CVSROOT: /cvs
Module name: src
Changes by: [email protected] 2026/01/13 03:10:14
Modified files:
sys/dev/pv : if_vio.c
Log message:
vio: Improve feature negotiation for LRO/TSO
OpenBSD requires that LRO can be switched on and off for things like
bridged vlan(4), vxlan(4), bpe(4). We currently only support switching
LRO on/off if the VIRTIO_NET_F_CTRL_GUEST_OFFLOADS feature was
negotiated. But this means if the hypervisor only offers
VIRTIO_NET_F_GUEST_TSO4/6 but not VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,
things will break. In this case we must redo feature negotation without
the GUEST_TSO4/6 features.
Also, if the hypervisor offers GUEST_TSO4/6 but not the
VIRTIO_NET_F_MRG_RXBUF feature, we currently put rx buffers with a
single 4k mbuf into the rx queue while the standard says we SHOULD
insert buffers of at least 65562 bytes. Apple Virtualization refuses to
work with this configuration. As 65562 is larger than MAXMCLBYTES, we
would need to rework how we allocate our rx buffers to make this work.
For now, we would to like to simply disable GUEST_TSO4/6 if MRG_RXBUF is
missing. Unfortunately, Apple Virtualization still refuses to work
unless HOST_TSO4/6 is also disabled. Therefore, we disable all TSO if
MRG_RXBUF is missing.
With lots of input from and tested by helg@
ok mlarkin@
