While we fence unplug requests from the outside, the VM can still
trigger unplug of virtio based memory devices, for example, in Linux
doing:
# echo 0 > /sys/bus/pci/slots/3/power
While doing that is not really expected to work without harming the
guest OS (e.g., removing a virtio-mem device while it still provides
memory), let's make sure that we properly handle it on the QEMU side.
We'll support unplugging of virtio-mem devices in some configurations
next.
Signed-off-by: David Hildenbrand <da...@redhat.com>
---
hw/i386/pc.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index fc52772fdd..fdd7062929 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1559,7 +1559,25 @@ static void
pc_virtio_md_pci_unplug_request(HotplugHandler *hotplug_dev,
static void pc_virtio_md_pci_unplug(HotplugHandler *hotplug_dev,
DeviceState *dev, Error **errp)
{
- /* We don't support hot unplug of virtio based memory devices */
+ HotplugHandler *hotplug_dev2 = qdev_get_bus_hotplug_handler(dev);
+ Error *local_err = NULL;
+
+ /* Unplug the memory device while it is still realized. */
+ memory_device_unplug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
+
+ if (hotplug_dev2) {
+ hotplug_handler_unplug(hotplug_dev2, dev, &local_err);
+ if (local_err) {
+ /* Not expected to fail ... but still try to recover. */
+ memory_device_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
+ error_propagate(errp, local_err);
+ return;
+ }
+ } else {
+ /* Very unexpected, but let's just try to do the right thing. */
+ warn_report("Unexpected unplug of virtio based memory device");
+ qdev_unrealize(dev);
+ }
}
static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
--
2.40.1
