[PATCH v2 2/3] Add virtio-sound-pci device

[Manos Pitsidianakis]

This patch adds a PCI wrapper device for the virtio-sound device.

To test this, you'll need a >=5.13 kernel compiled with
CONFIG_SND_VIRTIO=y, which at the time of writing most distros have off
by default.

Use with following flags in the invocation:

  -device virtio-sound-pci,disable-legacy=on

And an audio backend listed with `-audio driver=help` that works on
your host machine, e.g.:

Pulseaudio:
  -audio driver=pa,model=virtio-sound
sdl:
  -audio driver=sdl,model=virtio-sound
coreaudio (macos/darwin):
  -audio driver=coreaudio,model=virtio-sound
etc.

You can use speaker-test from alsa-tools to play noise, sines, or
WAV files.

Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
---
---
 hw/virtio/meson.build      |   1 +
 hw/virtio/virtio-snd-pci.c | 102 +++++++++++++++++++++++++++++++++++++
 include/hw/pci/pci.h       |   1 +
 softmmu/qdev-monitor.c     |   1 +
 4 files changed, 105 insertions(+)
 create mode 100644 hw/virtio/virtio-snd-pci.c

diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 8cf49af618..55d9426415 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -58,6 +58,7 @@ virtio_pci_ss.add(when: 'CONFIG_VIRTIO_SERIAL', if_true: 
files('virtio-serial-pc
 virtio_pci_ss.add(when: 'CONFIG_VIRTIO_PMEM', if_true: 
files('virtio-pmem-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VIRTIO_IOMMU', if_true: 
files('virtio-iommu-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VIRTIO_MEM', if_true: 
files('virtio-mem-pci.c'))
+virtio_pci_ss.add(when: 'CONFIG_VIRTIO_SND', if_true: 
files('virtio-snd-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_VDPA_DEV', if_true: 
files('vdpa-dev-pci.c'))
 
 specific_virtio_ss.add_all(when: 'CONFIG_VIRTIO_PCI', if_true: virtio_pci_ss)
diff --git a/hw/virtio/virtio-snd-pci.c b/hw/virtio/virtio-snd-pci.c
new file mode 100644
index 0000000000..1a41b53e07
--- /dev/null
+++ b/hw/virtio/virtio-snd-pci.c
@@ -0,0 +1,102 @@
+/*
+ * VIRTIO Sound Device PCI Bindings
+ *
+ * Copyright (c) 2023 Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.  See the COPYING file in the
+ * top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/audio/soundhw.h"
+#include "hw/virtio/virtio-pci.h"
+#include "hw/virtio/virtio-snd.h"
+
+typedef struct VirtIOSoundPCI VirtIOSoundPCI;
+
+/*
+ * virtio-snd-pci: This extends VirtioPCIProxy.
+ */
+#define TYPE_VIRTIO_SND_PCI "virtio-sound-pci-base"
+DECLARE_INSTANCE_CHECKER(VirtIOSoundPCI, VIRTIO_SOUND_PCI,
+                         TYPE_VIRTIO_SND_PCI)
+
+struct VirtIOSoundPCI {
+    VirtIOPCIProxy parent;
+    VirtIOSound vdev;
+};
+
+static Property virtio_snd_pci_properties[] = {
+    DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static const char *audiodev_id;
+
+static int virtio_snd_init_pci(PCIBus *init_bus, const char *audiodev)
+{
+    audiodev_id = audiodev;
+    return 0;
+}
+
+static void virtio_snd_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VirtIOSoundPCI *dev = VIRTIO_SOUND_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&dev->vdev);
+    VirtIOSound *vsnd = VIRTIO_SND(&dev->vdev);
+
+    /*
+     * According to spec, non-legacy virtio PCI devices are always little
+     * endian
+     */
+    vsnd->virtio_access_is_big_endian = false;
+
+
+    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus), errp);
+
+    qdev_prop_set_string(vdev, "audiodev", audiodev_id);
+
+    object_property_set_bool(OBJECT(vdev), "realized", true, errp);
+}
+
+static void virtio_snd_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *vpciklass = VIRTIO_PCI_CLASS(klass);
+    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+
+    vpciklass->realize = virtio_snd_pci_realize;
+    set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
+
+    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_SND;
+    pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
+    pcidev_k->class_id = PCI_CLASS_MULTIMEDIA_AUDIO;
+    device_class_set_props(dc, virtio_snd_pci_properties);
+}
+
+static void virtio_snd_pci_instance_init(Object *obj)
+{
+    VirtIOSoundPCI *dev = VIRTIO_SOUND_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_SND);
+}
+
+static const VirtioPCIDeviceTypeInfo virtio_snd_pci_info = {
+    .base_name     = TYPE_VIRTIO_SND_PCI,
+    .generic_name  = "virtio-sound-pci",
+    .instance_size = sizeof(VirtIOSoundPCI),
+    .instance_init = virtio_snd_pci_instance_init,
+    .class_init    = virtio_snd_pci_class_init,
+};
+
+static void virtio_snd_pci_register(void)
+{
+    virtio_pci_types_register(&virtio_snd_pci_info);
+    pci_register_soundhw("virtio-sound", "Virtio Sound Device",
+                         virtio_snd_init_pci);
+}
+
+type_init(virtio_snd_pci_register);
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index e6d0574a29..cf4216df81 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -85,6 +85,7 @@ extern bool pci_available;
 #define PCI_DEVICE_ID_VIRTIO_RNG         0x1005
 #define PCI_DEVICE_ID_VIRTIO_9P          0x1009
 #define PCI_DEVICE_ID_VIRTIO_VSOCK       0x1012
+#define PCI_DEVICE_ID_VIRTIO_SND         0x1019
 
 /*
  * modern virtio-pci devices get their id assigned automatically,
diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index b8d2c4dadd..49d68495a3 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -108,6 +108,7 @@ static const QDevAlias qdev_alias_table[] = {
     { "virtio-serial-device", "virtio-serial", QEMU_ARCH_VIRTIO_MMIO },
     { "virtio-serial-ccw", "virtio-serial", QEMU_ARCH_VIRTIO_CCW },
     { "virtio-serial-pci", "virtio-serial", QEMU_ARCH_VIRTIO_PCI},
+    { "virtio-sound-pci", "virtio-sound", QEMU_ARCH_VIRTIO_PCI},
     { "virtio-tablet-device", "virtio-tablet", QEMU_ARCH_VIRTIO_MMIO },
     { "virtio-tablet-ccw", "virtio-tablet", QEMU_ARCH_VIRTIO_CCW },
     { "virtio-tablet-pci", "virtio-tablet", QEMU_ARCH_VIRTIO_PCI },
-- 
2.39.2