[Qemu-devel] [PATCH 3/3] deal with guest panicked event

[Wen Congyang]

When the guest is panicked, it will write 0x1 to the port 0x505. So if
qemu reads 0x1 from this port, we can do the folloing three things
according to the parameter -onpanic:
1. emit QEVENT_GUEST_PANICKED only
2. emit QEVENT_GUEST_PANICKED and pause VM
3. emit QEVENT_GUEST_PANICKED and quit VM

Note: if we emit QEVENT_GUEST_PANICKED only, and the management
application does not receive this event(the management may not
run when the event is emitted), the management won't know the
guest is panicked.

Signed-off-by: Wen Congyang <address@hidden>
---
 kvm-all.c        |   84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 kvm-stub.c       |    9 ++++++
 kvm.h            |    3 ++
 monitor.c        |    3 ++
 monitor.h        |    1 +
 qapi-schema.json |    6 +++-
 qemu-options.hx  |   14 +++++++++
 qmp.c            |    3 +-
 vl.c             |   17 ++++++++++-
 9 files changed, 137 insertions(+), 3 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 9b73ccf..b5b0531 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -19,6 +19,7 @@
 #include <stdarg.h>
 
 #include <linux/kvm.h>
+#include <linux/kvm_para.h>
 
 #include "qemu-common.h"
 #include "qemu-barrier.h"
@@ -29,6 +30,8 @@
 #include "bswap.h"
 #include "memory.h"
 #include "exec-memory.h"
+#include "iorange.h"
+#include "qemu-objects.h"
 
 /* This check must be after config-host.h is included */
 #ifdef CONFIG_EVENTFD
@@ -1707,3 +1710,84 @@ int kvm_on_sigbus(int code, void *addr)
 {
     return kvm_arch_on_sigbus(code, addr);
 }
+
+/* Possible values for action parameter. */
+#define PANICKED_REPORT 1   /* emit QEVENT_GUEST_PANICKED only */
+#define PANICKED_PAUSE  2   /* emit QEVENT_GUEST_PANICKED and pause VM */
+#define PANICKED_QUIT   3   /* emit QEVENT_GUEST_PANICKED and quit VM */
+
+static int panicked_action = PANICKED_REPORT;
+
+static void kvm_pv_port_read(IORange *iorange, uint64_t offset, unsigned width,
+                             uint64_t *data)
+{
+    *data = (1 << KVM_PV_FEATURE_PANICKED);
+}
+
+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 panicked_perform_action(void)
+{
+    switch(panicked_action) {
+    case PANICKED_REPORT:
+        panicked_mon_event("report");
+        break;
+
+    case PANICKED_PAUSE:
+        panicked_mon_event("pause");
+        vm_stop(RUN_STATE_GUEST_PANICKED);
+        break;
+
+    case PANICKED_QUIT:
+        panicked_mon_event("quit");
+        exit(0);
+        break;
+    }
+}
+
+static void kvm_pv_port_write(IORange *iorange, uint64_t offset, unsigned 
width,
+                              uint64_t data)
+{
+    if (data == KVM_PV_PANICKED)
+        panicked_perform_action();
+}
+
+static void kvm_pv_port_destructor(IORange *iorange)
+{
+    g_free(iorange);
+}
+
+static IORangeOps pv_io_range_ops = {
+    .read = kvm_pv_port_read,
+    .write = kvm_pv_port_write,
+    .destructor = kvm_pv_port_destructor,
+};
+
+void kvm_pv_port_init(void)
+{
+    IORange *pv_io_range = g_malloc(sizeof(IORange));
+
+    iorange_init(pv_io_range, &pv_io_range_ops, 0x505, 1);
+    ioport_register(pv_io_range);
+}
+
+int select_panicked_action(const char *p)
+{
+    if (strcasecmp(p, "report") == 0)
+        panicked_action = PANICKED_REPORT;
+    else if (strcasecmp(p, "pause") == 0)
+        panicked_action = PANICKED_PAUSE;
+    else if (strcasecmp(p, "quit") == 0)
+        panicked_action = PANICKED_QUIT;
+    else
+        return -1;
+
+    return 0;
+}
diff --git a/kvm-stub.c b/kvm-stub.c
index 47c573d..4cf977e 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -128,3 +128,12 @@ int kvm_on_sigbus(int code, void *addr)
 {
     return 1;
 }
+
+void kvm_pv_port_init(void)
+{
+}
+
+int select_panicked_action(const char *p)
+{
+    return -1;
+}
diff --git a/kvm.h b/kvm.h
index 4ccae8c..95075cf 100644
--- a/kvm.h
+++ b/kvm.h
@@ -60,6 +60,9 @@ int kvm_has_gsi_routing(void);
 
 int kvm_allows_irq0_override(void);
 
