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, 508 insertions, 0 deletions

diff --git a/audio/sdlaudio.c b/audio/sdlaudio.c
new file mode 100644
index 000000000..c68c62a3e
--- /dev/null
+++ b/audio/sdlaudio.c
@@ -0,0 +1,508 @@
+/*
+ * QEMU SDL audio driver
+ *
+ * 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 <SDL.h>
+#include <SDL_thread.h>
+#include "qemu/module.h"
+#include "audio.h"
+
+#ifndef _WIN32
+#ifdef __sun__
+#define _POSIX_PTHREAD_SEMANTICS 1
+#elif defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
+#include <pthread.h>
+#endif
+#endif
+
+#define AUDIO_CAP "sdl"
+#include "audio_int.h"
+
+typedef struct SDLVoiceOut {
+    HWVoiceOut hw;
+    int exit;
+    int initialized;
+    Audiodev *dev;
+    SDL_AudioDeviceID devid;
+} SDLVoiceOut;
+
+typedef struct SDLVoiceIn {
+    HWVoiceIn hw;
+    int exit;
+    int initialized;
+    Audiodev *dev;
+    SDL_AudioDeviceID devid;
+} SDLVoiceIn;
+
+static void GCC_FMT_ATTR (1, 2) sdl_logerr (const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start (ap, fmt);
+    AUD_vlog (AUDIO_CAP, fmt, ap);
+    va_end (ap);
+
+    AUD_log (AUDIO_CAP, "Reason: %s\n", SDL_GetError ());
+}
+
+static int aud_to_sdlfmt (AudioFormat fmt)
+{
+    switch (fmt) {
+    case AUDIO_FORMAT_S8:
+        return AUDIO_S8;
+
+    case AUDIO_FORMAT_U8:
+        return AUDIO_U8;
+
+    case AUDIO_FORMAT_S16:
+        return AUDIO_S16LSB;
+
+    case AUDIO_FORMAT_U16:
+        return AUDIO_U16LSB;
+
+    case AUDIO_FORMAT_S32:
+        return AUDIO_S32LSB;
+
+    /* no unsigned 32-bit support in SDL */
+
+    case AUDIO_FORMAT_F32:
+        return AUDIO_F32LSB;
+
+    default:
+        dolog ("Internal logic error: Bad audio format %d\n", fmt);
+#ifdef DEBUG_AUDIO
+        abort ();
+#endif
+        return AUDIO_U8;
+    }
+}
+
+static int sdl_to_audfmt(int sdlfmt, AudioFormat *fmt, int *endianness)
+{
+    switch (sdlfmt) {
+    case AUDIO_S8:
+        *endianness = 0;
+        *fmt = AUDIO_FORMAT_S8;
+        break;
+
+    case AUDIO_U8:
+        *endianness = 0;
+        *fmt = AUDIO_FORMAT_U8;
+        break;
+
+    case AUDIO_S16LSB:
+        *endianness = 0;
+        *fmt = AUDIO_FORMAT_S16;
+        break;
+
+    case AUDIO_U16LSB:
+        *endianness = 0;
+        *fmt = AUDIO_FORMAT_U16;
+        break;
+
+    case AUDIO_S16MSB:
+        *endianness = 1;
+        *fmt = AUDIO_FORMAT_S16;
+        break;
+
+    case AUDIO_U16MSB:
+        *endianness = 1;
+        *fmt = AUDIO_FORMAT_U16;
+        break;
+
+    case AUDIO_S32LSB:
+        *endianness = 0;
+        *fmt = AUDIO_FORMAT_S32;
+        break;
+
+    case AUDIO_S32MSB:
+        *endianness = 1;
+        *fmt = AUDIO_FORMAT_S32;
+        break;
+
+    case AUDIO_F32LSB:
+        *endianness = 0;
+        *fmt = AUDIO_FORMAT_F32;
+        break;
+
+    case AUDIO_F32MSB:
+        *endianness = 1;
+        *fmt = AUDIO_FORMAT_F32;
+        break;
+
+    default:
+        dolog ("Unrecognized SDL audio format %d\n", sdlfmt);
+        return -1;
+    }
+
+    return 0;
+}
+
+static SDL_AudioDeviceID sdl_open(SDL_AudioSpec *req, SDL_AudioSpec *obt,
+                                  int rec)
+{
+    SDL_AudioDeviceID devid;
+#ifndef _WIN32
+    int err;
+    sigset_t new, old;
+
+    /* Make sure potential threads created by SDL don't hog signals.  */
+    err = sigfillset (&new);
+    if (err) {
+        dolog ("sdl_open: sigfillset failed: %s\n", strerror (errno));
