| Message ID | 20161212202617-mutt-send-email-mst@kernel.org |
|---|---|
| State | New |
| Headers | show |
On Mon, Dec 12, 2016 at 08:41:41PM +0200, Michael S. Tsirkin wrote: > On Mon, Dec 12, 2016 at 05:29:15PM +0000, Stefan Hajnoczi wrote: > > On Mon, Dec 12, 2016 at 01:34:05PM +0800, Cao jin wrote: > > > > > > > > > On 12/10/2016 04:39 AM, Eduardo Habkost wrote: > > > > Using latest qemu.git master: > > > > > > > > $ qemu-system-x86_64 -machine q35 -readconfig docs/q35-chipset.cfg -monitor stdio > > > > QEMU 2.7.93 monitor - type 'help' for more information > > > > (qemu) device_add e1000e,bus=ich9-pcie-port-4,addr=00 > > > > (qemu) device_add e1000e,bus=ich9-pcie-port-4,addr=08 > > > > Segmentation fault (core dumped) > > > > > > > > It crashes at: > > > > > > > > #7 0x000055555598d7dc in do_pci_register_device (errp=0x7fffffffbfd0, devfn=64, name=0x5555565df340 "e1000e", bus=0x555558487380, pci_dev=0x5555589cd000) > > > > at /home/ehabkost/rh/proj/virt/qemu/hw/pci/pci.c:983 > > > > 983 error_setg(errp, "PCI: slot %d function 0 already ocuppied by %s," > > > > (gdb) l > > > > 978 PCI_SLOT(devfn), PCI_FUNC(devfn), name, > > > > 979 bus->devices[devfn]->name); > > > > 980 return NULL; > > > > 981 } else if (dev->hotplugged && > > > > 982 pci_get_function_0(pci_dev)) { > > > > 983 error_setg(errp, "PCI: slot %d function 0 already ocuppied by %s," > > > > 984 " new func %s cannot be exposed to guest.", > > > > 985 PCI_SLOT(devfn), > > > > 986 bus->devices[PCI_DEVFN(PCI_SLOT(devfn), 0)]->name, > > > > 987 name); > > > > > > > > > > Thanks for informing me. I am kind of busy for now, so I suppose I will > > > investigate it after 2.8 release. > > > > Please let me know if this should be considered a release blocker. > > > > The proposed QEMU 2.8 release date is tomorrow (December 13th)! > > > > Stefan > > I don't see how it's a blocker, it's an illegal configuration. > Here's the fix. It's a rather obvious one. > I'll target the fix for 2.9. > Eduardo, I'd appreciate a tested-by tag. I confirm the patch fixes the crash, but the error message seems incorrect: the existing e1000e device is on slot 0 function 0, not slot 8. $ ./x86-kvm-build/x86_64-softmmu/qemu-system-x86_64 -machine q35 -readconfig docs/q35-chipset.cfg -monitor stdio QEMU 2.7.93 monitor - type 'help' for more information (qemu) device_add e1000e,bus=ich9-pcie-port-4,addr=00 (qemu) device_add e1000e,bus=ich9-pcie-port-4,addr=08 PCI: slot 8 function 0 already ocuppied by e1000e, new func e1000e cannot be exposed to guest. ^^^ > > --> > > pci: fix error message for express slots > > PCI Express downstream slot has a single PCI slot > behind it, using PCI_DEVFN(PCI_SLOT(devfn), 0) > does not give you function 0 in cases such as ARI > as well as some error cases. > > This is exactly what we are hitting: > $ qemu-system-x86_64 -machine q35 -readconfig docs/q35-chipset.cfg -monitor stdio > (qemu) device_add e1000e,bus=ich9-pcie-port-4,addr=00 > (qemu) device_add e1000e,bus=ich9-pcie-port-4,addr=08 > Segmentation fault (core dumped) > > The fix is to use the pci_get_function_0 API. > > Cc: qemu-stable@nongnu.org > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > Reported-by: Eduardo Habkost <ehabkost@redhat.com> > --- > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index 24fae16..339c531 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -983,7 +983,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus, > error_setg(errp, "PCI: slot %d function 0 already ocuppied by %s," > " new func %s cannot be exposed to guest.", > PCI_SLOT(devfn), > - bus->devices[PCI_DEVFN(PCI_SLOT(devfn), 0)]->name, > + pci_get_function_0(pci_dev)->name, > name); > > return NULL; > > -- > MST
diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 24fae16..339c531 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -983,7 +983,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus, error_setg(errp, "PCI: slot %d function 0 already ocuppied by %s," " new func %s cannot be exposed to guest.", PCI_SLOT(devfn), - bus->devices[PCI_DEVFN(PCI_SLOT(devfn), 0)]->name, + pci_get_function_0(pci_dev)->name, name); return NULL;