/* SPDX-License-Identifier: MIT */ /* * usbif.h * * USB I/O interface for Xen guest OSes. * * Copyright (C) 2009, FUJITSU LABORATORIES LTD. * Author: Noboru Iwamatsu <[email protected]> */ #ifndef __XEN_PUBLIC_IO_USBIF_H__ #define __XEN_PUBLIC_IO_USBIF_H__ #include "ring.h" #include "../grant_table.h" /* * Detailed Interface Description * ============================== * The pvUSB interface is using a split driver design: a frontend driver in * the guest and a backend driver in a driver domain (normally dom0) having * access to the physical USB device(s) being passed to the guest. * * The frontend and backend drivers use XenStore to initiate the connection * between them, the I/O activity is handled via two shared ring pages and an * event channel. As the interface between frontend and backend is at the USB * host connector level, multiple (up to 31) physical USB devices can be * handled by a single connection. * * The Xen pvUSB device name is "qusb", so the frontend's XenStore entries are * to be found under "device/qusb", while the backend's XenStore entries are * under "backend/<guest-dom-id>/qusb". * * When a new pvUSB connection is established, the frontend needs to setup the * two shared ring pages for communication and the event channel. The ring * pages need to be made available to the backend via the grant table * interface. * * One of the shared ring pages is used by the backend to inform the frontend * about USB device plug events (device to be added or removed). This is the * "conn-ring". * * The other ring page is used for USB I/O communication (requests and * responses). This is the "urb-ring". * * Feature and Parameter Negotiation * ================================= * The two halves of a Xen pvUSB driver utilize nodes within the XenStore to * communicate capabilities and to negotiate operating parameters. This * section enumerates these nodes which reside in the respective front and * backend portions of the XenStore, following the XenBus convention. * * Any specified default value is in effect if the corresponding XenBus node * is not present in the XenStore. * * XenStore nodes in sections marked "PRIVATE" are solely for use by the * driver side whose XenBus tree contains them. * ***************************************************************************** * Backend XenBus Nodes ***************************************************************************** * *------------------ Backend Device Identification (PRIVATE) ------------------ * * num-ports * Values: unsigned [1...31] * * Number of ports for this (virtual) USB host connector. * * usb-ver * Values: unsigned [1...2] * * USB version of this host connector: 1 = USB 1.1, 2 = USB 2.0. * * port/[1...31] * Values: string * * Physical USB device connected to the given port, e.g. "3-1.5". * ***************************************************************************** * Frontend XenBus Nodes ***************************************************************************** * *----------------------- Request Transport Parameters ----------------------- * * event-channel * Values: unsigned * * The identifier of the Xen event channel used to signal activity * in the ring buffer. * * urb-ring-ref * Values: unsigned * * The Xen grant reference granting permission for the backend to map * the sole page in a single page sized ring buffer. This is the ring * buffer for urb requests. * * conn-ring-ref * Values: unsigned * * The Xen grant reference granting permission for the backend to map * the sole page in a single page sized ring buffer. This is the ring * buffer for connection/disconnection requests. * * protocol * Values: string (XEN_IO_PROTO_ABI_*) * Default Value: XEN_IO_PROTO_ABI_NATIVE * * The machine ABI rules governing the format of all ring request and * response structures. * * Protocol Description * ==================== * *-------------------------- USB device plug events -------------------------- * * USB device plug events are send via the "conn-ring" shared page. As only * events are being sent, the respective requests from the frontend to the * backend are just dummy ones. * The events sent to the frontend have the following layout: * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | id | portnum | speed | 4 * +----------------+----------------+----------------+----------------+ * id - uint16_t, event id (taken from the actual frontend dummy request) * portnum - uint8_t, port number (1 ... 31) * speed - uint8_t, device XENUSB_SPEED_*, XENUSB_SPEED_NONE == unplug * * The dummy request: * 0 1 octet * +----------------+----------------+ * | id | 2 * +----------------+----------------+ * id - uint16_t, guest supplied value (no need for being unique) * *-------------------------- USB I/O request --------------------------------- * * A single USB I/O request on the "urb-ring" has the following layout: * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | id | nr_buffer_segs | 4 * +----------------+----------------+----------------+----------------+ * | pipe | 8 * +----------------+----------------+----------------+----------------+ * | transfer_flags | buffer_length | 12 * +----------------+----------------+----------------+----------------+ * | request type specific | 16 * | data | 20 * +----------------+----------------+----------------+----------------+ * | seg[0] | 24 * | data | 28 * +----------------+----------------+----------------+----------------+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| * +----------------+----------------+----------------+----------------+ * | seg[XENUSB_MAX_SEGMENTS_PER_REQUEST - 1] | 144 * | data | 148 * +----------------+----------------+----------------+----------------+ * Bit field bit