On Wed, Jan 13, 2016 at 12:37:59PM +0530, Aravinda Prasad wrote: > This patch introduces a new KVM capability to control > how KVM behaves on machine check exception (MCE). > Without this capability, KVM redirects machine check > exceptions to guest's 0x200 vector if the address in > error belongs to the guest. With this capability KVM > causes a guest exit with NMI exit reason. > > This is required to avoid problems if a new kernel/KVM > is used with an old QEMU for guests that don't issue > "ibm,nmi-register". As old QEMU does not understand the > NMI exit type, it treats it as a fatal error. However, > the guest could have handled the machine check error > if the exception was delivered to guest's 0x200 interrupt > vector instead of NMI exit in case of old QEMU. [snip] > @@ -1132,6 +1135,10 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, > break; > } > #endif /* CONFIG_KVM_XICS */ > + case KVM_CAP_PPC_FWNMI: > + r = 0; > + vcpu->kvm->arch.fwnmi_enabled = true; > + break; Might we ever want to set this flag back to false after setting it to true? If so perhaps we should do vcpu->kvm->arch.fwnmi_enabled = !!cap->args[0]. However, I admit I can't actually think of a situation where we would need to reset it. :) Paul. -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
