[PATCH v4 4/7] hw/nmi: Remove @cpu_index argument from nmi_inject()

["Philippe Mathieu-Daudé" <philmd@oss.qualcomm.com>]

From: Philippe Mathieu-Daudé <philmd@linaro.org>

nmi_monitor_handle() is not related to the monitor, rename
it as nmi_inject().

Return a boolean value indicating success / failure as
recommended by the Error API since commit e3fe3988d7
("error: Document Error API usage rules").

The 'cpu_index' argument is not used, remove it.
This officially drops the current CPU for HMP command.

Document nmi_inject() as suggested by Peter Maydell in
https://lore.kernel.org/qemu-devel/CAFEAcA-yALySmCJLbitCmYpiZKUXJNOavGJG9RYeo8fKqz7gcw@mail.gmail.com/.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
---
 include/hw/core/nmi.h  | 25 ++++++++++++++++++++++++-
 hw/core/nmi.c          |  9 ++++-----
 hw/ipmi/ipmi.c         |  3 +--
 hw/watchdog/watchdog.c |  2 +-
 system/cpus.c          |  2 +-
 hmp-commands.hx        |  2 +-
 6 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/include/hw/core/nmi.h b/include/hw/core/nmi.h
index 4c4ce79071d..2ff5be1e214 100644
--- a/include/hw/core/nmi.h
+++ b/include/hw/core/nmi.h
@@ -46,6 +46,29 @@ struct NMIClass {
     void (*nmi_monitor_handler)(NMIState *ns, Error **errp);
 };
 
-void nmi_monitor_handle(int cpu_index, Error **errp);
+/**
+ * nmi_inject: Inject an NMI, in a machine-specific way
+ * @errp: pointer to error object
+ *
+ * This function injects an NMI, in a machine-specific way. The
+ * intention is that this should typically trigger a guest kernel
+ * dump or reboot, and might happen as a result of user request
+ * from the monitor, watchdog timeouts, and similar events.
+ * (For example on the x86 PC it triggers an NMI on all CPUs,
+ * and on s390 it triggers the RESTART interrupt on the first CPU.)
+ *
+ * The NMI is injected by looking for QOM objects which
+ * implement the TYPE_NMI interface, and calling their nmi_monitor_handler
+ * method. Usually it is the machine model class that implements
+ * this interface.
+ *
+ * Not all machines implement NMI handling; this function
+ * will return an error if used on a machine which does not
+ * implement NMIs.
+ *
+ * On success, return %true.
+ * On failure, store an error through @errp and return %false.
+ */
+bool nmi_inject(Error **errp);
 
 #endif /* NMI_H */
diff --git a/hw/core/nmi.c b/hw/core/nmi.c
index ff6454437c1..2d890f2995d 100644
--- a/hw/core/nmi.c
+++ b/hw/core/nmi.c
@@ -22,11 +22,8 @@
 #include "qemu/osdep.h"
 #include "hw/core/nmi.h"
 #include "qapi/error.h"
-#include "qemu/module.h"
-#include "monitor/monitor.h"
 
 struct do_nmi_s {
-    int cpu_index;
     Error *err;
     bool handled;
 };
@@ -54,19 +51,21 @@ static int nmi_children(Object *o, struct do_nmi_s *ns)
     return object_child_foreach_recursive(o, do_nmi, ns);
 }
 
-void nmi_monitor_handle(int cpu_index, Error **errp)
+bool nmi_inject(Error **errp)
 {
     struct do_nmi_s ns = {
-        .cpu_index = cpu_index,
         .err = NULL,
         .handled = false
     };
 
     if (nmi_children(object_get_root(), &ns)) {
         error_propagate(errp, ns.err);
+        return false;
     } else if (!ns.handled) {
         error_setg(errp, "machine does not provide NMIs");
+        return false;
     }
+    return true;
 }
 
 static const TypeInfo nmi_info = {
diff --git a/hw/ipmi/ipmi.c b/hw/ipmi/ipmi.c
index 74818ff3cea..dedf23cb997 100644
--- a/hw/ipmi/ipmi.c
+++ b/hw/ipmi/ipmi.c
@@ -59,8 +59,7 @@ static int ipmi_do_hw_op(IPMIInterface *s, enum ipmi_op op, int checkonly)
         if (checkonly) {
             return 0;
         }
-        /* We don't care what CPU we use. */
-        nmi_monitor_handle(0, NULL);
+        nmi_inject(NULL);
         return 0;
 
     case IPMI_SHUTDOWN_VIA_ACPI_OVERTEMP:
diff --git a/hw/watchdog/watchdog.c b/hw/watchdog/watchdog.c
index 0842fe373ae..5f764a0c1b8 100644
--- a/hw/watchdog/watchdog.c
+++ b/hw/watchdog/watchdog.c
@@ -81,7 +81,7 @@ void watchdog_perform_action(void)
 
     case WATCHDOG_ACTION_INJECT_NMI:
         qapi_event_send_watchdog(WATCHDOG_ACTION_INJECT_NMI);
-        nmi_monitor_handle(0, NULL);
+        nmi_inject(NULL);
         break;
 
     default:
diff --git a/system/cpus.c b/system/cpus.c
index 97e5a5edee2..04809698de4 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -926,6 +926,6 @@ exit:
 
 void qmp_inject_nmi(Error **errp)
 {
-    nmi_monitor_handle(monitor_get_cpu_index(monitor_cur()), errp);
+    nmi_inject(errp);
 }
 
diff --git a/hmp-commands.hx b/hmp-commands.hx
index a1b77ae4044..b21f361ada0 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -869,7 +869,7 @@ ERST
         .cmd        = hmp_nmi,
     },
 SRST
-``nmi`` *cpu*
+``nmi``
   Inject an NMI, in a machine-specific way.
   Not all machines implement NMI handling.
 ERST
-- 
2.53.0