number 0 is always least significant bit, undefined bits must * be zero. * id - uint16_t, guest supplied value * nr_buffer_segs - uint16_t, number of segment entries in seg[] array * pipe - uint32_t, bit field with multiple information: * bits 0-4: port request to send to * bit 5: unlink request with specified id (cancel I/O) if set (see below) * bit 7: direction (1 = read from device) * bits 8-14: device number on port * bits 15-18: endpoint of device * bits 30-31: request type: 00 = isochronous, 01 = interrupt, * 10 = control, 11 = bulk * transfer_flags - uint16_t, bit field with processing flags: * bit 0: less data than specified allowed * buffer_length - uint16_t, total length of data * request type specific data - 8 bytes, see below * seg[] - array with 8 byte elements, see below * * Request type specific data for isochronous request: * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | interval | start_frame | 4 * +----------------+----------------+----------------+----------------+ * | number_of_packets | nr_frame_desc_segs | 8 * +----------------+----------------+----------------+----------------+ * interval - uint16_t, time interval in msecs between frames * start_frame - uint16_t, start frame number * number_of_packets - uint16_t, number of packets to transfer * nr_frame_desc_segs - uint16_t number of seg[] frame descriptors elements * * Request type specific data for interrupt request: * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | interval | 0 | 4 * +----------------+----------------+----------------+----------------+ * | 0 | 8 * +----------------+----------------+----------------+----------------+ * interval - uint16_t, time in msecs until interruption * * Request type specific data for control request: * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | data of setup packet | 4 * | | 8 * +----------------+----------------+----------------+----------------+ * * Request type specific data for bulk request: * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | 0 | 4 * | 0 | 8 * +----------------+----------------+----------------+----------------+ * * Request type specific data for unlink request: * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | unlink_id | 0 | 4 * +----------------+----------------+----------------+----------------+ * | 0 | 8 * +----------------+----------------+----------------+----------------+ * unlink_id - uint16_t, request id of request to terminate * * seg[] array element layout: * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | gref | 4 * +----------------+----------------+----------------+----------------+ * | offset | length | 8 * +----------------+----------------+----------------+----------------+ * gref - uint32_t, grant reference of buffer page * offset - uint16_t, offset of buffer start in page * length - uint16_t, length of buffer in page * *-------------------------- USB I/O response -------------------------------- * * 0 1 2 3 octet * +----------------+----------------+----------------+----------------+ * | id | start_frame | 4 * +----------------+----------------+----------------+----------------+ * | status | 8 * +----------------+----------------+----------------+----------------+ * | actual_length | 12 * +----------------+----------------+----------------+----------------+ * | error_count | 16 * +----------------+----------------+----------------+----------------+ * id - uint16_t, id of the request this response belongs to * start_frame - uint16_t, start_frame this response (iso requests only) * status - int32_t, XENUSB_STATUS_* (non-iso requests) * actual_length - uint32_t, actual size of data transferred * error_count - uint32_t, number of errors (iso requests) */ enum xenusb_spec_version { … }; /* * USB pipe in xenusb_request * * - port number: bits 0-4 * (USB_MAXCHILDREN is 31) * * - operation flag: bit 5 * (0 = submit urb, * 1 = unlink urb) * * - direction: bit 7 * (0 = Host-to-Device [Out] * 1 = Device-to-Host [In]) * * - device address: bits 8-14 * * - endpoint: bits 15-18 * * - pipe type: bits 30-31 * (00 = isochronous, 01 = interrupt, * 10 = control, 11 = bulk) */ #define XENUSB_PIPE_PORT_MASK … #define XENUSB_PIPE_UNLINK … #define XENUSB_PIPE_DIR … #define XENUSB_PIPE_DEV_MASK … #define XENUSB_PIPE_DEV_SHIFT … #define XENUSB_PIPE_EP_MASK … #define XENUSB_PIPE_EP_SHIFT … #define XENUSB_PIPE_TYPE_MASK … #define XENUSB_PIPE_TYPE_SHIFT … #define XENUSB_PIPE_TYPE_ISOC … #define XENUSB_PIPE_TYPE_INT … #define XENUSB_PIPE_TYPE_CTRL … #define XENUSB_PIPE_TYPE_BULK … #define xenusb_pipeportnum(pipe) … #define xenusb_setportnum_pipe(pipe, portnum) … #define xenusb_pipeunlink(pipe) … #define xenusb_pipesubmit(pipe) … #define xenusb_setunlink_pipe(pipe) … #define xenusb_pipein(pipe) … #define xenusb_pipeout(pipe) … #define xenusb_pipedevice(pipe) … #define xenusb_pipeendpoint(pipe) … #define xenusb_pipetype(pipe) … #define xenusb_pipeisoc(pipe) … #define xenusb_pipeint(pipe) … #define xenusb_pipectrl(pipe) … #define xenusb_pipebulk(pipe) … #define XENUSB_MAX_SEGMENTS_PER_REQUEST … #define XENUSB_MAX_PORTNR … #define XENUSB_RING_SIZE … /* * RING for transferring urbs. */ struct xenusb_request_segment { … }; struct xenusb_urb_request { … }; struct xenusb_urb_response { … }; DEFINE_RING_TYPES(xenusb_urb, struct xenusb_urb_request, struct xenusb_urb_response); #define XENUSB_URB_RING_SIZE … /* * RING for notifying connect/disconnect events to frontend */ struct xenusb_conn_request { … }; struct xenusb_conn_response { … }; DEFINE_RING_TYPES(xenusb_conn, struct xenusb_conn_request, struct xenusb_conn_response); #define XENUSB_CONN_RING_SIZE … #endif /* __XEN_PUBLIC_IO_USBIF_H__ */
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