search for: ept_misconfig

...gt; I don't know, but this is basically a bug in VMware, so you need > > > to ask them to fix their nested KVM-on-ESXi use case. > > > > We've encountered this problem, too. > > > > Strictly speaking, the bug is not in VMWare, but rather in KVM: on > > EPT_MISCONFIG vmexits it assumed the processor to set the instuction > > length field. This wasn't mandated by the spec but the real processors > > did that. OTOH some hypervisors (VMWare, Hyper-V) didn't do that for > > the nested hypervisor. As a result, when handling MMIO the gues...

Yes it works if I use force_tcg env variable On Sat, 24 Mar 2018 at 4:37 AM, Richard W.M. Jones <rjones@redhat.com> wrote: > > On Fri, Mar 23, 2018 at 05:35:38PM +0000, Tanmoy Sinha wrote: > > Thanks. Reading the defect and the associated thread in > > https://bugs.launchpad.net/qemu/+bug/1661386, I enabled performance > > counters in VMWare guest settings. Now the

...nce numbers: - Bulk transfer from guest to external physical server. [Guest]->vhost_net->tap--(XDP_REDIRECT)-->i40e --(wire)--> [Server] - Set 10us busypoll. - Guest disables checksum and TSO because of host XDP. - Measured single flow Mbps by netperf, and kicks by perf kvm stat (EPT_MISCONFIG event). Before After Mbps kicks/s Mbps kicks/s UDP_STREAM 1472byte 247758 27 Send 3645.37 6958.10 Recv 3588.56 6958.10 1byt...

...nce numbers: - Bulk transfer from guest to external physical server. [Guest]->vhost_net->tap--(XDP_REDIRECT)-->i40e --(wire)--> [Server] - Set 10us busypoll. - Guest disables checksum and TSO because of host XDP. - Measured single flow Mbps by netperf, and kicks by perf kvm stat (EPT_MISCONFIG event). Before After Mbps kicks/s Mbps kicks/s UDP_STREAM 1472byte 247758 27 Send 3645.37 6958.10 Recv 3588.56 6958.10 1byt...

...s to crib. > > > > I don't know, but this is basically a bug in VMware, so you need > > to ask them to fix their nested KVM-on-ESXi use case. > > We've encountered this problem, too. > > Strictly speaking, the bug is not in VMWare, but rather in KVM: on > EPT_MISCONFIG vmexits it assumed the processor to set the instuction > length field. This wasn't mandated by the spec but the real processors > did that. OTOH some hypervisors (VMWare, Hyper-V) didn't do that for > the nested hypervisor. As a result, when handling MMIO the guest > instruct...

...s not applied for most packets, so in most cases driver XDP was used. I was going to dig into it but not yet. > >> - Set 10us busypoll. >> - Guest disables checksum and TSO because of host XDP. >> - Measured single flow Mbps by netperf, and kicks by perf kvm stat >> ?? (EPT_MISCONFIG event). >> >> ???????????????????????????? Before????????????? After >> ?????????????????????????? Mbps? kicks/s????? Mbps? kicks/s >> UDP_STREAM 1472byte????????????? 247758???????????????? 27 >> ???????????????? Send?? 3645.37??????????? 6958.10 >> ????????????...

...s not applied for most packets, so in most cases driver XDP was used. I was going to dig into it but not yet. > >> - Set 10us busypoll. >> - Guest disables checksum and TSO because of host XDP. >> - Measured single flow Mbps by netperf, and kicks by perf kvm stat >> ?? (EPT_MISCONFIG event). >> >> ???????????????????????????? Before????????????? After >> ?????????????????????????? Mbps? kicks/s????? Mbps? kicks/s >> UDP_STREAM 1472byte????????????? 247758???????????????? 27 >> ???????????????? Send?? 3645.37??????????? 6958.10 >> ????????????...

...sfer from guest to external physical server. > [Guest]->vhost_net->tap--(XDP_REDIRECT)-->i40e --(wire)--> [Server] > - Set 10us busypoll. > - Guest disables checksum and TSO because of host XDP. > - Measured single flow Mbps by netperf, and kicks by perf kvm stat > (EPT_MISCONFIG event). > > Before After > Mbps kicks/s Mbps kicks/s > UDP_STREAM 1472byte 247758 27 > Send 3645.37 6958.10 > Recv 3588.56...

...r which is not supported by zercopy. We can only use XDP generic for zerocopy in this case. > >>> - Set 10us busypoll. >>> - Guest disables checksum and TSO because of host XDP. >>> - Measured single flow Mbps by netperf, and kicks by perf kvm stat >>> ?? (EPT_MISCONFIG event). >>> >>> ???????????????????????????? Before????????????? After >>> ?????????????????????????? Mbps? kicks/s????? Mbps? kicks/s >>> UDP_STREAM 1472byte????????????? 247758???????????????? 27 >>> ???????????????? Send?? 3645.37??????????? 6958.1...

...i40e --(wire)--> [Server] Just to confirm in this case since zerocopy is enabled, we are in fact use the generic XDP datapath? > - Set 10us busypoll. > - Guest disables checksum and TSO because of host XDP. > - Measured single flow Mbps by netperf, and kicks by perf kvm stat > (EPT_MISCONFIG event). > > Before After > Mbps kicks/s Mbps kicks/s > UDP_STREAM 1472byte 247758 27 > Send 3645.37 6958.10 > Recv 3588.56...

...umbers (tx): - Bulk transfer from guest to external physical server. [Guest]->vhost_net->tap--(XDP_REDIRECT)-->i40e --(wire)--> [Server] - Set 10us busypoll. - Guest disables checksum and TSO because of host XDP. - Measured single flow Mbps by netperf, and kicks by perf kvm stat (EPT_MISCONFIG event). Before After Mbps kicks/s Mbps kicks/s UDP_STREAM 1472byte 247758 27 Send 3645.37 6958.10 Recv 3588.56 6958.10 1byt...