Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 148 insertions, 0 deletions

diff --git a/audio/noaudio.c b/audio/noaudio.c
new file mode 100644
index 000000000..aac87dbc9
--- /dev/null
+++ b/audio/noaudio.c
@@ -0,0 +1,148 @@
+/*
+ * QEMU Timer based audio emulation
+ *
+ * Copyright (c) 2004-2005 Vassili Karpov (malc)
+ *
+ * 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.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/host-utils.h"
+#include "qemu/module.h"
+#include "audio.h"
+#include "qemu/timer.h"
+
+#define AUDIO_CAP "noaudio"
+#include "audio_int.h"
+
+typedef struct NoVoiceOut {
+    HWVoiceOut hw;
+    RateCtl rate;
+} NoVoiceOut;
+
+typedef struct NoVoiceIn {
+    HWVoiceIn hw;
+    RateCtl rate;
+} NoVoiceIn;
+
+static size_t no_write(HWVoiceOut *hw, void *buf, size_t len)
+{
+    NoVoiceOut *no = (NoVoiceOut *) hw;
+    return audio_rate_get_bytes(&hw->info, &no->rate, len);
+}
+
+static int no_init_out(HWVoiceOut *hw, struct audsettings *as, void *drv_opaque)
+{
+    NoVoiceOut *no = (NoVoiceOut *) hw;
+
+    audio_pcm_init_info (&hw->info, as);
+    hw->samples = 1024;
+    audio_rate_start(&no->rate);
+    return 0;
+}
+
+static void no_fini_out (HWVoiceOut *hw)
+{
+    (void) hw;
+}
+
+static void no_enable_out(HWVoiceOut *hw, bool enable)
+{
+    NoVoiceOut *no = (NoVoiceOut *) hw;
+
+    if (enable) {
+        audio_rate_start(&no->rate);
+    }
+}
+
+static int no_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
+{
+    NoVoiceIn *no = (NoVoiceIn *) hw;
+
+    audio_pcm_init_info (&hw->info, as);
+    hw->samples = 1024;
+    audio_rate_start(&no->rate);
+    return 0;
+}
+
+static void no_fini_in (HWVoiceIn *hw)
+{
+    (void) hw;
+}
+
+static size_t no_read(HWVoiceIn *hw, void *buf, size_t size)
+{
+    NoVoiceIn *no = (NoVoiceIn *) hw;
+    int64_t bytes = audio_rate_get_bytes(&hw->info, &no->rate, size);
+
+    audio_pcm_info_clear_buf(&hw->info, buf, bytes / hw->info.bytes_per_frame);
+    return bytes;
+}
+
+static void no_enable_in(HWVoiceIn *hw, bool enable)
+{
+    NoVoiceIn *no = (NoVoiceIn *) hw;
+
+    if (enable) {
+        audio_rate_start(&no->rate);
+    }
+}
+
+static void *no_audio_init(Audiodev *dev)
+{
+    return &no_audio_init;
+}
+
+static void no_audio_fini (void *opaque)
+{
+    (void) opaque;
+}
+
+static struct audio_pcm_ops no_pcm_ops = {
+    .init_out = no_init_out,
+    .fini_out = no_fini_out,
+    .write    = no_write,
+    .run_buffer_out = audio_generic_run_buffer_out,
+    .enable_out = no_enable_out,
+
+    .init_in  = no_init_in,
+    .fini_in  = no_fini_in,
+    .read     = no_read,
+    .run_buffer_in = audio_generic_run_buffer_in,
+    .enable_in = no_enable_in
+};
+
+static struct audio_driver no_audio_driver = {
+    .name           = "none",
+    .descr          = "Timer based audio emulation",
+    .init           = no_audio_init,
+    .fini           = no_audio_fini,
+    .pcm_ops        = &no_pcm_ops,
+    .can_be_default = 1,
+    .max_voices_out = INT_MAX,
+    .max_voices_in  = INT_MAX,
+    .voice_size_out = sizeof (NoVoiceOut),
+    .voice_size_in  = sizeof (NoVoiceIn)
+};
+
+static void register_audio_none(void)
+{
+    audio_driver_register(&no_audio_driver);
+}
+type_init(register_audio_none);