> On 31-May-2023, at 2:12 PM, Zhao Liu <zhao1....@intel.com> wrote:
>
> On Tue, May 30, 2023 at 08:20:34PM +0800, Tianrui Zhao wrote:
>> Date: Tue, 30 May 2023 20:20:34 +0800
>> From: Tianrui Zhao <zhaotian...@loongson.cn>
>> Subject: [PATCH] hw/smbios: fix thead count field in type 4 table
>> X-Mailer: git-send-email 2.39.1
>>
>> The thread_count value in smbios type_4 table should be
>> (ms->smp.cores * ms->smp.threads). As according to smbios spec 7.5
>> Processor Information (Type 4), the field "Thread Count" means the
>> "Number of threads per processor socket" rather than number of
>> threads per core.
>>
>> When apply this patch, use "-smp 4,sockets=1,cores=2,threads=2" to
>> boot VM, the dmidecode -t 4 shows like:
>>
>> Handle 0x0400, DMI type 4, 48 bytes
>> Processor Information
>> Socket Designation: CPU 0
>> ...
>> Core Count: 2
>> Core Enabled: 2
>> Thread Count: 4
>> Characteristics: None
>>
>> Signed-off-by: Tianrui Zhao <zhaotian...@loongson.cn>
>> ---
>> hw/smbios/smbios.c | 7 ++++---
>> 1 file changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
>> index d2007e70fb..56aeaa069d 100644
>> --- a/hw/smbios/smbios.c
>> +++ b/hw/smbios/smbios.c
>> @@ -713,6 +713,7 @@ static void smbios_build_type_4_table(MachineState *ms,
>> unsigned instance)
>> {
>> char sock_str[128];
>> size_t tbl_len = SMBIOS_TYPE_4_LEN_V28;
>> + int count;
>>
>> if (smbios_ep_type == SMBIOS_ENTRY_POINT_TYPE_64) {
>> tbl_len = SMBIOS_TYPE_4_LEN_V30;
>> @@ -749,15 +750,15 @@ static void smbios_build_type_4_table(MachineState
>> *ms, unsigned instance)
>>
>> t->core_count = (ms->smp.cores > 255) ? 0xFF : ms->smp.cores;
>> t->core_enabled = t->core_count;
>> -
>> - t->thread_count = (ms->smp.threads > 255) ? 0xFF : ms->smp.threads;
>> + count = ms->smp.cores * ms->smp.threads;
>
> Hi Ani & Tianrui,
>
> From the comment of CpuTopology (include/hw/boards.h):
>
> ms->cores means the "the number of cores in one cluster".
> ms->threads means the "the number of threads in one core".
>
> So ms->cores * ms->threads means the number of threads in one cluster
> not one socket.
Yes ok other than arm/virt I do not see any other arch that supports clusters.
>
> That's why I count the number of threads in a socket by "ms->smp.max_cpus
> / ms->smp.sockets" in [1].
>
> The other correct way is:
> ms->smp.cluster * ms->smp.cores * ms->smp.threads.
>
Sure, I prefer this calculation than what you have used.
> [1]: https://lists.gnu.org/archive/html/qemu-devel/2023-05/msg07229.html
>
> Thanks,
> Zhao
>
>> + t->thread_count = (count > 255) ? 0xFF : count;
>>
>> t->processor_characteristics = cpu_to_le16(0x02); /* Unknown */
>> t->processor_family2 = cpu_to_le16(0x01); /* Other */
>>
>> if (tbl_len == SMBIOS_TYPE_4_LEN_V30) {
>> t->core_count2 = t->core_enabled2 = cpu_to_le16(ms->smp.cores);
>> - t->thread_count2 = cpu_to_le16(ms->smp.threads);
>> + t->thread_count2 = cpu_to_le16(count);
>> }
>>
>> SMBIOS_BUILD_TABLE_POST;
>> --
>> 2.39.1
