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

[Sai Pavan Boddu <saipava@xilinx.com>]

HI Markus,

> -----Original Message-----
> From: Markus Armbruster <armbru@redhat.com>
> Sent: Friday, June 26, 2020 11:42 AM
> To: Sai Pavan Boddu <saipava@xilinx.com>
> Cc: 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>; Gerd
> Hoffmann <kraxel@redhat.com>; Paolo Bonzini <pbonzini@redhat.com>;
> Ying Fang <fangying1@huawei.com>; 'Marc-André Lureau'
> <marcandre.lureau@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 <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.
[Sai Pavan Boddu] This was my V1 implementation.
Changed it to non-qom structure after some feedback from @Gred. Felt like XHCIState will not be used standalone.

Thanks,
sai Pavan
> 
> Example: core device TYPE_SERIAL, PCI device TYPE_PCI_SERIAL, ISA device
> TYPE_ISA_SERIAL, sysbus devices TYPE_SERIAL_IO. TYPE_SERIAL_MM.