[PATCH v9 08/12] ARM/ARM64: KVM: Emulate PSCI v0.2 AFFINITY_INFO

[Anup Patel]

On Tue, Apr 15, 2014 at 4:25 PM, Marc Zyngier <marc.zyngier at arm.com> wrote:
> On Tue, Apr 15 2014 at  7:14:11 am BST, Anup Patel <anup.patel at 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 at linaro.org>
>> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
>> Reviewed-by: Christoffer Dall <christoffer.dall at 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 b964aa4..f6f9290 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) * 8)) - 1)
>
> Nit: Use MPIDR_LEVEL_MASK instead of 8.

OK, will use MPIDR_LEVEL_MASK here.

>
>> +
>> +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 return 0 (ON) else return 1 (OFF)
>
> Would be good to define symbolic values for these (and for ON_PENDING as
> well).

Sure, I will add them to uapi/linux/psci.h

>
>> +      */
>> +     kvm_for_each_vcpu(i, tmp, kvm) {
>> +             mpidr = kvm_vcpu_get_mpidr(tmp);
>> +             if (((mpidr & target_affinity_mask) == target_affinity) &&
>> +                 !tmp->arch.pause) {
>> +                     return 0;
>> +             }
>> +     }
>> +
>> +     return 1;
>> +}
>> +
>>  static inline 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_SUCCESS;
>> @@ -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;
>
> --
> Jazz is not dead. It just smells funny.
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--
Anup