Re: [PATCH] hw/virtio/vhost-user: support obtain vdpa device's mac address automatically

[Raphael Norwitz]

I have some concerns from the vhost-user-blk side.

 

>On Tue, Sep 13, 2022 at 5:13 PM Hao Chen <chenh@yusur.tech> wrote:

>> 

>> When use dpdk-vdpa tests vdpa device. You need to specify the mac address to

>> start the virtual machine through libvirt or qemu, but now, the libvirt or

>> qemu can call dpdk vdpa vendor driver's ops .get_config through vhost_net_get_config

>> to get the mac address of the vdpa hardware without manual configuration.

>> 

>> Signed-off-by: Hao Chen <chenh@yusur.tech>

> 

>Adding Cindy for comments.

> 

>Thanks

> 

>> ---

>>  hw/block/vhost-user-blk.c |  1 -

>>  hw/net/virtio-net.c       |  3 ++-

>>  hw/virtio/vhost-user.c    | 19 -------------------

>>  3 files changed, 2 insertions(+), 21 deletions(-)

>> 

>> diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c

>> index 9117222456..5dca4eab09 100644

>> --- a/hw/block/vhost-user-blk.c

>> +++ b/hw/block/vhost-user-blk.c

>> @@ -337,7 +337,6 @@ static int vhost_user_blk_connect(DeviceState *dev, Error **errp)

>> 

>>      vhost_dev_set_config_notifier(&s->dev, &blk_ops);

>> 

>> -    s->vhost_user.supports_config = true;

 

vhost-user-blk requires the backend to support VHOST_USER_PROTOCOL_F_CONFIG

and vhost_user.supports_config is used to enforce that.

 

Why are you removing it here?

 

 

>>      ret = vhost_dev_init(&s->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,

>>                           errp);

>>      if (ret < 0) {

>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c

>> index dd0d056fde..274ea84644 100644

>> --- a/hw/net/virtio-net.c

>> +++ b/hw/net/virtio-net.c

>> @@ -149,7 +149,8 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)

>>       * Is this VDPA? No peer means not VDPA: there's no way to

>>       * disconnect/reconnect a VDPA peer.

>>       */

>> -    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {

>> +    if ((nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) ||

>> +        (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER)) {

>>          ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,

>>                                     n->config_size);

>>          if (ret != -1) {

>> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c

>> index bd24741be8..8b01078249 100644

>> --- a/hw/virtio/vhost-user.c

>> +++ b/hw/virtio/vhost-user.c

>> @@ -2013,8 +2013,6 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,

>>      }

>> 

 

Why are you removing this? Can you expand on how it helps dpdk-vdpa.

 

>>      if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) {

>> -        bool supports_f_config = vus->supports_config ||

>> -            (dev->config_ops && dev->config_ops->vhost_dev_config_notifier);

>>          uint64_t protocol_features;

>> 

>>          dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;

>> @@ -2033,23 +2031,6 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,

>>           */

>>          protocol_features &= VHOST_USER_PROTOCOL_FEATURE_MASK;

>> 

>> -        if (supports_f_config) {

>> -            if (!virtio_has_feature(protocol_features,

>> -                                    VHOST_USER_PROTOCOL_F_CONFIG)) {

>> -                error_setg(errp, "vhost-user device expecting "

>> -                           "VHOST_USER_PROTOCOL_F_CONFIG but the vhost-user backend does "

>> -                           "not support it.");

>> -                return -EPROTO;

>> -            }

>> -        } else {

>> -            if (virtio_has_feature(protocol_features,

>> -                                   VHOST_USER_PROTOCOL_F_CONFIG)) {

>> -                warn_reportf_err(*errp, "vhost-user backend supports "

>> -                                 "VHOST_USER_PROTOCOL_F_CONFIG but QEMU does not.");

>> -                protocol_features &= ~(1ULL << VHOST_USER_PROTOCOL_F_CONFIG);

>> -            }

>> -        }

>> -

>>          /* final set of protocol features */

>>          dev->protocol_features = protocol_features;

>>          err = vhost_user_set_protocol_features(dev, dev->protocol_features);

>> --

>> 2.27.0

>> 

>