On 31.01.19 21:26, Collin Walling wrote: > On 1/30/19 10:57 AM, David Hildenbrand wrote: >> When resetting the guest we should unplug and remove all devices that >> are still pending. >> >> With this patch, the requested device will be unpluged on reboot >> (S390_RESET_EXTERNAL and S390_RESET_REIPL, which reset the pcihost bridge >> via qemu_devices_reset()). >> >> This approach is similar to what's done for acpi PCI hotplug in >> acpi_pcihp_reset() -> acpi_pcihp_update() -> >> acpi_pcihp_update_hotplug_bus() -> acpi_pcihp_eject_slot(). >> >> s390_pci_generate_plug_event()'s will still be generated, I guess this >> is not an issue. The same thing would happen right now when unplugging >> a device just before starting the guest. >> >> Signed-off-by: David Hildenbrand <da...@redhat.com> >> --- >> hw/s390x/s390-pci-bus.c | 15 +++++++++++++++ >> 1 file changed, 15 insertions(+) >> >> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c >> index 867801ccf9..b9b0f44087 100644 >> --- a/hw/s390x/s390-pci-bus.c >> +++ b/hw/s390x/s390-pci-bus.c >> @@ -1092,6 +1092,21 @@ static void s390_pcihost_reset(DeviceState *dev) >> { >> S390pciState *s = S390_PCI_HOST_BRIDGE(dev); >> PCIBus *bus = s->parent_obj.bus; >> + S390PCIBusDevice *pbdev, *next; >> + >> + /* Process all pending unplug requests */ >> + QTAILQ_FOREACH_SAFE(pbdev, &s->zpci_devs, link, next) { >> + if (pbdev->unplug_requested) { >> + if (pbdev->summary_ind) { >> + pci_dereg_irqs(pbdev); >> + } >> + if (pbdev->iommu->enabled) { >> + pci_dereg_ioat(pbdev->iommu); >> + } >> + pbdev->state = ZPCI_FS_STANDBY; >> + s390_pci_perform_unplug(pbdev); >> + } >> + } >> >> /* >> * When resetting a PCI bridge, the assigned numbers are set to 0. So >> > > Just "talking out loud" to reaffirm my understanding: > > The ..._unplug_request function will have already generated the > deconfigure unplug event, and the unplug_requested flag will be set. > Makes sense -- easy to follow. :)
Yes, that's how it should work :) > > The callback that this code is essentially replacing used to generate a > CONFIGURED_TO_STBRES plug event, but as I recall from a previous > conversation regarding PCI states, we can skip this event because we're > removing the device from the guest during a reset here (there are a few > reasons why we'd do this, but no sense in listing them here). Also makes > sense to me. Yes, it's pretty much to the guest like this device never existed. Thanks! > > Reviewed-by: Collin Walling <wall...@linux.ibm.com> > -- Thanks, David / dhildenb