Re: [Qemu-ppc] [RFC PATCH 04/17] KVM: PPC64: booke: Add guest computation mode for irq delivery

On 07/04/2012 08:40 AM, Alexander Graf wrote:

On 25.06.2012, at 14:26, Mihai Caraman wrote:

quoted

@@ -381,7 +386,8 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,

			set_guest_esr(vcpu, vcpu->arch.queued_esr);
		if (update_dear == true)
			set_guest_dear(vcpu, vcpu->arch.queued_dear);
-		kvmppc_set_msr(vcpu, vcpu->arch.shared->msr & msr_mask);
+		kvmppc_set_msr(vcpu, (vcpu->arch.shared->msr & msr_mask)
+				| msr_cm);

Please split this computation out into its own variable and apply the masking regardless. Something like

ulong new_msr = vcpu->arch.shared->msr;
if (vcpu->arch.epcr & SPRN_EPCR_ICM)
    new_msr |= MSR_CM;
new_msr &= msr_mask;
kvmppc_set_msr(vcpu, new_msr);

This will fail to clear MSR[CM] in the odd but legal situation where you
have MSR[CM] set but EPCR[ICM] unset.

-Scott