Re: [Xen-devel] [PATCH v3 1/2] xen-sndfront: add sound frontend driver
On Wed, Jan 21, 2015 at 5:14 PM, Stefano Stabellini stefano.stabell...@eu.citrix.com wrote: On Tue, 20 Jan 2015, Oleksandr Dmytryshyn wrote: This is Para-virtual sound driver. Frontend driver registers an virtual sound card and sends an PCM streams to the backend driver. Backend driver is an user-space application and uses ALSA with dmix plugin to play audio. Signed-off-by: Oleksandr Dmytryshyn oleksandr.dmytrys...@globallogic.com Signed-off-by: Iurii Konovalenko iurii.konovale...@globallogic.com The code isn't bad but we still lack a document that describes how the protocol works. It should have enough details in it to allow somebody to write a backend for it without looking at the frontend code. Without it, it is very difficult to tell if the frontend implementation is right. I'll describe a protocol in the next patch-set. There will be some description inside the file sndif.h. The rest I'll describe additionally. include/xen/interface/io/sndif.h | 208 ++ sound/drivers/Kconfig| 10 + sound/drivers/Makefile |2 + sound/drivers/xen-sndfront.c | 1478 ++ 4 files changed, 1698 insertions(+) create mode 100644 include/xen/interface/io/sndif.h create mode 100644 sound/drivers/xen-sndfront.c diff --git a/include/xen/interface/io/sndif.h b/include/xen/interface/io/sndif.h new file mode 100644 index 000..99e6f8e --- /dev/null +++ b/include/xen/interface/io/sndif.h @@ -0,0 +1,208 @@ +/** + * 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. + */ + +#ifndef __XEN_PUBLIC_IO_SNDIF_H__ +#define __XEN_PUBLIC_IO_SNDIF_H__ + +#include xen/interface/io/ring.h +#include xen/interface/grant_table.h + +/* + * Feature and Parameter Negotiation + * = + * The two halves of a Xen vsnd 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. + * + * All data in the 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. + * + * 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) -- + * + * stream_id + * Values: uint32_t + * + * Virtuelized stream number + * + * + *Frontend XenBus Nodes + * + * + *--- Request Transport Parameters --- + * + * event-channel + * Values: uint32_t + * + * The identifier of the Xen event channel used to signal activity + * in the ring buffer. + * + * ring-ref + * Values: uint32_t + * Notes: 6 + * + * The Xen grant reference granting permission for the backend
Re: [Xen-devel] [PATCH v3 1/2] xen-sndfront: add sound frontend driver
On Tue, 20 Jan 2015, Oleksandr Dmytryshyn wrote: This is Para-virtual sound driver. Frontend driver registers an virtual sound card and sends an PCM streams to the backend driver. Backend driver is an user-space application and uses ALSA with dmix plugin to play audio. Signed-off-by: Oleksandr Dmytryshyn oleksandr.dmytrys...@globallogic.com Signed-off-by: Iurii Konovalenko iurii.konovale...@globallogic.com The code isn't bad but we still lack a document that describes how the protocol works. It should have enough details in it to allow somebody to write a backend for it without looking at the frontend code. Without it, it is very difficult to tell if the frontend implementation is right. include/xen/interface/io/sndif.h | 208 ++ sound/drivers/Kconfig| 10 + sound/drivers/Makefile |2 + sound/drivers/xen-sndfront.c | 1478 ++ 4 files changed, 1698 insertions(+) create mode 100644 include/xen/interface/io/sndif.h create mode 100644 sound/drivers/xen-sndfront.c diff --git a/include/xen/interface/io/sndif.h b/include/xen/interface/io/sndif.h new file mode 100644 index 000..99e6f8e --- /dev/null +++ b/include/xen/interface/io/sndif.h @@ -0,0 +1,208 @@ +/** + * 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. + */ + +#ifndef __XEN_PUBLIC_IO_SNDIF_H__ +#define __XEN_PUBLIC_IO_SNDIF_H__ + +#include xen/interface/io/ring.h +#include xen/interface/grant_table.h + +/* + * Feature and Parameter Negotiation + * = + * The two halves of a Xen vsnd 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. + * + * All data in the 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. + * + * 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) -- + * + * stream_id + * Values: uint32_t + * + * Virtuelized stream number + * + * + *Frontend XenBus Nodes + * + * + *--- Request Transport Parameters --- + * + * event-channel + * Values: uint32_t + * + * The identifier of the Xen event channel used to signal activity + * in the ring buffer. + * + * ring-ref + * Values: uint32_t + * Notes: 6 + * + * The Xen grant reference granting permission for the backend to map + * the sole page in a single page sized ring buffer. + */ + +/* + * PCM FORMATS. + */ +#define SNDIF_PCM_FORMAT_S8 (0) +#define SNDIF_PCM_FORMAT_U8 (1) +#define SNDIF_PCM_FORMAT_S16_LE (2)
[Xen-devel] [PATCH v3 1/2] xen-sndfront: add sound frontend driver
This is Para-virtual sound driver. Frontend driver registers an virtual sound card and sends an PCM streams to the backend driver. Backend driver is an user-space application and uses ALSA with dmix plugin to play audio. Signed-off-by: Oleksandr Dmytryshyn oleksandr.dmytrys...@globallogic.com Signed-off-by: Iurii Konovalenko iurii.konovale...@globallogic.com --- include/xen/interface/io/sndif.h | 208 ++ sound/drivers/Kconfig| 10 + sound/drivers/Makefile |2 + sound/drivers/xen-sndfront.c | 1478 ++ 4 files changed, 1698 insertions(+) create mode 100644 include/xen/interface/io/sndif.h create mode 100644 sound/drivers/xen-sndfront.c diff --git a/include/xen/interface/io/sndif.h b/include/xen/interface/io/sndif.h new file mode 100644 index 000..99e6f8e --- /dev/null +++ b/include/xen/interface/io/sndif.h @@ -0,0 +1,208 @@ +/** + * 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. + */ + +#ifndef __XEN_PUBLIC_IO_SNDIF_H__ +#define __XEN_PUBLIC_IO_SNDIF_H__ + +#include xen/interface/io/ring.h +#include xen/interface/grant_table.h + +/* + * Feature and Parameter Negotiation + * = + * The two halves of a Xen vsnd 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. + * + * All data in the 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. + * + * 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) -- + * + * stream_id + * Values: uint32_t + * + * Virtuelized stream number + * + * + *Frontend XenBus Nodes + * + * + *--- Request Transport Parameters --- + * + * event-channel + * Values: uint32_t + * + * The identifier of the Xen event channel used to signal activity + * in the ring buffer. + * + * ring-ref + * Values: uint32_t + * Notes: 6 + * + * The Xen grant reference granting permission for the backend to map + * the sole page in a single page sized ring buffer. + */ + +/* + * PCM FORMATS. + */ +#define SNDIF_PCM_FORMAT_S8(0) +#define SNDIF_PCM_FORMAT_U8(1) +#define SNDIF_PCM_FORMAT_S16_LE(2) +#define SNDIF_PCM_FORMAT_S16_BE(3) +#define SNDIF_PCM_FORMAT_U16_LE(4) +#define SNDIF_PCM_FORMAT_U16_BE(5) + +/* low three bytes */ +#define SNDIF_PCM_FORMAT_S24_LE(6) + +/* low three bytes */ +#define SNDIF_PCM_FORMAT_S24_BE(7) + +/* low three bytes */ +#define SNDIF_PCM_FORMAT_U24_LE(8) + +/* low three bytes */ +#define SNDIF_PCM_FORMAT_U24_BE(9) +
