From patchwork Mon Mar 20 07:03:27 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Andrushchenko X-Patchwork-Id: 9633101 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9AA59602D6 for ; Mon, 20 Mar 2017 07:06:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 857B027F7F for ; Mon, 20 Mar 2017 07:06:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7989628047; Mon, 20 Mar 2017 07:06:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6902D27F7F for ; Mon, 20 Mar 2017 07:06:37 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cprLy-0003we-Qt; Mon, 20 Mar 2017 07:03:42 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cprLx-0003w3-TD for xen-devel@lists.xenproject.org; Mon, 20 Mar 2017 07:03:42 +0000 Received: from [193.109.254.147] by server-9.bemta-6.messagelabs.com id FE/62-14382-DCE7FC85; Mon, 20 Mar 2017 07:03:41 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrHIsWRWlGSWpSXmKPExsVyMfS6i+6ZuvM RBif/slh83zKZyYHR4/CHKywBjFGsmXlJ+RUJrBk/Js1gLJh6iani/f3FzA2M3xqZuhi5OIQE pjNKdGzbwgrisAi8ZJH4dKSfBcSREOhnlTg07SdQhhPIiZFovHuLuYuRA8iulJg3MRckLCSgK PH12XSoScuZJPY/PsUCkmATMJJYfuMHmC0ioCRxb9VksCJmgU5miWOLn7ODJIQFTCQeHNrOBG KzCKhKnFj4gBVkAa+Ak8Sj3wEQe+Ukbp7rZAaxOQWcJRZ9fscKsdhJYvmEQywTGAUWMDKsYtQ oTi0qSy3SNTLRSyrKTM8oyU3MzNE1NDDTy00tLk5MT81JTCrWS87P3cQIDC8GINjBuO9j5CFG SQ4mJVHe318ORQjxJeWnVGYkFmfEF5XmpBYfYpTh4FCS4F0w+0iEkGBRanpqRVpmDjDQYdISH DxKIry/QdK8xQWJucWZ6RCpU4yWHA9O7XrDxDFn9m4g+an/8BsmIZa8/LxUKXHeuyANAiANGa V5cONg0XiJUVZKmJcR6EAhnoLUotzMElT5V4ziHIxKwrxPQKbwZOaVwG19BXQQE9BB0/gOghx UkoiQkmpgrIry2R9TpL9r30zr0FcH/tb66B9k5f+QsVLP4O7ipRd/THdskP5oc+J0zYc1a47X BZ7jUmCy3feVQeLn3JDK6xxpXVYHOLS0omL4YqR33/j1/dHiulVKz0T69YX+7/jIsjnCc2WA0 TmTn681P3/gcOm7kLR0nfoBy0919s7xorssFs94z8fOocRSnJFoqMVcVJwIAABlqK7BAgAA X-Env-Sender: andr2000@gmail.com X-Msg-Ref: server-14.tower-27.messagelabs.com!1489993419!80185000!1 X-Originating-IP: [209.85.215.68] X-SpamReason: No, hits=0.5 required=7.0 tests=BODY_RANDOM_LONG X-StarScan-Received: X-StarScan-Version: 9.2.3; banners=-,-,- X-VirusChecked: Checked Received: (qmail 3126 invoked from network); 20 Mar 2017 07:03:39 -0000 Received: from mail-lf0-f68.google.com (HELO mail-lf0-f68.google.com) (209.85.215.68) by server-14.tower-27.messagelabs.com with AES128-GCM-SHA256 encrypted SMTP; 20 Mar 2017 07:03:39 -0000 Received: by mail-lf0-f68.google.com with SMTP id r36so9308133lfi.0 for ; Mon, 20 Mar 2017 00:03:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Q9fE+DXCx4B7riXA+Psk1LRs3MSzPrRiWP37kghTcOk=; b=jN603jCHNU4X/OPHOHsPAMe6mYHkwUX6DSoXIYYpJPKr/DPz7W+VOdc5UhPbep2x99 Eb3o/yXm0apGSXReC/W7ga+YqhCGe1XsU5QlhNnjtG/t8zEo+RnX2auS6LQJ2SrtWpaX l4wmst/gOtccuRQKpVAp3Ugo7A3DYJWf+NhX9pnU4S4e4ldN+BsJoQIEAbXpq/NaeoRl VNisDfEeHD7Tt5vYwM2/rT1Q10V1v31rQ3QE50SbZseOvea6hrjKiKm8XFmqiwWrMhYH bBxaUuq7q45qIBwkHGZi1UlCsKViewsM4lDgV2DsPbUHH8zn5wZkKmrqag92/7boWt3T jO9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Q9fE+DXCx4B7riXA+Psk1LRs3MSzPrRiWP37kghTcOk=; b=Lfc+WL8/j3iUYi3ZVeKSUhWB4B8aelb1MmAYcv0DVYWXZwk+4FnFU/vDGYP6hDmrMQ aBEGvSh/RKiQYGPm42PKNO7a6bkYcBnZA7ylLgkLijuuwDGD3uBVrfgCT8O4oIg5mrUu 80HDjKP2ywpgmnFAREFerNbOLibRBSNXE4Wi4Un6IlxwaHWQ+HVUnjH/hzIV9ql6Hu6Z 3sFIZ4+3oz8aL6f7uwrpgdgcY5qhIks3sSv1deodgRgGOgbEve0usnx5sf2x1B+gj9tI z/84Bzpc9juaXt6OcN158NuEq0IlQ7NpwAmuMxJFnysxSjqyXqfcWdpgIHDQVQGDlqvR PIkA== X-Gm-Message-State: AFeK/H3LOswOvM3irbxlStK2b1vY0lrpsJfmkGkVXj8YnFEon0W4ySRYdTwlgVkGN1AOPg== X-Received: by 10.25.150.82 with SMTP id y79mr7036974lfd.167.1489993418579; Mon, 20 Mar 2017 00:03:38 -0700 (PDT) Received: from a2k-HP-ProDesk-600-G2-SFF.kyiv.epam.com (ll-74.141.223.85.sovam.net.ua. [85.223.141.74]) by smtp.gmail.com with ESMTPSA id f2sm832765ljb.20.2017.03.20.00.03.36 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 20 Mar 2017 00:03:37 -0700 (PDT) From: Oleksandr Andrushchenko To: xen-devel@lists.xenproject.org Date: Mon, 20 Mar 2017 09:03:27 +0200 Message-Id: <1489993407-14323-2-git-send-email-andr2000@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1489993407-14323-1-git-send-email-andr2000@gmail.com> References: <1489993407-14323-1-git-send-email-andr2000@gmail.com> Cc: lars.kurth@citrix.com, iurii.konovalenko@globallogic.com, vlad.babchuk@gmail.com, oleksandr.dmytryshyn@globallogic.com, Oleksandr Andrushchenko , julien.grall@arm.com, andrii.anisov@gmail.com, olekstysh@gmail.com, andr2000@gmail.com, al1img@gmail.com, Oleksandr Grytsov , joculator@gmail.com Subject: [Xen-devel] [PATCH v18] xen/sndif: Add sound-device ABI X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Oleksandr Andrushchenko Add ABI for the two halves of a para-virtualized sound driver to communicate with each other. The ABI allows implementing audio playback and capture as well as volume control and possibility to mute/unmute audio sources. Note: depending on the use-case backend can expose more sound cards and PCM devices/streams than the underlying HW physically has by employing SW mixers, configuring virtual sound streams, channels etc. Thus, allowing fine tunned configurations per frontend. Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Oleksandr Andrushchenko Signed-off-by: Oleksandr Grytsov Signed-off-by: Oleksandr Dmytryshyn Signed-off-by: Iurii Konovalenko --- Changes since v1: * removed __attribute__((__packed__)) from all structures definitions Changes since v2: * removed all C structures * added protocol description between frontend and backend drivers Changes since v3: * fixed some typos * renamed XENSND_PCM_FORMAT_FLOAT_** to XENSND_PCM_FORMAT_F32_** * renamed XENSND_PCM_FORMAT_FLOAT64_** to XENSND_PCM_FORMAT_F64_** * added 'id' field to the request and response packets * renamed 'stream_id' to 'stream' in the packets description * renamed 'pcm_data_rate' to 'pcm_rate' in the packets description * renamed 'pcm_stream_type' to 'pcm_type' in the packets description * removed 'stream_id' field from the response packets Changes since v4: * renamed 'stream_id' back to the to 'stream' in the packets description * moved 'id' field to the upper position in the response packets Changes since v5: * Slightly reworked request/response packets * Size of the request/response packet is changed to the 64 bytes * Now parameters for the XENSND_OP_SET_VOLUME/XENSND_OP_GET_VOLUME are passed via shared page * Added parameters for the XenBus nodes (now each stream can be mapped to the defined sound device in the backend using those parameters) * Added XenBus state diagrams description Changes since v6: * Reworked streams description in the Backend XenBus Nodes Changes since v7: * re-worked backend device parameters to be more generic and flexible * extended frontend device parameters * slightly updated state machine description added mute/unmute commands * added constants for XenStore configuration strings (fields, PCM formats etc.) * changed request/response structure size from 64 octets to 16 * introduced dynamic buffer allocation instead of static XENSND_MAX_PAGES_PER_REQUEST * re-worked open request to allow dynamic buffer allocation * re-worked read/write/volume requests, so they don't pass grefs: buffer from the open request is used for these operations to pass data * specified type of the volume value to be a signed value in steps of 0.001 dBm, while 0 being 0dBm. * added Linux include file with structure definitions Changes since v8: * changed frontend-id to frontend_id * single sound card support, configured with bunch of devices/streams * clarifucation made on sample rates and formats expressed as decimals w/o any particular ordering * put description of migration/disconnection state * replaced __attribute__((packed)) to __packed * changed padding of ring structures to 64 to fit cache line * removeed #ifdef __KERNEL * explicitly stated which indices in XenStore configuration are contiguous * added description to what frontend's defaults are * made names of virtual card/devices optional * removed PCM_FORMAT_SPECIAL * changed volume units from dBm to dB Changes since v9: * removed sndif_linux.h * moved all structures from sndif_linux.h to sndif.h * structures padded where needed * fixed Hz comment Changes since v10: * fixed tabs to 4 spaces to comply with Xen coding style * added placeholders to empty structures (C89 concern) * added missing header includes Changes since v11: * added XENSND_RSP_NOTSUPP error code * changed gref[0] to gref[1] with comment * modified comments on empty structures * removed "__" from member names * fixed indentation * added padding in union xensnd_resp * changed __XEN_PUBLIC_IO_XENSND_H__ to __XEN_PUBLIC_IO_SNDIF_H__ Changes since v12: * changed indentation for defines * missed ";" after gref[1] * documentation changes * changed req/resp structures * changed xensnd_page_directory structure * pass buffer size in open request Changes since v13: * note on usage of grant ref 0 * all page sizes are XEN_PAGE_SIZE * padding/reserved cleanup/fixes * removed empty structures Changes since v14: * turn padding into reserved Changes since v15: * protocol description reworked * added offset to block notations * used -XEN_EXX for status reporting * added protocol versioning * removed stream_idx from the packet structure * changed xenstore paths Changes since v16: * updated XenStore path pattern * removed unused XenStore helper string constants * renamed gref_directory_start to gref_directory * added offset/length to volume, mute, unmute * added note on async use-cases * struct xensnd_rw_req is now used for read/write, volume set/get, mute, unmute Changes since v17: * add recovery flow into state diagrams section * re-position struct xensnd_rw_req in the document * make a note on common use of xensnd_rw_req for read/write, volume get/set, mute/unmute * add missing string constants for XenStore "versions" and "version" fields * add editor's block --- Signed-off-by: Oleksandr Andrushchenko --- xen/include/public/io/sndif.h | 803 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 803 insertions(+) create mode 100644 xen/include/public/io/sndif.h diff --git a/xen/include/public/io/sndif.h b/xen/include/public/io/sndif.h new file mode 100644 index 000000000000..c5c1978406b3 --- /dev/null +++ b/xen/include/public/io/sndif.h @@ -0,0 +1,803 @@ +/****************************************************************************** + * sndif.h + * + * Unified sound-device I/O interface for Xen guest OSes. