Add vhost-user-snd and virtio-snd-pci devices

Tested with rust-vmm vhost-user-sound daemon:

    RUST_LOG=trace cargo run --bin vhost-user-sound -- --socket /tmp/snd.sock --backend null

Invocation:

    qemu-system-x86_64  \
            -qmp unix:./qmp-sock,server,wait=off  \
            -m 4096 \
            -numa node,memdev=mem \
            -object memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on \
            -D qemu.log \
            -d guest_errors,trace:\*snd\*,trace:\*sound\*,trace:\*vhost\* \
            -chardev socket,id=vsnd,path=/tmp/snd.sock \
            -device vhost-user-snd-pci,chardev=vsnd,id=snd \
            /path/to/disk

hw/virtio/Kconfig

@@ -95,3 +95,8 @@ config VHOST_VDPA_DEV
     bool
     default y
     depends on VIRTIO && VHOST_VDPA && LINUX
+
+config VHOST_USER_SND
+    bool
+    default y
+    depends on VIRTIO && VHOST_USER

hw/virtio/meson.build

@@ -13,6 +13,9 @@ softmmu_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_GPIO'],
 softmmu_virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c'))
 softmmu_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_I2C'],
                        if_true: files('vhost-user-i2c-pci.c'))
+softmmu_virtio_ss.add(when: 'CONFIG_VHOST_USER_SND', if_true: files('vhost-user-snd.c'))
+softmmu_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_SND'],
+                      if_true: files('vhost-user-snd-pci.c'))
 
 specific_virtio_ss = ss.source_set()
 specific_virtio_ss.add(files('virtio.c'))

hw/virtio/vhost-user-snd-pci.c

@@ -0,0 +1,75 @@
+/*
+ * Vhost-user Sound virtio device PCI glue
+ *
+ * Copyright (c) 2023 Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/vhost-user-snd.h"
+#include "hw/virtio/virtio-pci.h"
+
+struct VHostUserSoundPCI {
+    VirtIOPCIProxy parent_obj;
+    VHostUserSound vdev;
+};
+
+typedef struct VHostUserSoundPCI VHostUserSoundPCI;
+
+#define TYPE_VHOST_USER_SND_PCI "vhost-user-snd-pci-base"
+
+DECLARE_INSTANCE_CHECKER(VHostUserSoundPCI, VHOST_USER_SND_PCI,
+                         TYPE_VHOST_USER_SND_PCI)
+
+static Property vhost_user_snd_pci_properties[] = {
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_user_snd_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VHostUserSoundPCI *dev = VHOST_USER_SND_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&dev->vdev);
+
+    vpci_dev->nvectors = 1;
+
+    qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
+}
+
+static void vhost_user_snd_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+    k->realize = vhost_user_snd_pci_realize;
+    set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
+    device_class_set_props(dc, vhost_user_snd_pci_properties);
+    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    pcidev_k->device_id = 0; /* Set by virtio-pci based on virtio id */
+    pcidev_k->revision = 0x00;
+    pcidev_k->class_id = PCI_CLASS_MULTIMEDIA_AUDIO;
+}
+
+static void vhost_user_snd_pci_instance_init(Object *obj)
+{
+    VHostUserSoundPCI *dev = VHOST_USER_SND_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_USER_SND);
+}
+
+static const VirtioPCIDeviceTypeInfo vhost_user_snd_pci_info = {
+    .base_name = TYPE_VHOST_USER_SND_PCI,
+    .non_transitional_name = "vhost-user-snd-pci",
+    .instance_size = sizeof(VHostUserSoundPCI),
+    .instance_init = vhost_user_snd_pci_instance_init,
+    .class_init = vhost_user_snd_pci_class_init,
+};
+
+static void vhost_user_snd_pci_register(void)
+{
+    virtio_pci_types_register(&vhost_user_snd_pci_info);
+}
+
+type_init(vhost_user_snd_pci_register);

hw/virtio/vhost-user-snd.c

@@ -0,0 +1,66 @@
+/*
+ * Vhost-user snd virtio device
+ *
+ * Copyright (c) 2023 Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
+ *
+ * Simple wrapper of the generic vhost-user-device.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/vhost-user-snd.h"
+#include "standard-headers/linux/virtio_ids.h"
+#include "standard-headers/linux/virtio_snd.h"
+
+static const VMStateDescription vu_snd_vmstate = {
+    .name = "vhost-user-snd",
+    .unmigratable = 1,
+};
+
+static Property vsnd_properties[] = {
+    DEFINE_PROP_CHR("chardev", VHostUserBase, chardev),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vu_snd_base_realize(DeviceState *dev, Error **errp)
+{
+    VHostUserBase *vub = VHOST_USER_BASE(dev);
+    VHostUserBaseClass *vubs = VHOST_USER_BASE_GET_CLASS(dev);
+
+    vub->virtio_id = VIRTIO_ID_SOUND;
+    vub->num_vqs = 4;
+    vub->config_size = sizeof(struct virtio_snd_config);
+
+    vubs->parent_realize(dev, errp);
+}
+
+static void vu_snd_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VHostUserBaseClass *vubc = VHOST_USER_BASE_CLASS(klass);
+
+    dc->vmsd = &vu_snd_vmstate;
+    device_class_set_props(dc, vsnd_properties);
+    device_class_set_parent_realize(dc, vu_snd_base_realize,
+                                    &vubc->parent_realize);
+
+    set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
+}
+
+static const TypeInfo vu_snd_info = {
+    .name = TYPE_VHOST_USER_SND,
+    .parent = TYPE_VHOST_USER_BASE,
+    .instance_size = sizeof(VHostUserSound),
+    .class_init = vu_snd_class_init,
+};
+
+static void vu_snd_register_types(void)
+{
+    type_register_static(&vu_snd_info);
+}
+
+type_init(vu_snd_register_types)

include/hw/virtio/vhost-user-snd.h

@@ -0,0 +1,26 @@
+/*
+ * Vhost-user Sound virtio device
+ *
+ * Copyright (c) 2021 Mathieu Poirier <mathieu.poirier@linaro.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef QEMU_VHOST_USER_SND_H
+#define QEMU_VHOST_USER_SND_H
+
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-user.h"
+#include "hw/virtio/vhost-user-device.h"
+
+#define TYPE_VHOST_USER_SND "vhost-user-snd"
+OBJECT_DECLARE_SIMPLE_TYPE(VHostUserSound, VHOST_USER_SND)
+
+struct VHostUserSound {
+    /*< private >*/
+    VHostUserBase parent;
+    /*< public >*/
+};
+
+#endif /* QEMU_VHOST_USER_SND_H */