memory_hotplug.c: handle dev->id = NULL in acpi_memory_hotplug_write()

qapi_event_send_mem_unplug_error() deals with @device being NULL by
replacing it with an empty string ("") when emitting the event. Aside
from the fact that this behavior (qapi visitor mapping NULL pointer to
"") can be patched/changed someday, there's also the lack of utility
that the event brings to listeners, e.g. "a memory unplug error happened
somewhere".

In theory we should just avoit emitting this event at all if dev->id is
NULL, but this would be an incompatible change to existing guests.
Instead, let's make the forementioned behavior explicit: if dev->id is
NULL, pass an empty string to qapi_event_send_mem_unplug_error().

Suggested-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210907004755.424931-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Daniel Henrique Barboza 2021-09-06 21:47:49 -03:00 committed by David Gibson
parent a3d67f3e5d
commit 99b2c06225

View File

@ -178,7 +178,7 @@ static void acpi_memory_hotplug_write(void *opaque, hwaddr addr, uint64_t data,
hotplug_handler_unplug(hotplug_ctrl, dev, &local_err);
if (local_err) {
trace_mhp_acpi_pc_dimm_delete_failed(mem_st->selector);
qapi_event_send_mem_unplug_error(dev->id,
qapi_event_send_mem_unplug_error(dev->id ? : "",
error_get_pretty(local_err));
error_free(local_err);
break;