+void kvm_pv_port_init(void);
+int select_panicked_action(const char *p);
+
 #ifdef NEED_CPU_H
 int kvm_init_vcpu(CPUArchState *env);
 
diff --git a/monitor.c b/monitor.c
index 12a6fe2..83cb059 100644
--- a/monitor.c
+++ b/monitor.c
@@ -493,6 +493,9 @@ void monitor_protocol_event(MonitorEvent event, QObject 
*data)
         case QEVENT_WAKEUP:
             event_name = "WAKEUP";
             break;
+        case QEVENT_GUEST_PANICKED:
+            event_name = "GUEST_PANICKED";
+            break;
         default:
             abort();
             break;
diff --git a/monitor.h b/monitor.h
index 0d49800..94e8a3c 100644
--- a/monitor.h
+++ b/monitor.h
@@ -41,6 +41,7 @@ typedef enum MonitorEvent {
     QEVENT_DEVICE_TRAY_MOVED,
     QEVENT_SUSPEND,
     QEVENT_WAKEUP,
+    QEVENT_GUEST_PANICKED,
     QEVENT_MAX,
 } MonitorEvent;
 
diff --git a/qapi-schema.json b/qapi-schema.json
index 2ca7195..ee5c9e9 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -119,11 +119,15 @@
 # @suspended: guest is suspended (ACPI S3)
 #
 # @watchdog: the watchdog action is configured to pause and has been triggered
+#
+# @guest-panicked: the panicked action is configured to pause and has been
+# triggered.
 ##
 { 'enum': 'RunState',
   'data': [ 'debug', 'inmigrate', 'internal-error', 'io-error', 'paused',
             'postmigrate', 'prelaunch', 'finish-migrate', 'restore-vm',
-            'running', 'save-vm', 'shutdown', 'suspended', 'watchdog' ] }
+            'running', 'save-vm', 'shutdown', 'suspended', 'watchdog',
+            'guest-panicked' ] }
 
 ##
 # @StatusInfo:
diff --git a/qemu-options.hx b/qemu-options.hx
index 8b66264..d3d21a1 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2743,6 +2743,20 @@ DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log,
     "-qtest-log LOG  specify tracing options\n",
     QEMU_ARCH_ALL)
 
+DEF("onpanic", HAS_ARG, QEMU_OPTION_onpanic, \
+    "-onpanic report|pause|quit\n" \
+    "                action when the guest is panicked [default=report]",
+    QEMU_ARCH_ALL)
+STEXI
address@hidden -onpanic @var{action}
+
+The @var{action} controls what QEmu will do when the guest is panicked.
+The default is @code{report} (emit QEVENT_GUEST_PANICKED only).
+Other possible actions are:
address@hidden (emit QEVENT_GUEST_PANICKED and pause VM),
address@hidden (emit QEVENT_GUEST_PANICKED and quit VM).
+ETEXI
+
 HXCOMM This is the last statement. Insert new options before this line!
 STEXI
 @end table
diff --git a/qmp.c b/qmp.c
index fee9fb2..a2d5ce9 100644
--- a/qmp.c
+++ b/qmp.c
@@ -148,7 +148,8 @@ void qmp_cont(Error **errp)
         error_set(errp, QERR_MIGRATION_EXPECTED);
         return;
     } else if (runstate_check(RUN_STATE_INTERNAL_ERROR) ||
-               runstate_check(RUN_STATE_SHUTDOWN)) {
+               runstate_check(RUN_STATE_SHUTDOWN) ||
+               runstate_check(RUN_STATE_GUEST_PANICKED)) {
         error_set(errp, QERR_RESET_REQUIRED);
         return;
     } else if (runstate_check(RUN_STATE_SUSPENDED)) {
diff --git a/vl.c b/vl.c
index 7f5fed8..8848506 100644
--- a/vl.c
+++ b/vl.c
@@ -367,6 +367,7 @@ static const RunStateTransition runstate_transitions_def[] 
= {
     { RUN_STATE_RUNNING, RUN_STATE_SAVE_VM },
     { RUN_STATE_RUNNING, RUN_STATE_SHUTDOWN },
     { RUN_STATE_RUNNING, RUN_STATE_WATCHDOG },
+    { RUN_STATE_RUNNING, RUN_STATE_GUEST_PANICKED },
 
     { RUN_STATE_SAVE_VM, RUN_STATE_RUNNING },
 
@@ -381,6 +382,9 @@ static const RunStateTransition runstate_transitions_def[] 
= {
     { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
     { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
 
+    { RUN_STATE_GUEST_PANICKED, RUN_STATE_PAUSED },
+    { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },
+
     { RUN_STATE_MAX, RUN_STATE_MAX },
 };
 
@@ -1537,7 +1541,8 @@ static bool main_loop_should_exit(void)
         qemu_system_reset(VMRESET_REPORT);
         resume_all_vcpus();
         if (runstate_check(RUN_STATE_INTERNAL_ERROR) ||
-            runstate_check(RUN_STATE_SHUTDOWN)) {
+            runstate_check(RUN_STATE_SHUTDOWN) ||
+            runstate_check(RUN_STATE_GUEST_PANICKED)) {
             runstate_set(RUN_STATE_PAUSED);
             vm_start();
         }
@@ -3202,6 +3207,12 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_qtest_log:
                 qtest_log = optarg;
                 break;
+            case QEMU_OPTION_onpanic:
+                if (select_panicked_action(optarg) == -1) {
+                    fprintf(stderr, "Unknown -onpanic parameter\n");
+                    exit(1);
+                }
+                break;
             default:
                 os_parse_cmd_args(popt->index, optarg);
             }
@@ -3634,6 +3645,10 @@ int main(int argc, char **argv, char **envp)
         }
     }
 
+    if (kvm_enabled()) {
+        kvm_pv_port_init();
+    }
+
     if (incoming) {
         Error *errp = NULL;
         int ret = qemu_start_incoming_migration(incoming, &errp);
-- 
1.7.1