From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:60968) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1glsZ2-0001M7-7p for qemu-devel@nongnu.org; Tue, 22 Jan 2019 04:41:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1glsZ1-0003cH-GS for qemu-devel@nongnu.org; Tue, 22 Jan 2019 04:41:48 -0500 From: David Hildenbrand Date: Tue, 22 Jan 2019 10:41:43 +0100 Message-Id: <20190122094143.8857-1-david@redhat.com> Subject: [Qemu-devel] [PATCH v1] s390x/pci: Warn when adding PCI devices without the 'zpci' feature List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-s390x@nongnu.org, Collin Walling , Thomas Huth , Christian Borntraeger , Cornelia Huck , Richard Henderson , David Hildenbrand 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. Signed-off-by: David Hildenbrand --- hw/s390x/s390-pci-bus.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c index b86a8bdcd4..e7d4f49611 100644 --- a/hw/s390x/s390-pci-bus.c +++ b/hw/s390x/s390-pci-bus.c @@ -863,6 +863,11 @@ 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("Adding PCI or zPCI devices without the 'zpci' CPU feature." + " The guest will not be able to see/use these devices."); + } + if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) { PCIDevice *pdev = PCI_DEVICE(dev); -- 2.17.2