Re: [Qemu-devel] [PATCH V2 3/7] virtio-device: refactor virtio-device.

[Anthony Liguori <aliguori@us.ibm.com>]

fred.konrad@greensocs.com writes:

> From: KONRAD Frederic <fred.konrad@greensocs.com>
>
> Create the virtio-device which is abstract. All the virtio-device can extend
> this class. It also add some functions to virtio-bus.
>
> Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
> ---
>  hw/virtio-bus.c | 35 +++++++++++++++++++++++++++++
>  hw/virtio-bus.h |  7 ++++++
>  hw/virtio.c     | 70 +++++++++++++++++++++++++++++++++++++++++++++++----------
>  hw/virtio.h     | 30 +++++++++++++++++++++++++
>  4 files changed, 130 insertions(+), 12 deletions(-)
>
> diff --git a/hw/virtio-bus.c b/hw/virtio-bus.c
> index 7813a89..ec43185 100644
> --- a/hw/virtio-bus.c
> +++ b/hw/virtio-bus.c
> @@ -127,6 +127,41 @@ size_t virtio_device_get_config_len(VirtioBusState *bus)
>      return bus->vdev->config_len;
>  }
>  
> +/* Get the features of the plugged device. */
> +uint32_t virtio_device_get_features(VirtioBusState *bus,
> +                                    uint32_t requested_features)
> +{
> +    VirtioDeviceClass *k;
> +    assert(bus->vdev != NULL);
> +    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);
> +    assert(k->get_features != NULL);
> +    return k->get_features(bus->vdev, requested_features);
> +}
> +
> +/* Get bad features of the plugged device. */
> +uint32_t virtio_device_get_bad_features(VirtioBusState *bus)
> +{
> +    VirtioDeviceClass *k;
> +    assert(bus->vdev != NULL);
> +    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);
> +    if (k->bad_features != NULL) {
> +        return k->bad_features(bus->vdev);
> +    } else {
> +        return 0;
> +    }
> +}
> +
> +/* Get config of the plugged device. */
> +void virtio_device_get_config(VirtioBusState *bus, uint8_t *config)
> +{
> +    VirtioDeviceClass *k;
> +    assert(bus->vdev != NULL);
> +    k = VIRTIO_DEVICE_GET_CLASS(bus->vdev);
> +    if (k->get_config != NULL) {
> +        k->get_config(bus->vdev, config);
> +    }
> +}
> +

If the prefix is "virtio_device" the first argument should be a
VirtIODevice not a virtio_bus.

You probably should introduce a virtio_bus_get_vdev() and then call
virtio_device(virtio_bus_get_vdev(bus), ...)

Or alternatively, rename these to:

