[PATCH v7 08/12] ARM/ARM64: KVM: Emulate PSCI v0.2 AFFINITY_INFO

[Anup Patel]

On 2 April 2014 18:34, Rob Herring <robherring2 at gmail.com> wrote:
> On Wed, Apr 2, 2014 at 5:42 AM, 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 |   67 +++++++++++++++++++++++++++++++++++++++++++++++++--
>>  1 file changed, 65 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
>> index b964aa4..5fccf0b 100644
>> --- a/arch/arm/kvm/psci.c
>> +++ b/arch/arm/kvm/psci.c
>> @@ -27,6 +27,31 @@
>>   * as described in ARM document number ARM DEN 0022A.
>>   */
>>
>> +static unsigned long psci_affinity_mask(unsigned long affinity_level)
>> +{
>> +       unsigned long affinity_mask = MPIDR_HWID_BITMASK;
>> +
>> +       switch (affinity_level) {
>> +       case 0: /* All affinity levels are valid */
>> +               affinity_mask &= ~0x0UL;
>> +               break;
>> +       case 1: /* Aff0 ignored */
>> +               affinity_mask &= ~0xFFUL;
>> +               break;
>> +       case 2: /* Aff0 and Aff1 ignored */
>> +               affinity_mask &= ~0xFFFFUL;
>> +               break;
>> +       case 3: /* Aff0, Aff1, and Aff2 ignored */
>> +               affinity_mask &= ~0xFFFFFFUL;
>> +               break;
>> +       default:
>> +               affinity_mask = 0;
>> +               break;
>> +       };
>> +
>> +       return affinity_mask;
>
> This function can be written as:
>
> if (affinity_level <= 3)
>     return MPIDR_HWID_BITMASK & ~GEN_MASK_ULL((affinity_level * 8) - 1, 0);
>
> return 0;

OK, I will simplify this.

--
Anup

>
>> +}
>> +
>>  static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
>>  {
>>         vcpu->arch.pause = true;
>> @@ -85,6 +110,42 @@ 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)
>> +        */
>> +       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 +193,10 @@ 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 +208,10 @@ 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;
>> --
>> 1.7.9.5
>>
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