On Tue, Oct 29, 2024 at 01:09:00PM +0000, Andrea Bolognani wrote:
On Tue, Oct 29, 2024 at 12:46:55PM +0000, Daniel P. Berrangé wrote:
A key difference that is probably relevant is that netbsd is using an e1000 NIC in QEMU, while openbsd is using a virtio-net NIC. At least when created by virt-manager.
AFAIR, QEMU's magic checksum offload only happens for virtio-net, so presumably our rules are incompatible with non-virtio-net NICs in someway.
Yes, that's it! The GNU/Hurd and Haiku guests are also using e1000, since virtio drivers are not available there; moreover, if I switch a random Linux guest from virtio-net to e1000 I can reproduce the issue there as well.
Incidentally, I think this has crossed the threshold where the cure is worse than the disease. We cannot ship the forthcoming libvirt release with a checksum "fix" that breaks all usage of NICs that aren't virtio-net, as that guarantees brokeness for all historical OS. If we can't quickly find a way to improve this, I think we need to revert (or disable) the checksum zero'ing fix for this release and spend more time investigating it. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|