Commit 703fef6f authored by David Hildenbrand's avatar David Hildenbrand Committed by Cornelia Huck
Browse files

s390x/pci: Warn when adding PCI devices without the 'zpci' feature 



We decided to always create the PCI host bridge, even if 'zpci' is not
enabled (due to migration compatibility). This however right now allows
to add zPCI/PCI devices to a VM although the guest will never actually see
them, confusing people that are using a simple CPU model that has no
'zpci' enabled - "Why isn't this working" (David Hildenbrand)

Let's check for 'zpci' and at least print a warning that this will not
work as expected. We could also bail out, however that might break
existing QEMU commandlines.

Reviewed-by: default avatarThomas Huth <thuth@redhat.com>
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Message-Id: <20190130155733.32742-4-david@redhat.com>
Reviewed-by: default avatarCollin Walling <walling@linux.ibm.com>
Signed-off-by: default avatarCornelia Huck <cohuck@redhat.com>
parent 150f4625

hw/s390x/s390-pci-bus.c

+6 −0
Original line number Diff line number Diff line
@@ -860,6 +860,12 @@ static void s390_pcihost_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev, 
{

    S390pciState *s = S390_PCI_HOST_BRIDGE(hotplug_dev);



    if (!s390_has_feat(S390_FEAT_ZPCI)) {

        warn_report("Plugging a PCI/zPCI device without the 'zpci' CPU "

                    "feature enabled; the guest will not be able to see/use "

                    "this device");

    }



    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {

        PCIDevice *pdev = PCI_DEVICE(dev);