Re: vtnet rxcsum broken for forwarding RELENG_13 ?

On 4/11/2022 8:07 PM, Matt Garber wrote:
> On Mon, Apr 11, 2022 at 7:15 PM mike tancsa <mike@sentex.net> wrote:
>
>
>     < details about busted rxsum snipped >
>
>     I opened up https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=263229
>
>
>
> Unless someone knows otherwise, I’ve been under the impression that PF 
> — or potentially any of the other FreeBSD firewalls (?), but I use PF 
> — has been “broken” in that regard on Linux KVM-based FreeBSD guests 
> for years. As such I’ve always needed to use csum_disable flags on the 
> vtnet interfaces or suffer *extremely* poor network performance, even 
> for servers not doing NAT forwarding.


For forwarding / routing it certainly under performs compared to what it 
can do on bare metal, but for my application I need more 
security/management than network speed. Plus we all have more use case 
experience with pf at the office.  It seems to top out at around 200Mb/s 
with the EM nics through the VM. My use case is perhaps 5-10Mb 
sustained. Hypervisor is CPU: AMD EPYC Processor (2100.07-MHz K8-class 
CPU).

     ---Mike


>
> E.g., see:
>
> https://serverfault.com/questions/817664/slow-network-fixed-adding-hw-vtnet-csum-disable-1-what-are-the-posible-side-effe
>
> https://forum.proxmox.com/threads/poor-virtio-network-performance-on-freebsd-guests.26289/
>
>
>
> —Matt
>