Re: [PATCH v10 08/12] ARM/ARM64: KVM: Emulate PSCI v0.2 AFFINITY_INFO

[Marc Zyngier <marc.zyngier@arm.com>]

On Mon, Apr 21 2014 at  2:00:02 pm BST, Anup Patel <anup.patel@linaro.org> wrote:
> This patch adds emulation of PSCI v0.2 AFFINITY_INFO function call
> for KVM ARM/ARM64. This is a VCPU-level function call which will be
> used to determine current state of given affinity level.
>
> Signed-off-by: Anup Patel <anup.patel@linaro.org>
> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
> ---
>  arch/arm/kvm/psci.c |   52 +++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 50 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
> index 4486d0f..122bc67 100644
> --- a/arch/arm/kvm/psci.c
> +++ b/arch/arm/kvm/psci.c
> @@ -27,6 +27,16 @@
>   * as described in ARM document number ARM DEN 0022A.
>   */
>  
> +#define AFFINITY_MASK(level)	~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)
> +
> +static unsigned long psci_affinity_mask(unsigned long affinity_level)
> +{
> +	if (affinity_level <= 3)
> +		return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level);
> +
> +	return 0;
> +}
> +
>  static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
>  {
>  	vcpu->arch.pause = true;
> @@ -85,6 +95,42 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
>  	return PSCI_RET_SUCCESS;
>  }
>  
> +static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
> +{
> +	int i;
> +	unsigned long mpidr;
> +	unsigned long target_affinity;
> +	unsigned long target_affinity_mask;
> +	unsigned long lowest_affinity_level;
> +	struct kvm *kvm = vcpu->kvm;
> +	struct kvm_vcpu *tmp;
> +
> +	target_affinity = *vcpu_reg(vcpu, 1);
> +	lowest_affinity_level = *vcpu_reg(vcpu, 2);
> +
> +	/* Determine target affinity mask */
> +	target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
> +	if (!target_affinity_mask)
> +		return PSCI_RET_INVALID_PARAMS;
> +
> +	/* Ignore other bits of target affinity */
> +	target_affinity &= target_affinity_mask;
> +
> +	/*
> +	 * If one or more VCPU matching target affinity are running
> +	 * then ON else OFF
> +	 */
> +	kvm_for_each_vcpu(i, tmp, kvm) {
> +		mpidr = kvm_vcpu_get_mpidr(tmp);
> +		if (((mpidr & target_affinity_mask) == target_affinity) &&
> +		    !tmp->arch.pause) {
> +			return PSCI_0_2_AFFINITY_LEVEL_ON;
> +		}
> +	}
> +
> +	return PSCI_0_2_AFFINITY_LEVEL_OFF;
> +}
> +
>  static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
>  {
>  	memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
> @@ -132,6 +178,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
>  	case PSCI_0_2_FN64_CPU_ON:
>  		val = kvm_psci_vcpu_on(vcpu);
>  		break;
> +	case PSCI_0_2_FN_AFFINITY_INFO:
> +	case PSCI_0_2_FN64_AFFINITY_INFO:
> +		val = kvm_psci_vcpu_affinity_info(vcpu);
> +		break;
>  	case PSCI_0_2_FN_SYSTEM_OFF:
>  		kvm_psci_system_off(vcpu);
>  		val = PSCI_RET_INTERNAL_FAILURE;
> @@ -143,12 +193,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
>  		ret = 0;
>  		break;
>  	case PSCI_0_2_FN_CPU_SUSPEND:
> -	case PSCI_0_2_FN_AFFINITY_INFO:
>  	case PSCI_0_2_FN_MIGRATE:
>  	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
>  	case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
>  	case PSCI_0_2_FN64_CPU_SUSPEND:
> -	case PSCI_0_2_FN64_AFFINITY_INFO:
>  	case PSCI_0_2_FN64_MIGRATE:
>  	case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
>  		val = PSCI_RET_NOT_SUPPORTED;

Acked-by: Marc Zyngier <marc.zyngier@arm.com>

	M.
-- 
Jazz is not dead. It just smells funny.