virtio_bus_get_vdev_*

>  static const TypeInfo virtio_bus_info = {
>      .name = TYPE_VIRTIO_BUS,
>      .parent = TYPE_BUS,
> diff --git a/hw/virtio-bus.h b/hw/virtio-bus.h
> index 8aa71b2..7bea64a 100644
> --- a/hw/virtio-bus.h
> +++ b/hw/virtio-bus.h
> @@ -87,5 +87,12 @@ int virtio_device_get_nvectors(VirtioBusState *bus);
>  void virtio_device_set_nvectors(VirtioBusState *bus, int nvectors);
>  /* Get the config_len field of the plugged device. */
>  size_t virtio_device_get_config_len(VirtioBusState *bus);
> +/* Get the features of the plugged device. */
> +uint32_t virtio_device_get_features(VirtioBusState *bus,
> +                                    uint32_t requested_features);
> +/* Get bad features of the plugged device. */
> +uint32_t virtio_device_get_bad_features(VirtioBusState *bus);
> +/* Get config of the plugged device. */
> +void virtio_device_get_config(VirtioBusState *bus, uint8_t *config);
>  
>  #endif /* VIRTIO_BUS_H */
> diff --git a/hw/virtio.c b/hw/virtio.c
> index 77b53a9..ca170c3 100644
> --- a/hw/virtio.c
> +++ b/hw/virtio.c
> @@ -17,6 +17,7 @@
>  #include "qemu/error-report.h"
>  #include "virtio.h"
>  #include "qemu/atomic.h"
> +#include "virtio-bus.h"
>  
>  /* The alignment to use between consumer and producer parts of vring.
>   * x86 pagesize again. */
> @@ -875,11 +876,16 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
>      return 0;
>  }
>  
> -void virtio_cleanup(VirtIODevice *vdev)
> +void virtio_common_cleanup(VirtIODevice *vdev)
>  {
>      qemu_del_vm_change_state_handler(vdev->vmstate);
>      g_free(vdev->config);
>      g_free(vdev->vq);
> +}
> +
> +void virtio_cleanup(VirtIODevice *vdev)
> +{
> +    virtio_common_cleanup(vdev);
>      g_free(vdev);
>  }
>  
> @@ -902,14 +908,10 @@ static void virtio_vmstate_change(void *opaque, int running, RunState state)
>      }
>  }
>  
> -VirtIODevice *virtio_common_init(const char *name, uint16_t device_id,
> -                                 size_t config_size, size_t struct_size)
> +void virtio_init(VirtIODevice *vdev, const char *name,
> +                 uint16_t device_id, size_t config_size)
>  {
> -    VirtIODevice *vdev;
>      int i;
> -
> -    vdev = g_malloc0(struct_size);
> -
>      vdev->device_id = device_id;
>      vdev->status = 0;
>      vdev->isr = 0;
> @@ -917,20 +919,28 @@ VirtIODevice *virtio_common_init(const char *name, uint16_t device_id,
>      vdev->config_vector = VIRTIO_NO_VECTOR;
>      vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_PCI_QUEUE_MAX);
>      vdev->vm_running = runstate_is_running();
> -    for(i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) {
> +    for (i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) {
>          vdev->vq[i].vector = VIRTIO_NO_VECTOR;
>          vdev->vq[i].vdev = vdev;
>      }
>  
>      vdev->name = name;
>      vdev->config_len = config_size;
> -    if (vdev->config_len)
> +    if (vdev->config_len) {
>          vdev->config = g_malloc0(config_size);
> -    else
> +    } else {
>          vdev->config = NULL;
> +    }
> +    vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change,
> +                                                     vdev);
> +}
>  
> -    vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, vdev);
> -
> +VirtIODevice *virtio_common_init(const char *name, uint16_t device_id,
> +                                 size_t config_size, size_t struct_size)
> +{
> +    VirtIODevice *vdev;
> +    vdev = g_malloc0(struct_size);
> +    virtio_init(vdev, name, device_id, config_size);
>      return vdev;
>  }
>  
> @@ -1056,3 +1066,39 @@ EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq)
>  {
>      return &vq->host_notifier;
>  }
> +
> +static int virtio_device_init(DeviceState *qdev)
> +{
> +    VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
> +    VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(qdev);
> +    assert(k->init != NULL);
> +    if (k->init(vdev) < 0) {
> +        return -1;
> +    }
> +    virtio_bus_plug_device(vdev);
> +    return 0;
> +}
> +
> +static void virtio_device_class_init(ObjectClass *klass, void *data)
> +{
> +    /* Set the default value here. */
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    dc->init = virtio_device_init;
> +    dc->bus_type = TYPE_VIRTIO_BUS;
> +}
> +
> +static const TypeInfo virtio_device_info = {
> +    .name = TYPE_VIRTIO_DEVICE,
> +    .parent = TYPE_DEVICE,
> +    .instance_size = sizeof(VirtIODevice),
> +    .class_init = virtio_device_class_init,
> +    .abstract = true,
> +    .class_size = sizeof(VirtioDeviceClass),
> +};
> +
> +static void virtio_register_types(void)
> +{
> +    type_register_static(&virtio_device_info);
> +}
> +
> +type_init(virtio_register_types)
> diff --git a/hw/virtio.h b/hw/virtio.h
> index 1dec9dc..a321fb2 100644
> --- a/hw/virtio.h
> +++ b/hw/virtio.h
> @@ -108,8 +108,17 @@ typedef struct {
>  
>  #define VIRTIO_NO_VECTOR 0xffff
>  
> +#define TYPE_VIRTIO_DEVICE "virtio-device"
> +#define VIRTIO_DEVICE_GET_CLASS(obj) \
> +        OBJECT_GET_CLASS(VirtioDeviceClass, obj, TYPE_VIRTIO_DEVICE)
> +#define VIRTIO_DEVICE_CLASS(klass) \
> +        OBJECT_CLASS_CHECK(VirtioDeviceClass, klass, TYPE_VIRTIO_DEVICE)
> +#define VIRTIO_DEVICE(obj) \
> +        OBJECT_CHECK(VirtIODevice, (obj), TYPE_VIRTIO_DEVICE)
> +
>  struct VirtIODevice
>  {
> +    DeviceState parent_obj;
>      const char *name;
>      uint8_t status;
>      uint8_t isr;
> @@ -119,6 +128,10 @@ struct VirtIODevice
>      void *config;
>      uint16_t config_vector;
>      int nvectors;
> +    /*
> +     * Function pointers will be removed at the end of the series as they are in
> +     * VirtioDeviceClass.
> +     */
>      uint32_t (*get_features)(VirtIODevice *vdev, uint32_t requested_features);
>      uint32_t (*bad_features)(VirtIODevice *vdev);
>      void (*set_features)(VirtIODevice *vdev, uint32_t val);
> @@ -134,6 +147,23 @@ struct VirtIODevice
>      VMChangeStateEntry *vmstate;
>  };
>  
> +typedef struct {

It's good form to not make this an anonymous struct.

Regards,

Anthony Liguori

> +    /* This is what a VirtioDevice must implement */
> +    DeviceClass parent;
> +    int (*init)(VirtIODevice *vdev);
> +    uint32_t (*get_features)(VirtIODevice *vdev, uint32_t requested_features);
> +    uint32_t (*bad_features)(VirtIODevice *vdev);
> +    void (*set_features)(VirtIODevice *vdev, uint32_t val);
> +    void (*get_config)(VirtIODevice *vdev, uint8_t *config);
> +    void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
> +    void (*reset)(VirtIODevice *vdev);
> +    void (*set_status)(VirtIODevice *vdev, uint8_t val);
> +} VirtioDeviceClass;
> +
> +void virtio_init(VirtIODevice *vdev, const char *name,
> +                         uint16_t device_id, size_t config_size);
> +void virtio_common_cleanup(VirtIODevice *vdev);
> +
>  VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
>                              void (*handle_output)(VirtIODevice *,
>                                                    VirtQueue *));
> -- 
> 1.7.11.7