[libvirt] [PATCH v2 RESEND 00/12] PCI passthrough support on s390

[Andrea Bolognani]

On Thu, 2018-07-26 at 12:22 +0100, Daniel P. Berrangé wrote:
> On Thu, Jul 26, 2018 at 07:17:03PM +0800, Yi Min Zhao wrote:
> > 在 2018/7/26 下午7:00, Andrea Bolognani 写道:
> > > From the test cases I see a zpci devices, with its own uid and fid,
> > > is created for the pci-bridge as well... Is that intentional?
> > 
> > Firstly pci bridge can be auto-generated if a pci device is to be plugged to
> > non-existing pci bus.
> > IIUC, pci-bridge is treated as a controller device in libvirt. So I think,
> > it's pretty readable not only
> > in libvirt xml but also in qtree, if we assign zpci device for it. Otherwise
> > address type of pci-bridge
> > is pci type but has no uid and fid. Isn't it odd?

Everything about zPCI is odd ;)

I guess there's no harm in creating an additional zpci device,
and as you say it will keep things a bit more consistent, which
is good.

> From the libvirt side we must avoid any scenario where QEMU auto-adds
> devices behind our back. If adding a device requires adding a controller
> libvirt must do this explicitly and record it in the XML.

Definitely. My question was whether the corresponding zpci device
should be created as well...

-- 
Andrea Bolognani / Red Hat / Virtualization