[Qemu-devel] [PATCH v14 3/4] introduce pvevent device to deal with panicked event

[Hu Tao]

pvevent device is used to send guest panic event from guest to qemu.

When guest panic happens, pvevent device driver will write a event
number to IO port 0x505(which is the IO port occupied by pvevent device,
by default). On receiving the event, pvevent device will pause guest
cpu(s), and send a qmp event QEVENT_GUEST_PANICKED.  

TODO: make the IO port configurable

Signed-off-by: Wen Congyang <address@hidden>
Signed-off-by: Hu Tao <address@hidden>
---
 hw/Makefile.objs |   2 +
 hw/pvevent.c     | 116 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 118 insertions(+)
 create mode 100644 hw/pvevent.c

diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index 40ebe46..edf499e 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -218,5 +218,7 @@ obj-$(CONFIG_KVM) += ivshmem.o
 obj-$(CONFIG_LINUX) += vfio_pci.o
 endif
 
+common-obj-y += pvevent.o
+
 $(obj)/baum.o: QEMU_CFLAGS += $(SDL_CFLAGS) 
 endif
diff --git a/hw/pvevent.c b/hw/pvevent.c
new file mode 100644
index 0000000..c7df77b
--- /dev/null
+++ b/hw/pvevent.c
@@ -0,0 +1,116 @@
+/*
+ * QEMU simulated pvevent device.
+ *
+ * Copyright Fujitsu, Corp. 2013
+ *
+ * Authors:
+ *     Wen Congyang <address@hidden>
+ *     Hu Tao <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include <qapi/qmp/qobject.h>
+#include <qapi/qmp/qjson.h>
+#include <monitor/monitor.h>
+#include <sysemu/sysemu.h>
+#include <sysemu/kvm.h>
+
+/* The bit of supported pv event */
+#define PVEVENT_F_PANICKED      0
+
+/* The pv event value */
+#define PVEVENT_PANICKED        (1 << PVEVENT_F_PANICKED)
+
+#define TYPE_ISA_PVEVENT_DEVICE    "pvevent"
+#define ISA_PVEVENT_DEVICE(obj)    \
+    OBJECT_CHECK(PVEventState, (obj), TYPE_ISA_PVEVENT_DEVICE)
+
+static void panicked_mon_event(const char *action)
+{
+    QObject *data;
+
+    data = qobject_from_jsonf("{ 'action': %s }", action);
+    monitor_protocol_event(QEVENT_GUEST_PANICKED, data);
+    qobject_decref(data);
+}
+
+static void handle_event(int event)
+{
+    if (event == PVEVENT_PANICKED) {
+        panicked_mon_event("pause");
+        vm_stop(RUN_STATE_GUEST_PANICKED);
+        return;
+    }
+}
+
+#include "hw/isa.h"
+
+typedef struct PVEventState {
+    ISADevice parent_obj;
+
+    MemoryRegion io;
+    uint16_t ioport;
+} PVEventState;
+
+/* return supported events on read */
+static uint64_t pvevent_ioport_read(void *opaque, hwaddr addr, unsigned size)
+{
+    return PVEVENT_PANICKED;
+}
+
+static void pvevent_ioport_write(void *opaque, hwaddr addr, uint64_t val,
+                                 unsigned size)
+{
+    handle_event(val);
+}
+
+static const MemoryRegionOps pvevent_ops = {
+    .read = pvevent_ioport_read,
+    .write = pvevent_ioport_write,
+    .impl = {
+        .min_access_size = 1,
+        .max_access_size = 1,
+    },
+};
+
+static int pvevent_isa_initfn(ISADevice *dev)
+{
+    PVEventState *s = ISA_PVEVENT_DEVICE(dev);
+
+    memory_region_init_io(&s->io, &pvevent_ops, s, "pvevent", 1);
+    isa_register_ioport(dev, &s->io, s->ioport);
+
+    return 0;
+}
+
+static Property pvevent_isa_properties[] = {
+    DEFINE_PROP_UINT16("ioport", PVEventState, ioport, 0x505),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void pvevent_isa_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
+
+    ic->init = pvevent_isa_initfn;
+    dc->no_user = 1;
+    dc->props = pvevent_isa_properties;
+}
+
+static TypeInfo pvevent_isa_info = {
+    .name          = TYPE_ISA_PVEVENT_DEVICE,
+    .parent        = TYPE_ISA_DEVICE,
+    .instance_size = sizeof(PVEventState),
+    .class_init    = pvevent_isa_class_init,
+};
+
+static void pvevent_register_types(void)
+{
+    type_register_static(&pvevent_isa_info);
+}
+
+type_init(pvevent_register_types)
-- 
1.8.1.4