hw/pci: add comment to explain checking for available function 0 in pci hotplug

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.

CC: mst@redhat.com
CC: mjt@tls.msk.ru
Signed-off-by: Ani Sinha <anisinha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
master
Ani Sinha 2023-07-11 12:33:01 +05:30 committed by Michael Tokarev
parent 8c0e8ed327
commit 67d045a0ef
1 changed files with 8 additions and 3 deletions

View File

@ -1183,9 +1183,14 @@ 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),