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/virtio/virtio.h" 21 22 struct virtio_serial_conf { 23 /* Max. number of ports we can have for a virtio-serial device */ 24 uint32_t max_virtserial_ports; 25 }; 26 27 #define TYPE_VIRTIO_SERIAL_PORT "virtio-serial-port" 28 #define VIRTIO_SERIAL_PORT(obj) \ 29 OBJECT_CHECK(VirtIOSerialPort, (obj), TYPE_VIRTIO_SERIAL_PORT) 30 #define VIRTIO_SERIAL_PORT_CLASS(klass) \ 31 OBJECT_CLASS_CHECK(VirtIOSerialPortClass, (klass), TYPE_VIRTIO_SERIAL_PORT) 32 #define VIRTIO_SERIAL_PORT_GET_CLASS(obj) \ 33 OBJECT_GET_CLASS(VirtIOSerialPortClass, (obj), TYPE_VIRTIO_SERIAL_PORT) 34 35 typedef struct VirtIOSerial VirtIOSerial; 36 typedef struct VirtIOSerialBus VirtIOSerialBus; 37 typedef struct VirtIOSerialPort VirtIOSerialPort; 38 39 typedef struct VirtIOSerialPortClass { 40 DeviceClass parent_class; 41 42 /* Is this a device that binds with hvc in the guest? */ 43 bool is_console; 44 45 /* 46 * The per-port (or per-app) realize function that's called when a 47 * new device is found on the bus. 48 */ 49 DeviceRealize realize; 50 /* 51 * Per-port unrealize function that's called when a port gets 52 * hot-unplugged or removed. 53 */ 54 DeviceUnrealize unrealize; 55 56 /* Callbacks for guest events */ 57 /* Guest opened/closed device. */ 58 void (*set_guest_connected)(VirtIOSerialPort *port, int guest_connected); 59 60 /* Enable/disable backend for virtio serial port */ 61 void (*enable_backend)(VirtIOSerialPort *port, bool enable); 62 63 /* Guest is now ready to accept data (virtqueues set up). */ 64 void (*guest_ready)(VirtIOSerialPort *port); 65 66 /* 67 * Guest has enqueued a buffer for the host to write into. 68 * Called each time a buffer is enqueued by the guest; 69 * irrespective of whether there already were free buffers the 70 * host could have consumed. 71 * 72 * This is dependent on both the guest and host end being 73 * connected. 74 */ 75 void (*guest_writable)(VirtIOSerialPort *port); 76 77 /* 78 * Guest wrote some data to the port. This data is handed over to 79 * the app via this callback. The app can return a size less than 80 * 'len'. In this case, throttling will be enabled for this port. 81 */ 82 ssize_t (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, 83 ssize_t len); 84 } VirtIOSerialPortClass; 85 86 /* 87 * This is the state that's shared between all the ports. Some of the 88 * state is configurable via command-line options. Some of it can be 89 * set by individual devices in their initfn routines. Some of the 90 * state is set by the generic qdev device init routine. 91 */ 92 struct VirtIOSerialPort { 93 DeviceState dev; 94 95 QTAILQ_ENTRY(VirtIOSerialPort) next; 96 97 /* 98 * This field gives us the virtio device as well as the qdev bus 99 * that we are associated with 100 */ 101 VirtIOSerial *vser; 102 103 VirtQueue *ivq, *ovq; 104 105 /* 106 * This name is sent to the guest and exported via sysfs. 107 * The guest could create symlinks based on this information. 108 * The name is in the reverse fqdn format, like org.qemu.console.0 109 */ 110 char *name; 111 112 /* 113 * This id helps identify ports between the guest and the host. 114 * The guest sends a "header" with this id with each data packet 115 * that it sends and the host can then find out which associated 116 * device to send out this data to 117 */ 118 uint32_t id; 119 120 /* 121 * This is the elem that we pop from the virtqueue. A slow 122 * backend that consumes guest data (e.g. the file backend for 123 * qemu chardevs) can cause the guest to block till all the output 124 * is flushed. This isn't desired, so we keep a note of the last 125 * element popped and continue consuming it once the backend 126 * becomes writable again. 127 */ 128 VirtQueueElement *elem; 129 130 /* 131 * The index and the offset into the iov buffer that was popped in 132 * elem above. 133 */ 134 uint32_t iov_idx; 135 uint64_t iov_offset; 136 137 /* 138 * When unthrottling we use a bottom-half to call flush_queued_data. 139 */ 140 QEMUBH *bh; 141 142 /* Is the corresponding guest device open? */ 143 bool guest_connected; 144 /* Is this device open for IO on the host? */ 145 bool host_connected; 146 /* Do apps not want to receive data? */ 147 bool throttled; 148 }; 149 150 /* The virtio-serial bus on top of which the ports will ride as devices */ 151 struct VirtIOSerialBus { 152 BusState qbus; 153 154 /* This is the parent device that provides the bus for ports. */ 155 VirtIOSerial *vser; 156 157 /* The maximum number of ports that can ride on top of this bus */ 158 uint32_t max_nr_ports; 159 }; 160 161 typedef struct VirtIOSerialPostLoad { 162 QEMUTimer *timer; 163 uint32_t nr_active_ports; 164 struct { 165 VirtIOSerialPort *port; 166 uint8_t host_connected; 167 } *connected; 168 } VirtIOSerialPostLoad; 169 170 struct VirtIOSerial { 171 VirtIODevice parent_obj; 172 173 VirtQueue *c_ivq, *c_ovq; 174 /* Arrays of ivqs and ovqs: one per port */ 175 VirtQueue **ivqs, **ovqs; 176 177 VirtIOSerialBus bus; 178 179 QTAILQ_HEAD(, VirtIOSerialPort) ports; 180 181 QLIST_ENTRY(VirtIOSerial) next; 182 183 /* bitmap for identifying active ports */ 184 uint32_t *ports_map; 185 186 struct VirtIOSerialPostLoad *post_load; 187 188 virtio_serial_conf serial; 189 190 uint64_t host_features; 191 }; 192 193 /* Interface to the virtio-serial bus */ 194 195 /* 196 * Open a connection to the port 197 * Returns 0 on success (always). 198 */ 199 int virtio_serial_open(VirtIOSerialPort *port); 200 201 /* 202 * Close the connection to the port 203 * Returns 0 on success (always). 204 */ 205 int virtio_serial_close(VirtIOSerialPort *port); 206 207 /* 208 * Send data to Guest 209 */ 210 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf, 211 size_t size); 212 213 /* 214 * Query whether a guest is ready to receive data. 215 */ 216 size_t virtio_serial_guest_ready(VirtIOSerialPort *port); 217 218 /* 219 * Flow control: Ports can signal to the virtio-serial core to stop 220 * sending data or re-start sending data, depending on the 'throttle' 221 * value here. 222 */ 223 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle); 224 225 #define TYPE_VIRTIO_SERIAL "virtio-serial-device" 226 #define VIRTIO_SERIAL(obj) \ 227 OBJECT_CHECK(VirtIOSerial, (obj), TYPE_VIRTIO_SERIAL) 228 229 #endif 230