Re: [PATCH v8 6/6] hw/pci: add comment explaining the reason for checking function 0 in hotplug

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jul 05, 2023 at 05:33:31PM +0530, Ani Sinha wrote:
> 
> 
> > On 05-Jul-2023, at 5:29 PM, Ani Sinha <anisinha@redhat.com> wrote:
> > 
> > This change is cosmetic. A comment is added explaining why we need to check for
> > the availability of function 0 when we hotplug a device.
> 
> Please ignore this patch. Its a duplicate of one already sent with an updated patch summary.

I'm not sure which one it is, sorry. Dropped this for now, repost later
pls.

> > 
> > CC: mst@redhat.com
> > Signed-off-by: Ani Sinha <anisinha@redhat.com>
> > ---
> > hw/pci/pci.c | 11 ++++++++---
> > 1 file changed, 8 insertions(+), 3 deletions(-)
> > 
> > diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> > index 62b393dfb7..7aee3a7f12 100644
> > --- a/hw/pci/pci.c
> > +++ b/hw/pci/pci.c
> > @@ -1181,9 +1181,14 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev,
> >                    PCI_SLOT(devfn), PCI_FUNC(devfn), name,
> >                    bus->devices[devfn]->name, bus->devices[devfn]->qdev.id);
> >         return NULL;
> > -    } else if (dev->hotplugged &&
> > -               !pci_is_vf(pci_dev) &&
> > -               pci_get_function_0(pci_dev)) {
> > +    } /*
> > +       * Populating function 0 triggers a scan from the guest that
> > +       * exposes other non-zero functions. Hence we need to ensure that
> > +       * function 0 wasn't added yet.
> > +       */
> > +    else if (dev->hotplugged &&
> > +             !pci_is_vf(pci_dev) &&
> > +             pci_get_function_0(pci_dev)) {
> >         error_setg(errp, "PCI: slot %d function 0 already occupied by %s,"
> >                    " new func %s cannot be exposed to guest.",
> >                    PCI_SLOT(pci_get_function_0(pci_dev)->devfn),
> > -- 
> > 2.39.1
> >