From nobody Fri Sep 26 18:52:41 2025 X-Original-To: net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4cYKTV3pf5z68jqN; Fri, 26 Sep 2025 18:52:46 +0000 (UTC) (envelope-from lists@jnielsen.net) Received: from webmail5.jnielsen.net (webmail5.jnielsen.net [IPv6:2607:f170:34:11::b0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "mail.freebsdsolutions.net", Issuer "R13" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4cYKTV2cTFz46m3; Fri, 26 Sep 2025 18:52:46 +0000 (UTC) (envelope-from lists@jnielsen.net) Authentication-Results: mx1.freebsd.org; none Received: from smtpclient.apple (161.dallas-19rh15rt.tx.dial-access.att.net [12.74.217.161]) (authenticated bits=0) by webmail5.jnielsen.net (8.18.1/8.18.1) with ESMTPSA id 58QIqgFH051227 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Fri, 26 Sep 2025 12:52:45 -0600 (MDT) (envelope-from lists@jnielsen.net) X-Authentication-Warning: webmail5.jnielsen.net: Host 161.dallas-19rh15rt.tx.dial-access.att.net [12.74.217.161] claimed to be smtpclient.apple Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: John Nielsen List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@FreeBSD.org Mime-Version: 1.0 (1.0) Subject: Re: Chelsio (cxgbe) VF on FreeBSD guest under KVM requires -rxcsum Date: Fri, 26 Sep 2025 12:52:41 -0600 Message-Id: References: Cc: net@freebsd.org, virtualization@freebsd.org, np@freebsd.org In-Reply-To: To: Michael Tuexen X-Mailer: iPhone Mail (22G100) X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:6364, ipnet:2607:f170:30::/44, country:US] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Queue-Id: 4cYKTV2cTFz46m3 > On Sep 26, 2025, at 1:46=E2=80=AFAM, Michael Tuexen wrote: > =EF=BB=BF >>=20 >> On 26. Sep 2025, at 02:58, John Nielsen wrote: >>=20 >> Not sure if this is a known issue or even an issue on the FreeBSD side bu= t decided to ask here first. I=E2=80=99m happy to put in a bug report if app= ropriate. >>=20 >> I have a hypervisor machine running Arch Linux with KVM, Qemu and libvirt= d. The machine has a Chelsio T520-CR adapter. I recently began passing throu= gh virtual functions of the NIC to several of the guests I run on the hyperv= isor. 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 r= eadily identified and configured (using DHCP in one case), and ping and ARP a= ppeared to work fine. However, TCP and UDP traffic to the guests never recei= ved a response. After some head-scratching and troubleshooting I discovered t= hat running =E2=80=9Cifconfig cxlv0 -rxcsum=E2=80=9D immediately allowed tra= ffic to flow as expected. >=20 > I don't have access to such a network card. Just to be clear: you are runn= ing the =E2=80=9Cifconfig cxlv0 -rxcsum=E2=80=9D command inside the guest ru= nning 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 physic= al machine running FreeBSD. >> As workarounds go that isn=E2=80=99t terrible, but I was surprised that t= he FreeBSD guests required this adjustment while the Windows one did not. >>=20 >> As a point of reference I have another hypervisor machine that runs FreeB= SD 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 =E2= =80=9C-rxcsum=E2=80=9D 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 lap= top. I=E2=80=99m aware that VF-to-PF communication is a special case. JN=