Re: [PATCH v2 3/3] usb/hcd-xhci: Split pci wrapper for xhci base model

[Markus Armbruster]

Sai Pavan Boddu <saipava@xilinx.com> writes:

> Hi Markus,
>
>> -----Original Message-----
>> From: Markus Armbruster <armbru@redhat.com>
>> Sent: Thursday, June 25, 2020 1:42 PM
>> To: Sai Pavan Boddu <saipava@xilinx.com>
>> Cc: Gerd Hoffmann <kraxel@redhat.com>; Peter Maydell
>> <peter.maydell@linaro.org>; Thomas Huth <thuth@redhat.com>; Eduardo
>> Habkost <ehabkost@redhat.com>; qemu-devel@nongnu.org; Alistair Francis
>> <alistair.francis@wdc.com>; 'Marc-André Lureau'
>> <marcandre.lureau@redhat.com>; Ying Fang <fangying1@huawei.com>;
>> Paolo Bonzini <pbonzini@redhat.com>; 'Philippe Mathieu-Daudé'
>> <philmd@redhat.com>
>> Subject: Re: [PATCH v2 3/3] usb/hcd-xhci: Split pci wrapper for xhci base
>> model
>> 
>> Sai Pavan Boddu <sai.pavan.boddu@xilinx.com> writes:
>> 
>> > This patch sets the base to use xhci as sysbus model, for which pci
>> > specific hooks are moved to hcd-xhci-pci.c. As a part of this
>> > requirment msi/msix interrupts handling is moved under XHCIPCIState,
>> > and XHCIState is  non qom object, make use of 'container_of' calls to
>> > retrive XHCIPciState. Made required changes for qemu-xhci-nec.
>> >
>> > Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
>> 
>> I can't see a "sysbus model".  What I can see is
>> 
>>          TYPE_DEVICE
>>               |
>>        TYPE_PCI_DEVICE
>>               |
>>         TYPE_XHCI_PCI (renamed from TYPE_XHCI)
>>           /       \
>> TYPE_QEMU_XHCI TYPE_NEC_XHCI
>> 
>> All but the two leaves are abstract.
>> 
>> Do you intend to add a "sysbus model" in a future patch?
> [Sai Pavan Boddu]  Yes. I would be sending it along with that a device which 
> would be using it. (i.e for zynqmp soc )
> Let me know, if its good to include hcd-xhci-sysbus.c here ?

I'm not sure this series is worthwhile this future patch.  Up to the
maintainer.

Here's a clean way to provide different bus connectors (say PCI and
sysbus) for the same core device:

Make the core device a TYPE_DEVICE.

For each desired bus, have a bus-specific device that contains a core
device.  Use object_initialize_child() for the component.

Example: core device TYPE_SERIAL, PCI device TYPE_PCI_SERIAL, ISA device
TYPE_ISA_SERIAL, sysbus devices TYPE_SERIAL_IO. TYPE_SERIAL_MM.