Re: [PATCH] pci: Display PCI IRQ pin in "info pci"

[Peter Xu <peterx@redhat.com>]

On Tue, Mar 17, 2020 at 03:02:57PM -0500, Eric Blake wrote:
> On 3/17/20 2:59 PM, Peter Xu wrote:
> > Sometimes it would be good to be able to read the pin number along
> > with the IRQ number allocated.  Since we'll dump the IRQ number, no
> > reason to not dump the pin information.  For example, the vfio-pci
> > device will overwrite the pin with the hardware pin number.  It would
> > be nice to know the pin number of one assigned device from QMP/HMP.
> > 
> > CC: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > CC: Alex Williamson <alex.williamson@redhat.com>
> > CC: Michael S. Tsirkin <mst@redhat.com>
> > CC: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
> > CC: Julia Suvorova <jusual@redhat.com>
> > CC: Markus Armbruster <armbru@redhat.com>
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> > 
> > This helped me to debug an IRQ sharing issue, so may good to have it
> > in master too.
> 
> We're right at soft freeze.
> 
> 
> > +++ b/qapi/misc.json
> > @@ -403,6 +403,8 @@
> >   #
> >   # @irq: if an IRQ is assigned to the device, the IRQ number
> >   #
> > +# @irq_pin: the IRQ pin, zero means no IRQ (since 5.1)
> > +#
> 
> But if we really do want it in 5.0, this needs a tweak.  Does the delay
> hurt?

No it won't; it's something good to have only.  I'll let the
maintainers to decide...

> 
> Naming convention: We prefer 'irq-pin' unless there is a consistency
> issue....
> 
> >   # @qdev_id: the device name of the PCI device
> >   #
> >   # @pci_bridge: if the device is a PCI bridge, the bridge information
> > @@ -417,8 +419,8 @@
> >   { 'struct': 'PciDeviceInfo',
> >     'data': {'bus': 'int', 'slot': 'int', 'function': 'int',
> >              'class_info': 'PciDeviceClass', 'id': 'PciDeviceId',
> > -           '*irq': 'int', 'qdev_id': 'str', '*pci_bridge': 'PciBridgeInfo',
> > -           'regions': ['PciMemoryRegion']} }
> > +           '*irq': 'int', 'irq_pin': 'int', 'qdev_id': 'str',
> > +           '*pci_bridge': 'PciBridgeInfo', 'regions': ['PciMemoryRegion'] }}
> 
> and the pre-existing pci_bridge is indeed the consistency issue.

Yeh, actually every key in this struct. :)

Thanks,

-- 
Peter Xu