Re: [Qemu-devel] [RFC PATCH] ssi-sd: Make devices picking up backends unavailable with -device

[Thomas Huth]

On 2018-09-26 11:00, Markus Armbruster wrote:
> Device models aren't supposed to go on fishing expeditions for
> backends.  They should expose suitable properties for the user to set.
> For onboard devices, board code sets them.
> 
> Device ssi-sd picks up its block backend in its init() method with
> drive_get_next() instead.  This mistake is already marked FIXME since
> commit af9e40a.
> 
> Unset user_creatable to remove the mistake from our external
> interface.  Since the SSI bus doesn't support hotplug, only -device
> can be affected.  Only certain ARM machines provide an SSI bus.
> 
> Signed-off-by: Markus Armbruster <address@hidden>
> ---
> Are there valid uses of -device ssi-sd?  If no, this patch is fine.
> If yes, this patch breaks them.  But fixing the FIXME will also break
> them.  What should we do?
> 
>  hw/sd/ssi-sd.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
> index 95a143bfba..ec7c7e6dbf 100644
> --- a/hw/sd/ssi-sd.c
> +++ b/hw/sd/ssi-sd.c
> @@ -284,6 +284,8 @@ static void ssi_sd_class_init(ObjectClass *klass, void 
> *data)
>      k->cs_polarity = SSI_CS_LOW;
>      dc->vmsd = &vmstate_ssi_sd;
>      dc->reset = ssi_sd_reset;
> +    /* Reason: init() method uses drive_get_next() */
> +    dc->cannot_instantiate_with_device_add_yet = true;

s/cannot_instantiate_with_device_add_yet = true/user_creatable = false/

Sounds like a good idea to me, if somebody then still needs this for
"-device", they should fix the FIXME first.

 Thomas