[Virtio-fs] [PATCH v5 0/6] virtio: cleanup vhost-user-generic and reduce c&p

[Virtio-fs] [PATCH v5 0/6] virtio: cleanup vhost-user-generic and reduce c&p

[Alex Bennée]

A lot of our vhost-user stubs are large chunks of boilerplate that do
(mostly) the same thing. This series continues the cleanups by
splitting the vhost-user-base and vhost-user-generic implementations.
After adding a new vq_size property the rng, gpio and i2c vhost-user
devices become simple specialisations of the common base defining the
ID, number of queues and potentially the config handling.

I've also added Manos' vhost-user-sound while I was at it.

Changes
-------

v5
  - addressing comments and tags
  - improved the docs

v4
  - dropped the F_TRANSPORT work for another series
  - added vhost-user-sound

Alex Bennée (5):
  virtio: split into vhost-user-base and vhost-user-device
  hw/virtio: derive vhost-user-rng from vhost-user-base
  hw/virtio: derive vhost-user-gpio from vhost-user-base
  hw/virtio: derive vhost-user-i2c from vhost-user-base
  docs/system: add a basic enumeration of vhost-user devices

Manos Pitsidianakis (1):
  hw/virtio: add vhost-user-snd and virtio-snd-pci devices

 docs/system/devices/vhost-user-rng.rst        |   2 +
 docs/system/devices/vhost-user.rst            |  60 ++-
 ...{vhost-user-device.h => vhost-user-base.h} |  21 +-
 include/hw/virtio/vhost-user-gpio.h           |  23 +-
 include/hw/virtio/vhost-user-i2c.h            |  14 +-
 include/hw/virtio/vhost-user-rng.h            |  11 +-
 include/hw/virtio/vhost-user-snd.h            |  26 ++
 hw/virtio/vhost-user-base.c                   | 345 +++++++++++++++
 hw/virtio/vhost-user-device-pci.c             |  10 +-
 hw/virtio/vhost-user-device.c                 | 335 +-------------
 hw/virtio/vhost-user-gpio.c                   | 407 +-----------------
 hw/virtio/vhost-user-i2c.c                    | 272 +-----------
 hw/virtio/vhost-user-rng.c                    | 278 +-----------
 hw/virtio/vhost-user-snd-pci.c                |  75 ++++
 hw/virtio/vhost-user-snd.c                    |  67 +++
 hw/virtio/Kconfig                             |   5 +
 hw/virtio/meson.build                         |  23 +-
 17 files changed, 683 insertions(+), 1291 deletions(-)
 rename include/hw/virtio/{vhost-user-device.h => vhost-user-base.h} (71%)
 create mode 100644 include/hw/virtio/vhost-user-snd.h
 create mode 100644 hw/virtio/vhost-user-base.c
 create mode 100644 hw/virtio/vhost-user-snd-pci.c
 create mode 100644 hw/virtio/vhost-user-snd.c

-- 
2.39.2

[Virtio-fs] [PATCH v5 1/6] virtio: split into vhost-user-base and vhost-user-device

[Alex Bennée]

Lets keep a cleaner split between the base class and the derived
vhost-user-device which we can use for generic vhost-user stubs. This
includes an update to introduce the vq_size property so the number of
entries in a virtq can be defined.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009095937.195728-2-alex.bennee@linaro.org>

---
v5
  - s/parent/parent_obj/
  - remove left over vhost-user-device.h
  - use DEFINE_TYPES
---
 ...{vhost-user-device.h => vhost-user-base.h} |  21 +-
 hw/virtio/vhost-user-base.c                   | 345 ++++++++++++++++++
 hw/virtio/vhost-user-device-pci.c             |  10 +-
 hw/virtio/vhost-user-device.c                 | 335 +----------------
 hw/virtio/meson.build                         |   1 +
 5 files changed, 370 insertions(+), 342 deletions(-)
 rename include/hw/virtio/{vhost-user-device.h => vhost-user-base.h} (71%)
 create mode 100644 hw/virtio/vhost-user-base.c

diff --git a/include/hw/virtio/vhost-user-device.h b/include/hw/virtio/vhost-user-base.h
similarity index 71%
rename from include/hw/virtio/vhost-user-device.h
rename to include/hw/virtio/vhost-user-base.h
index 3ddf88a146..51d0968b89 100644
--- a/include/hw/virtio/vhost-user-device.h
+++ b/include/hw/virtio/vhost-user-base.h
@@ -6,8 +6,8 @@
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
-#ifndef QEMU_VHOST_USER_DEVICE_H
-#define QEMU_VHOST_USER_DEVICE_H
+#ifndef QEMU_VHOST_USER_BASE_H
+#define QEMU_VHOST_USER_BASE_H
 
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/vhost-user.h"
@@ -17,11 +17,13 @@
 OBJECT_DECLARE_TYPE(VHostUserBase, VHostUserBaseClass, VHOST_USER_BASE)
 
 struct VHostUserBase {
-    VirtIODevice parent;
+    VirtIODevice parent_obj;
+
     /* Properties */
     CharBackend chardev;
     uint16_t virtio_id;
     uint32_t num_vqs;
+    uint32_t vq_size; /* can't exceed VIRTIO_QUEUE_MAX */
     uint32_t config_size;
     /* State tracking */
     VhostUserState vhost_user;
@@ -31,16 +33,17 @@ struct VHostUserBase {
     bool connected;
 };
 
-    /* needed so we can use the base realize after specialisation
-       tweaks */
+/*
+ * Needed so we can use the base realize after specialisation
+ * tweaks
+ */
 struct VHostUserBaseClass {
-    /*< private >*/
     VirtioDeviceClass parent_class;
-    /*< public >*/
+
     DeviceRealize parent_realize;
 };
 
-/* shared for the benefit of the derived pci class */
+
 #define TYPE_VHOST_USER_DEVICE "vhost-user-device"
 
