[Qemu-devel] [PATCH v6 2/4] target-s390x: Migrate to new NMI interface

[Alexey Kardashevskiy <aik@ozlabs.ru>]

This implements an NMI interface for s390 machine.

This removes #ifdef s390 branch in qmp_inject_nmi so new s390's
nmi_monitor_handler() callback is going to be used for NMI.

Since nmi_monitor_handler()-calling code is platform independent,
CPUState::cpu_index is used instead of S390CPU::env.cpu_num.
There should not be any change in behaviour as both @cpu_index and
@cpu_num are global CPU numbers.

Also, s390_cpu_restart() takes care of preforming operations in
the specific CPU thread so no extra measure is required here either.

Since the only error s390_cpu_restart() can return is ENOSYS, convert
it to QERR_UNSUPPORTED.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v6:
* supported NMI interface

v5:
* added ENOSYS -> QERR_UNSUPPORTED, qapi/qmp/qerror.h was added for this

v4:
* s/\<nmi\>/nmi_monitor_handler/

v3:
* now contains both old code removal and new code insertion, easier to
track changes

---
Is there any good reason to have @cpu_num in addition to @cpu_index?
Just asking :)
---
 cpus.c                 | 14 --------------
 hw/s390x/s390-virtio.c | 31 +++++++++++++++++++++++++++++++
 target-s390x/cpu.c     |  1 +
 3 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/cpus.c b/cpus.c
index da1f6a9..f3756b4 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1481,20 +1481,6 @@ void qmp_inject_nmi(Error **errp)
             apic_deliver_nmi(cpu->apic_state);
         }
     }
-#elif defined(TARGET_S390X)
-    CPUState *cs;
-    S390CPU *cpu;
-
-    CPU_FOREACH(cs) {
-        cpu = S390_CPU(cs);
-        if (cpu->env.cpu_num == monitor_get_cpu_index()) {
-            if (s390_cpu_restart(S390_CPU(cs)) == -1) {
-                error_set(errp, QERR_UNSUPPORTED);
-                return;
-            }
-            break;
-        }
-    }
 #else
     nmi(monitor_get_cpu_index(), errp);
 #endif
diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
index 93c7ace..9c5b7b2 100644
--- a/hw/s390x/s390-virtio.c
+++ b/hw/s390x/s390-virtio.c
@@ -38,6 +38,7 @@
 #include "hw/s390x/sclp.h"
 #include "hw/s390x/s390_flic.h"
 #include "hw/s390x/s390-virtio.h"
+#include "hw/nmi.h"
 
 //#define DEBUG_S390
 
@@ -51,6 +52,7 @@
 
 #define MAX_BLK_DEVS                    10
 #define ZIPL_FILENAME                   "s390-zipl.rom"
+#define TYPE_NMI_S390                   "s390_nmi"
 
 static VirtIOS390Bus *s390_bus;
 static S390CPU **ipi_states;
@@ -277,6 +279,9 @@ static void s390_init(MachineState *machine)
 
     /* Create VirtIO network adapters */
     s390_create_virtio_net((BusState *)s390_bus, "virtio-net-s390");
+
+    object_property_add_child(OBJECT(machine), "nmi",
+                              object_new(TYPE_NMI_S390), NULL);
 }
 
 static QEMUMachine s390_machine = {
@@ -295,8 +300,34 @@ static QEMUMachine s390_machine = {
     .is_default = 1,
 };
 
+static void s390_nmi(NMI *n, int cpu_index, Error **errp)
+{
+    CPUState *cs = qemu_get_cpu(cpu_index);
+
+    if (s390_cpu_restart(S390_CPU(cs))) {
+        error_set(errp, QERR_UNSUPPORTED);
+    }
+}
+
+static void s390_nmi_class_init(ObjectClass *oc, void *data)
+{
+    NMIClass *nc = NMI_CLASS(oc);
+    nc->nmi_monitor_handler = s390_nmi;
+}
+
+static const TypeInfo s390_nmi_info = {
+    .name          = TYPE_NMI_S390,
+    .parent        = TYPE_OBJECT,
+    .class_init    = s390_nmi_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_NMI },
+        { }
+    },
+};
+
 static void s390_machine_init(void)
 {
+    type_register_static(&s390_nmi_info);
     qemu_register_machine(&s390_machine);
 }
 
diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
index c3082b7..15142ff 100644
--- a/target-s390x/cpu.c
+++ b/target-s390x/cpu.c
@@ -27,6 +27,7 @@
 #include "qemu-common.h"
 #include "qemu/timer.h"
 #include "hw/hw.h"
+#include "qapi/qmp/qerror.h"
 #ifndef CONFIG_USER_ONLY
 #include "sysemu/arch_init.h"
 #endif
-- 
2.0.0