Emulate 10Gbps without VirtIo

[attax89]

Hello forum,
I'm playing around with proxmox VE and everything's good so far.
I'm currently facing an issue which not I'm not sure is addressable or not.

I'm firing up a VM which OS is an hardened Red Hat 7.7 version; see this as a black box.

After the OS is installed, it starts a network configuration wizard that looks for 10 Gbps interfaces and, as far as i can tell, it tries to verify that by using ethtool.
if the interface is not reporting 10Gbps (both as supported and negotiated speed), the wizard complains and stops.

At first I've tried with VirtIO nics, but as far as i understand, ethtool doesn't report correct speed due to how this is seen by the OS (which knows it's a paravirt interface ; https://serverfault.com/questions/738840/get-link-speed-of-an-virtio-net-network-adapter); i've then switched to vmxnet3 (that comes from vmware, where this setup works fine) and from ethtool i see the interface is capable of 10Gbps, but actual negotiation speed is 1Gbps (so the wizard stops again):

[root@hsx001 ~]# ethtool enpsf2
Settings for enpsf2:
        Supported ports: [ TP ]
        Supported link modes:   1000baseT/Full
                                10000baseT/Full
        Supported pause frame use: No
        Supports auto-negotiation: No
        Supported FEC modes: Not reported
        Advertised link modes:  Not reported
        Advertised pause frame use: No
        Advertised auto-negotiation: No
        Advertised FEC modes: Not reported
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: off
        MDI-X: Unknown
        Supports Wake-on: uag
        Wake-on: d
        Link detected: yes

Basically what i'm trying to achieve is to fake a 10Gbps net adapter, i'm not really interested in having the throughput, i just need that the OS "thinks" to have it.
any suggestion?
interface is on top of a Linux Bridge, and PVE version is 6.2-4. HW is the latest generation (10th) of Intel Nuc.

Thanks

 

[wolfgang]

Hi,

the speed is hardcoded in the kernel module/driver of your VM kernel.
So there is nothing you could do about it.

see
https://github.com/torvalds/linux/blob/master/drivers/net/virtio_net.c#L2251

 

[attax89]

Hi,

the speed is hardcoded in the kernel module/driver of your VM kernel.
So there is nothing you could do about it.

see
https://github.com/torvalds/linux/blob/master/drivers/net/virtio_net.c#L2251

Thanks for your reply Wolfgang.
So that is basically closing the road for VirtIO interface type.
But what about vmxnet3 type? Should it be able to be presented as 10Gbps? In fact it is reporting that it's able to be 10Gbps

 

[wolfgang]

This is for all NICs in Linux the same.

 

[Giovanni]

I'm facing the same issue as this post. I was able to replicate it on multiple linux live CDs...

filed a bug: https://bugzilla.proxmox.com/show_bug.cgi?id=5606