-#endif /* QEMU_VHOST_USER_DEVICE_H */
+#endif /* QEMU_VHOST_USER_BASE_H */
diff --git a/hw/virtio/vhost-user-base.c b/hw/virtio/vhost-user-base.c
new file mode 100644
index 0000000000..ebb4795ebf
--- /dev/null
+++ b/hw/virtio/vhost-user-base.c
@@ -0,0 +1,345 @@
+/*
+ * Base vhost-user-base implementation. This can be used to derive a
+ * more fully specified vhost-user backend either generically (see
+ * vhost-user-device) or via a specific stub for a device which
+ * encapsulates some fixed parameters.
+ *
+ * Copyright (c) 2023 Linaro Ltd
+ * Author: Alex Bennée <alex.bennee@linaro.org>
+ *
+ * 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-base.h"
+#include "qemu/error-report.h"
+
+static void vub_start(VirtIODevice *vdev)
+{
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    VHostUserBase *vub = VHOST_USER_BASE(vdev);
+    int ret, i;
+
+    if (!k->set_guest_notifiers) {
+        error_report("binding does not support guest notifiers");
+        return;
+    }
+
+    ret = vhost_dev_enable_notifiers(&vub->vhost_dev, vdev);
+    if (ret < 0) {
+        error_report("Error enabling host notifiers: %d", -ret);
+        return;
+    }
+
+    ret = k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, true);
+    if (ret < 0) {
+        error_report("Error binding guest notifier: %d", -ret);
+        goto err_host_notifiers;
+    }
+
+    vub->vhost_dev.acked_features = vdev->guest_features;
+
+    ret = vhost_dev_start(&vub->vhost_dev, vdev, true);
+    if (ret < 0) {
+        error_report("Error starting vhost-user-base: %d", -ret);
+        goto err_guest_notifiers;
+    }
+
+    /*
+     * guest_notifier_mask/pending not used yet, so just unmask
+     * everything here. virtio-pci will do the right thing by
+     * enabling/disabling irqfd.
+     */
+    for (i = 0; i < vub->vhost_dev.nvqs; i++) {
+        vhost_virtqueue_mask(&vub->vhost_dev, vdev, i, false);
+    }
+
+    return;
+
+err_guest_notifiers:
+    k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false);
+err_host_notifiers:
+    vhost_dev_disable_notifiers(&vub->vhost_dev, vdev);
+}
+
+static void vub_stop(VirtIODevice *vdev)
+{
+    VHostUserBase *vub = VHOST_USER_BASE(vdev);
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    int ret;
+
+    if (!k->set_guest_notifiers) {
+        return;
+    }
+
+    vhost_dev_stop(&vub->vhost_dev, vdev, true);
+
+    ret = k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false);
+    if (ret < 0) {
+        error_report("vhost guest notifier cleanup failed: %d", ret);
+        return;
+    }
+
+    vhost_dev_disable_notifiers(&vub->vhost_dev, vdev);
+}
+
+static void vub_set_status(VirtIODevice *vdev, uint8_t status)
+{
+    VHostUserBase *vub = VHOST_USER_BASE(vdev);
+    bool should_start = virtio_device_should_start(vdev, status);
+
+    if (vhost_dev_is_started(&vub->vhost_dev) == should_start) {
+        return;
+    }
+
+    if (should_start) {
+        vub_start(vdev);
+    } else {
+        vub_stop(vdev);
+    }
+}
+
+/*
+ * For an implementation where everything is delegated to the backend
+ * we don't do anything other than return the full feature set offered
+ * by the daemon (module the reserved feature bit).
+ */
+static uint64_t vub_get_features(VirtIODevice *vdev,
+                                 uint64_t requested_features, Error **errp)
+{
+    VHostUserBase *vub = VHOST_USER_BASE(vdev);
+    /* This should be set when the vhost connection initialises */
+    g_assert(vub->vhost_dev.features);
+    return vub->vhost_dev.features & ~(1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
+}
+
+/*
+ * To handle VirtIO config we need to know the size of the config
+ * space. We don't cache the config but re-fetch it from the guest
+ * every time in case something has changed.
+ */
+static void vub_get_config(VirtIODevice *vdev, uint8_t *config)
+{
+    VHostUserBase *vub = VHOST_USER_BASE(vdev);
+    Error *local_err = NULL;
+
+    /*
+     * There will have been a warning during vhost_dev_init, but lets
+     * assert here as nothing will go right now.
+     */
+    g_assert(vub->config_size && vub->vhost_user.supports_config == true);
+
+    if (vhost_dev_get_config(&vub->vhost_dev, config,
+                             vub->config_size, &local_err)) {
+        error_report_err(local_err);
+    }
+}
+
+/*
+ * When the daemon signals an update to the config we just need to
+ * signal the guest as we re-read the config on demand above.
+ */
+static int vub_config_notifier(struct vhost_dev *dev)
+{
+    virtio_notify_config(dev->vdev);
+    return 0;
+}
+
+const VhostDevConfigOps vub_config_ops = {
+    .vhost_dev_config_notifier = vub_config_notifier,
+};
+
+static void vub_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+    /*
+     * Not normally called; it's the daemon that handles the queue;
+     * however virtio's cleanup path can call this.
+     */
+}
+
+static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserBase *vub)
+{
+    vhost_user_cleanup(&vub->vhost_user);
+
+    for (int i = 0; i < vub->num_vqs; i++) {
+        VirtQueue *vq = g_ptr_array_index(vub->vqs, i);
+        virtio_delete_queue(vq);
+    }
+
+    virtio_cleanup(vdev);
+}
+
+static int vub_connect(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBase *vub = VHOST_USER_BASE(vdev);
+    struct vhost_dev *vhost_dev = &vub->vhost_dev;
+
+    if (vub->connected) {
+        return 0;
+    }
+    vub->connected = true;
+
+    /*
+     * If we support VHOST_USER_GET_CONFIG we must enable the notifier
+     * so we can ping the guest when it updates.
+     */
+    if (vub->vhost_user.supports_config) {
+        vhost_dev_set_config_notifier(vhost_dev, &vub_config_ops);
+    }
+
+    /* restore vhost state */
+    if (virtio_device_started(vdev, vdev->status)) {
+        vub_start(vdev);
+    }
+
+    return 0;
+}
+
+static void vub_disconnect(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBase *vub = VHOST_USER_BASE(vdev);
+
+    if (!vub->connected) {
+        return;
+    }
+    vub->connected = false;
+
+    if (vhost_dev_is_started(&vub->vhost_dev)) {
+        vub_stop(vdev);
+    }
+}
+
+static void vub_event(void *opaque, QEMUChrEvent event)
+{
+    DeviceState *dev = opaque;
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBase *vub = VHOST_USER_BASE(vdev);
+
+    switch (event) {
+    case CHR_EVENT_OPENED:
+        if (vub_connect(dev) < 0) {
+            qemu_chr_fe_disconnect(&vub->chardev);
+            return;
+        }
+        break;
+    case CHR_EVENT_CLOSED:
+        vub_disconnect(dev);
+        break;
+    case CHR_EVENT_BREAK:
+    case CHR_EVENT_MUX_IN:
+    case CHR_EVENT_MUX_OUT:
+        /* Ignore */
+        break;
+    }
+}
+
+static void vub_device_realize(DeviceState *dev, Error **errp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBase *vub = VHOST_USER_BASE(dev);
+    int ret;
+
+    if (!vub->chardev.chr) {
+        error_setg(errp, "vhost-user-base: missing chardev");
+        return;
+    }
+
+    if (!vub->virtio_id) {
+        error_setg(errp, "vhost-user-base: need to define device id");
+        return;
+    }
+
+    if (!vub->num_vqs) {
+        vub->num_vqs = 1; /* reasonable default? */
+    }
+
+    if (!vub->vq_size) {
+        vub->vq_size = 64;
+    }
+
+    /*
+     * We can't handle config requests unless we know the size of the
+     * config region, specialisations of the vhost-user-base will be
+     * able to set this.
+     */
+    if (vub->config_size) {
+        vub->vhost_user.supports_config = true;
+    }
+
+    if (!vhost_user_init(&vub->vhost_user, &vub->chardev, errp)) {
+        return;
+    }
+
+    virtio_init(vdev, vub->virtio_id, vub->config_size);
+
+    /*
+     * Disable guest notifiers, by default all notifications will be via the
+     * asynchronous vhost-user socket.
+     */
+    vdev->use_guest_notifier_mask = false;
+
+    /* Allocate queues */
+    vub->vqs = g_ptr_array_sized_new(vub->num_vqs);
+    for (int i = 0; i < vub->num_vqs; i++) {
+        g_ptr_array_add(vub->vqs,
+                        virtio_add_queue(vdev, vub->vq_size, vub_handle_output));
+    }
+
+    vub->vhost_dev.nvqs = vub->num_vqs;
+    vub->vhost_dev.vqs = g_new0(struct vhost_virtqueue, vub->vhost_dev.nvqs);
+
+    /* connect to backend */
+    ret = vhost_dev_init(&vub->vhost_dev, &vub->vhost_user,
+                         VHOST_BACKEND_TYPE_USER, 0, errp);
+
+    if (ret < 0) {
+        do_vhost_user_cleanup(vdev, vub);
+    }
+
+    qemu_chr_fe_set_handlers(&vub->chardev, NULL, NULL, vub_event, NULL,
+                             dev, NULL, true);
+}
+
+static void vub_device_unrealize(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserBase *vub = VHOST_USER_BASE(dev);
+    struct vhost_virtqueue *vhost_vqs = vub->vhost_dev.vqs;
+
+    /* This will stop vhost backend if appropriate. */
+    vub_set_status(vdev, 0);
+    vhost_dev_cleanup(&vub->vhost_dev);
+    g_free(vhost_vqs);
+    do_vhost_user_cleanup(vdev, vub);
+}
+
+static void vub_class_init(ObjectClass *klass, void *data)
+{
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+    vdc->realize = vub_device_realize;
+    vdc->unrealize = vub_device_unrealize;
+    vdc->get_features = vub_get_features;
+    vdc->get_config = vub_get_config;
+    vdc->set_status = vub_set_status;
+}
+
+static const TypeInfo vub_types[] = {
+    {
+        .name = TYPE_VHOST_USER_BASE,
+        .parent = TYPE_VIRTIO_DEVICE,
+        .instance_size = sizeof(VHostUserBase),
+        .class_init = vub_class_init,
+        .class_size = sizeof(VHostUserBaseClass),
+        .abstract = true
+    }
+};
+
+DEFINE_TYPES(vub_types)
diff --git a/hw/virtio/vhost-user-device-pci.c b/hw/virtio/vhost-user-device-pci.c
index 41f9b7905b..22a5e95b9c 100644
--- a/hw/virtio/vhost-user-device-pci.c
+++ b/hw/virtio/vhost-user-device-pci.c
@@ -9,21 +9,18 @@
 
 #include "qemu/osdep.h"
 #include "hw/qdev-properties.h"
-#include "hw/virtio/vhost-user-device.h"
+#include "hw/virtio/vhost-user-base.h"
 #include "hw/virtio/virtio-pci.h"
 
 struct VHostUserDevicePCI {
     VirtIOPCIProxy parent_obj;
+
     VHostUserBase vub;
 };
 
-typedef struct VHostUserDevicePCI VHostUserDevicePCI;
-
 #define TYPE_VHOST_USER_DEVICE_PCI "vhost-user-device-pci-base"
 
-DECLARE_INSTANCE_CHECKER(VHostUserDevicePCI,
-                         VHOST_USER_DEVICE_PCI,
-                         TYPE_VHOST_USER_DEVICE_PCI)
+OBJECT_DECLARE_SIMPLE_TYPE(VHostUserDevicePCI, VHOST_USER_DEVICE_PCI)
 
 static void vhost_user_device_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
 {
@@ -39,6 +36,7 @@ static void vhost_user_device_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_device_pci_realize;
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
     pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
diff --git a/hw/virtio/vhost-user-device.c b/hw/virtio/vhost-user-device.c
index 2b028cae08..4adc1e8991 100644
--- a/hw/virtio/vhost-user-device.c
+++ b/hw/virtio/vhost-user-device.c
@@ -1,7 +1,10 @@
 /*
- * Generic vhost-user stub. This can be used to connect to any
- * vhost-user backend. All configuration details must be handled by
- * the vhost-user daemon itself
+ * Generic vhost-user-device implementation for any vhost-user-backend
+ *
+ * This is a concrete implementation of vhost-user-base which can be
+ * configured via properties. It is useful for development and
+ * prototyping. It expects configuration details (if any) to be
+ * handled by the vhost-user daemon itself.
  *
  * Copyright (c) 2023 Linaro Ltd
  * Author: Alex Bennée <alex.bennee@linaro.org>
@@ -13,329 +16,9 @@
 #include "qapi/error.h"
 #include "hw/qdev-properties.h"
 #include "hw/virtio/virtio-bus.h"
-#include "hw/virtio/vhost-user-device.h"
+#include "hw/virtio/vhost-user-base.h"
 #include "qemu/error-report.h"
 
