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 #ifndef _QEMU_VIRTIO_SERIAL_H 16 #define _QEMU_VIRTIO_SERIAL_H 17 18 #include "standard-headers/linux/virtio_console.h" 19 #include "hw/qdev.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 /* Guest is now ready to accept data (virtqueues set up). */ 61 void (*guest_ready)(VirtIOSerialPort *port); 62 63 /* 64 * Guest has enqueued a buffer for the host to write into. 65 * Called each time a buffer is enqueued by the guest; 66 * irrespective of whether there already were free buffers the 67 * host could have consumed. 68 * 69 * This is dependent on both the guest and host end being 70 * connected. 71 */ 72 void (*guest_writable)(VirtIOSerialPort *port); 73 74 /* 75 * Guest wrote some data to the port. This data is handed over to 76 * the app via this callback. The app can return a size less than 77 * 'len'. In this case, throttling will be enabled for this port. 78 */ 79 ssize_t (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, 80 ssize_t len); 81 } VirtIOSerialPortClass; 82 83 /* 84 * This is the state that's shared between all the ports. Some of the 85 * state is configurable via command-line options. Some of it can be 86 * set by individual devices in their initfn routines. Some of the 87 * state is set by the generic qdev device init routine. 88 */ 89 struct VirtIOSerialPort { 90 DeviceState dev; 91 92 QTAILQ_ENTRY(VirtIOSerialPort) next; 93 94 /* 95 * This field gives us the virtio device as well as the qdev bus 96 * that we are associated with 97 */ 98 VirtIOSerial *vser; 99 100 VirtQueue *ivq, *ovq; 101 102 /* 103 * This name is sent to the guest and exported via sysfs. 104 * The guest could create symlinks based on this information. 105 * The name is in the reverse fqdn format, like org.qemu.console.0 106 */ 107 char *name; 108 109 /* 110 * This id helps identify ports between the guest and the host. 111 * The guest sends a "header" with this id with each data packet 112 * that it sends and the host can then find out which associated 113 * device to send out this data to 114 */ 115 uint32_t id; 116 117 /* 118 * This is the elem that we pop from the virtqueue. A slow 119 * backend that consumes guest data (e.g. the file backend for 120 * qemu chardevs) can cause the guest to block till all the output 121 * is flushed. This isn't desired, so we keep a note of the last 122 * element popped and continue consuming it once the backend 123 * becomes writable again. 124 */ 125 VirtQueueElement *elem; 126 127 /* 128 * The index and the offset into the iov buffer that was popped in 129 * elem above. 130 */ 131 uint32_t iov_idx; 132 uint64_t iov_offset; 133 134 /* 135 * When unthrottling we use a bottom-half to call flush_queued_data. 136 */ 137 QEMUBH *bh; 138 139 /* Is the corresponding guest device open? */ 140 bool guest_connected; 141 /* Is this device open for IO on the host? */ 142 bool host_connected; 143 /* Do apps not want to receive data? */ 144 bool throttled; 145 }; 146 147 /* The virtio-serial bus on top of which the ports will ride as devices */ 148 struct VirtIOSerialBus { 149 BusState qbus; 150 151 /* This is the parent device that provides the bus for ports. */ 152 VirtIOSerial *vser; 153 154 /* The maximum number of ports that can ride on top of this bus */ 155 uint32_t max_nr_ports; 156 }; 157 158 typedef struct VirtIOSerialPostLoad { 159 QEMUTimer *timer; 160 uint32_t nr_active_ports; 161 struct { 162 VirtIOSerialPort *port; 163 uint8_t host_connected; 164 } *connected; 165 } VirtIOSerialPostLoad; 166 167 struct VirtIOSerial { 168 VirtIODevice parent_obj; 169 170 VirtQueue *c_ivq, *c_ovq; 171 /* Arrays of ivqs and ovqs: one per port */ 172 VirtQueue **ivqs, **ovqs; 173 174 VirtIOSerialBus bus; 175 176 QTAILQ_HEAD(, VirtIOSerialPort) ports; 177 178 QLIST_ENTRY(VirtIOSerial) next; 179 180 /* bitmap for identifying active ports */ 181 uint32_t *ports_map; 182 183 struct VirtIOSerialPostLoad *post_load; 184 185 virtio_serial_conf serial; 186 }; 187 188 /* Interface to the virtio-serial bus */ 189 190 /* 191 * Open a connection to the port 192 * Returns 0 on success (always). 193 */ 194 int virtio_serial_open(VirtIOSerialPort *port); 195 196 /* 197 * Close the connection to the port 198 * Returns 0 on success (always). 199 */ 200 int virtio_serial_close(VirtIOSerialPort *port); 201 202 /* 203 * Send data to Guest 204 */ 205 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf, 206 size_t size); 207 208 /* 209 * Query whether a guest is ready to receive data. 210 */ 211 size_t virtio_serial_guest_ready(VirtIOSerialPort *port); 212 213 /* 214 * Flow control: Ports can signal to the virtio-serial core to stop 215 * sending data or re-start sending data, depending on the 'throttle' 216 * value here. 217 */ 218 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle); 219 220 #define TYPE_VIRTIO_SERIAL "virtio-serial-device" 221 #define VIRTIO_SERIAL(obj) \ 222 OBJECT_CHECK(VirtIOSerial, (obj), TYPE_VIRTIO_SERIAL) 223 224 #endif 225