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

[Alexander Graf]

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

> When delivering guest IRQs, update MSR computaion

computation

> mode according to guest
> interrupt computation mode found in EPCR.
> 
> Signed-off-by: Mihai Caraman <mihai.caraman at freescale.com>
> ---
> arch/powerpc/kvm/booke.c |    8 +++++++-
> 1 files changed, 7 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> index d15c4b5..93b48e0 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -287,6 +287,7 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
> 	bool crit;
> 	bool keep_irq = false;
> 	enum int_class int_class;
> +	ulong msr_cm = 0;
> 
> 	/* Truncate crit indicators in 32 bit mode */
> 	if (!(vcpu->arch.shared->msr & MSR_SF)) {
> @@ -299,6 +300,10 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
> 	/* ... and we're in supervisor mode */
> 	crit = crit && !(vcpu->arch.shared->msr & MSR_PR);
> 
> +#ifdef CONFIG_64BIT
> +	msr_cm = vcpu->arch.epcr & SPRN_EPCR_ICM ? MSR_CM : 0;
> +#endif

No need for the ifdef, no?. Just mask EPCR_ICM out in the 32-bit host case, then this check is always false on 32-bit hosts.

> +
> 	if (priority == BOOKE_IRQPRIO_EXTERNAL_LEVEL) {
> 		priority = BOOKE_IRQPRIO_EXTERNAL;
> 		keep_irq = true;
> @@ -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);

Alex