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

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

Manos Pitsidianakis <manos.pitsidianakis@linaro.org> writes:

> 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),

What does this control? In VirtIOPCIProxy class_code seems to be for
transitional devices. It's used inconsistently  across the code base
AFAICT.

> +    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 },