On 11/30/18 4:31 AM, Pierre Morel wrote:
On 29/11/2018 21:42, Tony Krowiak wrote:
On 11/22/18 11:35 AM, Pierre Morel wrote:
Two good reasons to use the base device as a child of the
AP BUS:
- We can easily find the device without traversing the qtree.
- In case we have different APdevice instantiation, VFIO with
interception or emulation, we will need the APDevice as
a parent device.
Signed-off-by: Pierre Morel <pmo...@linux.ibm.com>
---
hw/s390x/ap-device.c | 22 ++++++++++++++++++++++
hw/vfio/ap.c | 16 ++++++----------
include/hw/s390x/ap-device.h | 2 ++
3 files changed, 30 insertions(+), 10 deletions(-)
diff --git a/hw/s390x/ap-device.c b/hw/s390x/ap-device.c
index f5ac8db..554d5aa 100644
--- a/hw/s390x/ap-device.c
+++ b/hw/s390x/ap-device.c
@@ -11,13 +11,35 @@
#include "qemu/module.h"
#include "qapi/error.h"
#include "hw/qdev.h"
+#include "hw/s390x/ap-bridge.h"
#include "hw/s390x/ap-device.h"
+APDevice *s390_get_ap(void)
How about ap_get_device(void)?
Yes, keep same conventions.
+{
+ static DeviceState *apb;
Why static if you call s390_get_ap_bridge()
to retrieve it without first checking for NULL?
static are initialized as NULL.
Yes, but down below, you call s390_get_ap_bridge() to set apb
regardless of whether apb is NULL or not. It makes no sense to
declare is as static here. It is also redundant because the
s390_get_ap_bridge() function already caches it in a static
variable.
+ BusState *bus;
+ BusChild *child;
+ static APDevice *ap;
+
+ if (ap) {
+ return ap;
+ }
+
+ apb = s390_get_ap_bridge();
+ /* We have only a single child on the BUS */
+ bus = qdev_get_child_bus(apb, TYPE_AP_BUS
+ child = QTAILQ_FIRST(&bus->children);
+ assert(child != NULL);
+ ap = DO_UPCAST(APDevice, parent_obj, child->child);
I received a comment from Thomas Huth in Message ID
<2291104a-4cbf-e4fd-3496-fa0910beb...@redhat.com>
that DO_UPCAST should be avoided in new code. You should
create an AP_DEVICE macro for this in ap-device.h
Thanks I will do.
Regards,
Pierre
