Commit f0c9d64a exposed the issue that with a xenfv machine using
pci passthrough, acpi pci hotplug code was being executed by mistake.
Guard calls to acpi_pcihp_device_plug_cb (and corresponding
acpi_pcihp_device_unplug_cb) with a check for xen_enabled(). Without
this check I am seeing the following error report: "Unsupported bus.
Bus doesn't have property 'acpi-pcihp-bsel' set".

Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/acpi/piix4.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index a553a7e..c409374 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -385,7 +385,10 @@ static void piix4_device_plug_cb(HotplugHandler *hotplug_dev,
                                 dev, errp);
         }
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
-        acpi_pcihp_device_plug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev, errp);
+        if (!xen_enabled()) {
+            acpi_pcihp_device_plug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev,
+                                      errp);
+        }
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
         if (s->cpu_hotplug_legacy) {
             legacy_acpi_cpu_plug_cb(hotplug_dev, &s->gpe_cpu, dev, errp);
@@ -408,8 +411,10 @@ static void piix4_device_unplug_request_cb(HotplugHandler *hotplug_dev,
         acpi_memory_unplug_request_cb(hotplug_dev, &s->acpi_memory_hotplug,
                                       dev, errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
-        acpi_pcihp_device_unplug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev,
-                                    errp);
+        if (!xen_enabled()) {
+            acpi_pcihp_device_unplug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev,
+                                        errp);
+        }
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU) &&
                !s->cpu_hotplug_legacy) {
         acpi_cpu_unplug_request_cb(hotplug_dev, &s->cpuhp_state, dev, errp);
-- 
1.9.0

On Fri, 28 Apr 2017 05:57:06 -0600
Bruce Rogers <brogers@suse.com> wrote:

> Commit f0c9d64a exposed the issue that with a xenfv machine using
> pci passthrough, acpi pci hotplug code was being executed by mistake.
> Guard calls to acpi_pcihp_device_plug_cb (and corresponding
> acpi_pcihp_device_unplug_cb) with a check for xen_enabled(). Without
> this check I am seeing the following error report: "Unsupported bus.
> Bus doesn't have property 'acpi-pcihp-bsel' set".
> 
> Signed-off-by: Bruce Rogers <brogers@suse.com>

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  hw/acpi/piix4.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index a553a7e..c409374 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -385,7 +385,10 @@ static void piix4_device_plug_cb(HotplugHandler *hotplug_dev,
>                                  dev, errp);
>          }
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
> -        acpi_pcihp_device_plug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev, errp);
> +        if (!xen_enabled()) {
> +            acpi_pcihp_device_plug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev,
> +                                      errp);
> +        }
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
>          if (s->cpu_hotplug_legacy) {
>              legacy_acpi_cpu_plug_cb(hotplug_dev, &s->gpe_cpu, dev, errp);
> @@ -408,8 +411,10 @@ static void piix4_device_unplug_request_cb(HotplugHandler *hotplug_dev,
>          acpi_memory_unplug_request_cb(hotplug_dev, &s->acpi_memory_hotplug,
>                                        dev, errp);
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
> -        acpi_pcihp_device_unplug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev,
> -                                    errp);
> +        if (!xen_enabled()) {
> +            acpi_pcihp_device_unplug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev,
> +                                        errp);
> +        }
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU) &&
>                 !s->cpu_hotplug_legacy) {
>          acpi_cpu_unplug_request_cb(hotplug_dev, &s->cpuhp_state, dev, errp);