Re: [Qemu-devel] [PATCH 3/4] hw/net/virtio-net: Move DEFINE_VIRTIO_NET_FEATURES to virtio-net

[Shannon Zhao]

On Friday, 17 April 2015, Peter Maydell <address@hidden> wrote:
> On 17 April 2015 at 13:13, Shannon Zhao <address@hidden> wrote:
>> Move DEFINE_VIRTIO_NET_FEATURES to the backend virtio-net.
>> The transports just sync the host features from backend.
>>
>> Signed-off-by: Shannon Zhao <address@hidden>
>> Signed-off-by: Shannon Zhao <address@hidden>
>> ---
>>  hw/net/virtio-net.c            | 4 ++++
>>  hw/s390x/s390-virtio-bus.c     | 1 -
>>  hw/s390x/virtio-ccw.c          | 1 -
>>  hw/virtio/virtio-pci.c         | 1 -
>>  include/hw/virtio/virtio-net.h | 1 +
>>  5 files changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>> index 27adcc5..5d72e2d 100644
>> --- a/hw/net/virtio-net.c
>> +++ b/hw/net/virtio-net.c
>> @@ -446,6 +446,9 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
>>      VirtIONet *n = VIRTIO_NET(vdev);
>>      NetClientState *nc = qemu_get_queue(n->nic);
>>
>> +    /* First sync all virtio-net possible supported features */
>> +    features |= n->host_features;
>> +
>>      virtio_add_feature(&features, VIRTIO_NET_F_MAC);
>>
>>      if (!peer_has_vnet_hdr(n)) {
>> @@ -1714,6 +1717,7 @@ static void virtio_net_instance_init(Object *obj)
>>  }
>>
>>  static Property virtio_net_properties[] = {
>> +    DEFINE_VIRTIO_NET_FEATURES(VirtIONet, host_features),
>>      DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
>>      DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
>>                                                 TX_TIMER_INTERVAL),
>> diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
>> index 31fdf94..49c13e2 100644
>> --- a/hw/s390x/s390-virtio-bus.c
>> +++ b/hw/s390x/s390-virtio-bus.c
>> @@ -517,7 +517,6 @@ static void virtio_s390_device_plugged(DeviceState *d)
>>
>>  static Property s390_virtio_net_properties[] = {
>>      DEFINE_VIRTIO_COMMON_FEATURES(VirtIOS390Device, host_features),
>> -    DEFINE_VIRTIO_NET_FEATURES(VirtIOS390Device, host_features),
>>      DEFINE_PROP_END_OF_LIST(),
>>  };
>
> I'm confused. This seems to be the same "breaks backwards compatibility"
> implementation you suggested to me off-list and which I said
> wouldn't work.
>


Hi Peter,

The backwards compatibility is that with this patch the virtio-net-pci can still set these properties through the qemu comand line, right?

As I mentioned off list and in the cover letter, the virtio-net-pci has the ability to access the child's(here is virtio-net) properties. So it look like the wrapper has these properties.

> thanks
> -- PMM
>