> On Sep 26, 2025, at 1:46 AM, Michael Tuexen > <[email protected]> wrote: > >> >> On 26. Sep 2025, at 02:58, John Nielsen <[email protected]> wrote: >> >> Not sure if this is a known issue or even an issue on the FreeBSD side but >> decided to ask here first. I’m happy to put in a bug report if appropriate. >> >> I have a hypervisor machine running Arch Linux with KVM, Qemu and libvirtd. >> The machine has a Chelsio T520-CR adapter. I recently began passing through >> virtual functions of the NIC to several of the guests I run on the >> hypervisor. One of the guests runs Windows 11, and the change was seamless. >> Two of the guests are running FreeBSD (14.3 or so). On each of them the VFs >> were readily identified and configured (using DHCP in one case), and ping >> and ARP appeared to work fine. However, TCP and UDP traffic to the guests >> never received a response. After some head-scratching and troubleshooting I >> discovered that running “ifconfig cxlv0 -rxcsum” immediately allowed traffic >> to flow as expected. > > I don't have access to such a network card. Just to be clear: you are running > the “ifconfig cxlv0 -rxcsum” command inside the guest running FreeBSD, right?
Yes. > What is the peer, when you mention TCP and UDP do not work? Is it the host > running Linux? Is it another VM? Is it some external host? My laptop on the same subnet primarily, but. Also tested from another physical machine running FreeBSD. >> As workarounds go that isn’t terrible, but I was surprised that the FreeBSD >> guests required this adjustment while the Windows one did not. >> >> As a point of reference I have another hypervisor machine that runs FreeBSD >> 14-STABLE. It also has a > So the host runs FreeBSD and you use bhyve to run some VM? Yes >> Chelsio T520-CR adapter. FreeBSD guests on that machine do not require >> “-rxcsum” in order to use the Chelsio virtual functions. > The guests run FreeBSD-STABLE or Freebsd 14.3? > What is the peer, when you mention TCP and UDP do not work? Is it the host > running Linux? Is it another VM? Is it some external host? FreeBSD 14-STABLE circa 14.3 Multiple off-box same-subnet peers in this scenario as well including my laptop. I’m aware that VF-to-PF communication is a special case. JN
