Re: [PATCH] hw/smbios: add options for type 4 max_speed and current_speed

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

On 2/25/20 8:50 AM, Heyi Guo 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>
> 
> ---
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Igor Mammedov <imammedo@redhat.com>
> ---
>   hw/smbios/smbios.c | 22 +++++++++++++++++++---
>   qemu-options.hx    |  3 ++-
>   2 files changed, 21 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
> index ffd98727ee..1d5439643d 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 +1138,13 @@ 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
> +             * we set the default value to 2000MHz as we did before.
> +             */
> +            type4.max_speed = qemu_opt_get_number(opts, "max_speed", 2000);
> +            type4.current_speed = qemu_opt_get_number(opts, "current_speed",
> +                                                      2000);

Maybe check speeds are <= UINT16_MAX else set errp?

>               return;
>           case 11:
>               qemu_opts_validate(opts, qemu_smbios_type11_opts, &err);
> diff --git a/qemu-options.hx b/qemu-options.hx
> index ac315c1ac4..bc9ef0fda8 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}]
>