Re: [qemu-s390x] [PATCH v2] s390x/cpumodel: model PTFF subfunctions for Multiple-epoch facility

[Christian Borntraeger]

On 02/05/2018 11:29 AM, David Hildenbrand wrote:
> For now, the kernel does not properly indicate configured CPU subfunctions
> to the guest, but simply uses the host values (as support in KVM is still
> missing). That's why we missed to model the PTFF subfunctions that come
> with Multiple-epoch facility.
> 
> Let's properly add these, along with a new feature group.
> 
> Signed-off-by: David Hildenbrand <address@hidden>

Reviewed-by: Christian Borntraeger <address@hidden>

> ---
> 
> v1 -> v2:
> - s/MEPOCH/MULTIPLE_EPOCH/ (only internally visible)
> - Add the features to the z14 full model
> - Clear the features if Multiple-epoch facility is not installed
> 
>  target/s390x/cpu_features.c     |  5 +++++
>  target/s390x/cpu_features_def.h |  4 ++++
>  target/s390x/gen-features.c     | 11 +++++++++++
>  target/s390x/kvm.c              |  8 ++++++++
>  4 files changed, 28 insertions(+)
> 
> diff --git a/target/s390x/cpu_features.c b/target/s390x/cpu_features.c
> index 85d10b5710..a5619f2893 100644
> --- a/target/s390x/cpu_features.c
> +++ b/target/s390x/cpu_features.c
> @@ -156,8 +156,12 @@ static const S390FeatDef s390_features[] = {
>      FEAT_INIT("ptff-qpc", S390_FEAT_TYPE_PTFF, 3, "PTFF Query Physical 
> Clock"),
>      FEAT_INIT("ptff-qui", S390_FEAT_TYPE_PTFF, 4, "PTFF Query UTC 
> Information"),
>      FEAT_INIT("ptff-qtou", S390_FEAT_TYPE_PTFF, 5, "PTFF Query TOD Offset 
> User"),
> +    FEAT_INIT("ptff-qsie", S390_FEAT_TYPE_PTFF, 10, "PTFF Query Steering 
> Information Extended"),
> +    FEAT_INIT("ptff-qtoue", S390_FEAT_TYPE_PTFF, 13, "PTFF Query TOD Offset 
> User Extended"),
>      FEAT_INIT("ptff-sto", S390_FEAT_TYPE_PTFF, 65, "PTFF Set TOD Offset"),
>      FEAT_INIT("ptff-stou", S390_FEAT_TYPE_PTFF, 69, "PTFF Set TOD Offset 
> User"),
> +    FEAT_INIT("ptff-stoe", S390_FEAT_TYPE_PTFF, 73, "PTFF Set TOD Offset 
> Extended"),
> +    FEAT_INIT("ptff-stoue", S390_FEAT_TYPE_PTFF, 77, "PTFF Set TOD Offset 
> User Extended"),
> 
>      FEAT_INIT("kmac-dea", S390_FEAT_TYPE_KMAC, 1, "KMAC DEA"),
>      FEAT_INIT("kmac-tdea-128", S390_FEAT_TYPE_KMAC, 2, "KMAC TDEA-128"),
> @@ -445,6 +449,7 @@ static S390FeatGroupDef s390_feature_groups[] = {
>      FEAT_GROUP_INIT("plo", PLO, "Perform-locked-operation facility"),
>      FEAT_GROUP_INIT("tods", TOD_CLOCK_STEERING, "Tod-clock-steering 
> facility"),
>      FEAT_GROUP_INIT("gen13ptff", GEN13_PTFF, "PTFF enhancements introduced 
> with z13"),
> +    FEAT_GROUP_INIT("mepochptff", MULTIPLE_EPOCH_PTFF, "PTFF enhancements 
> introduced with Multiple-epoch facility"),
>      FEAT_GROUP_INIT("msa", MSA, "Message-security-assist facility"),
>      FEAT_GROUP_INIT("msa1", MSA_EXT_1, "Message-security-assist-extension 1 
> facility"),