+        return 0;
+    }
+    err = pthread_sigmask (SIG_BLOCK, &new, &old);
+    if (err) {
+        dolog ("sdl_open: pthread_sigmask failed: %s\n", strerror (err));
+        return 0;
+    }
+#endif
+
+    devid = SDL_OpenAudioDevice(NULL, rec, req, obt, 0);
+    if (!devid) {
+        sdl_logerr("SDL_OpenAudioDevice for %s failed\n",
+                   rec ? "recording" : "playback");
+    }
+
+#ifndef _WIN32
+    err = pthread_sigmask (SIG_SETMASK, &old, NULL);
+    if (err) {
+        dolog ("sdl_open: pthread_sigmask (restore) failed: %s\n",
+               strerror (errno));
+        /* We have failed to restore original signal mask, all bets are off,
+           so exit the process */
+        exit (EXIT_FAILURE);
+    }
+#endif
+    return devid;
+}
+
+static void sdl_close_out(SDLVoiceOut *sdl)
+{
+    if (sdl->initialized) {
+        SDL_LockAudioDevice(sdl->devid);
+        sdl->exit = 1;
+        SDL_UnlockAudioDevice(sdl->devid);
+        SDL_PauseAudioDevice(sdl->devid, 1);
+        sdl->initialized = 0;
+    }
+    if (sdl->devid) {
+        SDL_CloseAudioDevice(sdl->devid);
+        sdl->devid = 0;
+    }
+}
+
+static void sdl_callback_out(void *opaque, Uint8 *buf, int len)
+{
+    SDLVoiceOut *sdl = opaque;
+    HWVoiceOut *hw = &sdl->hw;
+
+    if (!sdl->exit) {
+
+        /* dolog("callback_out: len=%d avail=%zu\n", len, hw->pending_emul); */
+
+        while (hw->pending_emul && len) {
+            size_t write_len;
+            ssize_t start = (ssize_t)hw->pos_emul - hw->pending_emul;
+            if (start < 0) {
+                start += hw->size_emul;
+            }
+            assert(start >= 0 && start < hw->size_emul);
+
+            write_len = MIN(MIN(hw->pending_emul, len),
+                            hw->size_emul - start);
+
+            memcpy(buf, hw->buf_emul + start, write_len);
+            hw->pending_emul -= write_len;
+            len -= write_len;
+            buf += write_len;
+        }
+    }
+
+    /* clear remaining buffer that we couldn't fill with data */
+    if (len) {
+        audio_pcm_info_clear_buf(&hw->info, buf,
+                                 len / hw->info.bytes_per_frame);
+    }
+}
+
+static void sdl_close_in(SDLVoiceIn *sdl)
+{
+    if (sdl->initialized) {
+        SDL_LockAudioDevice(sdl->devid);
+        sdl->exit = 1;
+        SDL_UnlockAudioDevice(sdl->devid);
+        SDL_PauseAudioDevice(sdl->devid, 1);
+        sdl->initialized = 0;
+    }
+    if (sdl->devid) {
+        SDL_CloseAudioDevice(sdl->devid);
+        sdl->devid = 0;
+    }
+}
+
+static void sdl_callback_in(void *opaque, Uint8 *buf, int len)
+{
+    SDLVoiceIn *sdl = opaque;
+    HWVoiceIn *hw = &sdl->hw;
+
+    if (sdl->exit) {
+        return;
+    }
+
+    /* dolog("callback_in: len=%d pending=%zu\n", len, hw->pending_emul); */
+
+    while (hw->pending_emul < hw->size_emul && len) {
+        size_t read_len = MIN(len, MIN(hw->size_emul - hw->pos_emul,
+                                       hw->size_emul - hw->pending_emul));
+
+        memcpy(hw->buf_emul + hw->pos_emul, buf, read_len);
+
+        hw->pending_emul += read_len;
+        hw->pos_emul = (hw->pos_emul + read_len) % hw->size_emul;
+        len -= read_len;
+        buf += read_len;
+    }
+}
+
+#define SDL_WRAPPER_FUNC(name, ret_type, args_decl, args, dir) \
+    static ret_type glue(sdl_, name)args_decl                  \
