<div dir="ltr">Hi,<br><div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Jun 16, 2015 at 7:04 PM, Aleksey Ilyushin <span dir="ltr"><<a href="mailto:aleksey.ilyushin@oracle.com" target="_blank">aleksey.ilyushin@oracle.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="word-wrap:break-word"><br><div><span class=""><div>On 16 Jun 2015, at 19:53, Maarten Hoes <<a href="mailto:hoes.maarten@gmail.com" target="_blank">hoes.maarten@gmail.com</a>> wrote:</div><br><blockquote type="cite"><div dir="ltr"><div class="gmail_extra">Hi,<br><br></div><div class="gmail_extra"><div class="gmail_quote">On Tue, Jun 16, 2015 at 6:07 PM, Aleksey Ilyushin <span dir="ltr"><<a href="mailto:aleksey.ilyushin@oracle.com" target="_blank">aleksey.ilyushin@oracle.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="word-wrap:break-word">Please start by disabling both checksum and segmentation offloading in the guest (‘ethtool -K’ is the way to go).<span><br></span></div></blockquote><div><br>ethtool -K enp0s3 gives me the message: 'no features changed'. It also does not change the behavior.<br></div></div></div></div></blockquote></span>Well… do 'ethtool -k enp0s3’ first. This will give you the list of offloading features. Some of them will be turned on. Try turning them off one by one with ‘ethtool -K’. Start with TCP segmentation offloading, then try TCP checksums. For example, to turn off TCP segmentation offloading do 'ethtool -K enp0s3 tso off’ (if I remember correctly).<span class=""><br></span></div></div></blockquote><div><br><br>All of it seems to be already disabled/off for my vm:<br><br><br># ethtool -k enp0s3 | grep -i off<br>rx-checksumming: off<br>        tx-checksum-ipv4: off [fixed]<br>        tx-checksum-ipv6: off [fixed]<br>        tx-checksum-fcoe-crc: off [fixed]<br>        tx-checksum-sctp: off [fixed]<br>        tx-scatter-gather-fraglist: off [fixed]<br>tcp-segmentation-offload: off<br>        tx-tcp-segmentation: off [fixed]<br>        tx-tcp-ecn-segmentation: off [fixed]<br>        tx-tcp6-segmentation: off [fixed]<br>udp-fragmentation-offload: off [fixed]<br>generic-segmentation-offload: on<br>generic-receive-offload: on<br>large-receive-offload: off [fixed]<br>rx-vlan-offload: on<br>tx-vlan-offload: on [fixed]<br>ntuple-filters: off [fixed]<br>receive-hashing: off [fixed]<br>highdma: off [fixed]<br>vlan-challenged: off [fixed]<br>tx-lockless: off [fixed]<br>netns-local: off [fixed]<br>tx-gso-robust: off [fixed]<br>tx-fcoe-segmentation: off [fixed]<br>tx-gre-segmentation: off [fixed]<br>tx-ipip-segmentation: off [fixed]<br>tx-sit-segmentation: off [fixed]<br>tx-udp_tnl-segmentation: off [fixed]<br>tx-mpls-segmentation: off [fixed]<br>fcoe-mtu: off [fixed]<br>loopback: off [fixed]<br>rx-fcs: off<br>rx-all: off<br>tx-vlan-stag-hw-insert: off [fixed]<br>rx-vlan-stag-hw-parse: off [fixed]<br>rx-vlan-stag-filter: off [fixed]<br>busy-poll: off [fixed]<br><br></div></div>And specifically trying to set tcp segment offloading to off anyway (although that already seems to be the case), just results in an error:<br><br># ethtool -K enp0s3 tso off<br>Cannot change tcp-segmentation-offload<br></div><div class="gmail_extra"></div><div class="gmail_extra"><br><br></div><div class="gmail_extra">- Maarten<br></div></div></div>