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * Copyright (C) 2013-2015 GlobalLogic Inc. + * Copyright (C) 2016-2017 EPAM Systems Inc. + * + * Authors: Oleksandr Andrushchenko + * Oleksandr Grytsov + * Oleksandr Dmytryshyn + * Iurii Konovalenko + */ + +#ifndef __XEN_PUBLIC_IO_SNDIF_H__ +#define __XEN_PUBLIC_IO_SNDIF_H__ + +#include "ring.h" +#include "../grant_table.h" + +/* + ****************************************************************************** + * Feature and Parameter Negotiation + ****************************************************************************** + * + * Front->back notifications: when enqueuing a new request, sending a + * notification can be made conditional on xensnd_req (i.e., the generic + * hold-off mechanism provided by the ring macros). Backends must set + * xensnd_req appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()). + * + * Back->front notifications: when enqueuing a new response, sending a + * notification can be made conditional on xensnd_resp (i.e., the generic + * hold-off mechanism provided by the ring macros). Frontends must set + * xensnd_resp appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()). + * + * The two halves of a para-virtual sound card driver utilize nodes within + * XenStore to communicate capabilities and to negotiate operating parameters. + * This section enumerates these nodes which reside in the respective front and + * backend portions of XenStore, following the XenBus convention. + * + * All data in XenStore is stored as strings. Nodes specifying numeric + * values are encoded in decimal. Integer value ranges listed below are + * expressed as fixed sized integer types capable of storing the conversion + * of a properly formated node string, without loss of information. + * + ****************************************************************************** + * Example configuration + ****************************************************************************** + * + * Note: depending on the use-case backend can expose more sound cards and + * PCM devices/streams than the underlying HW physically has by employing + * SW mixers, configuring virtual sound streams, channels etc. + * + * This is an example of backend and frontend configuration: + * + *--------------------------------- Backend ----------------------------------- + * + * /local/domain/0/backend/vsnd/1/0/frontend-id = "1" + * /local/domain/0/backend/vsnd/1/0/frontend = "/local/domain/1/device/vsnd/0" + * /local/domain/0/backend/vsnd/1/0/state = "4" + * /local/domain/0/backend/vsnd/1/0/versions = "1,2" + * + *--------------------------------- Frontend ---------------------------------- + * + * /local/domain/1/device/vsnd/0/backend-id = "0" + * /local/domain/1/device/vsnd/0/backend = "/local/domain/0/backend/vsnd/1/0" + * /local/domain/1/device/vsnd/0/state = "4" + * /local/domain/1/device/vsnd/0/version = "1" + * + *----------------------------- Card configuration ---------------------------- + * + * /local/domain/1/device/vsnd/0/short-name = "Card short name" + * /local/domain/1/device/vsnd/0/long-name = "Card long name" + * /local/domain/1/device/vsnd/0/sample-rates = "8000,32000,44100,48000,96000" + * /local/domain/1/device/vsnd/0/sample-formats = "s8,u8,s16_le,s16_be" + * /local/domain/1/device/vsnd/0/buffer-size = "262144" + * + *------------------------------- PCM device 0 -------------------------------- + * + * /local/domain/1/device/vsnd/0/0/name = "General analog" + * /local/domain/1/device/vsnd/0/0/channels-max = "5" + * + *----------------------------- Stream 0, playback ---------------------------- + * + * /local/domain/1/device/vsnd/0/0/0/type = "p" + * /local/domain/1/device/vsnd/0/0/0/sample-formats = "s8,u8" + * /local/domain/1/device/vsnd/0/0/0/unique-id = "0" + * + * /local/domain/1/device/vsnd/0/0/0/ring-ref = "386" + * /local/domain/1/device/vsnd/0/0/0/event-channel = "15" + * + *------------------------------ Stream 1, capture ---------------------------- + * + * /local/domain/1/device/vsnd/0/0/1/type = "c" + * /local/domain/1/device/vsnd/0/0/1/channels-max = "2" + * /local/domain/1/device/vsnd/0/0/1/unique-id = "1" + * + * /local/domain/1/device/vsnd/0/0/1/ring-ref = "384" + * /local/domain/1/device/vsnd/0/0/1/event-channel = "13" + * + *------------------------------- PCM device 1 -------------------------------- + * + * /local/domain/1/device/vsnd/0/1/name = "HDMI-0" + * /local/domain/1/device/vsnd/0/1/sample-rates = "8000,32000,44100" + * + *------------------------------ Stream 0, capture ---------------------------- + * + * /local/domain/1/device/vsnd/0/1/0/type = "c" + * /local/domain/1/device/vsnd/0/1/0/unique-id = "2" + * + * /local/domain/1/device/vsnd/0/1/0/ring-ref = "387" + * /local/domain/1/device/vsnd/0/1/0/event-channel = "151" + * + *------------------------------- PCM device 2 -------------------------------- + * + * /local/domain/1/device/vsnd/0/2/name = "SPDIF" + * + *----------------------------- Stream 0, playback ---------------------------- + * + * /local/domain/1/device/vsnd/0/2/0/type = "p" + * /local/domain/1/device/vsnd/0/2/0/unique-id = "3" + * + * /local/domain/1/device/vsnd/0/2/0/ring-ref = "389" + * /local/domain/1/device/vsnd/0/2/0/event-channel = "152" + * + ****************************************************************************** + * Backend XenBus Nodes + ****************************************************************************** + * + *----------------------------- Protocol version ------------------------------ + * + * versions + * Values: + * + * List of XENSND_LIST_SEPARATOR separated protocol versions supported + * by the backend. For example "1,2,3". + * + ****************************************************************************** + * Frontend XenBus Nodes + ****************************************************************************** + * + *-------------------------------- Addressing --------------------------------- + * + * dom-id + * Values: + * + * Domain identifier. + * + * dev-id + * Values: + * + * Device identifier. + * + * pcm-dev-idx + * Values: + * + * Zero based contigous index of the PCM device. + * + * stream-idx + * Values: + * + * Zero based contigous index of the stream of the PCM device. + * + * The following pattern is used for addressing: + * /local/domain//device/vsnd////... + * + *----------------------------- Protocol version ------------------------------ + * + * version + * Values: + * + * Protocol version, chosen among the ones supported by the backend. + * + *------------------------------- PCM settings -------------------------------- + * + * Every virtualized sound frontend has a set of PCM devices and streams, each + * could be individually configured. Part of the PCM configuration can be + * defined at higher level of the hierarchy and be fully or partially re-used + * by the underlying layers. These configuration values are: + * o number of channels (min/max) + * o supported sample rates + * o supported sample formats. + * E.g. one can define these values for the whole card, device or stream. + * Every underlying layer in turn can re-define some or all of them to better + * fit its needs. For example, card may define number of channels to be + * in [1; 8] range, and some particular stream may be limited to [1; 2] only. + * The rule is that the underlying layer must be a subset of the upper layer + * range. + * + * channels-min + * Values: + * + * The minimum amount of channels that is supported, [1; channels-max]. + * Optional, if not set or omitted a value of 1 is used. + * + * channels-max + * Values: + * + * The maximum amount of channels that is supported. + * Must be at least . + * + * sample-rates + * Values: + * + * List of supported sample rates separated by XENSND_LIST_SEPARATOR. + * Sample rates are expressed as a list of decimal values w/o any + * ordering requirement. + * + * sample-formats + * Values: + * + * List of supported sample formats separated by XENSND_LIST_SEPARATOR. + * Items must not exceed XENSND_SAMPLE_FORMAT_MAX_LEN length. + * + * buffer-size + * Values: + * + * The maximum size in octets of the buffer to allocate per stream. + * + *----------------------- Virtual sound card settings ------------------------- + * short-name + * Values: + * + * Short name of the virtual sound card. Optional. + * + * long-name + * Values: + * + * Long name of the virtual sound card. Optional. + * + *----------------------------- Device settings ------------------------------- + * name + * Values: + * + * Name of the sound device within the virtual sound card. Optional. + * + *----------------------------- Stream settings ------------------------------- + * + * type + * Values: "p", "c" + * + * Stream type: "p" - playback stream, "c" - capture stream + * + * If both capture and playback are needed then two streams need to be + * defined under the same device. + * + * unique-id + * Values: + * + * After stream initialization it is assigned a unique ID (within