Re: [Qemu-devel] [PATCH v5 04/16] pc: forbid BSP removal

[Eduardo Habkost]

On Mon, Jul 18, 2016 at 10:31:22AM +0200, Igor Mammedov wrote:
> Boot CPU is assumed to always present in QEMU code, so
> untile that assumptions are gone, deny removal request,
> In another words QEMU won't support BSP hot-unplug.
> 
> Signed-off-by: Igor Mammedov <address@hidden>

Reviewed-by: Eduardo Habkost <address@hidden>

> ---
> v5:
>   - s/1st CPU (BSP)/Boot CPU/
>      Eduardo Habkost <address@hidden>
>   - intialize idx to -1 and assert on it,
>      Eduardo Habkost <address@hidden>
>     (note: that should nexer happen in current code as we don't
>      have stray CPUs and most likely never will, but it doesn't
>      hurt to cautios)
> ---
>  hw/i386/pc.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 110f1bf..e15fcc1 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1757,10 +1757,18 @@ out:
>  static void pc_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
>                                       DeviceState *dev, Error **errp)
>  {
> +    int idx = -1;
>      HotplugHandlerClass *hhc;
>      Error *local_err = NULL;
>      PCMachineState *pcms = PC_MACHINE(hotplug_dev);
>  
> +    pc_find_cpu_slot(pcms, CPU(dev), &idx);
> +    assert(idx != -1);
> +    if (idx == 0) {
> +        error_setg(&local_err, "Boot CPU is unpluggable");
> +        goto out;
> +    }
> +
>      hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
>      hhc->unplug_request(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
>  
> -- 
> 2.7.4
> 

-- 
Eduardo