Re: [Qemu-devel] [PATCH v2 6/6] s390x/pci: Unplug remaining requested devices on pcihost reset

[Cornelia Huck <cohuck@redhat.com>]

On Fri, 1 Feb 2019 16:06:43 +0100
David Hildenbrand <david@redhat.com> wrote:

> On 01.02.19 11:19, Cornelia Huck wrote:
> > On Wed, 30 Jan 2019 16:57:33 +0100
> > David Hildenbrand <david@redhat.com> 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

s/unpluged/unplugged/

> >> (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 <david@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  
> > 
> > I'm afraid this one doesn't quite apply without the first patches in
> > the series, and I'm not sure how to fix it up. I'll either take a
> > rebase on a codebase without patches 1-3, or this patch together with
> > patches 1-3 after they get acks (whatever comes first :)
> >   
> 
> I guess it's only the comment that get's added in patch #1, so no major
> conflicts.

As I'm now picking 1-3, this obviously fits without conflicts again :)