> -----Original Message----- > From: Avi Kivity [mailto:avi@xxxxxxxxxx] > Sent: Thursday, September 20, 2012 5:20 PM > To: Hao, Xudong > Cc: Marcelo Tosatti; kvm@xxxxxxxxxxxxxxx; Zhang, Xiantao > Subject: Re: [PATCH v3] kvm/fpu: Enable fully eager restore kvm FPU > >> >> On guest entry: > >> >> if (!lazy_fpu_allowed(vcpu)) > >> >> kvm_x86_ops->fpu_activate(vcpu); > >> > > >> > >> But we already have that: > >> > >> if (vcpu->fpu_active) > >> kvm_load_guest_fpu(vcpu); > >> > >> so why not manage fpu_active to be always set when needed? I don't > want > >> more checks in the entry path. > >> > > I means add fpu_active() in kvm_set_xcr(), not in guest entry. Then the > fpu_active will be set always when guest initialize xstate. > > > > @@ -574,6 +574,9 @@ int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, > u64 xcr) > > kvm_inject_gp(vcpu, 0); > > return 1; > > } > > + if (!lazy_fpu_allowed(vcpu)) > > + kvm_x86_ops->fpu_activate(vcpu); > > return 0; > > > > And of course on cr4 update. So a function update_lazy_fpu() to be > called from both places is needed. > Complete consideration, thanks. So I will define a function update_lazy_fpu(), insert it into kvm_set_xcr() and handle_cr(). Comments? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
