pci/pcihp: perform check for bus capability in pre_plug handler

Perform the check in the pre_plug handler. In addition, we need the
capability only if the device is actually hotplugged (and not created
during machine initialization). This is a preparation for coldplugging
pci devices via that hotplug handler.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 29 insertions, 8 deletions

diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index 80d42e1..5e7cef1 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -217,17 +217,24 @@ void acpi_pcihp_reset(AcpiPciHpState *s)
     acpi_pcihp_update(s);
 }
 
-void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
-                               DeviceState *dev, Error **errp)
+void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
+                                   DeviceState *dev, Error **errp)
 {
-    PCIDevice *pdev = PCI_DEVICE(dev);
-    int slot = PCI_SLOT(pdev->devfn);
-    int bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
-    if (bsel < 0) {
+    /* Only hotplugged devices need the hotplug capability. */
+    if (dev->hotplugged &&
+        acpi_pcihp_get_bsel(pci_get_bus(PCI_DEVICE(dev))) < 0) {
         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
                    ACPI_PCIHP_PROP_BSEL "' set");
         return;
     }
+}
+
+void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
+                               DeviceState *dev, Error **errp)
+{
+    PCIDevice *pdev = PCI_DEVICE(dev);
+    int slot = PCI_SLOT(pdev->devfn);
+    int bsel;
 
     /* Don't send event when device is enabled during qemu machine creation:
      * it is present on boot, no hotplug event is necessary. We do send an
@@ -236,6 +243,8 @@ void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
         return;
     }
 
+    bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
+    g_assert(bsel >= 0);
     s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
     acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
 }
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index 2f4dd03..f68e62d 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -371,6 +371,18 @@ static void piix4_pm_powerdown_req(Notifier *n, void *opaque)
     acpi_pm1_evt_power_down(&s->ar);
 }
 
+static void piix4_device_pre_plug_cb(HotplugHandler *hotplug_dev,
+                                    DeviceState *dev, Error **errp)
+{
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+        acpi_pcihp_device_pre_plug_cb(hotplug_dev, dev, errp);
+    } else if (!object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) &&
+               !object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
+        error_setg(errp, "acpi: device pre plug request for not supported"
+                   " device type: %s", object_get_typename(OBJECT(dev)));
+    }
+}
+
 static void piix4_device_plug_cb(HotplugHandler *hotplug_dev,
                                  DeviceState *dev, Error **errp)
 {
@@ -393,8 +405,7 @@ static void piix4_device_plug_cb(HotplugHandler *hotplug_dev,
             acpi_cpu_plug_cb(hotplug_dev, &s->cpuhp_state, dev, errp);
         }
     } else {
-        error_setg(errp, "acpi: device plug request for not supported device"
-                   " type: %s", object_get_typename(OBJECT(dev)));
+        g_assert_not_reached();
     }
 }
 
@@ -703,6 +714,7 @@ static void piix4_pm_class_init(ObjectClass *klass, void *data)
      */
     dc->user_creatable = false;
     dc->hotpluggable = false;
+    hc->pre_plug = piix4_device_pre_plug_cb;
     hc->plug = piix4_device_plug_cb;
     hc->unplug_request = piix4_device_unplug_request_cb;
     hc->unplug = piix4_device_unplug_cb;