-static void vub_start(VirtIODevice *vdev)
-{
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    VHostUserBase *vub = VHOST_USER_BASE(vdev);
-    int ret, i;
-
-    if (!k->set_guest_notifiers) {
-        error_report("binding does not support guest notifiers");
-        return;
-    }
-
-    ret = vhost_dev_enable_notifiers(&vub->vhost_dev, vdev);
-    if (ret < 0) {
-        error_report("Error enabling host notifiers: %d", -ret);
-        return;
-    }
-
-    ret = k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, true);
-    if (ret < 0) {
-        error_report("Error binding guest notifier: %d", -ret);
-        goto err_host_notifiers;
-    }
-
-    vub->vhost_dev.acked_features = vdev->guest_features;
-
-    ret = vhost_dev_start(&vub->vhost_dev, vdev, true);
-    if (ret < 0) {
-        error_report("Error starting vhost-user-device: %d", -ret);
-        goto err_guest_notifiers;
-    }
-
-    /*
-     * guest_notifier_mask/pending not used yet, so just unmask
-     * everything here. virtio-pci will do the right thing by
-     * enabling/disabling irqfd.
-     */
-    for (i = 0; i < vub->vhost_dev.nvqs; i++) {
-        vhost_virtqueue_mask(&vub->vhost_dev, vdev, i, false);
-    }
-
-    return;
-
-err_guest_notifiers:
-    k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false);
-err_host_notifiers:
-    vhost_dev_disable_notifiers(&vub->vhost_dev, vdev);
-}
-
-static void vub_stop(VirtIODevice *vdev)
-{
-    VHostUserBase *vub = VHOST_USER_BASE(vdev);
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    int ret;
-
-    if (!k->set_guest_notifiers) {
-        return;
-    }
-
-    vhost_dev_stop(&vub->vhost_dev, vdev, true);
-
-    ret = k->set_guest_notifiers(qbus->parent, vub->vhost_dev.nvqs, false);
-    if (ret < 0) {
-        error_report("vhost guest notifier cleanup failed: %d", ret);
-        return;
-    }
-
-    vhost_dev_disable_notifiers(&vub->vhost_dev, vdev);
-}
-
-static void vub_set_status(VirtIODevice *vdev, uint8_t status)
-{
-    VHostUserBase *vub = VHOST_USER_BASE(vdev);
-    bool should_start = virtio_device_should_start(vdev, status);
-
-    if (vhost_dev_is_started(&vub->vhost_dev) == should_start) {
-        return;
-    }
-
-    if (should_start) {
-        vub_start(vdev);
-    } else {
-        vub_stop(vdev);
-    }
-}
-
-/*
- * For an implementation where everything is delegated to the backend
- * we don't do anything other than return the full feature set offered
- * by the daemon (module the reserved feature bit).
- */
-static uint64_t vub_get_features(VirtIODevice *vdev,
-                                 uint64_t requested_features, Error **errp)
-{
-    VHostUserBase *vub = VHOST_USER_BASE(vdev);
-    /* This should be set when the vhost connection initialises */
-    g_assert(vub->vhost_dev.features);
-    return vub->vhost_dev.features & ~(1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
-}
-
-/*
- * To handle VirtIO config we need to know the size of the config
- * space. We don't cache the config but re-fetch it from the guest
- * every time in case something has changed.
- */
-static void vub_get_config(VirtIODevice *vdev, uint8_t *config)
-{
-    VHostUserBase *vub = VHOST_USER_BASE(vdev);
-    Error *local_err = NULL;
-
-    /*
-     * There will have been a warning during vhost_dev_init, but lets
-     * assert here as nothing will go right now.
-     */
-    g_assert(vub->config_size && vub->vhost_user.supports_config == true);
-
-    if (vhost_dev_get_config(&vub->vhost_dev, config,
-                             vub->config_size, &local_err)) {
-        error_report_err(local_err);
-    }
-}
-
-/*
- * When the daemon signals an update to the config we just need to
- * signal the guest as we re-read the config on demand above.
- */
-static int vub_config_notifier(struct vhost_dev *dev)
-{
-    virtio_notify_config(dev->vdev);
-    return 0;
-}
-
-const VhostDevConfigOps vub_config_ops = {
-    .vhost_dev_config_notifier = vub_config_notifier,
-};
-
-static void vub_handle_output(VirtIODevice *vdev, VirtQueue *vq)
-{
-    /*
-     * Not normally called; it's the daemon that handles the queue;
-     * however virtio's cleanup path can call this.
-     */
-}
-
-static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserBase *vub)
-{
-    vhost_user_cleanup(&vub->vhost_user);
-
-    for (int i = 0; i < vub->num_vqs; i++) {
-        VirtQueue *vq = g_ptr_array_index(vub->vqs, i);
-        virtio_delete_queue(vq);
-    }
-
-    virtio_cleanup(vdev);
-}
-
-static int vub_connect(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserBase *vub = VHOST_USER_BASE(vdev);
-    struct vhost_dev *vhost_dev = &vub->vhost_dev;
-
-    if (vub->connected) {
-        return 0;
-    }
-    vub->connected = true;
-
-    /*
-     * If we support VHOST_USER_GET_CONFIG we must enable the notifier
-     * so we can ping the guest when it updates.
-     */
-    if (vub->vhost_user.supports_config) {
-        vhost_dev_set_config_notifier(vhost_dev, &vub_config_ops);
-    }
-
-    /* restore vhost state */
-    if (virtio_device_started(vdev, vdev->status)) {
-        vub_start(vdev);
-    }
-
-    return 0;
-}
-
-static void vub_disconnect(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserBase *vub = VHOST_USER_BASE(vdev);
-
-    if (!vub->connected) {
-        return;
-    }
-    vub->connected = false;
-
-    if (vhost_dev_is_started(&vub->vhost_dev)) {
-        vub_stop(vdev);
-    }
-}
-
-static void vub_event(void *opaque, QEMUChrEvent event)
-{
-    DeviceState *dev = opaque;
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserBase *vub = VHOST_USER_BASE(vdev);
-
-    switch (event) {
-    case CHR_EVENT_OPENED:
-        if (vub_connect(dev) < 0) {
-            qemu_chr_fe_disconnect(&vub->chardev);
-            return;
-        }
-        break;
-    case CHR_EVENT_CLOSED:
-        vub_disconnect(dev);
-        break;
-    case CHR_EVENT_BREAK:
-    case CHR_EVENT_MUX_IN:
-    case CHR_EVENT_MUX_OUT:
-        /* Ignore */
-        break;
-    }
-}
-
-static void vub_device_realize(DeviceState *dev, Error **errp)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserBase *vub = VHOST_USER_BASE(dev);
-    int ret;
-
-    if (!vub->chardev.chr) {
-        error_setg(errp, "vhost-user-device: missing chardev");
-        return;
-    }
-
-    if (!vub->virtio_id) {
-        error_setg(errp, "vhost-user-device: need to define device id");
-        return;
-    }
-
-    if (!vub->num_vqs) {
-        vub->num_vqs = 1; /* reasonable default? */
-    }
-
-    /*
-     * We can't handle config requests unless we know the size of the
-     * config region, specialisations of the vhost-user-device will be
-     * able to set this.
-     */
-    if (vub->config_size) {
-        vub->vhost_user.supports_config = true;
-    }
-
-    if (!vhost_user_init(&vub->vhost_user, &vub->chardev, errp)) {
-        return;
-    }
-
-    virtio_init(vdev, vub->virtio_id, vub->config_size);
-
-    /*
-     * Disable guest notifiers, by default all notifications will be via the
-     * asynchronous vhost-user socket.
-     */
-    vdev->use_guest_notifier_mask = false;
-
-    /* Allocate queues */
-    vub->vqs = g_ptr_array_sized_new(vub->num_vqs);
-    for (int i = 0; i < vub->num_vqs; i++) {
-        g_ptr_array_add(vub->vqs,
-                        virtio_add_queue(vdev, 4, vub_handle_output));
-    }
-
-    vub->vhost_dev.nvqs = vub->num_vqs;
-    vub->vhost_dev.vqs = g_new0(struct vhost_virtqueue, vub->vhost_dev.nvqs);
-
-    /* connect to backend */
-    ret = vhost_dev_init(&vub->vhost_dev, &vub->vhost_user,
-                         VHOST_BACKEND_TYPE_USER, 0, errp);
-
-    if (ret < 0) {
-        do_vhost_user_cleanup(vdev, vub);
-    }
-
-    qemu_chr_fe_set_handlers(&vub->chardev, NULL, NULL, vub_event, NULL,
-                             dev, NULL, true);
-}
-
-static void vub_device_unrealize(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserBase *vub = VHOST_USER_BASE(dev);
-    struct vhost_virtqueue *vhost_vqs = vub->vhost_dev.vqs;
-
-    /* This will stop vhost backend if appropriate. */
-    vub_set_status(vdev, 0);
-    vhost_dev_cleanup(&vub->vhost_dev);
-    g_free(vhost_vqs);
-    do_vhost_user_cleanup(vdev, vub);
-}
-
-static void vub_class_init(ObjectClass *klass, void *data)
-{
-    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
-
-    vdc->realize = vub_device_realize;
-    vdc->unrealize = vub_device_unrealize;
-    vdc->get_features = vub_get_features;
-    vdc->get_config = vub_get_config;
-    vdc->set_status = vub_set_status;
-}
-
-static const TypeInfo vub_info = {
-    .name = TYPE_VHOST_USER_BASE,
-    .parent = TYPE_VIRTIO_DEVICE,
-    .instance_size = sizeof(VHostUserBase),
-    .class_init = vub_class_init,
-    .class_size = sizeof(VHostUserBaseClass),
-    .abstract = true
-};
-
-
 /*
  * The following is a concrete implementation of the base class which
  * allows the user to define the key parameters via the command line.
@@ -349,6 +32,7 @@ static const VMStateDescription vud_vmstate = {
 static Property vud_properties[] = {
     DEFINE_PROP_CHR("chardev", VHostUserBase, chardev),
     DEFINE_PROP_UINT16("virtio-id", VHostUserBase, virtio_id, 0),
+    DEFINE_PROP_UINT32("vq_size", VHostUserBase, vq_size, 64),
     DEFINE_PROP_UINT32("num_vqs", VHostUserBase, num_vqs, 1),
     DEFINE_PROP_UINT32("config_size", VHostUserBase, config_size, 0),
     DEFINE_PROP_END_OF_LIST(),
@@ -366,14 +50,11 @@ static void vud_class_init(ObjectClass *klass, void *data)
 static const TypeInfo vud_info = {
     .name = TYPE_VHOST_USER_DEVICE,
     .parent = TYPE_VHOST_USER_BASE,
-    .instance_size = sizeof(VHostUserBase),
     .class_init = vud_class_init,
-    .class_size = sizeof(VHostUserBaseClass),
 };
 
 static void vu_register_types(void)
 {
-    type_register_static(&vub_info);
     type_register_static(&vud_info);
 }
 
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index c0055a7832..51c3f97c2d 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -17,6 +17,7 @@ if have_vhost
   if have_vhost_user
     # fixme - this really should be generic
     specific_virtio_ss.add(files('vhost-user.c'))
+    system_virtio_ss.add(files('vhost-user-base.c'))
     system_virtio_ss.add(files('vhost-user-device.c'))
     system_virtio_ss.add(when: 'CONFIG_VIRTIO_PCI', if_true: files('vhost-user-device-pci.c'))
   endif
-- 
2.39.2

[Virtio-fs] [PATCH v5 2/6] hw/virtio: derive vhost-user-rng from vhost-user-base

[Alex Bennée]

Now we can take advantage of our new base class and make
vhost-user-rng a much simpler boilerplate wrapper. Also as this
doesn't require any target specific hacks we only need to build the
stubs once.

Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009095937.195728-3-alex.bennee@linaro.org>

---
v5
  - don't remove the in-QEMU RNG emulation!
---
 include/hw/virtio/vhost-user-rng.h |  11 +-
 hw/virtio/vhost-user-rng.c         | 278 +++--------------------------
 hw/virtio/meson.build              |   9 +-
 3 files changed, 31 insertions(+), 267 deletions(-)

diff --git a/include/hw/virtio/vhost-user-rng.h b/include/hw/virtio/vhost-user-rng.h
index ddd9f01eea..6cffe28807 100644
--- a/include/hw/virtio/vhost-user-rng.h
+++ b/include/hw/virtio/vhost-user-rng.h
@@ -12,21 +12,14 @@
 #include "hw/virtio/virtio.h"
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/vhost-user.h"
-#include "chardev/char-fe.h"
+#include "hw/virtio/vhost-user-base.h"
 
 #define TYPE_VHOST_USER_RNG "vhost-user-rng"
 OBJECT_DECLARE_SIMPLE_TYPE(VHostUserRNG, VHOST_USER_RNG)
 
 struct VHostUserRNG {
     /*< private >*/
-    VirtIODevice parent;
-    CharBackend chardev;
-    struct vhost_virtqueue *vhost_vq;
-    struct vhost_dev vhost_dev;
-    VhostUserState vhost_user;
-    VirtQueue *req_vq;
-    bool connected;
-
+    VHostUserBase parent;
     /*< public >*/
 };
 
diff --git a/hw/virtio/vhost-user-rng.c b/hw/virtio/vhost-user-rng.c
index efc54cd3fb..01879c863d 100644
--- a/hw/virtio/vhost-user-rng.c
+++ b/hw/virtio/vhost-user-rng.c
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2021 Mathieu Poirier <mathieu.poirier@linaro.org>
  *
- * Implementation seriously tailored on vhost-user-i2c.c
+ * Simple wrapper of the generic vhost-user-device.
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
@@ -13,281 +13,47 @@
 #include "hw/qdev-properties.h"
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/vhost-user-rng.h"
-#include "qemu/error-report.h"
 #include "standard-headers/linux/virtio_ids.h"
 
