Re: [PATCH v2] hw/smbios: add options for type 4 max-speed and current-speed

[Heyi Guo <guoheyi@huawei.com>]

On 2020/3/2 21:52, Igor Mammedov wrote:
> On Mon, 2 Mar 2020 17:29:10 +0800
> Heyi Guo <guoheyi@huawei.com> wrote:
>
>> Common VM users sometimes care about CPU speed, so we add two new
>> options to allow VM vendors to present CPU speed to their users.
>> Normally these information can be fetched from host smbios.
>>
>> Strictly speaking, the "max speed" and "current speed" in type 4
>> are not really for the max speed and current speed of processor, for
>> "max speed" identifies a capability of the system, and "current speed"
>> identifies the processor's speed at boot (see smbios spec), but some
>> applications do not tell the differences.
>>
>> Signed-off-by: Heyi Guo <guoheyi@huawei.com>
> With comment fixed as suggested below:
>    Reviewed-by: Igor Mammedov <imammedo@redhat.com>

Thanks; I've fixed that in v3 and add your R-b :)


>
> PS:
> pls add/extend test cases for these options (default and custom settings).
> (see test_smbios_structs() for example)
> I'd do it as an additional patch.

Let me take some time to learn how to write such test cases :)

Thanks,

Heyi


>
>
>> ---
>> Cc: "Michael S. Tsirkin" <mst@redhat.com>
>> Cc: Igor Mammedov <imammedo@redhat.com>
>> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
>>
>> v1 -> v2:
>> - change "_" in option names to "-"
>> - check if option value is too large to fit in SMBIOS type 4 speed fields.
>>
>> ---
>>   hw/smbios/smbios.c | 28 +++++++++++++++++++++++++---
>>   qemu-options.hx    |  3 ++-
>>   2 files changed, 27 insertions(+), 4 deletions(-)
>>
>> diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
>> index ffd98727ee..77135a1eca 100644
>> --- a/hw/smbios/smbios.c
>> +++ b/hw/smbios/smbios.c
>> @@ -94,6 +94,8 @@ static struct {
>>   
>>   static struct {
>>       const char *sock_pfx, *manufacturer, *version, *serial, *asset, *part;
>> +    uint32_t max_speed;
>> +    uint32_t current_speed;
>>   } type4;
>>   
>>   static struct {
>> @@ -272,6 +274,14 @@ static const QemuOptDesc qemu_smbios_type4_opts[] = {
>>           .name = "version",
>>           .type = QEMU_OPT_STRING,
>>           .help = "version number",
>> +    },{
>> +        .name = "max-speed",
>> +        .type = QEMU_OPT_NUMBER,
>> +        .help = "max speed in MHz",
>> +    },{
>> +        .name = "current-speed",
>> +        .type = QEMU_OPT_NUMBER,
>> +        .help = "speed at system boot in MHz",
>>       },{
>>           .name = "serial",
>>           .type = QEMU_OPT_STRING,
>> @@ -586,9 +596,8 @@ static void smbios_build_type_4_table(MachineState *ms, unsigned instance)
>>       SMBIOS_TABLE_SET_STR(4, processor_version_str, type4.version);
>>       t->voltage = 0;
>>       t->external_clock = cpu_to_le16(0); /* Unknown */
>> -    /* SVVP requires max_speed and current_speed to not be unknown. */
>> -    t->max_speed = cpu_to_le16(2000); /* 2000 MHz */
>> -    t->current_speed = cpu_to_le16(2000); /* 2000 MHz */
>> +    t->max_speed = cpu_to_le16(type4.max_speed);
>> +    t->current_speed = cpu_to_le16(type4.current_speed);
>>       t->status = 0x41; /* Socket populated, CPU enabled */
>>       t->processor_upgrade = 0x01; /* Other */
>>       t->l1_cache_handle = cpu_to_le16(0xFFFF); /* N/A */
>> @@ -1129,6 +1138,19 @@ void smbios_entry_add(QemuOpts *opts, Error **errp)
>>               save_opt(&type4.serial, opts, "serial");
>>               save_opt(&type4.asset, opts, "asset");
>>               save_opt(&type4.part, opts, "part");
>> +            /*
>> +             * SVVP requires max_speed and current_speed to not be unknown, and
> double negation is hard to read, so
>
> s/
> to not be unknown
> /
> to be set and not being 0 which counts as unknown (SMBIOS 3.1.0/Table 21)
> /
>
>> +             * we set the default value to 2000MHz as we did before.
> s/,and we set/. Set/
>
>> +             */
>> +            type4.max_speed = qemu_opt_get_number(opts, "max-speed", 2000);
>> +            type4.current_speed = qemu_opt_get_number(opts, "current-speed",
>> +                                                      2000);
>> +            if (type4.max_speed > UINT16_MAX ||
>> +                type4.current_speed > UINT16_MAX) {
>> +                error_setg(errp, "SMBIOS CPU speed is too large (> %d)",
>> +                           UINT16_MAX);
>> +            }
>> +
>>               return;
>>           case 11:
>>               qemu_opts_validate(opts, qemu_smbios_type11_opts, &err);
>> diff --git a/qemu-options.hx b/qemu-options.hx
>> index ac315c1ac4..7a2f7c1f66 100644
>> --- a/qemu-options.hx
>> +++ b/qemu-options.hx
>> @@ -2233,6 +2233,7 @@ DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
>>       "                specify SMBIOS type 3 fields\n"
>>       "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
>>       "              [,asset=str][,part=str]\n"
>> +    "              [,max-speed=%d][,current-speed=%d]\n"
>>       "                specify SMBIOS type 4 fields\n"
>>       "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
>>       "               [,asset=str][,part=str][,speed=%d]\n"
>> @@ -2255,7 +2256,7 @@ Specify SMBIOS type 2 fields
>>   @item -smbios type=3[,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,sku=@var{str}]
>>   Specify SMBIOS type 3 fields
>>   
>> -@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}]
>> +@item -smbios type=4[,sock_pfx=@var{str}][,manufacturer=@var{str}][,version=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}][,max-speed=@var{%d}][,current-speed=@var{%d}]
>>   Specify SMBIOS type 4 fields
>>   
>>   @item -smbios type=17[,loc_pfx=@var{str}][,bank=@var{str}][,manufacturer=@var{str}][,serial=@var{str}][,asset=@var{str}][,part=@var{str}][,speed=@var{%d}]
>
> .