Re: FreeBSD guest on Linux KVM, some vtnet(4) packets don't arrive

> On 10. Apr 2026, at 11:54, Lexi Winter <[email protected]> wrote:
> 
> Michael Tuexen wrote in <[email protected]>:
>>> On 10. Apr 2026, at 11:24, Lexi Winter <[email protected]> wrote:
>>> pci0: <POWER Hypervisor PCI bus> on pcib0
>>> virtio_pci0: <VirtIO PCI (modern) Network adapter> port 0x20-0x3f mem 0x81030000-0x81030fff,0x210000000000-0x210000003fff irq 4610 at device 2.0 numa-domain 0 on pci0
>>> vtnet0: <VirtIO Networking Adapter> numa-domain 0 on virtio_pci0
>>> vtnet0: Invalid max_virtqueue_pairs value: 65535. Multiqueue feature disabled.
>>> virtio_pci0: virtqueue 1 (vtnet0-tx0) does not exist (size is zero)
>>> virtio_pci0: cannot allocate virtqueue 1: 19
>>> vtnet0: cannot allocate virtqueues
>>> device_attach: vtnet0 attach returned 19
>> 
>> I guess this is related to
>> https://cgit.FreeBSD.org/src/commit/?id=0b39d72d0491c77e3e9883015b1fac46663c71de
>> You can put
>> hw.virtio.pci.transitional=0
>> in /boot/loader.conf to get the old behavior. Does that help?
> 
> yes, this seems to fix the new vtnet issue.  now i'll go back to getting
> world to build so i can do some OpenSSL tests :-)
Thanks for confirming. Timo will look into the vtnet issue. This looks similar to
a problem when running a FreeBSD guest using VirtualBox on an arm64 Mac. Just
that legacy drivers don't work, modern do work:
https://github.com/VirtualBox/virtualbox/issues/569
That was one of the motivations to switch the default value. You are using QEMU on
a Linux amd64 host, right? Or are you using a ppc64 host? It would be great if
we could reproduce the problem locally.

Best regards
Michael
> 
> thanks.