On Sun, May 13, 2012 at 06:56:23PM +0300, Gleb Natapov wrote: > > + However, hypervisor can set and clear this memory bit at any time: > > + therefore to make sure hypervisor does not interrupt the > > + guest and clear the least significant bit in the memory area > > + in the window between guest testing it to detect > > + whether it can skip EOI apic write and between guest > > + clearing it to signal EOI to the hypervisor, > > + guest must both read the least sgnificant bit in the memory area and > > + clear it using a single CPU instruction, such as test and clear, or > > + compare and exchange. > > + > Looks good, but everything below this is here by mistake. Ugh. Right. Good catch, > Are You still > going to resend host side patch to address my other comment? Yes, like this. I'll give more people a chance to review first though. diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 77e0244..c7e6ffb 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1490,6 +1490,7 @@ int kvm_pv_enable_apic_eoi(struct kvm_vcpu *vcpu, u64 data) if (eoi_enabled(vcpu)) eoi_clr_pending(vcpu); vcpu->arch.eoi.msr_val = data; - kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.eoi.data, addr); - return 0; + if (!eoi_enabled(vcpu)) + return 0; + return kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.eoi.data, addr); } -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
