Re: [PATCH v2] hw/virtio/vhost-user: support obtain vdpa device's mac address automatically

[Raphael Norwitz]

If I read your response on the other thread correctly, this change is intended

to prioritize the MAC address exposed by DPDK over the one provided by the

QEMU command line? Sounds reasonable in principle, but I would get confirmation

from vDPA/vhost-net maintainers.

 

That said the way you’re hacking the vhost-user code breaks a valuable check for

bad vhost-user-blk backends. I would suggest finding another implementation which

does not regress functionality for other device types.

 

 

>From: Hao Chen <chenh@yusur.tech>

> 

>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.

> 

>v1->v2:

>Only copy ETH_ALEN data of netcfg for some vdpa device such as

>NVIDIA BLUEFIELD DPU(BF2)'s netcfg->status is not right.

>We only need the mac address and don't care about the status field.

> 

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

>---

> hw/block/vhost-user-blk.c |  1 -

> hw/net/virtio-net.c       |  7 +++++++

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

> 3 files changed, 7 insertions(+), 20 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;

>     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..90405083b1 100644

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

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

>@@ -166,6 +166,13 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)

>             }

>             memcpy(config, &netcfg, n->config_size);

>         }

>+    } else if (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) {

>+               /* Automatically obtain the mac address of the vdpa device

>+                * when using the dpdk vdpa */

>+                memcpy(config, &netcfg, ETH_ALEN);

>     }

> }

> 

>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,

>     }

> 

>     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

>