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