On 03.01.2019 19:32, Alan Haff wrote: > I'm setting up a KVM-hosted guest in a SLES12 VM running under z/VM and I'm > not able to get networking going in the KVM guest. > > Host: z/VM 6.4 > KVM host: SLES12SP4 > KVM guest: SLES12SP4 > > (The KVM host must run under z/VM; I don't have any control over that.)
For what its worth, this will have non-ideal performance, but it should work anyway. Reason is that z/VM "emulates" the hardware virtualization (the sie instruction) in that case. In fact, it actually tries to translate KVMs sie control blocks into a shadow control block and runs the KVM guest as a shadowed z/VM guest and fakes the result so that the kvm host "sees" what it would see on real hardware. It also has to shadow all page table actions of the kvm host, so I strongly suggest to have enough memory (no paging) in the KVM host to minimize the impact. Not sure about z/VM, but I would guess that paging in z/VM also hurts as this also requires tear down of shadow page tables - this is at least the case when running KVM under KVM. We usually do not test this scenario, but I know that some developers do have at least one development system with KVM under z/VM so it gets some testing. Not sure if you can talk about that, but I am interested in the use case. I expect to have z/VM guests all over the place (in your case another z/VM guest) or KVM only installations. Mixed mode only with different LPARs. Are there interesting use cases that would suggest that we invest more time in making sure that KVM runs well under z/VM? [...] > The macvtap0 device does get created when I start the KVM guest with 'virsh > start sles12': as already said, can you use layer2? Christian ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
