xref: /openbmc/qemu/include/hw/virtio/virtio-bus.h (revision 4e116893)
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     bool (*iommu_enabled)(DeviceState *d);
97 };
98 
99 struct VirtioBusState {
100     BusState parent_obj;
101 
102     /*
103      * Set if ioeventfd has been started.
104      */
105     bool ioeventfd_started;
106 
107     /*
108      * Set if ioeventfd has been grabbed by vhost.  When ioeventfd
109      * is grabbed by vhost, we track its started/stopped state (which
110      * depends in turn on the virtio status register), but do not
111      * register a handler for the ioeventfd.  When ioeventfd is
112      * released, if ioeventfd_started is true we finally register
113      * the handler so that QEMU's device model can use ioeventfd.
114      */
115     int ioeventfd_grabbed;
116 };
117 
118 void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp);
119 void virtio_bus_reset(VirtioBusState *bus);
120 void virtio_bus_device_unplugged(VirtIODevice *bus);
121 /* Get the device id of the plugged device. */
122 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus);
123 /* Get the config_len field of the plugged device. */
124 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus);
125 /* Get bad features of the plugged device. */
126 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus);
127 /* Get config of the plugged device. */
128 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config);
129 /* Set config of the plugged device. */
130 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config);
131 
132 static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus)
133 {
134     BusState *qbus = &bus->parent_obj;
135     BusChild *kid = QTAILQ_FIRST(&qbus->children);
136     DeviceState *qdev = kid ? kid->child : NULL;
137 
138     /* This is used on the data path, the cast is guaranteed
139      * to succeed by the qdev machinery.
140      */
141     return (VirtIODevice *)qdev;
142 }
143 
144 /* Return whether the proxy allows ioeventfd.  */
145 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus);
146 /* Start the ioeventfd. */
147 int virtio_bus_start_ioeventfd(VirtioBusState *bus);
148 /* Stop the ioeventfd. */
149 void virtio_bus_stop_ioeventfd(VirtioBusState *bus);
150 /* Tell the bus that vhost is grabbing the ioeventfd. */
151 int virtio_bus_grab_ioeventfd(VirtioBusState *bus);
152 /* bus that vhost is not using the ioeventfd anymore. */
153 void virtio_bus_release_ioeventfd(VirtioBusState *bus);
154 /* Switch from/to the generic ioeventfd handler */
155 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign);
156 /* Tell the bus that the ioeventfd handler is no longer required. */
157 void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n);
158 /* Whether the IOMMU is enabled for this device */
159 bool virtio_bus_device_iommu_enabled(VirtIODevice *vdev);
160 #endif /* VIRTIO_BUS_H */
161