The virtio-console device has recently been updated to support multiple devices and multiple ports. These ports can also function as generic serial ports. Reflect these changes in the spec. Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx> --- virtio-spec/virtio-spec-0.8.3.lyx.orig 2010-01-20 19:21:02.239131766 +0530 +++ virtio-spec/virtio-spec-0.8.3.lyx 2010-01-20 19:21:02.228131971 +0530 @@ -1,4 +1,4 @@ -#LyX 1.6.4 created this file. For more info see http://www.lyx.org/ +#LyX 1.6.5 created this file. For more info see http://www.lyx.org/ \lyxformat 345 \begin_document \begin_header @@ -36,7 +36,7 @@ \paperpagestyle default \tracking_changes true \output_changes true -\author "" +\author "Amit Shah" \author "" \end_header @@ -4371,9 +4371,33 @@ \end_layout \begin_layout Standard -The virtio console device is a simple device for text input and output. - One or more empty buffers are placed in the receive queue for incoming - keystrokes, and outgoing characters are placed in the transmit queue. +The virtio console device is a simple device for +\change_inserted 0 1262777844 +data +\change_deleted 0 1262777844 +text +\change_unchanged + input and output. + +\change_inserted 0 1263990903 +A device may have one or more ports. + Each port has a pair of input and output virtqueues. + Moreover, a device has a pair of control IO virtqueues. + The control virtqueues are used to communicate information between the + device and the driver about ports being opened and closed on either side + of the connection, indication from the host about whether a particular + port is a console port, port hotunplug, etc. + For data IO, o +\change_deleted 0 1263990904 +O +\change_unchanged +ne or more empty buffers are placed in the receive queue for incoming +\change_inserted 0 1263965568 +data +\change_deleted 0 1263990911 +keystrokes, +\change_unchanged + and outgoing characters are placed in the transmit queue. \end_layout \begin_layout Section* @@ -4393,8 +4417,19 @@ \end_layout \begin_layout Description -Virtqueues 0:receiveq. - 1:transmitq. +Virtqueues 0:receiveq +\change_inserted 0 1263965615 +(port0) +\change_unchanged +. + 1:transmitq +\change_inserted 0 1263965633 +(port0), 2:control receiveq, 3:control transmitq, 4:receiveq(port1), 5:transmitq +(port1), ... +\change_deleted 0 1263965580 +. +\change_unchanged + \end_layout \begin_layout Description @@ -4412,6 +4447,18 @@ \end_inset (0) Configuration cols and rows fields are valid. +\change_inserted 0 1263965646 + +\end_layout + +\begin_layout Description + +\change_inserted 0 1263990941 +VIRTIO_CONSOLE_F_MULTIPORT(1) Device has support for multiple ports; configurati +on fields nr_ports and max_nr_ports are valid and control virtqueues will + be used. +\change_unchanged + \end_layout \end_deeper @@ -4425,7 +4472,16 @@ \end_inset layout The size of the console is supplied in the configuration space if - the VIRTIO_CONSOLE_F_SIZE feature is set: + the VIRTIO_CONSOLE_F_SIZE feature is set +\change_inserted 0 1263965899 +. + Furthermore, if the VIRTIO_CONSOLE_F_MULTIPORT feature is set, the maximum + number of ports supported by the device and the number of ports currently + active can be fetched. +\change_deleted 0 1263965839 +: +\change_unchanged + \begin_inset listings inline false status open @@ -4443,6 +4499,30 @@ \begin_layout Plain Layout u16 rows; +\change_inserted 0 1263965922 + +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263965904 + +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263965912 + + u32 max_nr_ports; +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263965914 + + u32 nr_ports; +\change_unchanged + \end_layout \begin_layout Plain Layout @@ -4462,10 +4542,32 @@ \begin_layout Enumerate If the VIRTIO_CONSOLE_F_SIZE feature is negotiated, the driver can read the console dimensions from the configuration fields. +\change_inserted 0 1263965931 + +\end_layout + +\begin_layout Enumerate + +\change_inserted 0 1263991285 +If the VIRTIO_CONSOLE_F_MULTIPORT feature is negotiated, the driver can + spawn multiple ports, not all of which may be attached to a console. + Some could be generic ports. + In this case, the control virtqueues are enabled and according to the nr_ports + configuration-space value, the appropriate number of ports and corresponding + virtqueues are spawned. + After creating and initializing each port, a VIRTIO_CONSOLE_PORT_READY + control message is sent to the host for that port so the host can let us + know of any additional configuration options set for that port. +\change_unchanged + \end_layout \begin_layout Enumerate -The receiveq is populated with one or more receive buffers. +The receiveq +\change_inserted 0 1263966035 +for each port +\change_unchanged +is populated with one or more receive buffers. \end_layout \begin_layout Section* @@ -4473,8 +4575,15 @@ \end_layout \begin_layout Enumerate -For console output, a buffer containing the characters is placed in the - transmitq. +For +\change_deleted 0 1263966990 +console +\change_unchanged +output, a buffer containing the characters is placed in the +\change_inserted 0 1263966995 +port's +\change_unchanged +transmitq. \begin_inset Foot status collapsed @@ -4490,14 +4599,141 @@ \end_layout \begin_layout Enumerate -When a buffer is used in the receiveq, the contents is the input to the - console. +When a buffer is used in the receiveq +\change_inserted 0 1263967036 + (signalled by an interrupt) +\change_unchanged +, the contents is the input to the +\change_deleted 0 1263967042 +console. +\change_inserted 0 1263967164 +port associated with the virtqueue for which the notification was received. +\change_unchanged + \end_layout \begin_layout Enumerate If the driver negotiated the VIRTIO_CONSOLE_F_SIZE feature, a configuration change interrupt may occur. The updated size can be read from the configuration fields. +\change_inserted 0 1263966908 + +\end_layout + +\begin_layout Enumerate + +\change_inserted 0 1263967171 +If the driver negotiated the VIRTIO_CONSOLE_F_MULTIPORT feature, a configuration + change interrupt may occur that bumps up the value of nr_ports. + In this case, ports are hot-added. +\end_layout + +\begin_layout Enumerate + +\change_inserted 0 1263991858 +Changes to ports' state are effected by control messages. + Appropriate action is taken on the port indicated in the control message. + The layout of the structure of the control buffer and the events associated + are: +\begin_inset listings +inline false +status open + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +struct virtio_console_control { +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991937 + + uint32_t id; /* Port number */ +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991940 + + uint16_t event; /* The kind of control event */ +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991943 + + uint16_t value; /* Extra information for the event */ +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +}; +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +/* Some events for the internal messages (control packets) */ +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +#define VIRTIO_CONSOLE_PORT_READY 0 +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +#define VIRTIO_CONSOLE_CONSOLE_PORT 1 +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +#define VIRTIO_CONSOLE_RESIZE 2 +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +#define VIRTIO_CONSOLE_PORT_OPEN 3 +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +#define VIRTIO_CONSOLE_PORT_NAME 4 +\end_layout + +\begin_layout Plain Layout + +\change_inserted 0 1263991870 + +#define VIRTIO_CONSOLE_PORT_REMOVE 5 +\change_unchanged + +\end_layout + +\end_inset + + \end_layout \begin_layout Chapter* _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
