On Mon, Nov 04, 2013 at 10:05:58AM +0100, Alexander Graf wrote: > > Yeah, we really need to check that guest vpcu == host vcpu for HV KVM.
In general I agree, but the one difficulty I see is that a check for exact equality will interact badly with qemu's habit of picking a specific processor version when the user specifies something general like "POWER7". So if the user does -cpu POWER7 on a machine with (for example) a POWER7 v2.1 processor, but qemu arbitrarily picks the PVR for POWER7 v2.3, then it will fail, which will be completely puzzling to the user -- "I asked for POWER7, and it is a POWER7, what's the problem??". Maybe if the user asks for a non-specific processor type, and the host's PVR matches the request, then qemu should take the host's PVR rather than just picking some arbitrary processor version. Paul.
