[PATCH v7 02/12] Add virtio-sound-pci device

[Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>]

This patch adds a PCI wrapper device for the virtio-sound device.
It is necessary to instantiate a virtio-snd device in a guest.
All sound logic will be added to the virtio-snd device in the following
commits.

To add this device with a guest, 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:

Pulseaudio:
  -audio driver=pa,model=virtio
  or
  -audio driver=pa,model=virtio,server=/run/user/1000/pulse/native
sdl:
  -audio driver=sdl,model=virtio
coreaudio (macos/darwin):
  -audio driver=coreaudio,model=virtio
etc.

Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
---
 hw/virtio/meson.build      |  1 +
 hw/virtio/virtio-snd-pci.c | 97 ++++++++++++++++++++++++++++++++++++++
 softmmu/qdev-monitor.c     |  1 +
 3 files changed, 99 insertions(+)
 create mode 100644 hw/virtio/virtio-snd-pci.c

diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 120d4bfa0a..5e5a83a4ee 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -63,6 +63,7 @@ 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'))
 virtio_pci_ss.add(when: 'CONFIG_VIRTIO_MD', if_true: files('virtio-md-pci.c'))
 
diff --git a/hw/virtio/virtio-snd-pci.c b/hw/virtio/virtio-snd-pci.c
new file mode 100644
index 0000000000..a6a530d161
--- /dev/null
+++ b/hw/virtio/virtio-snd-pci.c
@@ -0,0 +1,97 @@
+/*
+ * 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 "qapi/error.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"
+DECLARE_INSTANCE_CHECKER(VirtIOSoundPCI, VIRTIO_SND_PCI,
+                         TYPE_VIRTIO_SND_PCI)
+
+struct VirtIOSoundPCI {
+    VirtIOPCIProxy parent;
+    VirtIOSound vdev;
+};
+
+static Property virtio_snd_pci_properties[] = {
+    DEFINE_AUDIO_PROPERTIES(VirtIOSoundPCI, vdev.card),
+    DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
+                    VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
+    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
+                       DEV_NVECTORS_UNSPECIFIED),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_snd_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VirtIOSoundPCI *dev = VIRTIO_SND_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&dev->vdev);
+
+    if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
+        vpci_dev->nvectors = 2;
+    }
+
+    virtio_pci_force_virtio_1(vpci_dev);
+    qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
+}
+
+static void virtio_snd_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *vpciklass = VIRTIO_PCI_CLASS(klass);
+
+    device_class_set_props(dc, virtio_snd_pci_properties);
+    dc->desc = "Virtio Sound";
+    set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
+
+    vpciklass->realize = virtio_snd_pci_realize;
+}
+
+static void virtio_snd_pci_instance_init(Object *obj)
+{
+    VirtIOSoundPCI *dev = VIRTIO_SND_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_SND);
+}
+
+static const VirtioPCIDeviceTypeInfo virtio_snd_pci_info = {
+    .generic_name  = TYPE_VIRTIO_SND_PCI,
+    .instance_size = sizeof(VirtIOSoundPCI),
+    .instance_init = virtio_snd_pci_instance_init,
+    .class_init    = virtio_snd_pci_class_init,
+};
+
+/* Create a Virtio Sound PCI device, so '-audio driver,model=virtio' works. */
+static int virtio_snd_pci_init(PCIBus *bus, const char *audiodev)
+{
+    DeviceState *dev;
+
+    dev = qdev_new(TYPE_VIRTIO_SND_PCI);
+    qdev_prop_set_string(dev, "audiodev", audiodev);
+    qdev_realize_and_unref(dev, BUS(bus), &error_fatal);
+    return 0;
+}
+
+static void virtio_snd_pci_register(void)
+{
+    virtio_pci_types_register(&virtio_snd_pci_info);
+    pci_register_soundhw("virtio", "Virtio Sound", virtio_snd_pci_init);
+}
+
+type_init(virtio_snd_pci_register);
diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index 74f4e41338..2e9835ad88 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