-static const int feature_bits[] = {
-    VIRTIO_F_RING_RESET,
-    VHOST_INVALID_FEATURE_BIT
-};
-
-static void vu_rng_start(VirtIODevice *vdev)
-{
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    int ret;
-    int i;
-
-    if (!k->set_guest_notifiers) {
-        error_report("binding does not support guest notifiers");
-        return;
-    }
-
-    ret = vhost_dev_enable_notifiers(&rng->vhost_dev, vdev);
-    if (ret < 0) {
-        error_report("Error enabling host notifiers: %d", -ret);
-        return;
-    }
-
-    ret = k->set_guest_notifiers(qbus->parent, rng->vhost_dev.nvqs, true);
-    if (ret < 0) {
-        error_report("Error binding guest notifier: %d", -ret);
-        goto err_host_notifiers;
-    }
-
-    rng->vhost_dev.acked_features = vdev->guest_features;
-    ret = vhost_dev_start(&rng->vhost_dev, vdev, true);
-    if (ret < 0) {
-        error_report("Error starting vhost-user-rng: %d", -ret);
-        goto err_guest_notifiers;
-    }
-
-    /*
-     * guest_notifier_mask/pending not used yet, so just unmask
-     * everything here. virtio-pci will do the right thing by
-     * enabling/disabling irqfd.
-     */
-    for (i = 0; i < rng->vhost_dev.nvqs; i++) {
-        vhost_virtqueue_mask(&rng->vhost_dev, vdev, i, false);
-    }
-
-    return;
-
-err_guest_notifiers:
-    k->set_guest_notifiers(qbus->parent, rng->vhost_dev.nvqs, false);
-err_host_notifiers:
-    vhost_dev_disable_notifiers(&rng->vhost_dev, vdev);
-}
-
-static void vu_rng_stop(VirtIODevice *vdev)
-{
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    int ret;
-
-    if (!k->set_guest_notifiers) {
-        return;
-    }
-
-    vhost_dev_stop(&rng->vhost_dev, vdev, true);
-
-    ret = k->set_guest_notifiers(qbus->parent, rng->vhost_dev.nvqs, false);
-    if (ret < 0) {
-        error_report("vhost guest notifier cleanup failed: %d", ret);
-        return;
-    }
-
-    vhost_dev_disable_notifiers(&rng->vhost_dev, vdev);
-}
-
-static void vu_rng_set_status(VirtIODevice *vdev, uint8_t status)
-{
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-    bool should_start = virtio_device_should_start(vdev, status);
-
-    if (vhost_dev_is_started(&rng->vhost_dev) == should_start) {
-        return;
-    }
-
-    if (should_start) {
-        vu_rng_start(vdev);
-    } else {
-        vu_rng_stop(vdev);
-    }
-}
-
-static uint64_t vu_rng_get_features(VirtIODevice *vdev,
-                                    uint64_t requested_features, Error **errp)
-{
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-
-    return vhost_get_features(&rng->vhost_dev, feature_bits,
-                              requested_features);
-}
-
-static void vu_rng_handle_output(VirtIODevice *vdev, VirtQueue *vq)
-{
-    /*
-     * Not normally called; it's the daemon that handles the queue;
-     * however virtio's cleanup path can call this.
-     */
-}
-
-static void vu_rng_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask)
-{
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-
-    vhost_virtqueue_mask(&rng->vhost_dev, vdev, idx, mask);
-}
-
-static bool vu_rng_guest_notifier_pending(VirtIODevice *vdev, int idx)
-{
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-
-    return vhost_virtqueue_pending(&rng->vhost_dev, idx);
-}
-
-static void vu_rng_connect(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-
-    if (rng->connected) {
-        return;
-    }
-
-    rng->connected = true;
-
-    /* restore vhost state */
-    if (virtio_device_started(vdev, vdev->status)) {
-        vu_rng_start(vdev);
-    }
-}
-
-static void vu_rng_disconnect(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-
-    if (!rng->connected) {
-        return;
-    }
-
-    rng->connected = false;
-
-    if (vhost_dev_is_started(&rng->vhost_dev)) {
-        vu_rng_stop(vdev);
-    }
-}
-
-static void vu_rng_event(void *opaque, QEMUChrEvent event)
-{
-    DeviceState *dev = opaque;
-
-    switch (event) {
-    case CHR_EVENT_OPENED:
-        vu_rng_connect(dev);
-        break;
-    case CHR_EVENT_CLOSED:
-        vu_rng_disconnect(dev);
-        break;
-    case CHR_EVENT_BREAK:
-    case CHR_EVENT_MUX_IN:
-    case CHR_EVENT_MUX_OUT:
-        /* Ignore */
-        break;
-    }
-}
-
-static void vu_rng_device_realize(DeviceState *dev, Error **errp)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserRNG *rng = VHOST_USER_RNG(dev);
-    int ret;
-
-    if (!rng->chardev.chr) {
-        error_setg(errp, "missing chardev");
-        return;
-    }
-
-    if (!vhost_user_init(&rng->vhost_user, &rng->chardev, errp)) {
-        return;
-    }
-
-    virtio_init(vdev, VIRTIO_ID_RNG, 0);
-
-    rng->req_vq = virtio_add_queue(vdev, 4, vu_rng_handle_output);
-    if (!rng->req_vq) {
-        error_setg_errno(errp, -1, "virtio_add_queue() failed");
-        goto virtio_add_queue_failed;
-    }
-
-    rng->vhost_dev.nvqs = 1;
-    rng->vhost_dev.vqs = g_new0(struct vhost_virtqueue, rng->vhost_dev.nvqs);
-    ret = vhost_dev_init(&rng->vhost_dev, &rng->vhost_user,
-                         VHOST_BACKEND_TYPE_USER, 0, errp);
-    if (ret < 0) {
-        error_setg_errno(errp, -ret, "vhost_dev_init() failed");
-        goto vhost_dev_init_failed;
-    }
-
-    qemu_chr_fe_set_handlers(&rng->chardev, NULL, NULL, vu_rng_event, NULL,
-                             dev, NULL, true);
-
-    return;
-
-vhost_dev_init_failed:
-    g_free(rng->vhost_dev.vqs);
-    virtio_delete_queue(rng->req_vq);
-virtio_add_queue_failed:
-    virtio_cleanup(vdev);
-    vhost_user_cleanup(&rng->vhost_user);
-}
-
-static void vu_rng_device_unrealize(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserRNG *rng = VHOST_USER_RNG(dev);
-    struct vhost_virtqueue *vhost_vqs = rng->vhost_dev.vqs;
-
-    vu_rng_set_status(vdev, 0);
-
-    vhost_dev_cleanup(&rng->vhost_dev);
-    g_free(vhost_vqs);
-    virtio_delete_queue(rng->req_vq);
-    virtio_cleanup(vdev);
-    vhost_user_cleanup(&rng->vhost_user);
-}
-
-static struct vhost_dev *vu_rng_get_vhost(VirtIODevice *vdev)
-{
-    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
-    return &rng->vhost_dev;
-}
-
 static const VMStateDescription vu_rng_vmstate = {
     .name = "vhost-user-rng",
     .unmigratable = 1,
 };
 
-static Property vu_rng_properties[] = {
-    DEFINE_PROP_CHR("chardev", VHostUserRNG, chardev),
+static Property vrng_properties[] = {
+    DEFINE_PROP_CHR("chardev", VHostUserBase, chardev),
     DEFINE_PROP_END_OF_LIST(),
 };
 
+static void vu_rng_base_realize(DeviceState *dev, Error **errp)
+{
+    VHostUserBase *vub = VHOST_USER_BASE(dev);
+    VHostUserBaseClass *vubs = VHOST_USER_BASE_GET_CLASS(dev);
+
+    /* Fixed for RNG */
+    vub->virtio_id = VIRTIO_ID_RNG;
+    vub->num_vqs = 1;
+    vub->vq_size = 4;
+
+    vubs->parent_realize(dev, errp);
+}
+
 static void vu_rng_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
-    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+    VHostUserBaseClass *vubc = VHOST_USER_BASE_CLASS(klass);
 
-    device_class_set_props(dc, vu_rng_properties);
     dc->vmsd = &vu_rng_vmstate;
-    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
+    device_class_set_props(dc, vrng_properties);
+    device_class_set_parent_realize(dc, vu_rng_base_realize,
+                                    &vubc->parent_realize);
 
-    vdc->realize = vu_rng_device_realize;
-    vdc->unrealize = vu_rng_device_unrealize;
-    vdc->get_features = vu_rng_get_features;
-    vdc->set_status = vu_rng_set_status;
-    vdc->guest_notifier_mask = vu_rng_guest_notifier_mask;
-    vdc->guest_notifier_pending = vu_rng_guest_notifier_pending;
-    vdc->get_vhost = vu_rng_get_vhost;
+    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 }
 
 static const TypeInfo vu_rng_info = {
     .name = TYPE_VHOST_USER_RNG,
-    .parent = TYPE_VIRTIO_DEVICE,
+    .parent = TYPE_VHOST_USER_BASE,
     .instance_size = sizeof(VHostUserRNG),
     .class_init = vu_rng_class_init,
 };
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 51c3f97c2d..b5c1a461e3 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -18,8 +18,15 @@ if have_vhost
     # fixme - this really should be generic
     specific_virtio_ss.add(files('vhost-user.c'))
     system_virtio_ss.add(files('vhost-user-base.c'))
+
+    # MMIO Stubs
     system_virtio_ss.add(files('vhost-user-device.c'))
+    system_virtio_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng.c'))
+
+    # PCI Stubs
     system_virtio_ss.add(when: 'CONFIG_VIRTIO_PCI', if_true: files('vhost-user-device-pci.c'))
+    system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_RNG'],
+                         if_true: files('vhost-user-rng-pci.c'))
   endif
   if have_vhost_vdpa
     system_virtio_ss.add(files('vhost-vdpa.c'))
@@ -37,7 +44,6 @@ specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_VSOCK', if_true: files('vhost-us
 specific_virtio_ss.add(when: 'CONFIG_VIRTIO_RNG', if_true: files('virtio-rng.c'))
 specific_virtio_ss.add(when: 'CONFIG_VIRTIO_MEM', if_true: files('virtio-mem.c'))
 specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c'))
-specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng.c'))
 specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_GPIO', if_true: files('vhost-user-gpio.c'))
 specific_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_GPIO'], if_true: files('vhost-user-gpio-pci.c'))
 specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_SCMI', if_true: files('vhost-user-scmi.c'))
@@ -49,7 +55,6 @@ virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_VSOCK', if_true: files('vhost-user-vs
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_BLK', if_true: files('vhost-user-blk-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_INPUT', if_true: files('vhost-user-input-pci.c'))
-virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_SCSI', if_true: files('vhost-user-scsi-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_SCSI', if_true: files('vhost-scsi-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_FS', if_true: files('vhost-user-fs-pci.c'))
-- 
2.39.2

[Virtio-fs] [PATCH v5 3/6] hw/virtio: derive vhost-user-gpio from vhost-user-base

[Alex Bennée]

Now the new base class supports config handling we can take advantage
and make vhost-user-gpio a much simpler boilerplate wrapper. Also as
this doesn't require any target specific hacks we only need to build
the stubs once.

