Re: [PATCH v2 15/16] tests: bios-tables-test: Add test for smbios type4 thread count2

[Michael S. Tsirkin]

On Thu, Sep 28, 2023 at 08:59:42PM +0800, Zhao Liu wrote:
> From: Zhao Liu <zhao1.liu@intel.com>
> 
> This tests the commit 7298fd7de5551 ("hw/smbios: Fix thread count in
> type4").
> 
> In smbios_build_type_4_table() (hw/smbios/smbios.c), if the number of
> threads in the socket is more than 255, then smbios type4 table encodes
> threads per socket into the thread count2 field.
> 
> So for the topology in this case, there're the following considerations:
> 1. threads per socket should be more than 255 to ensure we could cover
>    the thread count2 field.
> 2. The original bug was that threads per socket was miscalculated, so
>    now we should configure as many topology levels as possible (mutiple
>    sockets & dies, no module since x86 hasn't supported it) to cover
>    more general topology scenarios, to ensure that the threads per
>    socket encoded in the thread count2 field is correct.
> 3. For the more general topology, we should also add "cpus" (presented
>    threads for machine) and "maxcpus" (total threads for machine) to
>    make sure that configuring unpluged CPUs in smp (cpus < maxcpus)
>    does not affect the correctness of threads per socket for thread
>    count2 field.
> 
> Based on these considerations, select the topology as the follow:
> 
> -smp cpus=210,maxcpus=520,sockets=2,dies=2,cores=65,threads=2
> 
> The expected thread count2 = threads per socket = threads (2)
> * cores (65) * dies (2) = 260.
> 
> Suggested-by: Igor Mammedov <imammedo@redhat.com>
> Signed-off-by: Zhao Liu <zhao1.liu@intel.com>

There's a problem here: not all hosts support such high
number of vCPUs.
Number of hotpluggable cpus requested (520) exceeds the maximum cpus
supported by KVM (288)
socket_accept failed: Resource temporarily unavailable
**

Dropped for now pls come up with a solution.


> ---
> Changes since v1:
>  * Dropped the extra variable: uint64_t thread_count2_addr. (Igor)
>  * Added description of the consideration for topology selection of this
>    case in commit message. (Igor)
> ---
>  tests/qtest/bios-tables-test.c | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/tests/qtest/bios-tables-test.c b/tests/qtest/bios-tables-test.c
> index f8e3e349e09f..58119d8979c6 100644
> --- a/tests/qtest/bios-tables-test.c
> +++ b/tests/qtest/bios-tables-test.c
> @@ -96,6 +96,7 @@ typedef struct {
>      uint8_t smbios_core_count;
>      uint16_t smbios_core_count2;
>      uint8_t smbios_thread_count;
> +    uint16_t smbios_thread_count2;
>      uint8_t *required_struct_types;
>      int required_struct_types_len;
>      int type4_count;
> @@ -644,6 +645,7 @@ static void smbios_cpu_test(test_data *data, uint32_t 
> addr,
>      uint8_t thread_count, expected_thread_count = data->smbios_thread_count;
>      uint16_t speed, expected_speed[2];
>      uint16_t core_count2, expected_core_count2 = data->smbios_core_count2;
> +    uint16_t thread_count2, expected_thread_count2 = 
> data->smbios_thread_count2;
>      int offset[2];
>      int i;
>  
> @@ -680,6 +682,15 @@ static void smbios_cpu_test(test_data *data, uint32_t 
> addr,
>          if (expected_core_count == 0xFF && expected_core_count2) {
>              g_assert_cmpuint(core_count2, ==, expected_core_count2);
>          }
> +
> +        thread_count2 = qtest_readw(data->qts,
> +                            addr + offsetof(struct smbios_type_4,
> +                            thread_count2));
> +
> +        /* Thread Count has reached its limit, checking Thread Count 2 */
> +        if (expected_thread_count == 0xFF && expected_thread_count2) {
> +            g_assert_cmpuint(thread_count2, ==, expected_thread_count2);
> +        }
>      }
>  }
>  
> @@ -1050,6 +1061,7 @@ static void test_acpi_q35_tcg_thread_count(void)
>          .required_struct_types = base_required_struct_types,
>          .required_struct_types_len = ARRAY_SIZE(base_required_struct_types),
>          .smbios_thread_count = 27,
> +        .smbios_thread_count2 = 27,
>      };
>  
>      test_acpi_one("-machine smbios-entry-point-type=64 "
> @@ -1058,6 +1070,23 @@ static void test_acpi_q35_tcg_thread_count(void)
>      free_test_data(&data);
>  }
>  
> +static void test_acpi_q35_tcg_thread_count2(void)
> +{
> +    test_data data = {
> +        .machine = MACHINE_Q35,
> +        .variant = ".thread-count2",
> +        .required_struct_types = base_required_struct_types,
> +        .required_struct_types_len = ARRAY_SIZE(base_required_struct_types),
> +        .smbios_thread_count = 0xFF,
> +        .smbios_thread_count2 = 260,
> +    };
> +
> +    test_acpi_one("-machine smbios-entry-point-type=64 "
> +                  "-smp 
> cpus=210,maxcpus=520,sockets=2,dies=2,cores=65,threads=2",
> +                  &data);
> +    free_test_data(&data);
> +}
> +
>  static void test_acpi_q35_tcg_bridge(void)
>  {
>      test_data data = {};
> @@ -2216,6 +2245,8 @@ int main(int argc, char *argv[])
>                                 test_acpi_q35_tcg_core_count2);
>                  qtest_add_func("acpi/q35/thread-count",
>                                 test_acpi_q35_tcg_thread_count);
> +                qtest_add_func("acpi/q35/thread-count2",
> +                               test_acpi_q35_tcg_thread_count2);
>              }
>              if (qtest_has_device("virtio-iommu-pci")) {
>                  qtest_add_func("acpi/q35/viot", test_acpi_q35_viot);
> -- 
> 2.34.1