diff options
author | Juergen Gross <jgross@suse.com> | 2021-11-23 14:20:46 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-13 14:58:31 +0100 |
commit | bae9401dff62d1ac46504a343db8a69e5ac390f6 (patch) | |
tree | 80f1770785d426a089c941b275eeb31282509ea4 /include/xen/interface | |
parent | 666f3de741f7ce66119b375145d471e89fac21ff (diff) |
usb: Add Xen pvUSB protocol description
Add the definition of pvUSB protocol used between the pvUSB frontend in
a Xen domU and the pvUSB backend in a Xen driver domain (usually Dom0).
This header was originally provided by Fujitsu for Xen based on Linux
2.6.18.
Changes are:
- adapt to Linux kernel style guide
- use Xen namespace
- add lots of comments
- don't use kernel internal defines
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20211123132048.5335-2-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/xen/interface')
-rw-r--r-- | include/xen/interface/io/usbif.h | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/include/xen/interface/io/usbif.h b/include/xen/interface/io/usbif.h new file mode 100644 index 000000000000..a70e0b93178b --- /dev/null +++ b/include/xen/interface/io/usbif.h @@ -0,0 +1,405 @@ +/* SPDX-License-Identifier: MIT */ + +/* + * usbif.h + * + * USB I/O interface for Xen guest OSes. + * + * Copyright (C) 2009, FUJITSU LABORATORIES LTD. + * Author: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com> + */ + +#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 { + XENUSB_VER_UNKNOWN = 0, + XENUSB_VER_USB11, + XENUSB_VER_USB20, + XENUSB_VER_USB30, /* not supported yet */ +}; + +/* + * 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 0x0000001f +#define XENUSB_PIPE_UNLINK 0x00000020 +#define XENUSB_PIPE_DIR 0x00000080 +#define XENUSB_PIPE_DEV_MASK 0x0000007f +#define XENUSB_PIPE_DEV_SHIFT 8 +#define XENUSB_PIPE_EP_MASK 0x0000000f +#define XENUSB_PIPE_EP_SHIFT 15 +#define XENUSB_PIPE_TYPE_MASK 0x00000003 +#define XENUSB_PIPE_TYPE_SHIFT 30 +#define XENUSB_PIPE_TYPE_ISOC 0 +#define XENUSB_PIPE_TYPE_INT 1 +#define XENUSB_PIPE_TYPE_CTRL 2 +#define XENUSB_PIPE_TYPE_BULK 3 + +#define xenusb_pipeportnum(pipe) ((pipe) & XENUSB_PIPE_PORT_MASK) +#define xenusb_setportnum_pipe(pipe, portnum) ((pipe) | (portnum)) + +#define xenusb_pipeunlink(pipe) ((pipe) & XENUSB_PIPE_UNLINK) +#define xenusb_pipesubmit(pipe) (!xenusb_pipeunlink(pipe)) +#define xenusb_setunlink_pipe(pipe) ((pipe) | XENUSB_PIPE_UNLINK) + +#define xenusb_pipein(pipe) ((pipe) & XENUSB_PIPE_DIR) +#define xenusb_pipeout(pipe) (!xenusb_pipein(pipe)) + +#define xenusb_pipedevice(pipe) \ + (((pipe) >> XENUSB_PIPE_DEV_SHIFT) & XENUSB_PIPE_DEV_MASK) + +#define xenusb_pipeendpoint(pipe) \ + (((pipe) >> XENUSB_PIPE_EP_SHIFT) & XENUSB_PIPE_EP_MASK) + +#define xenusb_pipetype(pipe) \ + (((pipe) >> XENUSB_PIPE_TYPE_SHIFT) & XENUSB_PIPE_TYPE_MASK) +#define xenusb_pipeisoc(pipe) (xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_ISOC) +#define xenusb_pipeint(pipe) (xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_INT) +#define xenusb_pipectrl(pipe) (xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_CTRL) +#define xenusb_pipebulk(pipe) (xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_BULK) + +#define XENUSB_MAX_SEGMENTS_PER_REQUEST (16) +#define XENUSB_MAX_PORTNR 31 +#define XENUSB_RING_SIZE 4096 + +/* + * RING for transferring urbs. + */ +struct xenusb_request_segment { + grant_ref_t gref; + uint16_t offset; + uint16_t length; +}; + +struct xenusb_urb_request { + uint16_t id; /* request id */ + uint16_t nr_buffer_segs; /* number of urb->transfer_buffer segments */ + + /* basic urb parameter */ + uint32_t pipe; + uint16_t transfer_flags; +#define XENUSB_SHORT_NOT_OK 0x0001 + uint16_t buffer_length; + union { + uint8_t ctrl[8]; /* setup_packet (Ctrl) */ + + struct { + uint16_t interval; /* maximum (1024*8) in usb core */ + uint16_t start_frame; /* start frame */ + uint16_t number_of_packets; /* number of ISO packet */ + uint16_t nr_frame_desc_segs; /* number of iso_frame_desc segments */ + } isoc; + + struct { + uint16_t interval; /* maximum (1024*8) in usb core */ + uint16_t pad[3]; + } intr; + + struct { + uint16_t unlink_id; /* unlink request id */ + uint16_t pad[3]; + } unlink; + + } u; + + /* urb data segments */ + struct xenusb_request_segment seg[XENUSB_MAX_SEGMENTS_PER_REQUEST]; +}; + +struct xenusb_urb_response { + uint16_t id; /* request id */ + uint16_t start_frame; /* start frame (ISO) */ + int32_t status; /* status (non-ISO) */ +#define XENUSB_STATUS_OK 0 +#define XENUSB_STATUS_NODEV (-19) +#define XENUSB_STATUS_INVAL (-22) +#define XENUSB_STATUS_STALL (-32) +#define XENUSB_STATUS_IOERROR (-71) +#define XENUSB_STATUS_BABBLE (-75) +#define XENUSB_STATUS_SHUTDOWN (-108) + int32_t actual_length; /* actual transfer length */ + int32_t error_count; /* number of ISO errors */ +}; + +DEFINE_RING_TYPES(xenusb_urb, struct xenusb_urb_request, struct xenusb_urb_response); +#define XENUSB_URB_RING_SIZE __CONST_RING_SIZE(xenusb_urb, XENUSB_RING_SIZE) + +/* + * RING for notifying connect/disconnect events to frontend + */ +struct xenusb_conn_request { + uint16_t id; +}; + +struct xenusb_conn_response { + uint16_t id; /* request id */ + uint8_t portnum; /* port number */ + uint8_t speed; /* usb_device_speed */ +#define XENUSB_SPEED_NONE 0 +#define XENUSB_SPEED_LOW 1 +#define XENUSB_SPEED_FULL 2 +#define XENUSB_SPEED_HIGH 3 +}; + +DEFINE_RING_TYPES(xenusb_conn, struct xenusb_conn_request, struct xenusb_conn_response); +#define XENUSB_CONN_RING_SIZE __CONST_RING_SIZE(xenusb_conn, XENUSB_RING_SIZE) + +#endif /* __XEN_PUBLIC_IO_USBIF_H__ */ |