Re: [PATCH v4 2/2] tests/unit: Add an unit test for smp parsing

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 10/28/21 17:09, Philippe Mathieu-Daudé wrote:
> From: Yanan Wang <wangyanan55@huawei.com>
> 
> Now that we have a generic parser smp_parse(), let's add an unit
> test for the code. All possible valid/invalid SMP configurations
> that the user can specify are covered.
> 
> Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
> Reviewed-by: Andrew Jones <drjones@redhat.com>
> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Message-Id: <20211026034659.22040-3-wangyanan55@huawei.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  tests/unit/test-smp-parse.c | 594 ++++++++++++++++++++++++++++++++++++
>  MAINTAINERS                 |   1 +
>  tests/unit/meson.build      |   1 +
>  3 files changed, 596 insertions(+)
>  create mode 100644 tests/unit/test-smp-parse.c

> +static struct SMPTestData data_generic_valid[] = {
> +    {
> +        /* config: no configuration provided
> +         * expect: cpus=1,sockets=1,cores=1,threads=1,maxcpus=1 */

[1]

> +        .config = SMP_CONFIG_GENERIC(F, 0, F, 0, F, 0, F, 0, F, 0),
> +        .expect_prefer_sockets = CPU_TOPOLOGY_GENERIC(1, 1, 1, 1, 1),
> +        .expect_prefer_cores   = CPU_TOPOLOGY_GENERIC(1, 1, 1, 1, 1),
> +    }, {

> +static void test_generic(void)
> +{
> +    Object *obj = object_new(TYPE_MACHINE);
> +    MachineState *ms = MACHINE(obj);
> +    MachineClass *mc = MACHINE_GET_CLASS(obj);

Watch out, while you create a machine instance in each
test, there is only one machine class registered (see
type_register_static(&smp_machine_info) below in [2]),
...

> +    SMPTestData *data = &(SMPTestData){0};
> +    int i;
> +
> +    smp_machine_class_init(mc);
> +
> +    for (i = 0; i < ARRAY_SIZE(data_generic_valid); i++) {
> +        *data = data_generic_valid[i];
> +        unsupported_params_init(mc, data);
> +
> +        smp_parse_test(ms, data, true);
> +
> +        /* Unsupported parameters can be provided with their values as 1 */
> +        data->config.has_dies = true;
> +        data->config.dies = 1;
> +        smp_parse_test(ms, data, true);
> +    }
> +
> +    /* Reset the supported min CPUs and max CPUs */
> +    mc->min_cpus = 2;
> +    mc->max_cpus = 511;

... and here you are modifying the single machine class state, ...

> +
> +    for (i = 0; i < ARRAY_SIZE(data_generic_invalid); i++) {
> +        *data = data_generic_invalid[i];
> +        unsupported_params_init(mc, data);
> +
> +        smp_parse_test(ms, data, false);
> +    }
> +
> +    object_unref(obj);
> +}
> +
> +static void test_with_dies(void)
> +{
> +    Object *obj = object_new(TYPE_MACHINE);
> +    MachineState *ms = MACHINE(obj);
> +    MachineClass *mc = MACHINE_GET_CLASS(obj);

... so here the machine class state is inconsistent, ...

> +    SMPTestData *data = &(SMPTestData){0};
> +    unsigned int num_dies = 2;
> +    int i;
> +
> +    smp_machine_class_init(mc);
> +    mc->smp_props.dies_supported = true;
> +
> +    for (i = 0; i < ARRAY_SIZE(data_generic_valid); i++) {
> +        *data = data_generic_valid[i];
> +        unsupported_params_init(mc, data);
> +
> +        /* when dies parameter is omitted, it will be set as 1 */
> +        data->expect_prefer_sockets.dies = 1;
> +        data->expect_prefer_cores.dies = 1;
> +
> +        smp_parse_test(ms, data, true);

... in particular the first test [1] is tested with mc->min_cpus = 2.

I wonder why you are not getting:

Output error report: Invalid SMP CPUs 1. The min CPUs supported by
machine '(null)' is 2

for [1].

> +
> +        /* when dies parameter is specified */
> +        data->config.has_dies = true;
> +        data->config.dies = num_dies;
> +        if (data->config.has_cpus) {
> +            data->config.cpus *= num_dies;
> +        }
> +        if (data->config.has_maxcpus) {
> +            data->config.maxcpus *= num_dies;
> +        }
> +
> +        data->expect_prefer_sockets.dies = num_dies;
> +        data->expect_prefer_sockets.cpus *= num_dies;
> +        data->expect_prefer_sockets.max_cpus *= num_dies;
> +        data->expect_prefer_cores.dies = num_dies;
> +        data->expect_prefer_cores.cpus *= num_dies;
> +        data->expect_prefer_cores.max_cpus *= num_dies;
> +
> +        smp_parse_test(ms, data, true);
> +    }
> +
> +    for (i = 0; i < ARRAY_SIZE(data_with_dies_invalid); i++) {
> +        *data = data_with_dies_invalid[i];
> +        unsupported_params_init(mc, data);
> +
> +        smp_parse_test(ms, data, false);
> +    }
> +
> +    object_unref(obj);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +    g_test_init(&argc, &argv, NULL);
> +
> +    module_call_init(MODULE_INIT_QOM);
> +    type_register_static(&smp_machine_info);

[2]