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

[Jason Wang <jasowang@redhat.com>]

On Fri, Sep 23, 2022 at 11:55 AM houyl@yusur.tech <houyl@yusur.tech> wrote:
>
> On Thu, 22 Sep 2022 09:34:41 +0800 Jason Wang<jasowang@redhat.com>  wrote:
>
>
> >On Thu, Sep 22, 2022 at 1:58 AM Raphael Norwitz
> ><raphael.norwitz@nutanix.com> wrote:
> >>
> >> 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.
>
> >I think the best way is to (and it seems easier)
>
> >1) have the management layer to make sure the mac came from cli
> >matches the underlayer vDPA
>
>  Agreed, that's no problem.
>
> >2) having a sanity check and fail the device initialization if they don't match
>
> However, one MAC address for integrity check is from the cli, and the other MAC address is from the vDPA device,
> How to get it?

VHOST_USER_GET_CONFIG?

Thanks

>
> The current situation is if MAC came from cli don't match the underlayer vDPA, the virtual machine can still start without any hints.
>
> Thanks
>
>
> >Thanks
>
> >>
> >>
> >>
> >> 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
> >>
> >> >
> >>
> >>
>