the front + * driver), so every stream of the frontend can be identified by the + * backend by this ID. This is not equal to stream-idx as the later is + * zero based within the device, but this index is contigous within the + * driver. + * + *-------------------- Stream Request Transport Parameters -------------------- + * + * event-channel + * Values: + * + * The identifier of the Xen event channel used to signal activity + * in the ring buffer. + * + * ring-ref + * Values: + * + * The Xen grant reference granting permission for the backend to map + * a sole page in a single page sized ring buffer. + * + ****************************************************************************** + * STATE DIAGRAMS + ****************************************************************************** + * + * Tool stack creates front and back state nodes with initial state + * XenbusStateInitialising. + * Tool stack creates and sets up frontend sound configuration nodes per domain. + * + * Front Back + * ================================= ===================================== + * XenbusStateInitialising XenbusStateInitialising + * o Query backend device identification + * data. + * o Open and validate backend device. + * | + * | + * V + * XenbusStateInitWait + * + * o Query frontend configuration + * o Allocate and initialize + * event channels per configured + * playback/capture stream. + * o Publish transport parameters + * that will be in effect during + * this connection. + * | + * | + * V + * XenbusStateInitialised + * + * o Query frontend transport parameters. + * o Connect to the event channels. + * | + * | + * V + * XenbusStateConnected + * + * o Create and initialize OS + * virtual sound device instances + * as per configuration. + * | + * | + * V + * XenbusStateConnected + * + * XenbusStateUnknown + * XenbusStateClosed + * XenbusStateClosing + * o Remove virtual sound device + * o Remove event channels + * | + * | + * V + * XenbusStateClosed + * + *------------------------------- Recovery flow ------------------------------- + * + * In case of frontend unrecoverable errors backend handles that as + * if frontend goes into the XenbusStateClosed state. + * + * In case of backend unrecoverable errors frontend tries removing + * the virtualized device. If this is possible at the moment of error, + * then frontend goes into the XenbusStateInitialising state and is ready for + * new connection with backend. If the virtualized device is still in use and + * cannot be removed, then frontend goes into the XenbusStateReconfiguring state + * until either the virtualized device removed or backend initiates a new + * connection. On the virtualized device removal frontend goes into the + * XenbusStateInitialising state. + * + * Note on XenbusStateReconfiguring state of the frontend: if backend has + * unrecoverable errors then frontend cannot send requests to the backend + * and thus cannot provide functionality of the virtualized device anymore. + * After backend is back to normal the virtualized device may still hold some + * state: configuration in use, allocated buffers, client application state etc. + * So, in most cases, this will require frontend to implement complex recovery + * reconnect logic. Instead, by going into XenbusStateReconfiguring state, + * frontend will make sure no new clients of the virtualized device are + * accepted, allow existing client(s) to exit gracefully by signaling error + * state etc. + * Once all the clients are gone frontend can reinitialize the virtualized + * device and get into XenbusStateInitialising state again signaling the + * backend that a new connection can be made. + * + * There are multiple conditions possible under which frontend will go from + * XenbusStateReconfiguring into XenbusStateInitialising, some of them are OS + * specific. For example: + * 1. The underlying OS framework may provide callbacks to signal that the last + * client of the virtualized device has gone and the device can be removed + * 2. Frontend can schedule a deferred work (timer/tasklet/workqueue) + * to periodically check if this is the right time to re-try removal of + * the virtualized device. + * 3. By any other means. + * + ****************************************************************************** + * PCM FORMATS + ****************************************************************************** + * + * XENSND_PCM_FORMAT_[_] + * + * format: or + * S - signed, U - unsigned, F - float + * bits - 8, 16, 24, 32 + * name - MU_LAW, GSM, etc. + * + * endian: , may be absent + * LE - Little endian, BE - Big endian + */ +#define XENSND_PCM_FORMAT_S8 0 +#define XENSND_PCM_FORMAT_U8 1 +#define XENSND_PCM_FORMAT_S16_LE 2 +#define XENSND_PCM_FORMAT_S16_BE 3 +#define XENSND_PCM_FORMAT_U16_LE 4 +#define XENSND_PCM_FORMAT_U16_BE 5 +#define XENSND_PCM_FORMAT_S24_LE 