On 24/04/20 13:37, Jon Doron wrote: > +static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host) > +{ > + struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu); > + > + if (!syndbg->active && !host) > + return 1; > + One small thing: is the ENABLE_CAP and active field needed? Can you just check if the guest has the syndbg CPUID bits set? Thanks, Paolo