On Tue, Jul 19, 2022 at 01:25:42PM +0000, Eli Cohen wrote: > Hi, > > > > mlx5_vdpa is offering VIRTIO_NET_F_MTU. However the driver (is it qemu > responsibility?) does not accept and it ends up not negotiated. qemu is responsible for passing features to driver. > > > I don't see how can the driver refuse to negotiate this. What if the hardware > has a limitation with respect to mtu? Then it can fail FEATURES_OK > > > I noticed this when I created the device with mtu of 1000. I expected the > netdev at the vm to have mtu of 1000 and any attempt to go beyond should fail > but that's not the case. > > > > Comments? Any chance mtu is too small? if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) { int mtu = virtio_cread16(vdev, offsetof(struct virtio_net_config, mtu)); if (mtu < MIN_MTU) __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU); } any chance it's on power or another BE system? -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization