Re: [Qemu-devel] [PULL 4/4] hw/acpi/vmgenid: prevent more than one vmgenid device

[Laszlo Ersek]

On 03/22/17 17:01, Michael S. Tsirkin wrote:
> From: Laszlo Ersek <address@hidden>
> 
> A system with multiple VMGENID devices is undefined in the VMGENID spec by
> omission.
> 
> Cc: "Michael S. Tsirkin" <address@hidden>
> Cc: Ben Warren <address@hidden>
> Cc: Igor Mammedov <address@hidden>
> Cc: Paolo Bonzini <address@hidden>
> Signed-off-by: Laszlo Ersek <address@hidden>
> Reviewed-by: Michael S. Tsirkin <address@hidden>
> Signed-off-by: Michael S. Tsirkin <address@hidden>

Can you please add the feedback tags from Igor and Ben?

http://mid.mail-archive.com/address@hidden
http://mid.mail-archive.com/address@hidden

> Binary file /tmp/tmp.IaAwzHwwsQ matches

I'm not sure what this means.

Thanks,
Laszlo

> ---
>  include/hw/acpi/vmgenid.h | 1 +
>  hw/acpi/vmgenid.c         | 8 ++++++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/include/hw/acpi/vmgenid.h b/include/hw/acpi/vmgenid.h
> index 8578476..7beb959 100644
> --- a/include/hw/acpi/vmgenid.h
> +++ b/include/hw/acpi/vmgenid.h
> @@ -24,6 +24,7 @@ typedef struct VmGenIdState {
>      bool write_pointer_available;
>  } VmGenIdState;
>  
> +/* returns NULL unless there is exactly one device */
>  static inline Object *find_vmgenid_dev(void)
>  {
>      return object_resolve_path_type("", VMGENID_DEVICE, NULL);
> diff --git a/hw/acpi/vmgenid.c b/hw/acpi/vmgenid.c
> index c3ddcc8..a32b847 100644
> --- a/hw/acpi/vmgenid.c
> +++ b/hw/acpi/vmgenid.c
> @@ -221,6 +221,14 @@ static void vmgenid_realize(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> +    /* Given that this function is executing, there is at least one VMGENID
> +     * device. Check if there are several.
> +     */
> +    if (!find_vmgenid_dev()) {
> +        error_setg(errp, "at most one %s device is permitted", 
> VMGENID_DEVICE);
> +        return;
> +    }
> +
>      qemu_register_reset(vmgenid_handle_reset, vms);
>  }
>  
>