+    {                                                          \
+        ret_type ret;                                          \
+        glue(SDLVoice, dir) *sdl = (glue(SDLVoice, dir) *)hw;  \
+                                                               \
+        SDL_LockAudioDevice(sdl->devid);                       \
+        ret = glue(audio_generic_, name)args;                  \
+        SDL_UnlockAudioDevice(sdl->devid);                     \
+                                                               \
+        return ret;                                            \
+    }
+
+#define SDL_WRAPPER_VOID_FUNC(name, args_decl, args, dir)      \
+    static void glue(sdl_, name)args_decl                      \
+    {                                                          \
+        glue(SDLVoice, dir) *sdl = (glue(SDLVoice, dir) *)hw;  \
+                                                               \
+        SDL_LockAudioDevice(sdl->devid);                       \
+        glue(audio_generic_, name)args;                        \
+        SDL_UnlockAudioDevice(sdl->devid);                     \
+    }
+
+SDL_WRAPPER_FUNC(get_buffer_out, void *, (HWVoiceOut *hw, size_t *size),
+                 (hw, size), Out)
+SDL_WRAPPER_FUNC(put_buffer_out, size_t,
+                 (HWVoiceOut *hw, void *buf, size_t size), (hw, buf, size), Out)
+SDL_WRAPPER_FUNC(write, size_t,
+                 (HWVoiceOut *hw, void *buf, size_t size), (hw, buf, size), Out)
+SDL_WRAPPER_FUNC(read, size_t, (HWVoiceIn *hw, void *buf, size_t size),
+                 (hw, buf, size), In)
+SDL_WRAPPER_FUNC(get_buffer_in, void *, (HWVoiceIn *hw, size_t *size),
+                 (hw, size), In)
+SDL_WRAPPER_VOID_FUNC(put_buffer_in, (HWVoiceIn *hw, void *buf, size_t size),
+                      (hw, buf, size), In)
+#undef SDL_WRAPPER_FUNC
+#undef SDL_WRAPPER_VOID_FUNC
+
+static void sdl_fini_out(HWVoiceOut *hw)
+{
+    SDLVoiceOut *sdl = (SDLVoiceOut *)hw;
+
+    sdl_close_out(sdl);
+}
+
+static int sdl_init_out(HWVoiceOut *hw, struct audsettings *as,
+                        void *drv_opaque)
+{
+    SDLVoiceOut *sdl = (SDLVoiceOut *)hw;
+    SDL_AudioSpec req, obt;
+    int endianness;
+    int err;
+    AudioFormat effective_fmt;
+    Audiodev *dev = drv_opaque;
+    AudiodevSdlPerDirectionOptions *spdo = dev->u.sdl.out;
+    struct audsettings obt_as;
+
+    req.freq = as->freq;
+    req.format = aud_to_sdlfmt (as->fmt);
+    req.channels = as->nchannels;
+    /*
+     * This is wrong. SDL samples are QEMU frames. The buffer size will be
+     * the requested buffer size multiplied by the number of channels.
+     */
+    req.samples = audio_buffer_samples(
+        qapi_AudiodevSdlPerDirectionOptions_base(spdo), as, 11610);
+    req.callback = sdl_callback_out;
+    req.userdata = sdl;
+
+    sdl->dev = dev;
+    sdl->devid = sdl_open(&req, &obt, 0);
+    if (!sdl->devid) {
+        return -1;
+    }
+
+    err = sdl_to_audfmt(obt.format, &effective_fmt, &endianness);
+    if (err) {
+        sdl_close_out(sdl);
+        return -1;
+    }
+
+    obt_as.freq = obt.freq;
+    obt_as.nchannels = obt.channels;
+    obt_as.fmt = effective_fmt;
+    obt_as.endianness = endianness;
+
+    audio_pcm_init_info (&hw->info, &obt_as);
+    hw->samples = (spdo->has_buffer_count ? spdo->buffer_count : 4) *
+        obt.samples;
+
+    sdl->initialized = 1;
+    sdl->exit = 0;
+    return 0;
+}
+