Message-Id: <20230418162140.373219-12-alex.bennee@linaro.org>
Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009095937.195728-4-alex.bennee@linaro.org>
---
 include/hw/virtio/vhost-user-gpio.h |  23 +-
 hw/virtio/vhost-user-gpio.c         | 407 ++--------------------------
 hw/virtio/meson.build               |   5 +-
 3 files changed, 22 insertions(+), 413 deletions(-)

diff --git a/include/hw/virtio/vhost-user-gpio.h b/include/hw/virtio/vhost-user-gpio.h
index a9d3f9b049..5201d5f072 100644
--- a/include/hw/virtio/vhost-user-gpio.h
+++ b/include/hw/virtio/vhost-user-gpio.h
@@ -12,33 +12,14 @@
 #include "hw/virtio/virtio.h"
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/vhost-user.h"
-#include "standard-headers/linux/virtio_gpio.h"
-#include "chardev/char-fe.h"
+#include "hw/virtio/vhost-user-base.h"
 
 #define TYPE_VHOST_USER_GPIO "vhost-user-gpio-device"
 OBJECT_DECLARE_SIMPLE_TYPE(VHostUserGPIO, VHOST_USER_GPIO);
 
 struct VHostUserGPIO {
     /*< private >*/
-    VirtIODevice parent_obj;
-    CharBackend chardev;
-    struct virtio_gpio_config config;
-    struct vhost_virtqueue *vhost_vqs;
-    struct vhost_dev vhost_dev;
-    VhostUserState vhost_user;
-    VirtQueue *command_vq;
-    VirtQueue *interrupt_vq;
-    /**
-     * There are at least two steps of initialization of the
-     * vhost-user device. The first is a "connect" step and
-     * second is a "start" step. Make a separation between
-     * those initialization phases by using two fields.
-     *
-     * @connected: see vu_gpio_connect()/vu_gpio_disconnect()
-     * @started_vu: see vu_gpio_start()/vu_gpio_stop()
-     */
-    bool connected;
-    bool started_vu;
+    VHostUserBase parent;
     /*< public >*/
 };
 
diff --git a/hw/virtio/vhost-user-gpio.c b/hw/virtio/vhost-user-gpio.c
index 3d7fae3984..9f37c25415 100644
--- a/hw/virtio/vhost-user-gpio.c
+++ b/hw/virtio/vhost-user-gpio.c
@@ -11,388 +11,25 @@
 #include "hw/qdev-properties.h"
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/vhost-user-gpio.h"
-#include "qemu/error-report.h"
 #include "standard-headers/linux/virtio_ids.h"
-#include "trace.h"
+#include "standard-headers/linux/virtio_gpio.h"
 
-#define REALIZE_CONNECTION_RETRIES 3
-#define VHOST_NVQS 2
-
-/* Features required from VirtIO */
-static const int feature_bits[] = {
-    VIRTIO_F_VERSION_1,
-    VIRTIO_F_NOTIFY_ON_EMPTY,
-    VIRTIO_RING_F_INDIRECT_DESC,
-    VIRTIO_RING_F_EVENT_IDX,
-    VIRTIO_GPIO_F_IRQ,
-    VIRTIO_F_RING_RESET,
-    VHOST_INVALID_FEATURE_BIT
-};
-
-static void vu_gpio_get_config(VirtIODevice *vdev, uint8_t *config)
-{
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-
-    memcpy(config, &gpio->config, sizeof(gpio->config));
-}
-
-static int vu_gpio_config_notifier(struct vhost_dev *dev)
-{
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(dev->vdev);
-
-    memcpy(dev->vdev->config, &gpio->config, sizeof(gpio->config));
-    virtio_notify_config(dev->vdev);
-
-    return 0;
-}
-
-const VhostDevConfigOps gpio_ops = {
-    .vhost_dev_config_notifier = vu_gpio_config_notifier,
+static Property vgpio_properties[] = {
+    DEFINE_PROP_CHR("chardev", VHostUserBase, chardev),
+    DEFINE_PROP_END_OF_LIST(),
 };
 
-static int vu_gpio_start(VirtIODevice *vdev)
-{
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-    struct vhost_dev *vhost_dev = &gpio->vhost_dev;
-    int ret, i;
-
-    if (!k->set_guest_notifiers) {
-        error_report("binding does not support guest notifiers");
-        return -ENOSYS;
-    }
-
-    ret = vhost_dev_enable_notifiers(vhost_dev, vdev);
-    if (ret < 0) {
-        error_report("Error enabling host notifiers: %d", ret);
-        return ret;
-    }
-
-    ret = k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, true);
-    if (ret < 0) {
-        error_report("Error binding guest notifier: %d", ret);
-        goto err_host_notifiers;
-    }
-
-    /*
-     * Before we start up we need to ensure we have the final feature
-     * set needed for the vhost configuration. The backend may also
-     * apply backend_features when the feature set is sent.
-     */
-    vhost_ack_features(&gpio->vhost_dev, feature_bits, vdev->guest_features);
-
-    ret = vhost_dev_start(&gpio->vhost_dev, vdev, false);
-    if (ret < 0) {
-        error_report("Error starting vhost-user-gpio: %d", ret);
-        goto err_guest_notifiers;
-    }
-    gpio->started_vu = true;
-
-    /*
-     * guest_notifier_mask/pending not used yet, so just unmask
-     * everything here. virtio-pci will do the right thing by
-     * enabling/disabling irqfd.
-     */
-    for (i = 0; i < gpio->vhost_dev.nvqs; i++) {
-        vhost_virtqueue_mask(&gpio->vhost_dev, vdev, i, false);
-    }
-
-    /*
-     * As we must have VHOST_USER_F_PROTOCOL_FEATURES (because
-     * VHOST_USER_GET_CONFIG requires it) we need to explicitly enable
-     * the vrings.
-     */
-    g_assert(vhost_dev->vhost_ops &&
-             vhost_dev->vhost_ops->vhost_set_vring_enable);
-    ret = vhost_dev->vhost_ops->vhost_set_vring_enable(vhost_dev, true);
-    if (ret == 0) {
-        return 0;
-    }
-
-    error_report("Failed to start vrings for vhost-user-gpio: %d", ret);
-
-err_guest_notifiers:
-    k->set_guest_notifiers(qbus->parent, gpio->vhost_dev.nvqs, false);
-err_host_notifiers:
-    vhost_dev_disable_notifiers(&gpio->vhost_dev, vdev);
-
-    return ret;
-}
-
-static void vu_gpio_stop(VirtIODevice *vdev)
-{
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    struct vhost_dev *vhost_dev = &gpio->vhost_dev;
-    int ret;
-
-    if (!gpio->started_vu) {
-        return;
-    }
-    gpio->started_vu = false;
-
-    if (!k->set_guest_notifiers) {
-        return;
-    }
-
-    vhost_dev_stop(vhost_dev, vdev, false);
-
-    ret = k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, false);
-    if (ret < 0) {
-        error_report("vhost guest notifier cleanup failed: %d", ret);
-        return;
-    }
-
-    vhost_dev_disable_notifiers(vhost_dev, vdev);
-}
-
-static void vu_gpio_set_status(VirtIODevice *vdev, uint8_t status)
-{
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-    bool should_start = virtio_device_should_start(vdev, status);
-
-    trace_virtio_gpio_set_status(status);
-
-    if (!gpio->connected) {
-        return;
-    }
-
-    if (vhost_dev_is_started(&gpio->vhost_dev) == should_start) {
-        return;
-    }
-
-    if (should_start) {
-        if (vu_gpio_start(vdev)) {
-            qemu_chr_fe_disconnect(&gpio->chardev);
-        }
-    } else {
-        vu_gpio_stop(vdev);
-    }
-}
-
-static uint64_t vu_gpio_get_features(VirtIODevice *vdev, uint64_t features,
-                                     Error **errp)
-{
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-
-    return vhost_get_features(&gpio->vhost_dev, feature_bits, features);
-}
-
-static void vu_gpio_handle_output(VirtIODevice *vdev, VirtQueue *vq)
-{
-    /*
-     * Not normally called; it's the daemon that handles the queue;
-     * however virtio's cleanup path can call this.
-     */
-}
-
-static void vu_gpio_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask)
-{
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-
-    /*
-     * Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
-     * as the macro of configure interrupt's IDX, If this driver does not
-     * support, the function will return
-     */
-
-    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
-        return;
-    }
-
-    vhost_virtqueue_mask(&gpio->vhost_dev, vdev, idx, mask);
-}
-
-static struct vhost_dev *vu_gpio_get_vhost(VirtIODevice *vdev)
-{
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-    return &gpio->vhost_dev;
-}
-
-static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserGPIO *gpio)
-{
-    virtio_delete_queue(gpio->command_vq);
-    virtio_delete_queue(gpio->interrupt_vq);
-    g_free(gpio->vhost_vqs);
-    virtio_cleanup(vdev);
-    vhost_user_cleanup(&gpio->vhost_user);
-}
-
-static int vu_gpio_connect(DeviceState *dev, Error **errp)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-    struct vhost_dev *vhost_dev = &gpio->vhost_dev;
-    int ret;
-
-    if (gpio->connected) {
-        return 0;
-    }
-    gpio->connected = true;
-
-    vhost_dev_set_config_notifier(vhost_dev, &gpio_ops);
-    gpio->vhost_user.supports_config = true;
-
-    gpio->vhost_dev.nvqs = VHOST_NVQS;
-    gpio->vhost_dev.vqs = gpio->vhost_vqs;
-
-    ret = vhost_dev_init(vhost_dev, &gpio->vhost_user,
-                         VHOST_BACKEND_TYPE_USER, 0, errp);
-    if (ret < 0) {
-        return ret;
-    }
-
-    /* restore vhost state */
-    if (virtio_device_started(vdev, vdev->status)) {
-        vu_gpio_start(vdev);
-    }
-
-    return 0;
-}
-
-static void vu_gpio_event(void *opaque, QEMUChrEvent event);
-
-static void vu_gpio_disconnect(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-
-    if (!gpio->connected) {
-        return;
-    }
-    gpio->connected = false;
-
-    vu_gpio_stop(vdev);
-    vhost_dev_cleanup(&gpio->vhost_dev);
-
-    /* Re-instate the event handler for new connections */
-    qemu_chr_fe_set_handlers(&gpio->chardev,
-                             NULL, NULL, vu_gpio_event,
-                             NULL, dev, NULL, true);
-}
-
-static void vu_gpio_event(void *opaque, QEMUChrEvent event)
-{
-    DeviceState *dev = opaque;
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev);
-    Error *local_err = NULL;
-
-    switch (event) {
-    case CHR_EVENT_OPENED:
-        if (vu_gpio_connect(dev, &local_err) < 0) {
-            qemu_chr_fe_disconnect(&gpio->chardev);
-            return;
-        }
-        break;
-    case CHR_EVENT_CLOSED:
-        /* defer close until later to avoid circular close */
-        vhost_user_async_close(dev, &gpio->chardev, &gpio->vhost_dev,
-                               vu_gpio_disconnect);
-        break;
-    case CHR_EVENT_BREAK:
-    case CHR_EVENT_MUX_IN:
-    case CHR_EVENT_MUX_OUT:
-        /* Ignore */
-        break;
-    }
-}
-
-static int vu_gpio_realize_connect(VHostUserGPIO *gpio, Error **errp)
+static void vgpio_realize(DeviceState *dev, Error **errp)
 {
-    VirtIODevice *vdev = &gpio->parent_obj;
-    DeviceState *dev = &vdev->parent_obj;
-    struct vhost_dev *vhost_dev = &gpio->vhost_dev;
-    int ret;
-
-    ret = qemu_chr_fe_wait_connected(&gpio->chardev, errp);
-    if (ret < 0) {
-        return ret;
-    }
-
-    /*
-     * vu_gpio_connect() may have already connected (via the event
-     * callback) in which case it will just report success.
-     */
-    ret = vu_gpio_connect(dev, errp);
-    if (ret < 0) {
-        qemu_chr_fe_disconnect(&gpio->chardev);
-        return ret;
-    }
-    g_assert(gpio->connected);
-
-    ret = vhost_dev_get_config(vhost_dev, (uint8_t *)&gpio->config,
-                               sizeof(gpio->config), errp);
-
-    if (ret < 0) {
-        error_report("vhost-user-gpio: get config failed");
-
-        qemu_chr_fe_disconnect(&gpio->chardev);
-        vhost_dev_cleanup(vhost_dev);
-        return ret;
-    }
-
-    return 0;
-}
-
-static void vu_gpio_device_realize(DeviceState *dev, Error **errp)
-{
-    ERRP_GUARD();
-
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(dev);
-    int retries, ret;
-
-    if (!gpio->chardev.chr) {
-        error_setg(errp, "vhost-user-gpio: chardev is mandatory");
-        return;
-    }
+    VHostUserBase *vub = VHOST_USER_BASE(dev);
+    VHostUserBaseClass *vubc = VHOST_USER_BASE_GET_CLASS(dev);
 
