_obj;
134 BusChild *kid = QTAILQ_FIRST(&qbus->children);
135 DeviceState *qdev = kid ? kid->child : NULL;
136
137 /* This is used on the data path, the cast is guaranteed
138 * to succeed by the qdev machinery.
139 */
140 return (VirtIODevice *)qdev;
141 }
142
143 /* Return whether the proxy allows ioeventfd. */
144 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus);
145 /* Start the ioeventfd. */
146 int virtio_bus_start_ioeventfd(VirtioBusState *bus);
147 /* Stop the ioeventfd. */
148 void virtio_bus_stop_ioeventfd(VirtioBusState *bus);
149 /* Tell the bus that vhost is grabbing the ioeventfd. */
150 int virtio_bus_grab_ioeventfd(VirtioBusState *bus);
151 /* bus that vhost is not using the ioeventfd anymore. */
152 void virtio_bus_release_ioeventfd(VirtioBusState *bus);
153 /* Switch from/to the generic ioeventfd handler */
154 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign);
155 /* Tell the bus that the ioeventfd handler is no longer required. */
156 void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n);
157
158 #endif /* VIRTIO_BUS_H */