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. :) 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. Reviewed-by: Collin Walling <wall...@linux.ibm.com>