>      FEAT_GROUP_INIT("msa2", MSA_EXT_2, "Message-security-assist-extension 2 
> facility"),
> diff --git a/target/s390x/cpu_features_def.h b/target/s390x/cpu_features_def.h
> index 4d930871b4..7c5915c7b2 100644
> --- a/target/s390x/cpu_features_def.h
> +++ b/target/s390x/cpu_features_def.h
> @@ -151,8 +151,12 @@ typedef enum {
>      S390_FEAT_PTFF_QPT,
>      S390_FEAT_PTFF_QUI,
>      S390_FEAT_PTFF_QTOU,
> +    S390_FEAT_PTFF_QSIE,
> +    S390_FEAT_PTFF_QTOUE,
>      S390_FEAT_PTFF_STO,
>      S390_FEAT_PTFF_STOU,
> +    S390_FEAT_PTFF_STOE,
> +    S390_FEAT_PTFF_STOUE,
> 
>      /* KMAC */
>      S390_FEAT_KMAC_DEA,
> diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
> index 58b6ac484e..716b06f726 100644
> --- a/target/s390x/gen-features.c
> +++ b/target/s390x/gen-features.c
> @@ -59,6 +59,12 @@
>      S390_FEAT_PTFF_QTOU, \
>      S390_FEAT_PTFF_STOU
> 
> +#define S390_FEAT_GROUP_MULTIPLE_EPOCH_PTFF \
> +    S390_FEAT_PTFF_QSIE, \
> +    S390_FEAT_PTFF_QTOUE, \
> +    S390_FEAT_PTFF_STOE, \
> +    S390_FEAT_PTFF_STOUE
> +
>  #define S390_FEAT_GROUP_MSA \
>      S390_FEAT_MSA, \
>      S390_FEAT_KMAC_DEA, \
> @@ -219,6 +225,9 @@ static uint16_t group_TOD_CLOCK_STEERING[] = {
>  static uint16_t group_GEN13_PTFF[] = {
>      S390_FEAT_GROUP_GEN13_PTFF,
>  };
> +static uint16_t group_MULTIPLE_EPOCH_PTFF[] = {
> +    S390_FEAT_GROUP_MULTIPLE_EPOCH_PTFF,
> +};
>  static uint16_t group_MSA[] = {
>      S390_FEAT_GROUP_MSA,
>  };
> @@ -466,6 +475,7 @@ static uint16_t full_GEN14_GA1[] = {
>      S390_FEAT_CMM_NT,
>      S390_FEAT_HPMA2,
>      S390_FEAT_SIE_KSS,
> +    S390_FEAT_GROUP_MULTIPLE_EPOCH_PTFF,
>  };
> 
>  /* Default features (in order of release)
> @@ -665,6 +675,7 @@ static FeatGroupDefSpec FeatGroupDef[] = {
>      FEAT_GROUP_INITIALIZER(PLO),
>      FEAT_GROUP_INITIALIZER(TOD_CLOCK_STEERING),
>      FEAT_GROUP_INITIALIZER(GEN13_PTFF),
> +    FEAT_GROUP_INITIALIZER(MULTIPLE_EPOCH_PTFF),
>      FEAT_GROUP_INITIALIZER(MSA),
>      FEAT_GROUP_INITIALIZER(MSA_EXT_1),
>      FEAT_GROUP_INITIALIZER(MSA_EXT_2),
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index bfd14723f1..deb870921b 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -2221,6 +2221,14 @@ void kvm_s390_get_host_cpu_model(S390CPUModel *model, 
> Error **errp)
>          return;
>      }
> 
> +    /* PTFF subfunctions might be indicated although kernel support missing 
> */
> +    if (!test_bit(S390_FEAT_MULTIPLE_EPOCH, model->features)) {
> +        clear_bit(S390_FEAT_PTFF_QSIE, model->features);
> +        clear_bit(S390_FEAT_PTFF_QTOUE, model->features);
> +        clear_bit(S390_FEAT_PTFF_STOE, model->features);
> +        clear_bit(S390_FEAT_PTFF_STOUE, model->features);
> +    }
> +
>      /* with cpu model support, CMM is only indicated if really available */
>      if (kvm_s390_cmma_available()) {
>          set_bit(S390_FEAT_CMM, model->features);
>