[Qemu-devel] [PATCH] Clarify error message when a PCI slot is already in use (v2)

["Daniel P. Berrange" <berrange@redhat.com>]

When mistakenly configuring two devices in the same PCI slot,
QEMU gives a not entirely obvious message about a 'devfn' being
in use:

$ qemu -device rtl8139 -device virtio-balloon-pci,bus=pci.0,addr=0x3
qemu-kvm: -device virtio-balloon-pci,bus=pci.0,addr=0x3: PCI: devfn 24 not available for virtio-balloon-pci, in use by rtl8139

The user does not configure 'devfn' numbers, they use slot+function.
Thus the error messages should be reported back to the user with that
same terminology rather than the internal QEMU terminology. This
patch makes it report:

$ qemu -device rtl8139 -device virtio-balloon-pci,bus=pci.0,addr=0x3
qemu: -device virtio-balloon-pci,bus=pci.0,addr=0x3.7: PCI: slot 3 function 0 not available for virtio-balloon-pci, in use by rtl8139

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 hw/pci.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index cbbd1dd..cd7ce8d 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -609,12 +609,12 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
             if (!bus->devices[devfn])
                 goto found;
         }
-        error_report("PCI: no devfn available for %s, all in use", name);
+        error_report("PCI: no slot/function available for %s, all in use", name);
         return NULL;
     found: ;
     } else if (bus->devices[devfn]) {
-        error_report("PCI: devfn %d not available for %s, in use by %s",
-                     devfn, name, bus->devices[devfn]->name);
+        error_report("PCI: slot %d function %d not available for %s, in use by %s",
+                     PCI_SLOT(devfn), PCI_FUNC(devfn), name, bus->devices[devfn]->name);
         return NULL;
     }
     pci_dev->bus = bus;
-- 
1.6.6.1