graphic: 0.990 assembly: 0.990 device: 0.989 mistranslation: 0.987 boot: 0.983 semantic: 0.983 instruction: 0.982 KVM: 0.981 network: 0.976 vnc: 0.965 socket: 0.964 other: 0.959 Netperf tests cause i82551 network down 1. boot up a guest with 82551 nic # qemu-kvm -net nic,model=i82551 ... 2. launch netperf server in the guest 3.on the host for b in 32 64 128 256 512 1024 1460 2048 4096 8192 9000 16384 32768 65495 65507 do ./netperf -t TCP_STREAM -f m -H -P 0 -l 10 -- -m $b done for b in 32 64 128 256 512 1024 1460 2048 4096 8192 9000 16384 32768 65495 65507 do ./netperf -t UDP_STREAM -f m -H -P 0 -l 10 -- -m $b done Result: Guest network becomes down netperf client output: ./netperf -t TCP_STREAM -f m -H 10.66.9.39 -P 0 -l 10 -- -m 32 87380 16384 32 10.97 19.61 ./netperf -t TCP_STREAM -f m -H 10.66.9.39 -P 0 -l 10 -- -m 64 87380 16384 64 11.55 79.68 ./netperf -t TCP_STREAM -f m -H 10.66.9.39 -P 0 -l 10 -- -m 128 87380 16384 128 10.16 14.20 ./netperf -t TCP_STREAM -f m -H 10.66.9.39 -P 0 -l 10 -- -m 256 87380 16384 256 11.17 12.85 ./netperf -t TCP_STREAM -f m -H 10.66.9.39 -P 0 -l 10 -- -m 512 87380 16384 512 10.01 16.38 ./netperf -t TCP_STREAM -f m -H 10.66.9.39 -P 0 -l 10 -- -m 1024 Interrupted system call netperf: remote error 4./netperf -t TCP_STREAM -f m -H 10.66.9.39 -P 0 -l 10 -- -m 1460 establish control: are you sure there is a netserver listening on 10.66.9.39 at port 12865? establish_control could not establish the control connection from 0.0.0.0 port 0 address family AF_UNSPEC to 10.66.9.39 port 12865 address family AF_UNSPEC ./netperf -t TCP_STREAM -f m -H 10.66.9.39 -P 0 -l 10 -- -m 2048 qemu debug message: .... EE100 nic_receive command 0x0000, link 0x3d3e6822, addr 0xffffffff, size 1518 EE100 nic_can_receive 0x29a0180 EE100 nic_receive 0x29a0180 received broadcast, len=60 EE100 nic_receive Receive buffer (0 bytes) too small for data (60 bytes); data truncated EE100 nic_receive command 0x8000, link 0x37b32022, addr 0xffffffff, size 0 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EE100 nic_receive receive: Running out of frames ^^^^^^^^^^^^^^^^^^^^^^^^ EE100 eepro100_write1 addr=Command/Status+1 val=0x20 kvm version: qemu-kvm: commit 525e3df73e40290e95743d4c8f8b64d8d9cbe021 Date: Mon Jul 4 13:36:06 2011 +0300 related fix in driver: http://marc.info/?l=linux-netdev&m=118859393206222&w=3 1. When bug reproduces, we can only capture arp request in the tap device. # tcpdump -i tap0 tcpdump: WARNING: tap0: no IPv4 address assigned tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on tap0, link-type EN10MB (Ethernet), capture size 65535 bytes 16:14:11.741203 ARP, Request who-has 10.66.8.167 tell 10.66.8.252, length 28 16:14:12.741186 ARP, Request who-has 10.66.8.167 tell 10.66.8.252, length 28 16:14:13.741183 ARP, Request who-has 10.66.8.167 tell 10.66.8.252, length 28 2. Execute 'system_reset' in qemu monitor, guest could not get ip address. # tcpdump -i tap0 tcpdump: WARNING: tap0: no IPv4 address assigned tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on tap0, link-type EN10MB (Ethernet), capture size 65535 bytes 16:16:21.508588 IP6 :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28 16:16:21.682585 IP6 :: > ff02::1:ff12:3456: ICMP6, neighbor solicitation, who has fe80::5054:ff:fe12:3456, length 24 16:16:22.682616 IP6 fe80::5054:ff:fe12:3456 > ff02::2: ICMP6, router solicitation, length 16 16:16:23.105303 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 52:54:00:12:34:56 (oui Unknown), length 300 16:16:25.837597 IP6 fe80::5054:ff:fe12:3456 > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28 16:16:26.682594 IP6 fe80::5054:ff:fe12:3456 > ff02::2: ICMP6, router solicitation, length 16 16:16:30.111097 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 52:54:00:12:34:56 (oui Unknown), length 300 16:16:30.682598 IP6 fe80::5054:ff:fe12:3456 > ff02::2: ICMP6, router solicitation, length 16 16:16:39.112289 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 52:54:00:12:34:56 (oui Unknown), length 300 16:16:43.107232 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 52:54:00:12:34:56 (oui Unknown), length 300 The patch mentioned in comment #3 had been included in the kernel here: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7734f6e6bcd7ba78b00e93e74a4ddafd9886cdea So I guess we can close this bug nowadays? Or can you still reproduce this issue with the current kernel and current version of QEMU? There hasn't been a reply to my question in the last comment within months, so I assume nobody cares about this anymore. So I'm closing this ticket now...