1 /* 2 * Virtio Serial / Console Support 3 * 4 * Copyright IBM, Corp. 2008 5 * Copyright Red Hat, Inc. 2009, 2010 6 * 7 * Authors: 8 * Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> 9 * Amit Shah <amit.shah@redhat.com> 10 * 11 * This work is licensed under the terms of the GNU GPL, version 2. See 12 * the COPYING file in the top-level directory. 13 * 14 */ 15 16 #ifndef QEMU_VIRTIO_SERIAL_H 17 #define QEMU_VIRTIO_SERIAL_H 18 19 #include "standard-headers/linux/virtio_console.h" 20 #include "hw/qdev.h" 21 #include "hw/virtio/virtio.h" 22 23 struct virtio_serial_conf { 24 /* Max. number of ports we can have for a virtio-serial device */ 25 uint32_t max_virtserial_ports; 26 }; 27 28 #define TYPE_VIRTIO_SERIAL_PORT "virtio-serial-port" 29 #define VIRTIO_SERIAL_PORT(obj) \ 30 OBJECT_CHECK(VirtIOSerialPort, (obj), TYPE_VIRTIO_SERIAL_PORT) 31 #define VIRTIO_SERIAL_PORT_CLASS(klass) \ 32 OBJECT_CLASS_CHECK(VirtIOSerialPortClass, (klass), TYPE_VIRTIO_SERIAL_PORT) 33 #define VIRTIO_SERIAL_PORT_GET_CLASS(obj) \ 34 OBJECT_GET_CLASS(VirtIOSerialPortClass, (obj), TYPE_VIRTIO_SERIAL_PORT) 35 36 typedef struct VirtIOSerial VirtIOSerial; 37 typedef struct VirtIOSerialBus VirtIOSerialBus; 38 typedef struct VirtIOSerialPort VirtIOSerialPort; 39 40 typedef struct VirtIOSerialPortClass { 41 DeviceClass parent_class; 42 43 /* Is this a device that binds with hvc in the guest? */ 44 bool is_console; 45 46 /* 47 * The per-port (or per-app) realize function that's called when a 48 * new device is found on the bus. 49 */ 50 DeviceRealize realize; 51 /* 52 * Per-port unrealize function that's called when a port gets 53 * hot-unplugged or removed. 54 */ 55 DeviceUnrealize unrealize; 56 57 /* Callbacks for guest events */ 58 /* Guest opened/closed device. */ 59 void (*set_guest_connected)(VirtIOSerialPort *port, int guest_connected); 60 61 /* Guest is now ready to accept data (virtqueues set up). */ 62 void (*guest_ready)(VirtIOSerialPort *port); 63 64 /* 65 * Guest has enqueued a buffer for the host to write into. 66 * Called each time a buffer is enqueued by the guest; 67 * irrespective of whether there already were free buffers the 68 * host could have consumed. 69 * 70 * This is dependent on both the guest and host end being 71 * connected. 72 */ 73 void (*guest_writable)(VirtIOSerialPort *port); 74 75 /* 76 * Guest wrote some data to the port. This data is handed over to 77 * the app via this callback. The app can return a size less than 78 * 'len'. In this case, throttling will be enabled for this port. 79 */ 80 ssize_t (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, 81 ssize_t len); 82 } VirtIOSerialPortClass; 83 84 /* 85 * This is the state that's shared between all the ports. Some of the 86 * state is configurable via command-line options. Some of it can be 87 * set by individual devices in their initfn routines. Some of the 88 * state is set by the generic qdev device init routine. 89 */ 90 struct VirtIOSerialPort { 91 DeviceState dev; 92 93 QTAILQ_ENTRY(VirtIOSerialPort) next; 94 95 /* 96 * This field gives us the virtio device as well as the qdev bus 97 * that we are associated with 98 */ 99 VirtIOSerial *vser; 100 101 VirtQueue *ivq, *ovq; 102 103 /* 104 * This name is sent to the guest and exported via sysfs. 105 * The guest could create symlinks based on this information. 106 * The name is in the reverse fqdn format, like org.qemu.console.0 107 */ 108 char *name; 109 110 /* 111 * This id helps identify ports between the guest and the host. 112 * The guest sends a "header" with this id with each data packet 113 * that it sends and the host can then find out which associated 114 * device to send out this data to 115 */ 116 uint32_t id; 117 118 /* 119 * This is the elem that we pop from the virtqueue. A slow 120 * backend that consumes guest data (e.g. the file backend for 121 * qemu chardevs) can cause the guest to block till all the output 122 * is flushed. This isn't desired, so we keep a note of the last 123 * element popped and continue consuming it once the backend 124 * becomes writable again. 125 */ 126 VirtQueueElement *elem; 127 128 /* 129 * The index and the offset into the iov buffer that was popped in 130 * elem above. 131 */ 132 uint32_t iov_idx; 133 uint64_t iov_offset; 134 135 /* 136 * When unthrottling we use a bottom-half to call flush_queued_data. 137 */ 138 QEMUBH *bh; 139 140 /* Is the corresponding guest device open? */ 141 bool guest_connected; 142 /* Is this device open for IO on the host? */ 143 bool host_connected; 144 /* Do apps not want to receive data? */ 145 bool throttled; 146 }; 147 148 /* The virtio-serial bus on top of which the ports will ride as devices */ 149 struct VirtIOSerialBus { 150 BusState qbus; 151 152 /* This is the parent device that provides the bus for ports. */ 153 VirtIOSerial *vser; 154 155 /* The maximum number of ports that can ride on top of this bus */ 156 uint32_t max_nr_ports; 157 }; 158 159 typedef struct VirtIOSerialPostLoad { 160 QEMUTimer *timer; 161 uint32_t nr_active_ports; 162 struct { 163 VirtIOSerialPort *port; 164 uint8_t host_connected; 165 } *connected; 166 } VirtIOSerialPostLoad; 167 168 struct VirtIOSerial { 169 VirtIODevice parent_obj; 170 171 VirtQueue *c_ivq, *c_ovq; 172 /* Arrays of ivqs and ovqs: one per port */ 173 VirtQueue **ivqs, **ovqs; 174 175 VirtIOSerialBus bus; 176 177 QTAILQ_HEAD(, VirtIOSerialPort) ports; 178 179 QLIST_ENTRY(VirtIOSerial) next; 180 181 /* bitmap for identifying active ports */ 182 uint32_t *ports_map; 183 184 struct VirtIOSerialPostLoad *post_load; 185 186 virtio_serial_conf serial; 187 188 uint64_t host_features; 189 }; 190 191 /* Interface to the virtio-serial bus */ 192 193 /* 194 * Open a connection to the port 195 * Returns 0 on success (always). 196 */ 197 int virtio_serial_open(VirtIOSerialPort *port); 198 199 /* 200 * Close the connection to the port 201 * Returns 0 on success (always). 202 */ 203 int virtio_serial_close(VirtIOSerialPort *port); 204 205 /* 206 * Send data to Guest 207 */ 208 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf, 209 size_t size); 210 211 /* 212 * Query whether a guest is ready to receive data. 213 */ 214 size_t virtio_serial_guest_ready(VirtIOSerialPort *port); 215 216 /* 217 * Flow control: Ports can signal to the virtio-serial core to stop 218 * sending data or re-start sending data, depending on the 'throttle' 219 * value here. 220 */ 221 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle); 222 223 #define TYPE_VIRTIO_SERIAL "virtio-serial-device" 224 #define VIRTIO_SERIAL(obj) \ 225 OBJECT_CHECK(VirtIOSerial, (obj), TYPE_VIRTIO_SERIAL) 226 227 #endif 228