On Thu, Feb 08, 2018 at 11:46:24AM +0100, Kashyap Chamarthy wrote: > On Wed, Feb 07, 2018 at 11:26:14PM +0100, David Hildenbrand wrote: > > On 07.02.2018 16:31, Kashyap Chamarthy wrote: > > [...] > > > Sounds like a similar problem as in > > https://bugzilla.kernel.org/show_bug.cgi?id=198621 > > > > In short: there is no (live) migration support for nested VMX yet. So as > > soon as your guest is using VMX itself ("nVMX"), this is not expected to > > work. > > Actually, live migration with nVMX _does_ work insofar as you have > _identical_ CPUs on both source and destination — i.e. use the QEMU > '-cpu host' for the L1 guests. At least that's been the case in my > experience. FWIW, I frequently use that setup in my test environments. Correcting my erroneous statement above: For live migration to work in a nested KVM setup, it is _not_ mandatory to use "-cpu host". I just did another test. Here I used libvirt's 'host-model' for both source and destination L1 guests, _and_ for L2 guest. Migrated the L2 to destination L1, worked great. In my setup, both my L1 guests recieved the following CPU configuration (in QEMU command-line): [...] -cpu Haswell-noTSX,vme=on,ss=on,vmx=on,f16c=on,rdrand=on,\ hypervisor=on,arat=on,tsc_adjust=on,xsaveopt=on,pdpe1gb=on,abm=on,aes=off [...] And the L2 guest recieved this: [...] -cpu Haswell-noTSX,vme=on,ss=on,f16c=on,rdrand=on,hypervisor=on,\ arat=on,tsc_adjust=on,xsaveopt=on,pdpe1gb=on,abm=on,aes=off,invpcid=off [...] -- /kashyap