6 +#define XENSND_PCM_FORMAT_S24_BE 7 +#define XENSND_PCM_FORMAT_U24_LE 8 +#define XENSND_PCM_FORMAT_U24_BE 9 +#define XENSND_PCM_FORMAT_S32_LE 10 +#define XENSND_PCM_FORMAT_S32_BE 11 +#define XENSND_PCM_FORMAT_U32_LE 12 +#define XENSND_PCM_FORMAT_U32_BE 13 +#define XENSND_PCM_FORMAT_F32_LE 14 /* 4-byte float, IEEE-754 32-bit, */ +#define XENSND_PCM_FORMAT_F32_BE 15 /* range -1.0 to 1.0 */ +#define XENSND_PCM_FORMAT_F64_LE 16 /* 8-byte float, IEEE-754 64-bit, */ +#define XENSND_PCM_FORMAT_F64_BE 17 /* range -1.0 to 1.0 */ +#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE 18 +#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE 19 +#define XENSND_PCM_FORMAT_MU_LAW 20 +#define XENSND_PCM_FORMAT_A_LAW 21 +#define XENSND_PCM_FORMAT_IMA_ADPCM 22 +#define XENSND_PCM_FORMAT_MPEG 23 +#define XENSND_PCM_FORMAT_GSM 24 + +/* + ****************************************************************************** + * REQUEST CODES + ****************************************************************************** + */ +#define XENSND_OP_OPEN 0 +#define XENSND_OP_CLOSE 1 +#define XENSND_OP_READ 2 +#define XENSND_OP_WRITE 3 +#define XENSND_OP_SET_VOLUME 4 +#define XENSND_OP_GET_VOLUME 5 +#define XENSND_OP_MUTE 6 +#define XENSND_OP_UNMUTE 7 + +/* + ****************************************************************************** + * XENSTORE FIELD AND PATH NAME STRINGS, HELPERS + ****************************************************************************** + */ +#define XENSND_DRIVER_NAME "vsnd" + +#define XENSND_LIST_SEPARATOR "," +/* Field names */ +#define XENSND_FIELD_BE_VERSIONS "versions" +#define XENSND_FIELD_FE_VERSION "version" +#define XENSND_FIELD_VCARD_SHORT_NAME "short-name" +#define XENSND_FIELD_VCARD_LONG_NAME "long-name" +#define XENSND_FIELD_RING_REF "ring-ref" +#define XENSND_FIELD_EVT_CHNL "event-channel" +#define XENSND_FIELD_DEVICE_NAME "name" +#define XENSND_FIELD_TYPE "type" +#define XENSND_FIELD_STREAM_UNIQUE_ID "unique-id" +#define XENSND_FIELD_CHANNELS_MIN "channels-min" +#define XENSND_FIELD_CHANNELS_MAX "channels-max" +#define XENSND_FIELD_SAMPLE_RATES "sample-rates" +#define XENSND_FIELD_SAMPLE_FORMATS "sample-formats" +#define XENSND_FIELD_BUFFER_SIZE "buffer-size" + +/* Stream type field values. */ +#define XENSND_STREAM_TYPE_PLAYBACK "p" +#define XENSND_STREAM_TYPE_CAPTURE "c" +/* Sample rate max string length */ +#define XENSND_SAMPLE_RATE_MAX_LEN 11 +/* Sample format field values */ +#define XENSND_SAMPLE_FORMAT_MAX_LEN 24 + +#define XENSND_PCM_FORMAT_S8_STR "s8" +#define XENSND_PCM_FORMAT_U8_STR "u8" +#define XENSND_PCM_FORMAT_S16_LE_STR "s16_le" +#define XENSND_PCM_FORMAT_S16_BE_STR "s16_be" +#define XENSND_PCM_FORMAT_U16_LE_STR "u16_le" +#define XENSND_PCM_FORMAT_U16_BE_STR "u16_be" +#define XENSND_PCM_FORMAT_S24_LE_STR "s24_le" +#define XENSND_PCM_FORMAT_S24_BE_STR "s24_be" +#define XENSND_PCM_FORMAT_U24_LE_STR "u24_le" +#define XENSND_PCM_FORMAT_U24_BE_STR "u24_be" +#define XENSND_PCM_FORMAT_S32_LE_STR "s32_le" +#define XENSND_PCM_FORMAT_S32_BE_STR "s32_be" +#define XENSND_PCM_FORMAT_U32_LE_STR "u32_le" +#define XENSND_PCM_FORMAT_U32_BE_STR "u32_be" +#define XENSND_PCM_FORMAT_F32_LE_STR "float_le" +#define XENSND_PCM_FORMAT_F32_BE_STR "float_be" +#define XENSND_PCM_FORMAT_F64_LE_STR "float64_le" +#define XENSND_PCM_FORMAT_F64_BE_STR "float64_be" +#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE_STR "iec958_subframe_le" +#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE_STR "iec958_subframe_be" +#define XENSND_PCM_FORMAT_MU_LAW_STR "mu_law" +#define XENSND_PCM_FORMAT_A_LAW_STR "a_law" +#define XENSND_PCM_FORMAT_IMA_ADPCM_STR "ima_adpcm" +#define XENSND_PCM_FORMAT_MPEG_STR "mpeg" +#define XENSND_PCM_FORMAT_GSM_STR "gsm" + + +/* + ****************************************************************************** + * STATUS RETURN CODES + ****************************************************************************** + * + * Status return code is zero on success and -XEN_EXX on failure. + * + ****************************************************************************** + * Assumptions + ****************************************************************************** + * o usage of grant reference 0 as invalid grant reference: + * grant reference 0 is valid, but never exposed to a PV driver, + * because of the fact it is already in use/reserved by the PV console. + * o all references in this document to page sizes must be treated + * as pages of size XEN_PAGE_SIZE unless otherwise noted. + * + ****************************************************************************** + * Description of the protocol between frontend and backend driver + ****************************************************************************** + * + * The two halves of a Para-virtual sound driver communicate with + * each other using