From 703fef6fcf3edcbf169c90b6196fcf88f9e9765a Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 30 Jan 2019 16:57:30 +0100 Subject: [PATCH] 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: Thomas Huth Signed-off-by: David Hildenbrand Message-Id: <20190130155733.32742-4-david@redhat.com> Reviewed-by: Collin Walling Signed-off-by: Cornelia Huck --- hw/s390x/s390-pci-bus.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c index d85bc34617..3816fb1f11 100644 --- a/hw/s390x/s390-pci-bus.c +++ b/hw/s390x/s390-pci-bus.c @@ -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);