-    if (!vhost_user_init(&gpio->vhost_user, &gpio->chardev, errp)) {
-        return;
-    }
+    /* Fixed for GPIO */
+    vub->virtio_id = VIRTIO_ID_GPIO;
+    vub->num_vqs = 2;
+    vub->config_size = sizeof(struct virtio_gpio_config);
 
-    virtio_init(vdev, VIRTIO_ID_GPIO, sizeof(gpio->config));
-
-    gpio->command_vq = virtio_add_queue(vdev, 256, vu_gpio_handle_output);
-    gpio->interrupt_vq = virtio_add_queue(vdev, 256, vu_gpio_handle_output);
-    gpio->vhost_vqs = g_new0(struct vhost_virtqueue, VHOST_NVQS);
-
-    gpio->connected = false;
-
-    qemu_chr_fe_set_handlers(&gpio->chardev, NULL, NULL, vu_gpio_event, NULL,
-                             dev, NULL, true);
-
-    retries = REALIZE_CONNECTION_RETRIES;
-    g_assert(!*errp);
-    do {
-        if (*errp) {
-            error_prepend(errp, "Reconnecting after error: ");
-            error_report_err(*errp);
-            *errp = NULL;
-        }
-        ret = vu_gpio_realize_connect(gpio, errp);
-    } while (ret < 0 && retries--);
-
-    if (ret < 0) {
-        do_vhost_user_cleanup(vdev, gpio);
-    }
-
-    return;
-}
-
-static void vu_gpio_device_unrealize(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserGPIO *gpio = VHOST_USER_GPIO(dev);
-
-    vu_gpio_set_status(vdev, 0);
-    qemu_chr_fe_set_handlers(&gpio->chardev, NULL, NULL, NULL, NULL, NULL, NULL,
-                             false);
-    vhost_dev_cleanup(&gpio->vhost_dev);
-    do_vhost_user_cleanup(vdev, gpio);
+    vubc->parent_realize(dev, errp);
 }
 
 static const VMStateDescription vu_gpio_vmstate = {
@@ -400,31 +37,21 @@ static const VMStateDescription vu_gpio_vmstate = {
     .unmigratable = 1,
 };
 
-static Property vu_gpio_properties[] = {
-    DEFINE_PROP_CHR("chardev", VHostUserGPIO, chardev),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void vu_gpio_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
-    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+    VHostUserBaseClass *vubc = VHOST_USER_BASE_CLASS(klass);
 
-    device_class_set_props(dc, vu_gpio_properties);
     dc->vmsd = &vu_gpio_vmstate;
+    device_class_set_props(dc, vgpio_properties);
+    device_class_set_parent_realize(dc, vgpio_realize,
+                                    &vubc->parent_realize);
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
-    vdc->realize = vu_gpio_device_realize;
-    vdc->unrealize = vu_gpio_device_unrealize;
-    vdc->get_features = vu_gpio_get_features;
-    vdc->get_config = vu_gpio_get_config;
-    vdc->set_status = vu_gpio_set_status;
-    vdc->guest_notifier_mask = vu_gpio_guest_notifier_mask;
-    vdc->get_vhost = vu_gpio_get_vhost;
 }
 
 static const TypeInfo vu_gpio_info = {
     .name = TYPE_VHOST_USER_GPIO,
-    .parent = TYPE_VIRTIO_DEVICE,
+    .parent = TYPE_VHOST_USER_BASE,
     .instance_size = sizeof(VHostUserGPIO),
     .class_init = vu_gpio_class_init,
 };
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index b5c1a461e3..87042e5901 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -21,10 +21,13 @@ if have_vhost
 
     # MMIO Stubs
     system_virtio_ss.add(files('vhost-user-device.c'))
+    system_virtio_ss.add(when: 'CONFIG_VHOST_USER_GPIO', if_true: files('vhost-user-gpio.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng.c'))
 
     # PCI Stubs
     system_virtio_ss.add(when: 'CONFIG_VIRTIO_PCI', if_true: files('vhost-user-device-pci.c'))
+    system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_GPIO'],
+                         if_true: files('vhost-user-gpio-pci.c'))
     system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_RNG'],
                          if_true: files('vhost-user-rng-pci.c'))
   endif
@@ -44,8 +47,6 @@ specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_VSOCK', if_true: files('vhost-us
 specific_virtio_ss.add(when: 'CONFIG_VIRTIO_RNG', if_true: files('virtio-rng.c'))
 specific_virtio_ss.add(when: 'CONFIG_VIRTIO_MEM', if_true: files('virtio-mem.c'))
 specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c'))
-specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_GPIO', if_true: files('vhost-user-gpio.c'))
-specific_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_GPIO'], if_true: files('vhost-user-gpio-pci.c'))
 specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_SCMI', if_true: files('vhost-user-scmi.c'))
 specific_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_SCMI'], if_true: files('vhost-user-scmi-pci.c'))
 
-- 
2.39.2

[Virtio-fs] [PATCH v5 4/6] hw/virtio: derive vhost-user-i2c from vhost-user-base

[Alex Bennée]

Now we can take advantage of the new base class and make
vhost-user-i2c a much simpler boilerplate wrapper. Also as this
doesn't require any target specific hacks we only need to build the
stubs once.

Message-Id: <20230418162140.373219-13-alex.bennee@linaro.org>
Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009095937.195728-5-alex.bennee@linaro.org>
---
 include/hw/virtio/vhost-user-i2c.h |  14 +-
 hw/virtio/vhost-user-i2c.c         | 272 ++---------------------------
 hw/virtio/meson.build              |   5 +-
 3 files changed, 23 insertions(+), 268 deletions(-)

diff --git a/include/hw/virtio/vhost-user-i2c.h b/include/hw/virtio/vhost-user-i2c.h
index 0f7acd40e3..a8fcb108db 100644
--- a/include/hw/virtio/vhost-user-i2c.h
+++ b/include/hw/virtio/vhost-user-i2c.h
@@ -9,23 +9,17 @@
 #ifndef QEMU_VHOST_USER_I2C_H
 #define QEMU_VHOST_USER_I2C_H
 
+#include "hw/virtio/virtio.h"
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/vhost-user.h"
+#include "hw/virtio/vhost-user-base.h"
 
 #define TYPE_VHOST_USER_I2C "vhost-user-i2c-device"
+
 OBJECT_DECLARE_SIMPLE_TYPE(VHostUserI2C, VHOST_USER_I2C)
 
 struct VHostUserI2C {
-    VirtIODevice parent;
-    CharBackend chardev;
-    struct vhost_virtqueue *vhost_vq;
-    struct vhost_dev vhost_dev;
-    VhostUserState vhost_user;
-    VirtQueue *vq;
-    bool connected;
+    VHostUserBase parent;
 };
 
-/* Virtio Feature bits */
-#define VIRTIO_I2C_F_ZERO_LENGTH_REQUEST		0
-
 #endif /* QEMU_VHOST_USER_I2C_H */
diff --git a/hw/virtio/vhost-user-i2c.c b/hw/virtio/vhost-user-i2c.c
index 4eef3f0633..a464f5e039 100644
--- a/hw/virtio/vhost-user-i2c.c
+++ b/hw/virtio/vhost-user-i2c.c
@@ -14,253 +14,22 @@
 #include "qemu/error-report.h"
 #include "standard-headers/linux/virtio_ids.h"
 
-static const int feature_bits[] = {
-    VIRTIO_I2C_F_ZERO_LENGTH_REQUEST,
-    VIRTIO_F_RING_RESET,
-    VHOST_INVALID_FEATURE_BIT
+static Property vi2c_properties[] = {
+    DEFINE_PROP_CHR("chardev", VHostUserBase, chardev),
+    DEFINE_PROP_END_OF_LIST(),
 };
 
