Commit 4e82ef05 authored by David Hildenbrand's avatar David Hildenbrand Committed by Cornelia Huck
Browse files

s390x/cpumodel: implement QMP interface "query-cpu-model-comparison" 



Let's implement that interface by reusing our convertion code implemented
for expansion.

We use CPU generations and CPU features to calculate the result. This
means, that a zEC12 cannot simply be converted into a z13 by stripping
of features. This is required, as other magic values (e.g. maximum
address sizes) belong to a CPU generation and cannot simply be
emulated by an older generation.

Acked-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Message-Id: <20160905085244.99980-30-dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent 137974ce

qapi-schema.json

+2 −1
Original line number Diff line number Diff line
@@ -3232,7 +3232,8 @@ 
#   global properties may affect expansion of CPU models. Using

#   query-cpu-model-expansion while using these is not advised.

#

# Some architectures may not support comparing CPU models.

# Some architectures may not support comparing CPU models. s390x supports

# comparing CPU models.

#

# Returns: a CpuModelBaselineInfo. Returns an error if comparing CPU models is

#          not supported, if a model cannot be used, if a model contains

target-s390x/cpu_models.c

+84 −0
Original line number Diff line number Diff line
@@ -450,6 +450,90 @@ CpuModelExpansionInfo *arch_query_cpu_model_expansion(CpuModelExpansionType type 
    cpu_info_from_model(expansion_info->model, &s390_model, delta_changes);

    return expansion_info;

}



static void list_add_feat(const char *name, void *opaque)

{

    strList **last = (strList **) opaque;

    strList *entry;



    entry = g_malloc0(sizeof(*entry));

    entry->value = g_strdup(name);

    entry->next = *last;

    *last = entry;

}



CpuModelCompareInfo *arch_query_cpu_model_comparison(CpuModelInfo *infoa,

                                                     CpuModelInfo *infob,

                                                     Error **errp)

{

    CpuModelCompareResult feat_result, gen_result;

    CpuModelCompareInfo *compare_info;

    S390FeatBitmap missing, added;

    S390CPUModel modela, modelb;



    /* convert both models to our internal representation */

    cpu_model_from_info(&modela, infoa, errp);

    if (*errp) {

        return NULL;

    }

    cpu_model_from_info(&modelb, infob, errp);

    if (*errp) {

        return NULL;

    }

    compare_info = g_malloc0(sizeof(*compare_info));



    /* check the cpu generation and ga level */

    if (modela.def->gen == modelb.def->gen) {

        if (modela.def->ec_ga == modelb.def->ec_ga) {

            /* ec and corresponding bc are identical */

            gen_result = CPU_MODEL_COMPARE_RESULT_IDENTICAL;

        } else if (modela.def->ec_ga < modelb.def->ec_ga) {

            gen_result = CPU_MODEL_COMPARE_RESULT_SUBSET;

        } else {

            gen_result = CPU_MODEL_COMPARE_RESULT_SUPERSET;

        }

    } else if (modela.def->gen < modelb.def->gen) {

        gen_result = CPU_MODEL_COMPARE_RESULT_SUBSET;

    } else {

        gen_result = CPU_MODEL_COMPARE_RESULT_SUPERSET;

    }

    if (gen_result != CPU_MODEL_COMPARE_RESULT_IDENTICAL) {

        /* both models cannot be made identical */

        list_add_feat("type", &compare_info->responsible_properties);

    }



    /* check the feature set */

    if (bitmap_equal(modela.features, modelb.features, S390_FEAT_MAX)) {

        feat_result = CPU_MODEL_COMPARE_RESULT_IDENTICAL;

    } else {

        bitmap_andnot(missing, modela.features, modelb.features, S390_FEAT_MAX);

        s390_feat_bitmap_to_ascii(missing,

                                  &compare_info->responsible_properties,

                                  list_add_feat);

        bitmap_andnot(added, modelb.features, modela.features, S390_FEAT_MAX);

        s390_feat_bitmap_to_ascii(added, &compare_info->responsible_properties,

                                  list_add_feat);

        if (bitmap_empty(missing, S390_FEAT_MAX)) {

            feat_result = CPU_MODEL_COMPARE_RESULT_SUBSET;

        } else if (bitmap_empty(added, S390_FEAT_MAX)) {

            feat_result = CPU_MODEL_COMPARE_RESULT_SUPERSET;

        } else {

            feat_result = CPU_MODEL_COMPARE_RESULT_INCOMPATIBLE;

        }

    }



    /* combine the results */

    if (gen_result == feat_result) {

        compare_info->result = gen_result;

    } else if (feat_result == CPU_MODEL_COMPARE_RESULT_IDENTICAL) {

        compare_info->result = gen_result;

    } else if (gen_result == CPU_MODEL_COMPARE_RESULT_IDENTICAL) {

        compare_info->result = feat_result;

    } else {

        compare_info->result = CPU_MODEL_COMPARE_RESULT_INCOMPATIBLE;

    }

    return compare_info;

}

#endif



static void check_consistency(const S390CPUModel *model)