shared pages and event channels. + * Shared page contains a ring with request/response packets. + * + * Packets, used for input/output operations, e.g. read/write, set/get volume, + * etc., provide offset/length fields in order to allow asynchronous protocol + * operation with buffer space sharing: part of the buffer allocated at + * XENSND_OP_OPEN can be used for audio samples and part, for example, + * for volume control. + * + * All reserved fields in the structures below must be 0. + * + *---------------------------------- Requests --------------------------------- + * + * All request packets have the same length (32 octets) + * All request packets have common header: + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | id | operation | reserved | 4 + * +----------------+----------------+----------------+----------------+ + * | reserved | 8 + * +----------------+----------------+----------------+----------------+ + * id - uint16_t, private guest value, echoed in response + * operation - uint8_t, operation code, XENSND_OP_??? + * + * For all packets which use offset and length: + * offset - uint32_t, read or write data offset within the shared buffer, + * passed with XENSND_OP_OPEN request, octets, + * [0; XENSND_OP_OPEN.buffer_sz - 1]. + * length - uint32_t, read or write data length, octets + * + * Request open - open a PCM stream for playback or capture: + * + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | id | XENSND_OP_OPEN | reserved | 4 + * +----------------+----------------+----------------+----------------+ + * | reserved | 8 + * +----------------+----------------+----------------+----------------+ + * | pcm_rate | 12 + * +----------------+----------------+----------------+----------------+ + * | pcm_format | pcm_channels | reserved | 16 + * +----------------+----------------+----------------+----------------+ + * | buffer_sz | 20 + * +----------------+----------------+----------------+----------------+ + * | gref_directory | 24 + * +----------------+----------------+----------------+----------------+ + * | reserved | 28 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | reserved | 32 + * +----------------+----------------+----------------+----------------+ + * + * pcm_rate - uint32_t, stream data rate, Hz + * pcm_format - uint8_t, XENSND_PCM_FORMAT_XXX value + * pcm_channels - uint8_t, number of channels of this stream, + * [channels-min; channels-max] + * buffer_sz - uint32_t, buffer size to be allocated, octets + * gref_directory - grant_ref_t, a reference to the first shared page + * describing shared buffer references. At least one page exists. If shared + * buffer size (buffer_sz) exceeds what can be addressed by this single page, + * then reference to the next page must be supplied (see gref_dir_next_page + * below) + */ + +struct xensnd_open_req { + uint32_t pcm_rate; + uint8_t pcm_format; + uint8_t pcm_channels; + uint16_t reserved; + uint32_t buffer_sz; + grant_ref_t gref_directory; +}; + +/* + * Shared page for XENSND_OP_OPEN buffer descriptor (gref_directory in the + * request) employs a list of pages, describing all pages of the shared data + * buffer: + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | gref_dir_next_page | 4 + * +----------------+----------------+----------------+----------------+ + * | gref[0] | 8 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | gref[i] | i*4+8 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | gref[N - 1] | N*4+8 + * +----------------+----------------+----------------+----------------+ + * + * gref_dir_next_page - grant_ref_t, reference to the next page describing + * page directory. Must be 0 if there are no more pages in the list. + * gref[i] - grant_ref_t, reference to a shared page of the buffer + * allocated at XENSND_OP_OPEN + * + * Number of grant_ref_t entries in the whole page directory is not + * passed, but instead can be calculated as: + * num_grefs_total = (XENSND_OP_OPEN.buffer_sz + XEN_PAGE_SIZE - 1) / + * XEN_PAGE_SIZE + */ + +struct xensnd_page_directory { + grant_ref_t gref_dir_next_page; + grant_ref_t gref[1]; /* Variable length */ +}; + +/* + * Request close - close an opened pcm stream: + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | id | XENSND_OP_CLOSE| reserved | 4 + * +----------------+----------------+----------------+----------------+ + * | reserved | 8 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | reserved | 32 + * +----------------+----------------+----------------+----------------+ + * + * Request read/write - used for read (for capture) or write (for playback): + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | id | operation | reserved | 4 + * +----------------+----------------+----------------+----------------+ + * | reserved | 8 + * +----------------+----------------+----------------+----------------+ + * | offset | 12 + * +----------------+----------------+----------------+----------------+ + * | length | 16 + * +----------------+----------------+----------------+----------------+ + * | reserved | 20 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | reserved | 32 + * +----------------+----------------+----------------+----------------+ + * + * operation - XENSND_OP_READ for read or XENSND_OP_WRITE for write + */ + +struct xensnd_rw_req { + uint32_t offset; + uint32_t length; +}; + +/* + * Request set/get volume - set/get channels' volume of the stream given: + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | id | operation | reserved | 4 + * +----------------+----------------+----------------+----------------+ + * | reserved | 8 + * +----------------+----------------+----------------+----------------+ + * | offset | 12 + * +----------------+----------------+----------------+----------------+ + * | length | 16 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | reserved | 32 + * +----------------+----------------+----------------+----------------+ + * + * operation - XENSND_OP_SET_VOLUME for volume set + * or XENSND_OP_GET_VOLUME for volume get + * Buffer passed with XENSND_OP_OPEN is used to exchange volume + * values: + * + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | channel[0] | 4 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | channel[i] | i*4 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | channel[N - 1] | (N-1)*4 + * +----------------+----------------+----------------+----------------+ + * + * N = XENSND_OP_OPEN.pcm_channels + * i - uint8_t, index of a channel + * channel[i] - sint32_t, volume of i-th channel + * Volume is expressed as a signed value in steps of 0.001 dB, + * while 0 being 0 dB. + * + * Request mute/unmute - mute/unmute stream: + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | id | operation | reserved | 4 + * +----------------+----------------+----------------+----------------+ + * | reserved | 8 + * +----------------+----------------+----------------+----------------+ + * | offset | 12 + * +----------------+----------------+----------------+----------------+ + * | length | 16 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | reserved | 32 + * +----------------+----------------+----------------+----------------+ + * + * operation - XENSND_OP_MUTE for mute or XENSND_OP_UNMUTE for unmute + * Buffer passed with XENSND_OP_OPEN is used to exchange mute/unmute + * values: + * + * 0 octet + * +----------------+----------------+----------------+----------------+ + * | channel[0] | 4 + * +----------------+----------------+----------------+----------------+ + * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | channel[i] | i*4 + * +----------------+----------------+----------------+----------------+ + * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | channel[N - 1] | (N-1)*4 + * +----------------+----------------+----------------+----------------+ + * + * N = XENSND_OP_OPEN.pcm_channels + * i - uint8_t, index of a channel + * channel[i] - uint8_t, non-zero if i-th channel needs to be muted/unmuted + * + *------------------------------------ N.B. ----------------------------------- + * + * The 'struct xensnd_rw_req' is also used for XENSND_OP_SET_VOLUME, + * XENSND_OP_GET_VOLUME, XENSND_OP_MUTE, XENSND_OP_UNMUTE. + */ + +/* + *---------------------------------- Responses -------------------------------- + * + * All response packets have the same length (32 octets) + * + * Response for all requests: + * 0 1 2 3 octet + * +----------------+----------------+----------------+----------------+ + * | id | operation | reserved | 4 + * +----------------+----------------+----------------+----------------+ + * | status | 8 + * +----------------+----------------+----------------+----------------+ + * | reserved | 12 + * +----------------+----------------+----------------+----------------+ + * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| + * +----------------+----------------+----------------+----------------+ + * | reserved | 32 + * +----------------+----------------+----------------+----------------+ + * + * id - uint16_t, copied from the request + * operation - uint8_t, XENSND_OP_* - copied from request + * status - int32_t, response status, zero on success and -XEN_EXX on failure + */ + +struct xensnd_req { + uint16_t id; + uint8_t operation; + uint8_t reserved[5]; + union { + struct xensnd_open_req open; + struct xensnd_rw_req rw; + uint8_t reserved[24]; + } op; +}; + +struct xensnd_resp { + uint16_t id; + uint8_t operation; + uint8_t reserved; + int32_t status; + uint8_t reserved1[24]; +}; + +DEFINE_RING_TYPES(xen_sndif, struct xensnd_req, struct xensnd_resp); + +#endif /* __XEN_PUBLIC_IO_SNDIF_H__ */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */