[PATCH 1/4] nmi: add MCE class for implementing machine check injection commands

[Nicholas Piggin]

Like commit 9cb805fd26 ("cpus: Define callback for QEMU "nmi" command")
this implements a machine check injection command framework and defines
a monitor command for ppc.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 include/hw/nmi.h             | 20 ++++++++++++
 include/monitor/hmp-target.h |  1 -
 include/monitor/hmp.h        |  1 +
 hw/core/nmi.c                | 61 ++++++++++++++++++++++++++++++++++++
 monitor/hmp-cmds.c           |  1 +
 target/ppc/ppc-qmp-cmds.c    | 10 ++++++
 hmp-commands.hx              | 20 +++++++++++-
 7 files changed, 112 insertions(+), 2 deletions(-)

diff --git a/include/hw/nmi.h b/include/hw/nmi.h
index fff41bebc6..09f9ca122a 100644
--- a/include/hw/nmi.h
+++ b/include/hw/nmi.h
@@ -42,4 +42,24 @@ struct NMIClass {
 
 void nmi_monitor_handle(int cpu_index, Error **errp);
 
+
+#define TYPE_MCE "mce"
+
+#define MCE_CLASS(klass) \
+     OBJECT_CLASS_CHECK(MCEClass, (klass), TYPE_MCE)
+#define MCE_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(MCEClass, (obj), TYPE_MCE)
+#define MCE(obj) \
+     INTERFACE_CHECK(MCEState, (obj), TYPE_MCE)
+
+typedef struct MCEState MCEState;
+
+typedef struct MCEClass {
+    InterfaceClass parent_class;
+
+    void (*mce_monitor_handler)(MCEState *n, const QDict *qdict, Error **errp);
+} MCEClass;
+
+void mce_monitor_handle(const QDict *qdict, Error **errp);
+
 #endif /* NMI_H */
diff --git a/include/monitor/hmp-target.h b/include/monitor/hmp-target.h
index d78e979f05..dec6dba8e5 100644
--- a/include/monitor/hmp-target.h
+++ b/include/monitor/hmp-target.h
@@ -46,7 +46,6 @@ CPUState *mon_get_cpu(Monitor *mon);
 
 void hmp_info_mem(Monitor *mon, const QDict *qdict);
 void hmp_info_tlb(Monitor *mon, const QDict *qdict);
-void hmp_mce(Monitor *mon, const QDict *qdict);
 void hmp_info_local_apic(Monitor *mon, const QDict *qdict);
 void hmp_info_sev(Monitor *mon, const QDict *qdict);
 void hmp_info_sgx(Monitor *mon, const QDict *qdict);
diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
index 13f9a2dedb..fe14a855a0 100644
--- a/include/monitor/hmp.h
+++ b/include/monitor/hmp.h
@@ -56,6 +56,7 @@ void hmp_ringbuf_read(Monitor *mon, const QDict *qdict);
 void hmp_cont(Monitor *mon, const QDict *qdict);
 void hmp_system_wakeup(Monitor *mon, const QDict *qdict);
 void hmp_nmi(Monitor *mon, const QDict *qdict);
+void hmp_mce(Monitor *mon, const QDict *qdict);
 void hmp_info_network(Monitor *mon, const QDict *qdict);
 void hmp_set_link(Monitor *mon, const QDict *qdict);
 void hmp_balloon(Monitor *mon, const QDict *qdict);
diff --git a/hw/core/nmi.c b/hw/core/nmi.c
index a7bce8a04a..d653f054eb 100644
--- a/hw/core/nmi.c
+++ b/hw/core/nmi.c
@@ -85,3 +85,64 @@ static void nmi_register_types(void)
 }
 