-static void vu_i2c_start(VirtIODevice *vdev)
-{
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
-    int ret, i;
-
-    if (!k->set_guest_notifiers) {
-        error_report("binding does not support guest notifiers");
-        return;
-    }
-
-    ret = vhost_dev_enable_notifiers(&i2c->vhost_dev, vdev);
-    if (ret < 0) {
-        error_report("Error enabling host notifiers: %d", -ret);
-        return;
-    }
-
-    ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, true);
-    if (ret < 0) {
-        error_report("Error binding guest notifier: %d", -ret);
-        goto err_host_notifiers;
-    }
-
-    i2c->vhost_dev.acked_features = vdev->guest_features;
-
-    ret = vhost_dev_start(&i2c->vhost_dev, vdev, true);
-    if (ret < 0) {
-        error_report("Error starting vhost-user-i2c: %d", -ret);
-        goto err_guest_notifiers;
-    }
-
-    /*
-     * guest_notifier_mask/pending not used yet, so just unmask
-     * everything here. virtio-pci will do the right thing by
-     * enabling/disabling irqfd.
-     */
-    for (i = 0; i < i2c->vhost_dev.nvqs; i++) {
-        vhost_virtqueue_mask(&i2c->vhost_dev, vdev, i, false);
-    }
-
-    return;
-
-err_guest_notifiers:
-    k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false);
-err_host_notifiers:
-    vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev);
-}
-
-static void vu_i2c_stop(VirtIODevice *vdev)
-{
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    int ret;
-
-    if (!k->set_guest_notifiers) {
-        return;
-    }
-
-    vhost_dev_stop(&i2c->vhost_dev, vdev, true);
-
-    ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false);
-    if (ret < 0) {
-        error_report("vhost guest notifier cleanup failed: %d", ret);
-        return;
-    }
-
-    vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev);
-}
-
-static void vu_i2c_set_status(VirtIODevice *vdev, uint8_t status)
-{
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
-    bool should_start = virtio_device_should_start(vdev, status);
-
-    if (vhost_dev_is_started(&i2c->vhost_dev) == should_start) {
-        return;
-    }
-
-    if (should_start) {
-        vu_i2c_start(vdev);
-    } else {
-        vu_i2c_stop(vdev);
-    }
-}
-
-static uint64_t vu_i2c_get_features(VirtIODevice *vdev,
-                                    uint64_t requested_features, Error **errp)
-{
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
-
-    virtio_add_feature(&requested_features, VIRTIO_I2C_F_ZERO_LENGTH_REQUEST);
-    return vhost_get_features(&i2c->vhost_dev, feature_bits, requested_features);
-}
-
-static void vu_i2c_handle_output(VirtIODevice *vdev, VirtQueue *vq)
-{
-    /*
-     * Not normally called; it's the daemon that handles the queue;
-     * however virtio's cleanup path can call this.
-     */
-}
-
-static void vu_i2c_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask)
-{
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
-
-    /*
-     * We don't support interrupts, return early if index is set to
-     * VIRTIO_CONFIG_IRQ_IDX.
-     */
-    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
-        return;
-    }
-
-    vhost_virtqueue_mask(&i2c->vhost_dev, vdev, idx, mask);
-}
-
-static bool vu_i2c_guest_notifier_pending(VirtIODevice *vdev, int idx)
-{
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
-
-    /*
-     * We don't support interrupts, return early if index is set to
-     * VIRTIO_CONFIG_IRQ_IDX.
-     */
-    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
-        return false;
-    }
-
-    return vhost_virtqueue_pending(&i2c->vhost_dev, idx);
-}
-
-static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserI2C *i2c)
-{
-    vhost_user_cleanup(&i2c->vhost_user);
-    virtio_delete_queue(i2c->vq);
-    virtio_cleanup(vdev);
-}
-
-static int vu_i2c_connect(DeviceState *dev)
+static void vi2c_realize(DeviceState *dev, Error **errp)
 {
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
+    VHostUserBase *vub = VHOST_USER_BASE(dev);
+    VHostUserBaseClass *vubc = VHOST_USER_BASE_GET_CLASS(dev);
 
-    if (i2c->connected) {
-        return 0;
-    }
-    i2c->connected = true;
+    /* Fixed for I2C */
+    vub->virtio_id = VIRTIO_ID_I2C_ADAPTER;
+    vub->num_vqs = 1;
+    vub->vq_size = 4;
 
-    /* restore vhost state */
-    if (virtio_device_started(vdev, vdev->status)) {
-        vu_i2c_start(vdev);
-    }
-
-    return 0;
-}
-
-static void vu_i2c_disconnect(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
-
-    if (!i2c->connected) {
-        return;
-    }
-    i2c->connected = false;
-
-    if (vhost_dev_is_started(&i2c->vhost_dev)) {
-        vu_i2c_stop(vdev);
-    }
-}
-
-static void vu_i2c_event(void *opaque, QEMUChrEvent event)
-{
-    DeviceState *dev = opaque;
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
-
-    switch (event) {
-    case CHR_EVENT_OPENED:
-        if (vu_i2c_connect(dev) < 0) {
-            qemu_chr_fe_disconnect(&i2c->chardev);
-            return;
-        }
-        break;
-    case CHR_EVENT_CLOSED:
-        vu_i2c_disconnect(dev);
-        break;
-    case CHR_EVENT_BREAK:
-    case CHR_EVENT_MUX_IN:
-    case CHR_EVENT_MUX_OUT:
-        /* Ignore */
-        break;
-    }
-}
-
-static void vu_i2c_device_realize(DeviceState *dev, Error **errp)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserI2C *i2c = VHOST_USER_I2C(dev);
-    int ret;
-
-    if (!i2c->chardev.chr) {
-        error_setg(errp, "vhost-user-i2c: missing chardev");
-        return;
-    }
-
-    if (!vhost_user_init(&i2c->vhost_user, &i2c->chardev, errp)) {
-        return;
-    }
-
-    virtio_init(vdev, VIRTIO_ID_I2C_ADAPTER, 0);
-
-    i2c->vhost_dev.nvqs = 1;
-    i2c->vq = virtio_add_queue(vdev, 4, vu_i2c_handle_output);
-    i2c->vhost_dev.vqs = g_new0(struct vhost_virtqueue, i2c->vhost_dev.nvqs);
-
-    ret = vhost_dev_init(&i2c->vhost_dev, &i2c->vhost_user,
-                         VHOST_BACKEND_TYPE_USER, 0, errp);
-    if (ret < 0) {
-        g_free(i2c->vhost_dev.vqs);
-        do_vhost_user_cleanup(vdev, i2c);
-    }
-
-    qemu_chr_fe_set_handlers(&i2c->chardev, NULL, NULL, vu_i2c_event, NULL,
-                             dev, NULL, true);
-}
-
-static void vu_i2c_device_unrealize(DeviceState *dev)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-    VHostUserI2C *i2c = VHOST_USER_I2C(dev);
-    struct vhost_virtqueue *vhost_vqs = i2c->vhost_dev.vqs;
-
-    /* This will stop vhost backend if appropriate. */
-    vu_i2c_set_status(vdev, 0);
-    vhost_dev_cleanup(&i2c->vhost_dev);
-    g_free(vhost_vqs);
-    do_vhost_user_cleanup(vdev, i2c);
+    vubc->parent_realize(dev, errp);
 }
 
 static const VMStateDescription vu_i2c_vmstate = {
@@ -268,30 +37,21 @@ static const VMStateDescription vu_i2c_vmstate = {
     .unmigratable = 1,
 };
 
-static Property vu_i2c_properties[] = {
-    DEFINE_PROP_CHR("chardev", VHostUserI2C, chardev),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void vu_i2c_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
-    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+    VHostUserBaseClass *vubc = VHOST_USER_BASE_CLASS(klass);
 
-    device_class_set_props(dc, vu_i2c_properties);
     dc->vmsd = &vu_i2c_vmstate;
+    device_class_set_props(dc, vi2c_properties);
+    device_class_set_parent_realize(dc, vi2c_realize,
+                                    &vubc->parent_realize);
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
-    vdc->realize = vu_i2c_device_realize;
-    vdc->unrealize = vu_i2c_device_unrealize;
-    vdc->get_features = vu_i2c_get_features;
-    vdc->set_status = vu_i2c_set_status;
-    vdc->guest_notifier_mask = vu_i2c_guest_notifier_mask;
-    vdc->guest_notifier_pending = vu_i2c_guest_notifier_pending;
 }
 
 static const TypeInfo vu_i2c_info = {
     .name = TYPE_VHOST_USER_I2C,
-    .parent = TYPE_VIRTIO_DEVICE,
+    .parent = TYPE_VHOST_USER_BASE,
     .instance_size = sizeof(VHostUserI2C),
     .class_init = vu_i2c_class_init,
 };
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 87042e5901..0a4d29ace6 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -22,12 +22,15 @@ if have_vhost
     # MMIO Stubs
     system_virtio_ss.add(files('vhost-user-device.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_GPIO', if_true: files('vhost-user-gpio.c'))
+    system_virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng.c'))
 
     # PCI Stubs
     system_virtio_ss.add(when: 'CONFIG_VIRTIO_PCI', if_true: files('vhost-user-device-pci.c'))
     system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_GPIO'],
                          if_true: files('vhost-user-gpio-pci.c'))
+    system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_I2C'],
+                         if_true: files('vhost-user-i2c-pci.c'))
     system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_RNG'],
                          if_true: files('vhost-user-rng-pci.c'))
   endif
@@ -46,7 +49,6 @@ specific_virtio_ss.add(when: 'CONFIG_VHOST_VSOCK', if_true: files('vhost-vsock.c
 specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_VSOCK', if_true: files('vhost-user-vsock.c'))
 specific_virtio_ss.add(when: 'CONFIG_VIRTIO_RNG', if_true: files('virtio-rng.c'))
 specific_virtio_ss.add(when: 'CONFIG_VIRTIO_MEM', if_true: files('virtio-mem.c'))
-specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c'))
 specific_virtio_ss.add(when: 'CONFIG_VHOST_USER_SCMI', if_true: files('vhost-user-scmi.c'))
 specific_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_SCMI'], if_true: files('vhost-user-scmi-pci.c'))
 
@@ -54,7 +56,6 @@ virtio_pci_ss = ss.source_set()
 virtio_pci_ss.add(when: 'CONFIG_VHOST_VSOCK', if_true: files('vhost-vsock-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_VSOCK', if_true: files('vhost-user-vsock-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_BLK', if_true: files('vhost-user-blk-pci.c'))
-virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_INPUT', if_true: files('vhost-user-input-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_SCSI', if_true: files('vhost-user-scsi-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_SCSI', if_true: files('vhost-scsi-pci.c'))
-- 
2.39.2

[Virtio-fs] [PATCH v5 5/6] hw/virtio: add vhost-user-snd and virtio-snd-pci devices

[Alex Bennée]

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

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

[AJB: imported from https://github.com/epilys/qemu-virtio-snd/commit/54ae1cdd15fef2d88e9e387a175f099a38c636f4.patch]

