On Mon, May 25, 2020 at 10:45:11AM +0200, David Hildenbrand wrote:
> E.g., with "pc-q35-4.2", trying to coldplug a virtio-pmem-pci devices
> results in
> "virtio-pmem-pci not supported on this bus"
>
> Reasons is, that the bus does not support hotplug and, therefore, does
> not have a hotplug handler. Let's allow coldplugging virtio-pmem devices
> on such buses. The hotplug order is only relevant for virtio-pmem-pci
> when the guest is already alive and the device is visible before
> memory_device_plug() wired up the memory device bits.
>
> Hotplug attempts will still fail with:
> "Error: Bus 'pcie.0' does not support hotplugging"
>
> Hotunplug attempts will still fail with:
> "Error: Bus 'pcie.0' does not support hotplugging"
>
> Reported-by: Vivek Goyal <vgo...@redhat.com>
> Cc: Pankaj Gupta <pankaj.gupta.li...@gmail.com>
> Cc: Igor Mammedov <imamm...@redhat.com>
> Cc: Paolo Bonzini <pbonz...@redhat.com>
> Cc: Richard Henderson <r...@twiddle.net>
> Cc: Eduardo Habkost <ehabk...@redhat.com>
> Cc: "Michael S. Tsirkin" <m...@redhat.com>
> Cc: Marcel Apfelbaum <marcel.apfelb...@gmail.com>
> Signed-off-by: David Hildenbrand <da...@redhat.com>
I assume you are still debugging Vivek's issues, right?
Let me know when you feel it's time to merge this ...
> ---
> hw/i386/pc.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 2128f3d6fe..c740495eb6 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1663,13 +1663,13 @@ static void
> pc_virtio_pmem_pci_pre_plug(HotplugHandler *hotplug_dev,
> HotplugHandler *hotplug_dev2 = qdev_get_bus_hotplug_handler(dev);
> Error *local_err = NULL;
>
> - if (!hotplug_dev2) {
> + if (!hotplug_dev2 && dev->hotplugged) {
> /*
> * Without a bus hotplug handler, we cannot control the plug/unplug
> - * order. This should never be the case on x86, however better add
> - * a safety net.
> + * order. We should never reach this point when hotplugging on x86,
> + * however, better add a safety net.
> */
> - error_setg(errp, "virtio-pmem-pci not supported on this bus.");
> + error_setg(errp, "virtio-pmem-pci hotplug not supported on this
> bus.");
> return;
> }
> /*
> @@ -1678,7 +1678,7 @@ static void pc_virtio_pmem_pci_pre_plug(HotplugHandler
> *hotplug_dev,
> */
> memory_device_pre_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev), NULL,
> &local_err);
> - if (!local_err) {
> + if (!local_err && hotplug_dev2) {
> hotplug_handler_pre_plug(hotplug_dev2, dev, &local_err);
> }
> error_propagate(errp, local_err);
> @@ -1696,9 +1696,11 @@ static void pc_virtio_pmem_pci_plug(HotplugHandler
> *hotplug_dev,
> * device bits.
> */
> memory_device_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
> - hotplug_handler_plug(hotplug_dev2, dev, &local_err);
> - if (local_err) {
> - memory_device_unplug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
> + if (hotplug_dev2) {
> + hotplug_handler_plug(hotplug_dev2, dev, &local_err);
> + if (local_err) {
> + memory_device_unplug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
> + }
> }
> error_propagate(errp, local_err);
> }
> --
> 2.25.4
