----- Original Message ----- > From: "Jared" <list-virt@xxxxxxxxxxx> > To: libvir-list@xxxxxxxxxx > Sent: Saturday, July 21, 2012 5:46:18 AM > Subject: Preferred CPU model not allowed by hypervisor > > Hi. > > I'm having a weird problem where libvirt/qemu/kvm won't let me use > the model > processor I have defined in my domain's config file. Instead, I get > the > error message in libvirtd.log that: > > warning : x86Decode:1346 : Preferred CPU model Nehalem not allowed by > hypervisor; closest supported model will be used > > If I review the qemu log for that particular domain, I see that my > CPU has > been changed to this: > > -cpu kvm64,+lahf_lm,+popcnt,+sse4.2,+sse4.1,+ssse3 > > (in other places, I see it set to core2duo rather than kvm64) > > However, it *should* be Nehalem. For some background, I'm running > lvm on a > westmere proc, which is the successor to Nehalem. I'm specifying > Nehalem as > the target platform, though, to make it easier to migrate to another > server > if necessary. I do have this same problem if I set this to Westmere, > though, so it's not unique to Nehalem. > > As for support and capabilities, libvirt correctly detects my host > CPU as > Westmere: > > $ virsh capabilities | grep model > <model>Westmere</model> > > qemu-kvm does (as far as I can tell) support Nehalem: > > $ qemu-kvm -cpu ?model | grep Nehalem > x86 Nehalem Intel Core i7 9xx (Nehalem Class Core i7) > > Nehalem is defined in qmeu's target-x86_64.conf: > > grep Nehalem /etc/qemu/target-x86_64.conf > name = "Nehalem" > model_id = "Intel Core i7 9xx (Nehalem Class Core i7)" > > And if I run a cpu check on the processor, it seems to work fine: > > $ qemu-kvm -cpu Nehalem,check > VNC server running on `127.0.0.1:5900' > > So, I I'm creating the new domain as a virt-install with the qemu-kvm > backend as follows: > > virt-install --name=test --ram=1024 --arch=x86_64 --vcpus=2 > --cpu=Nehalem > --virt-type=kvm <SNIP> > > This results in the following cpu configuration: > <cpu mode='custom' match='exact'> > <model fallback='allow'>Nehalem</model> > </cpu> > > > But then, when I start this domain, I get the error message posted > above. > > Any ideas what's going on here? I'm at a loss, and unfortunately I > don't > have much experience with kvm/libvirt just yet so I don't know what I > should > be focusing on for troubleshooting. Would appreciate any suggestions > or > guidance. Have a look here https://bugzilla.redhat.com/show_bug.cgi?id=804224 > > Thanks. > > -- > Jared > > -- > libvir-list mailing list > libvir-list@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/libvir-list > -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list