Re: [Qemu-devel] [PATCH v6 wave 2 1/3] hw/isa/lpc_ich9: add SMI feature negotiation via fw_cfg

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 12 Jan 2017 19:24:44 +0100
Laszlo Ersek <lersek@redhat.com> wrote:

[...]
> +static void smi_features_ok_callback(void *opaque)
> +{
> +    ICH9LPCState *lpc = opaque;
> +    uint64_t guest_features;
> +
> +    if (lpc->smi_features_ok) {
> +        /* negotiation already complete, features locked */
> +        return;
> +    }
> +
> +    memcpy(&guest_features, lpc->smi_guest_features_le, sizeof guest_features);
> +    le64_to_cpus(&guest_features);
> +    if (guest_features & ~lpc->smi_host_features) {
> +        /* guest requests invalid features, leave @features_ok at zero */
> +        return;
> +    }
> +
> +    /* valid feature subset requested, lock it down, report success */
> +    lpc->smi_negotiated_features = guest_features;
> +    lpc->smi_features_ok = 1;
> +}
[...]

> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT8_ARRAY(smi_guest_features_le, ICH9LPCState,
> +                            sizeof(uint64_t)),
> +        VMSTATE_UINT8(smi_features_ok, ICH9LPCState),
> +        VMSTATE_UINT64(smi_negotiated_features, ICH9LPCState),

Couldn't smi_negotiated_features be derived from
smi_guest_features_le on target side?


> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>  static const VMStateDescription vmstate_ich9_lpc = {
>      .name = "ICH9LPC",
>      .version_id = 1,
> @@ -683,6 +761,7 @@ static const VMStateDescription vmstate_ich9_lpc = {
>      },
>      .subsections = (const VMStateDescription*[]) {
>          &vmstate_ich9_rst_cnt,
> +        &vmstate_ich9_smi_feat,
>          NULL
>      }
>  };