On 23/08/2018 19:11, Eduardo Habkost wrote: >>> We don't want QEMU to refuse to run if the kernel doesn't have >>> KVM_CAP_GET_MSR_FEATURES. We can treat missing capability as >>> equivalent to returning an empty list of MSRs. >> Yes. I'll let caller (kvm_arch_init) ignore the return value but a >> simple warning. > Warnings tend to be ignored and are generally a sign that QEMU > isn't doing the right thing. Sometimes we have no choice, but I > don't think that's the case here. > > As far as I can see, we have only two possibilities here: > 1) The host can run a VM that behaves exactly as requested on the > command-line (no warning required). > 2) The host can't run the requested configuration (fatal error, > not a warning).
Right, but if KVM_CAP_GET_MSR_FEATURES is not available I guess you can assume the MSRs to be zero for everything except "-cpu host". Paolo