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009095937.195728-6-alex.bennee@linaro.org>
---
 include/hw/virtio/vhost-user-snd.h | 26 +++++++++++
 hw/virtio/vhost-user-snd-pci.c     | 75 ++++++++++++++++++++++++++++++
 hw/virtio/vhost-user-snd.c         | 67 ++++++++++++++++++++++++++
 hw/virtio/Kconfig                  |  5 ++
 hw/virtio/meson.build              |  3 ++
 5 files changed, 176 insertions(+)
 create mode 100644 include/hw/virtio/vhost-user-snd.h
 create mode 100644 hw/virtio/vhost-user-snd-pci.c
 create mode 100644 hw/virtio/vhost-user-snd.c

diff --git a/include/hw/virtio/vhost-user-snd.h b/include/hw/virtio/vhost-user-snd.h
new file mode 100644
index 0000000000..a1627003a0
--- /dev/null
+++ b/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-base.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 */
diff --git a/hw/virtio/vhost-user-snd-pci.c b/hw/virtio/vhost-user-snd-pci.c
new file mode 100644
index 0000000000..d61cfdae63
--- /dev/null
+++ b/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);
diff --git a/hw/virtio/vhost-user-snd.c b/hw/virtio/vhost-user-snd.c
new file mode 100644
index 0000000000..9a217543f8
--- /dev/null
+++ b/hw/virtio/vhost-user-snd.c
@@ -0,0 +1,67 @@
+/*
+ * 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);
+    vub->vq_size = 64;
+
+    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)
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index 92c9cf6c96..aa63ff7fd4 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -101,6 +101,11 @@ config VHOST_VDPA_DEV
     default y
     depends on VIRTIO && VHOST_VDPA && LINUX
 
+config VHOST_USER_SND
+    bool
+    default y
+    depends on VIRTIO && VHOST_USER
+
 config VHOST_USER_SCMI
     bool
     default y
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 0a4d29ace6..118d4d4da7 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -24,6 +24,7 @@ if have_vhost
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_GPIO', if_true: files('vhost-user-gpio.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng.c'))
+    system_virtio_ss.add(when: 'CONFIG_VHOST_USER_SND', if_true: files('vhost-user-snd.c'))
 
     # PCI Stubs
     system_virtio_ss.add(when: 'CONFIG_VIRTIO_PCI', if_true: files('vhost-user-device-pci.c'))
@@ -33,6 +34,8 @@ if have_vhost
                          if_true: files('vhost-user-i2c-pci.c'))
     system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_RNG'],
                          if_true: files('vhost-user-rng-pci.c'))
+    system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_SND'],
+                         if_true: files('vhost-user-snd-pci.c'))
   endif
   if have_vhost_vdpa
     system_virtio_ss.add(files('vhost-vdpa.c'))
-- 
2.39.2

[Virtio-fs] [PATCH v5 6/6] docs/system: add a basic enumeration of vhost-user devices

[Alex Bennée]

Make it clear the vhost-user-device is intended for expert use only.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009095937.195728-7-alex.bennee@linaro.org>

---
v5
  - split vhost-user-device out of the table
  - sort the table alphabetically
  - add sound and scmi devices
---
 docs/system/devices/vhost-user-rng.rst |  2 +
 docs/system/devices/vhost-user.rst     | 60 +++++++++++++++++++++++++-
 2 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/docs/system/devices/vhost-user-rng.rst b/docs/system/devices/vhost-user-rng.rst
index a145d4105c..ead1405326 100644
--- a/docs/system/devices/vhost-user-rng.rst
+++ b/docs/system/devices/vhost-user-rng.rst
@@ -1,3 +1,5 @@
+.. _vhost_user_rng:
+
 QEMU vhost-user-rng - RNG emulation
 ===================================
 
diff --git a/docs/system/devices/vhost-user.rst b/docs/system/devices/vhost-user.rst
index a80e95a48a..3e9fd2eba5 100644
--- a/docs/system/devices/vhost-user.rst
+++ b/docs/system/devices/vhost-user.rst
@@ -8,13 +8,71 @@ outside of QEMU itself. To do this there are a number of things
 required.
 
 vhost-user device
-===================
+=================
 
 These are simple stub devices that ensure the VirtIO device is visible
 to the guest. The code is mostly boilerplate although each device has
 a ``chardev`` option which specifies the ID of the ``--chardev``
 device that connects via a socket to the vhost-user *daemon*.
 
+Each device will have an virtio-mmio and virtio-pci variant. See your
+platform details for what sort of virtio bus to use.
+
+.. list-table:: vhost-user devices
+  :widths: 20 20 60
+  :header-rows: 1
+
+  * - Device
+    - Type
+    - Notes
+  * - vhost-user-blk
+    - Block storage
+    - See contrib/vhost-user-blk
+  * - vhost-user-fs
+    - File based storage driver
+    - See https://gitlab.com/virtio-fs/virtiofsd
+  * - vhost-user-gpio
+    - Proxy gpio pins to host
+    - See https://github.com/rust-vmm/vhost-device
+  * - vhost-user-gpu
+    - GPU driver
+    - See contrib/vhost-user-gpu
+  * - vhost-user-i2c
+    - Proxy i2c devices to host
+    - See https://github.com/rust-vmm/vhost-device
+  * - vhost-user-input
+    - Generic input driver
+    - See contrib/vhost-user-input
+  * - vhost-user-rng
+    - Entropy driver
+    - :ref:`vhost_user_rng`
+  * - vhost-user-scmi
+    - System Control and Management Interface
+    - See https://github.com/rust-vmm/vhost-device
+  * - vhost-user-snd
+    - Audio device
+    - See https://github.com/rust-vmm/vhost-device/staging
+  * - vhost-user-scsi
+    - SCSI based storage
+    - See contrib/vhost-user-scsi
+  * - vhost-user-vsock
+    - Socket based communication
+    - See https://github.com/rust-vmm/vhost-device
+
+The referenced *daemons* are not exhaustive, any conforming backend
+implementing the device and using the vhost-user protocol should work.
+
+vhost-user-device
+^^^^^^^^^^^^^^^^^
+
+The vhost-user-device is a generic development device intended for
+expert use while developing new backends. The user needs to specify
+all the required parameters including:
+
+  - Device ``virtio-id``
+  - The ``num_vqs`` it needs and their ``vq_size``
+  - The ``config_size`` if needed
+
 vhost-user daemon
 =================
 
-- 
2.39.2

Re: [Virtio-fs] [PATCH v5 5/6] hw/virtio: add vhost-user-snd and virtio-snd-pci devices

[Viresh Kumar]

On 19-10-23, 10:56, Alex Bennée wrote:
> From: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> 
> 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
> 
> [AJB: imported from https://github.com/epilys/qemu-virtio-snd/commit/54ae1cdd15fef2d88e9e387a175f099a38c636f4.patch]
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Missing SOB from Manos ?

> Message-Id: <20231009095937.195728-6-alex.bennee@linaro.org>

-- 
viresh

Re: [Virtio-fs] [PATCH v5 5/6] hw/virtio: add vhost-user-snd and virtio-snd-pci devices

[Alex Bennée]

Viresh Kumar <viresh.kumar@linaro.org> writes:

> On 19-10-23, 10:56, Alex Bennée wrote:
>> From: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
>> 
>> 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
>> 
>> [AJB: imported from https://github.com/epilys/qemu-virtio-snd/commit/54ae1cdd15fef2d88e9e387a175f099a38c636f4.patch]
>> 
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>
> Missing SOB from Manos ?

oops, guess I need a respin then ;-)

>
>> Message-Id: <20231009095937.195728-6-alex.bennee@linaro.org>


-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

Re: [Virtio-fs] [PATCH v5 5/6] hw/virtio: add vhost-user-snd and virtio-snd-pci devices

[Michael S. Tsirkin]

On Fri, Oct 20, 2023 at 09:16:03AM +0100, Alex Bennée wrote:
> 
> Viresh Kumar <viresh.kumar@linaro.org> writes:
> 
> > On 19-10-23, 10:56, Alex Bennée wrote:
> >> From: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> >> 
> >> 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
> >> 
> >> [AJB: imported from https://github.com/epilys/qemu-virtio-snd/commit/54ae1cdd15fef2d88e9e387a175f099a38c636f4.patch]
> >> 
> >> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> >
> > Missing SOB from Manos ?
> 
> oops, guess I need a respin then ;-)

Just ask Manos to send his S.O.B in a reply.


> >
> >> Message-Id: <20231009095937.195728-6-alex.bennee@linaro.org>
> 
> 
> -- 
> Alex Bennée
> Virtualisation Tech Lead @ Linaro

Re: [Virtio-fs] [PATCH v5 5/6] hw/virtio: add vhost-user-snd and virtio-snd-pci devices

[Manos Pitsidianakis]

On Fri, 20 Oct 2023 12:02, "Michael S. Tsirkin" <mst@redhat.com> wrote:
>On Fri, Oct 20, 2023 at 09:16:03AM +0100, Alex Bennée wrote:
>> 
>> Viresh Kumar <viresh.kumar@linaro.org> writes:
>> 
>> > On 19-10-23, 10:56, Alex Bennée wrote:
>> >> From: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
>> >> 
>> >> 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
>> >> 
>> >> [AJB: imported from https://github.com/epilys/qemu-virtio-snd/commit/54ae1cdd15fef2d88e9e387a175f099a38c636f4.patch]
>> >> 
>> >> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> >
>> > Missing SOB from Manos ?
>> 
>> oops, guess I need a respin then ;-)
>
>Just ask Manos to send his S.O.B in a reply.

Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>

Re: [Virtio-fs] [PATCH v5 0/6] virtio: cleanup vhost-user-generic and reduce c&p

[Alex Bennée]

Alex Bennée <alex.bennee@linaro.org> writes:

> A lot of our vhost-user stubs are large chunks of boilerplate that do
> (mostly) the same thing. This series continues the cleanups by
> splitting the vhost-user-base and vhost-user-generic implementations.
> After adding a new vq_size property the rng, gpio and i2c vhost-user
> devices become simple specialisations of the common base defining the
> ID, number of queues and potentially the config handling.
>
> I've also added Manos' vhost-user-sound while I was at it.

Ping MST. Any more comments or happy to take as is?

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

Re: [Virtio-fs] [PATCH v5 0/6] virtio: cleanup vhost-user-generic and reduce c&p

[Michael S. Tsirkin]

On Tue, Oct 24, 2023 at 06:14:36PM +0100, Alex Bennée wrote:
> 
> Alex Bennée <alex.bennee@linaro.org> writes:
> 
> > A lot of our vhost-user stubs are large chunks of boilerplate that do
> > (mostly) the same thing. This series continues the cleanups by
> > splitting the vhost-user-base and vhost-user-generic implementations.
> > After adding a new vq_size property the rng, gpio and i2c vhost-user
> > devices become simple specialisations of the common base defining the
> > ID, number of queues and potentially the config handling.
> >
> > I've also added Manos' vhost-user-sound while I was at it.
> 
> Ping MST. Any more comments or happy to take as is?

It's tagged already.

> -- 
> Alex Bennée
> Virtualisation Tech Lead @ Linaro