[PATCH 2/6] KVM: PPC: Book3E: Refactor SPE/FP exit handling

[Alexander Graf]

On 03.07.2013, at 14:42, Mihai Caraman wrote:

> SPE/FP/AltiVec interrupts share the same numbers. Refactor SPE/FP exit handling
> to accommodate AltiVec later. Detect the targeted unit at run time since it can
> be configured in the kernel but not featured on hardware.
> 
> Signed-off-by: Mihai Caraman <mihai.caraman at freescale.com>
> ---
> arch/powerpc/kvm/booke.c |  102 +++++++++++++++++++++++++++++++---------------
> arch/powerpc/kvm/booke.h |    1 +
> 2 files changed, 70 insertions(+), 33 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
> index fb47e85..113961f 100644
> --- a/arch/powerpc/kvm/booke.c
> +++ b/arch/powerpc/kvm/booke.c
> @@ -89,6 +89,15 @@ void kvmppc_dump_vcpu(struct kvm_vcpu *vcpu)
> 	}
> }
> 
> +static inline bool kvmppc_supports_spe(void)
> +{
> +#ifdef CONFIG_SPE
> +		if (cpu_has_feature(CPU_FTR_SPE))
> +			return true;
> +#endif
> +	return false;
> +}
> +
> #ifdef CONFIG_SPE
> void kvmppc_vcpu_disable_spe(struct kvm_vcpu *vcpu)
> {
> @@ -99,7 +108,7 @@ void kvmppc_vcpu_disable_spe(struct kvm_vcpu *vcpu)
> 	preempt_enable();
> }
> 
> -static void kvmppc_vcpu_enable_spe(struct kvm_vcpu *vcpu)
> +void kvmppc_vcpu_enable_spe(struct kvm_vcpu *vcpu)
> {
> 	preempt_disable();
> 	enable_kernel_spe();
> @@ -118,6 +127,14 @@ static void kvmppc_vcpu_sync_spe(struct kvm_vcpu *vcpu)
> 	}
> }
> #else
> +void kvmppc_vcpu_disable_spe(struct kvm_vcpu *vcpu)
> +{
> +}
> +
> +void kvmppc_vcpu_enable_spe(struct kvm_vcpu *vcpu)
> +{
> +}
> +
> static void kvmppc_vcpu_sync_spe(struct kvm_vcpu *vcpu)
> {
> }
> @@ -943,48 +960,67 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
> 		r = RESUME_GUEST;
> 		break;
> 
> -#ifdef CONFIG_SPE
> 	case BOOKE_INTERRUPT_SPE_ALTIVEC_UNAVAIL: {
> -		if (vcpu->arch.shared->msr & MSR_SPE)
> -			kvmppc_vcpu_enable_spe(vcpu);
> -		else
> -			kvmppc_booke_queue_irqprio(vcpu,
> -						   BOOKE_IRQPRIO_SPE_ALTIVEC_UNAVAIL);
> +		if (kvmppc_supports_spe()) {
> +			bool enabled = false;
> +
> +#ifndef CONFIG_KVM_BOOKE_HV
> +			if (vcpu->arch.shared->msr & MSR_SPE) {
> +				kvmppc_vcpu_enable_spe(vcpu);
> +				enabled = true;
> +			}
> +#endif

Why the #ifdef? On HV capable systems kvmppc_supports_spe() will just always return false. And I don't really understand why HV would be special in the first place here. Is it because we're accessing shared->msr?

> +			if (!enabled)
> +				kvmppc_booke_queue_irqprio(vcpu,
> +					BOOKE_IRQPRIO_SPE_ALTIVEC_UNAVAIL);
> +		} else {
> +			/*
> +			 * Guest wants SPE, but host kernel doesn't support it.

host kernel or hardware


Alex