+static void sdl_enable_out(HWVoiceOut *hw, bool enable)
+{
+    SDLVoiceOut *sdl = (SDLVoiceOut *)hw;
+
+    SDL_PauseAudioDevice(sdl->devid, !enable);
+}
+
+static void sdl_fini_in(HWVoiceIn *hw)
+{
+    SDLVoiceIn *sdl = (SDLVoiceIn *)hw;
+
+    sdl_close_in(sdl);
+}
+
+static int sdl_init_in(HWVoiceIn *hw, audsettings *as, void *drv_opaque)
+{
+    SDLVoiceIn *sdl = (SDLVoiceIn *)hw;
+    SDL_AudioSpec req, obt;
+    int endianness;
+    int err;
+    AudioFormat effective_fmt;
+    Audiodev *dev = drv_opaque;
+    AudiodevSdlPerDirectionOptions *spdo = dev->u.sdl.in;
+    struct audsettings obt_as;
+
+    req.freq = as->freq;
+    req.format = aud_to_sdlfmt(as->fmt);
+    req.channels = as->nchannels;
+    /* SDL samples are QEMU frames */
+    req.samples = audio_buffer_frames(
+        qapi_AudiodevSdlPerDirectionOptions_base(spdo), as, 11610);
+    req.callback = sdl_callback_in;
+    req.userdata = sdl;
+
+    sdl->dev = dev;
+    sdl->devid = sdl_open(&req, &obt, 1);
+    if (!sdl->devid) {
+        return -1;
+    }
+
+    err = sdl_to_audfmt(obt.format, &effective_fmt, &endianness);
+    if (err) {
+        sdl_close_in(sdl);
+        return -1;
+    }
+
+    obt_as.freq = obt.freq;
+    obt_as.nchannels = obt.channels;
+    obt_as.fmt = effective_fmt;
+    obt_as.endianness = endianness;
+
+    audio_pcm_init_info(&hw->info, &obt_as);
+    hw->samples = (spdo->has_buffer_count ? spdo->buffer_count : 4) *
+        obt.samples;
+    hw->size_emul = hw->samples * hw->info.bytes_per_frame;
+    hw->buf_emul = g_malloc(hw->size_emul);
+    hw->pos_emul = hw->pending_emul = 0;
+
+    sdl->initialized = 1;
+    sdl->exit = 0;
+    return 0;
+}
+
+static void sdl_enable_in(HWVoiceIn *hw, bool enable)
+{
+    SDLVoiceIn *sdl = (SDLVoiceIn *)hw;
+
+    SDL_PauseAudioDevice(sdl->devid, !enable);
+}
+
+static void *sdl_audio_init(Audiodev *dev)
+{
+    if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
+        sdl_logerr ("SDL failed to initialize audio subsystem\n");
+        return NULL;
+    }
+
+    return dev;
+}
+
+static void sdl_audio_fini (void *opaque)
+{
+    SDL_QuitSubSystem (SDL_INIT_AUDIO);
+}
+
+static struct audio_pcm_ops sdl_pcm_ops = {
+    .init_out = sdl_init_out,
+    .fini_out = sdl_fini_out,
+  /* wrapper for audio_generic_write */
+    .write    = sdl_write,
+  /* wrapper for audio_generic_get_buffer_out */
+    .get_buffer_out = sdl_get_buffer_out,
+  /* wrapper for audio_generic_put_buffer_out */
+    .put_buffer_out = sdl_put_buffer_out,
+    .enable_out = sdl_enable_out,
+    .init_in = sdl_init_in,
+    .fini_in = sdl_fini_in,
+  /* wrapper for audio_generic_read */
+    .read = sdl_read,
+  /* wrapper for audio_generic_get_buffer_in */
+    .get_buffer_in = sdl_get_buffer_in,
+  /* wrapper for audio_generic_put_buffer_in */
+    .put_buffer_in = sdl_put_buffer_in,
+    .enable_in = sdl_enable_in,
+};
+
+static struct audio_driver sdl_audio_driver = {
+    .name           = "sdl",
+    .descr          = "SDL http://www.libsdl.org",
+    .init           = sdl_audio_init,
+    .fini           = sdl_audio_fini,
+    .pcm_ops        = &sdl_pcm_ops,
+    .can_be_default = 1,
+    .max_voices_out = INT_MAX,
+    .max_voices_in  = INT_MAX,
+    .voice_size_out = sizeof(SDLVoiceOut),
+    .voice_size_in  = sizeof(SDLVoiceIn),
+};
+
+static void register_audio_sdl(void)
+{
+    audio_driver_register(&sdl_audio_driver);
+}
+type_init(register_audio_sdl);