xref: /qemu/include/hw/audio/virtio-snd.h (revision eb9ad377bb94d2d98d18cfccc431a028361385c6)
1 /*
2  * VIRTIO Sound Device conforming to
3  *
4  * "Virtual I/O Device (VIRTIO) Version 1.2
5  * Committee Specification Draft 01
6  * 09 May 2022"
7  *
8  * Copyright (c) 2023 Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
9  * Copyright (C) 2019 OpenSynergy GmbH
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or
12  * (at your option) any later version.  See the COPYING file in the
13  * top-level directory.
14  */
15 
16 #ifndef QEMU_VIRTIO_SOUND_H
17 #define QEMU_VIRTIO_SOUND_H
18 
19 #include "hw/virtio/virtio.h"
20 #include "audio/audio.h"
21 #include "standard-headers/linux/virtio_ids.h"
22 #include "standard-headers/linux/virtio_snd.h"
23 
24 #define TYPE_VIRTIO_SND "virtio-sound-device"
25 #define VIRTIO_SND(obj) \
26         OBJECT_CHECK(VirtIOSound, (obj), TYPE_VIRTIO_SND)
27 
28 /* CONFIGURATION SPACE */
29 
30 typedef struct virtio_snd_config virtio_snd_config;
31 
32 /* COMMON DEFINITIONS */
33 
34 /* common header for request/response*/
35 typedef struct virtio_snd_hdr virtio_snd_hdr;
36 
37 /* event notification */
38 typedef struct virtio_snd_event virtio_snd_event;
39 
40 /* common control request to query an item information */
41 typedef struct virtio_snd_query_info virtio_snd_query_info;
42 
43 /* JACK CONTROL MESSAGES */
44 
45 typedef struct virtio_snd_jack_hdr virtio_snd_jack_hdr;
46 
47 /* jack information structure */
48 typedef struct virtio_snd_jack_info virtio_snd_jack_info;
49 
50 /* jack remapping control request */
51 typedef struct virtio_snd_jack_remap virtio_snd_jack_remap;
52 
53 /*
54  * PCM CONTROL MESSAGES
55  */
56 typedef struct virtio_snd_pcm_hdr virtio_snd_pcm_hdr;
57 
58 /* PCM stream info structure */
59 typedef struct virtio_snd_pcm_info virtio_snd_pcm_info;
60 
61 /* set PCM stream params */
62 typedef struct virtio_snd_pcm_set_params virtio_snd_pcm_set_params;
63 
64 /* I/O request header */
65 typedef struct virtio_snd_pcm_xfer virtio_snd_pcm_xfer;
66 
67 /* I/O request status */
68 typedef struct virtio_snd_pcm_status virtio_snd_pcm_status;
69 
70 /* device structs */
71 
72 typedef struct VirtIOSound VirtIOSound;
73 
74 typedef struct VirtIOSoundPCMStream VirtIOSoundPCMStream;
75 
76 typedef struct virtio_snd_ctrl_command virtio_snd_ctrl_command;
77 
78 typedef struct VirtIOSoundPCM VirtIOSoundPCM;
79 
80 struct VirtIOSoundPCM {
81     VirtIOSound *snd;
82     /*
83      * PCM parameters are a separate field instead of a VirtIOSoundPCMStream
84      * field, because the operation of PCM control requests is first
85      * VIRTIO_SND_R_PCM_SET_PARAMS and then VIRTIO_SND_R_PCM_PREPARE; this
86      * means that some times we get parameters without having an allocated
87      * stream yet.
88      */
89     virtio_snd_pcm_set_params *pcm_params;
90     VirtIOSoundPCMStream **streams;
91 };
92 
93 struct VirtIOSoundPCMStream {
94     VirtIOSoundPCM *pcm;
95     virtio_snd_pcm_info info;
96     virtio_snd_pcm_set_params params;
97     uint32_t id;
98     /* channel position values (VIRTIO_SND_CHMAP_XXX) */
99     uint8_t positions[VIRTIO_SND_CHMAP_MAX_SIZE];
100     VirtIOSound *s;
101     bool flushing;
102     audsettings as;
103     union {
104         SWVoiceIn *in;
105         SWVoiceOut *out;
106     } voice;
107     bool active;
108 };
109 
110 /*
111  * PCM stream state machine.
112  * -------------------------
113  *
114  * 5.14.6.6.1 PCM Command Lifecycle
115  * ================================
116  *
117  * A PCM stream has the following command lifecycle:
118  * - `SET PARAMETERS`
119  *   The driver negotiates the stream parameters (format, transport, etc) with
120  *   the device.
121  *   Possible valid transitions: `SET PARAMETERS`, `PREPARE`.
122  * - `PREPARE`
123  *   The device prepares the stream (allocates resources, etc).
124  *   Possible valid transitions: `SET PARAMETERS`, `PREPARE`, `START`,
125  *   `RELEASE`. Output only: the driver transfers data for pre-buffing.
126  * - `START`
127  *   The device starts the stream (unmute, putting into running state, etc).
128  *   Possible valid transitions: `STOP`.
129  *   The driver transfers data to/from the stream.
130  * - `STOP`
131  *   The device stops the stream (mute, putting into non-running state, etc).
132  *   Possible valid transitions: `START`, `RELEASE`.
133  * - `RELEASE`
134  *   The device releases the stream (frees resources, etc).
135  *   Possible valid transitions: `SET PARAMETERS`, `PREPARE`.
136  *
137  * +---------------+ +---------+ +---------+ +-------+ +-------+
138  * | SetParameters | | Prepare | | Release | | Start | | Stop  |
139  * +---------------+ +---------+ +---------+ +-------+ +-------+
140  *         |-             |           |          |         |
141  *         ||             |           |          |         |
142  *         |<             |           |          |         |
143  *         |------------->|           |          |         |
144  *         |<-------------|           |          |         |
145  *         |              |-          |          |         |
146  *         |              ||          |          |         |
147  *         |              |<          |          |         |
148  *         |              |--------------------->|         |
149  *         |              |---------->|          |         |
150  *         |              |           |          |-------->|
151  *         |              |           |          |<--------|
152  *         |              |           |<-------------------|
153  *         |<-------------------------|          |         |
154  *         |              |<----------|          |         |
155  *
156  * CTRL in the VirtIOSound device
157  * ==============================
158  *
159  * The control messages that affect the state of a stream arrive in the
160  * `virtio_snd_handle_ctrl()` queue callback and are of type `struct
161  * virtio_snd_ctrl_command`. They are stored in a queue field in the device
162  * type, `VirtIOSound`. This allows deferring the CTRL request completion if
163  * it's not immediately possible due to locking/state reasons.
164  *
165  * The CTRL message is finally handled in `process_cmd()`.
166  */
167 struct VirtIOSound {
168     VirtIODevice parent_obj;
169 
170     VirtQueue *queues[VIRTIO_SND_VQ_MAX];
171     uint64_t features;
172     VirtIOSoundPCM *pcm;
173     QEMUSoundCard card;
174     VMChangeStateEntry *vmstate;
175     virtio_snd_config snd_conf;
176     QemuMutex cmdq_mutex;
177     QTAILQ_HEAD(, virtio_snd_ctrl_command) cmdq;
178     bool processing_cmdq;
179 };
180 
181 struct virtio_snd_ctrl_command {
182     VirtQueueElement *elem;
183     VirtQueue *vq;
184     virtio_snd_hdr ctrl;
185     virtio_snd_hdr resp;
186     QTAILQ_ENTRY(virtio_snd_ctrl_command) next;
187 };
188 #endif
189