Re: [libvirt] [PATCH 4/4] qemu: default to kvm32/kvm64 when KVM is enabled

On Mon, Jan 23, 2012 at 05:23:32PM +0100, Paolo Bonzini wrote: > On 01/23/2012 05:03 PM, Daniel P. Berrange wrote: >>>>> > The qemu32/qemu64 models are weird in that the exact combination of >>>>> > CPUID flags does not match any actual processor. kvm32 and kvm64 are >>>>> > a better match when not using TCG. Use them when -cpu is only needed >>>>> > to hardcode a 32-bit guest arch or for kvmclock. >>>> >>>> I don't think we can do this as it means the guest CPU may change unexpectedly >>>> for existing domains. A 32b domain started on current libvirt would see qemu32, >>>> while the same domain started after this patch would see kvm32. >> Also, IIUC, kvm32 is a fairly newly introduced CPU type for KVM - ie most >> deployments of KVM won't support it. > > Ok, I'll redo this patch with just kvm64. As the wrong subject in > 0/3 show, it was an afterthought. Is kvm64 actually any more widely supported than kvm32 ? I though they were all fairly new. If I'm wrong, then we could trivially provide a kvm32, by using the kvm64 model, and subtracting the the "long mode" CPU flag.