 type_init(nmi_register_types)
+
+struct do_mce_s {
+    const QDict *qdict;
+    Error *err;
+    bool handled;
+};
+
+static void mce_children(Object *o, struct do_mce_s *ns);
+
+static int do_mce(Object *o, void *opaque)
+{
+    struct do_mce_s *ms = opaque;
+    MCEState *m = (MCEState *) object_dynamic_cast(o, TYPE_MCE);
+
+    if (m) {
+        MCEClass *mc = MCE_GET_CLASS(m);
+
+        ms->handled = true;
+        mc->mce_monitor_handler(m, ms->qdict, &ms->err);
+        if (ms->err) {
+            return -1;
+        }
+    }
+    mce_children(o, ms);
+
+    return 0;
+}
+
+static void mce_children(Object *o, struct do_mce_s *ms)
+{
+    object_child_foreach(o, do_mce, ms);
+}
+
+void mce_monitor_handle(const QDict *qdict, Error **errp)
+{
+    struct do_mce_s ms = {
+        .qdict = qdict,
+        .err = NULL,
+        .handled = false
+    };
+
+    mce_children(object_get_root(), &ms);
+    if (ms.handled) {
+        error_propagate(errp, ms.err);
+    } else {
+        error_setg(errp, "machine does not provide MCEs");
+    }
+}
+
+static const TypeInfo mce_info = {
+    .name          = TYPE_MCE,
+    .parent        = TYPE_INTERFACE,
+    .class_size    = sizeof(MCEClass),
+};
+
+static void mce_register_types(void)
+{
+    type_register_static(&mce_info);
+}
+
+type_init(mce_register_types)
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 871898ac46..0e46c107b6 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -28,6 +28,7 @@
 #include "hw/intc/intc.h"
 #include "qemu/log.h"
 #include "sysemu/sysemu.h"
+#include "hw/nmi.h"
 
 bool hmp_handle_error(Monitor *mon, Error *err)
 {
diff --git a/target/ppc/ppc-qmp-cmds.c b/target/ppc/ppc-qmp-cmds.c
index ee0b99fce7..43fa5980d2 100644
--- a/target/ppc/ppc-qmp-cmds.c
+++ b/target/ppc/ppc-qmp-cmds.c
@@ -31,6 +31,7 @@
 #include "qapi/qapi-commands-machine-target.h"
 #include "cpu-models.h"
 #include "cpu-qom.h"
+#include "hw/nmi.h"
 
 static target_long monitor_get_ccr(Monitor *mon, const struct MonitorDef *md,
                                    int val)
@@ -91,6 +92,15 @@ void hmp_info_tlb(Monitor *mon, const QDict *qdict)
     dump_mmu(env1);
 }
 
+void hmp_mce(Monitor *mon, const QDict *qdict)
+{
+    Error *err = NULL;
+
+    mce_monitor_handle(qdict, &err);
+
+    hmp_handle_error(mon, err);
+}
+
 const MonitorDef monitor_defs[] = {
     { "fpscr", offsetof(CPUPPCState, fpscr) },
     /* Next instruction pointer */
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 765349ed14..384cf5d0c4 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1509,12 +1509,30 @@ ERST
         .cmd        = hmp_mce,
     },
 
-#endif
 SRST
 ``mce`` *cpu* *bank* *status* *mcgstatus* *addr* *misc*
   Inject an MCE on the given CPU (x86 only).
 ERST
 
+#endif
+
+#if defined(TARGET_PPC)
+
+    {
+        .name       = "mce",
+        .args_type  = "cpu_index:i,srr1_mask:l,dsisr:i,dar:l,recovered:i",
+        .params     = "cpu srr1_mask dsisr dar recovered",
+        .help       = "inject a MCE on the given CPU",
+        .cmd        = hmp_mce,
+    },
+
+SRST
+``mce`` *cpu* *srr1_mask* *dsisr* *dar* *recovered*
+  Inject a low-level MCE on the given CPU (PPC only).
+ERST
+
+#endif
+
 #ifdef CONFIG_POSIX
     {
         .name       = "getfd",
-- 
2.42.0