> On Mon, Feb 17, 2020 at 01:31:08AM +0100, Alexandre wrote: > > Hello, > > > > I am running an OpenBSD/armv7 guest on a QEMU 4.2.0 "virt" machine host; > > see the attached file (from_qemu_virt.dts) for the fdt of the guest > > machine, it has only a virtio-mmio bus with a virtio-net device attached. > > > > The QEMU command line is also attached, together with source and bin for > > the tiny bootloader for the bsd kernel (from the distfiles of 6.6 release) > > used as QEMU "bios". > > > > I used the netdev user backend. > > > > Boot is OK (see dmesg.txt). > > > > The vio network interface is configured by dhclient and we have this: > > > > my# ifconfig > > lo0: flags=8049 mtu 32768 > > index 3 priority 0 llprio 3 > > groups: lo > > inet6 ::1 prefixlen 128 > > inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3 > > inet 127.0.0.1 netmask 0xff000000 > > vio0: flags=808843 mtu > > 1500 > > lladdr 52:54:00:12:34:56 > > index 1 priority 0 llprio 3 > > groups: egress > > media: Ethernet autoselect > > status: active > > inet 10.0.2.15 netmask 0xffffff00 broadcast 10.0.2.255 > > enc0: flags=0<> > > index 2 priority 0 llprio 3 > > groups: enc > > status: active > > pflog0: flags=141 mtu 33168 > > index 4 priority 0 llprio 3 > > groups: pflog > > > > my# route -n show > > Routing tables > > > > Internet: > > Destination Gateway Flags Refs Use Mtu Prio > > Iface > > default 10.0.2.2 UGS 0 0 - 8 vio0 > > 224/4 127.0.0.1 URS 0 0 32768 8 lo0 > > 10.0.2/24 10.0.2.15 UCn 1 0 - 4 vio0 > > 10.0.2.2 52:55:0a0:00:02:02 UHLch 1 4 - 3 > > vio0 > > 10.0.2.15 52:54:00:12:34:56 UHLl 0 46 - 1 vio0 > > 10.0.2.255 10.0.2.15 UHb 0 0 - 1 vio0 > > 127/8 127.0.0.1 UGRS 0 0 32768 8 lo0 > > 127.0.0.1 127.0.0.1 UHhl 1 2 32768 1 lo0 > > [[ edited Inet6 routes ..]] > > > > Ping works OK from the guest to the host ICMP Echo requests are correctly > > sent and Echo replies correctly received. It does not work from the guest > > to a public IP (but that's fine, it is a known limitation of QEMU net user). > > > > UDP packets are OK in the direction guest --> host, but not in reverse host > > --> guest. This cause failure of DNS resolution for instance. TCP packets > > have the same problem (the guest sends the SYN, which is received by the > > host who sends the SYN-ACK, but the SYN-ACK is not "seen" by the OBSD guest > > and connect timeouts). > > > > What's surprising (to me !) is that packets are visible on tcpdump on the > > guest (with 0 packets "dropped by kernel") > > > > Steps to reproduce: > > > > on guest: > > > > my# tcpdump -w test.dump -p& > > [1] 13288 > > my# tcpdump: listening on vio0, link-type EN10MB > > my# nc -v -u 10.0.2.2 2222 > > Connection to 10.0.2.2 2222 port [udp/*] succeeded! > > hello from guest (<<-- typed on the guest console) > > > > on host: > > > > $ nc -l -v -u -p 2222 > > listening on 0.0.0.0:2222 ... > > connect to 127.0.0.1:2222 from localhost.localdomain:60487 (127.0.0.1:60487) > > hello from guest (-->> got this from the guest) > > hello from host (<<-- typed on the host console, NOT shown on the guest > > console) > > > > Now the tcpdump -neX on the guest is attached, you can see that the reply > > packets are seen by the kernel but forwarded to beyond "to user space". I > > also attached tcpdump on the guest, no difference is shown. > > > > I tried the 0x02 flags of vio (see dmesg) with no effect. The same with > > 0x100 or by guetting the vio0 interface in promiscuous mode with tcpdump. > > > > pf has default rules (block return all, pass all flags S/SA, X11 and dpb > > builder blocking). Same problem with pf disabled. When appropriate log > > rules are configured, I see the faulty packets in pflogd journal as in the > > guest tcpdump. > > > > > > Maybe netstat -s -p ip and netstat -s -p udp help to find the cause of the > packet drops. Also check pfctl -si if one of those counters change when > you send UDP packets to the guest. > > I normally used qemu with the tap virtio option (using > -net nic,vlan=$id,macaddr=$mac,model=virtio -net tap,vlan=$id,fd=$fd), > never had issues with that.
I confirm it is a problem with in4_cksum on ARM. Networking is OK when I either: * change --- sys/dev/pv/vio.c.old +++ sys/dev/pv/vio.c - m->m_pkthdr.csum_flags = 0; + m->m_pkthdr.csum_flags = M_UDP_CSUM_IN_OK | M_TCP_CSUM_IN_OK; so as to disable checksum verification by udp_input() OR: * use the portable C implementation of in4_cksum instead of the ARM one by doing --- sys/arch/arm/conf/files.arm.old +++ sys/arch/arm/conf/files.arm - file arch/arm/arm/in_cksum_arm.S + file netinet/in_cksum.c + file netinet/in4_cksum.c Best regards Alexandre
