On Fri, 09 Jul 2021 13:25:43 +0200
Markus Armbruster <arm...@redhat.com> wrote:
> Igor Mammedov <imamm...@redhat.com> writes:
>
> > On Thu, 08 Jul 2021 15:08:57 +0200
> > Markus Armbruster <arm...@redhat.com> wrote:
> >
> >> Daniel Henrique Barboza <danielhb...@gmail.com> writes:
> >>
> >> > MEM_UNPLUG_ERROR is deprecated since the introduction of
> >> > DEVICE_UNPLUG_ERROR. Keep emitting both while the deprecation of
> >> > MEM_UNPLUG_ERROR is pending.
> >> >
> >> > CC: Michael S. Tsirkin <m...@redhat.com>
> >> > CC: Igor Mammedov <imamm...@redhat.com>
> >> > Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
> >> > Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com>
> >> > ---
> >> > hw/acpi/memory_hotplug.c | 13 +++++++++++--
> >> > 1 file changed, 11 insertions(+), 2 deletions(-)
> >> >
> >> > diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
> >> > index af37889423..fb9f4d2de7 100644
> >> > --- a/hw/acpi/memory_hotplug.c
> >> > +++ b/hw/acpi/memory_hotplug.c
> >> > @@ -8,6 +8,7 @@
> >> > #include "qapi/error.h"
> >> > #include "qapi/qapi-events-acpi.h"
> >> > #include "qapi/qapi-events-machine.h"
> >> > +#include "qapi/qapi-events-qdev.h"
> >> >
> >> > #define MEMORY_SLOTS_NUMBER "MDNR"
> >> > #define MEMORY_HOTPLUG_IO_REGION "HPMR"
> >> > @@ -177,9 +178,17 @@ static void acpi_memory_hotplug_write(void *opaque,
> >> > hwaddr addr, uint64_t data,
> >> > /* call pc-dimm unplug cb */
> >> > hotplug_handler_unplug(hotplug_ctrl, dev, &local_err);
> >> > if (local_err) {
> >> > + const char *error_pretty = error_get_pretty(local_err);
> >> > +
> >> > trace_mhp_acpi_pc_dimm_delete_failed(mem_st->selector);
> >> > - qapi_event_send_mem_unplug_error(dev->id,
> >> > -
> >> > error_get_pretty(local_err));
> >> > +
> >> > + /*
> >> > + * Send both MEM_UNPLUG_ERROR and DEVICE_UNPLUG_ERROR
> >> > + * while the deprecation of MEM_UNPLUG_ERROR is
> >> > + * pending.
> >> > + */
> >> > + qapi_event_send_mem_unplug_error(dev->id, error_pretty);
> >> > + qapi_event_send_device_unplug_error(dev->id,
> >> > error_pretty);
> >> > error_free(local_err);
> >> > break;
> >> > }
> >>
> >> Same question as for PATCH 2: can dev->id be null?
> > only theoretically (if memory device were created directly without
> > using device_add), which as far as I know is not the case as all
> > memory devices are created using -device/device_add so far.
> >
> > ( for device_add case see qdev_device_add->qdev_set_id where
> > 'id' is set to user provided or to generated "device[%d]" value)
>
> Something is set to a generated value, but it's not dev->id :)
>
> void qdev_set_id(DeviceState *dev, const char *id)
>
> @id is the value of id=... It may be null.
>
> dev->id still is null here.
>
> {
> if (id) {
> dev->id = id;
> }
>
> dev->id is now the value of id=... It may be null.
>
> if (dev->id) {
> object_property_add_child(qdev_get_peripheral(), dev->id,
> OBJECT(dev));
>
> If the user specified id=..., add @dev as child of /peripheral. The
> child's name is the (non-null) value of id=...
>
> } else {
> static int anon_count;
> gchar *name = g_strdup_printf("device[%d]", anon_count++);
> object_property_add_child(qdev_get_peripheral_anon(), name,
> OBJECT(dev));
> g_free(name);
>
> Else, add @dev as child of /peripheral-anon. The child's name is made
> up.
>
>
> }
> }
>
> dev->id is still the value of id=..., i.e. it may be null.
yep, I was wrong and confused it child name in QOM tree.
> Sure dereferencing dev->id in acpi_memory_hotplug_write() is safe?
it aren't safe since guest may trigger this error when
memory-device is created without id.
