On 03/04/2025 14.49, Shalini Chellathurai Saroja wrote:
On 2025-04-02 09:52, Thomas Huth wrote:
On 31/03/2025 16.00, Shalini Chellathurai Saroja wrote:
Add Control-Program Identification (CPI) device to QOM only when the virtual
machine supports CPI. CPI is supported from "s390-ccw-virtio-10.0" machine
and higher.
Signed-off-by: Shalini Chellathurai Saroja <shal...@linux.ibm.com>
---
hw/s390x/event-facility.c | 27 ++++++++++++++++++++++-----
hw/s390x/s390-virtio-ccw.c | 1 +
2 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
index c0fb6e098c..cb23bbc54b 100644
--- a/hw/s390x/event-facility.c
+++ b/hw/s390x/event-facility.c
@@ -22,6 +22,7 @@
#include "hw/s390x/sclp.h"
#include "migration/vmstate.h"
#include "hw/s390x/event-facility.h"
+#include "hw/qdev-properties.h"
typedef struct SCLPEventsBus {
BusState qbus;
@@ -54,6 +55,7 @@ struct SCLPEventFacility {
bool allow_all_mask_sizes;
/* length of the receive mask */
uint16_t mask_length;
+ bool use_cpi;
};
/* return true if any child has event pending set */
@@ -455,11 +457,20 @@ static void realize_event_facility(DeviceState
*dev, Error **errp)
qdev_unrealize(DEVICE(&event_facility->quiesce));
return;
}
- if (!qdev_realize(DEVICE(&event_facility->cpi),
- BUS(&event_facility->sbus), errp)) {
- qdev_unrealize(DEVICE(&event_facility->quiesce));
- qdev_unrealize(DEVICE(&event_facility->cpu_hotplug));
- return;
+ /*
+ * Add sclpcpi device to QOM only when the virtual machine supports
+ * Control-Program Identification. It is supported by "s390-ccw-
virtio-10.0"
+ * machine and higher.
+ */
+ if (!event_facility->use_cpi) {
+ object_unparent(OBJECT(&event_facility->cpi));
+ } else {
+ if (!qdev_realize(DEVICE(&event_facility->cpi),
+ BUS(&event_facility->sbus), errp)) {
+ qdev_unrealize(DEVICE(&event_facility->quiesce));
+ qdev_unrealize(DEVICE(&event_facility->cpu_hotplug));
+ return;
+ }
Hmm, first doing object_initialize_child() in init_event_facility()
and then unparenting it here again in case we are running with an
older machine type is a little bit ugly. I wonder whether it would be
nicer to add the QOM object from ccw_init() init instead, similar to
what we do with the SCLP-console in s390_create_sclpconsole() ? If
you've got some spare minutes, could you please give it a try whether
that looks nicer?
Hello Thomas,
Sure. Did you mean like the code below?, if yes, the use_cpi is always true
when adding the sclpcpi device from ccw_init(). The use_cpi is set to false
at a later point, when the machine type is 9.2 or older. This means the
sclpcpi device is always added, the output and the code are provided below.
Please let me know how to proceed, thank you very much.
...
@@ -499,6 +485,7 @@ static void init_event_facility_class(ObjectClass
*klass, void *data)
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
k->command_handler = command_handler;
k->event_pending = event_pending;
+ k->use_cpi = use_cpi;
}
...
diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-
facility.h
index f445d2f9f5..ba20161023 100644
--- a/include/hw/s390x/event-facility.h
+++ b/include/hw/s390x/event-facility.h
@@ -204,6 +204,7 @@ struct SCLPEventFacilityClass {
SysBusDeviceClass parent_class;
void (*command_handler)(SCLPEventFacility *ef, SCCB *sccb, uint64_t
code);
bool (*event_pending)(SCLPEventFacility *ef);
+ bool (*use_cpi)(SCLPEventFacility *ef);
};
Hi,
you certainly don't need the (*use_cpi) callback here.
I'd suggest to:
1) Add a boolean flag to S390CcwMachineClass in s390-virtio-ccw.h called
"use_cpi", "cpi_allowed", "has_cpi" or whatever.
2) Set that flag to true in ccw_machine_class_init() (similar to that
hpage_1m_allowed flag)
3) Set that flag to false in ccw_machine_9_2_class_options() so that it gets
disabled for older machine type classes. Important: use the class_options()
function here, not the instance_options()! Also not that this should go into
the ccw_machine_10_0_class_options() functions instead once v10.0 has been
released.
4) In ccw_init() you should now be able to use "S390CcwMachineClass *s390mc
= S390_CCW_MACHINE_CLASS(mc)" to query the flag from the machine class.
HTH,
Thomas
