[PATCH 1/2] Handle KVM hypercall panic on guest crash

[Daniel Gollub <gollub@xxxxxxxxxxxxx>]

If the guest crash and the crash/panic handler calls
the KVM panic hypercall the KVM API notifies this with
KVM_EXIT_PANIC.

The VM status gets extended with "panic" to obtain
this status via the QEMU monitor.
---
 kvm-all.c               |    4 ++++
 kvm/include/linux/kvm.h |    1 +
 monitor.c               |    8 ++++++--
 sysemu.h                |    1 +
 vl.c                    |    2 ++
 5 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index 629f727..9771f91 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1029,6 +1029,10 @@ int kvm_cpu_exec(CPUState *env)
             qemu_system_reset_request();
             ret = EXCP_INTERRUPT;
             break;
+        case KVM_EXIT_PANIC:
+            panic = 1;
+            ret = 1;
+            break;
         case KVM_EXIT_UNKNOWN:
             fprintf(stderr, "KVM: unknown exit, hardware reason %" PRIx64 "\n",
                     (uint64_t)run->hw.hardware_exit_reason);
diff --git a/kvm/include/linux/kvm.h b/kvm/include/linux/kvm.h
index e46729e..207871c 100644
--- a/kvm/include/linux/kvm.h
+++ b/kvm/include/linux/kvm.h
@@ -161,6 +161,7 @@ struct kvm_pit_config {
 #define KVM_EXIT_NMI              16
 #define KVM_EXIT_INTERNAL_ERROR   17
 #define KVM_EXIT_OSI              18
+#define KVM_EXIT_PANIC            19
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 #define KVM_INTERNAL_ERROR_EMULATION 1
diff --git a/monitor.c b/monitor.c
index 59a3e76..fd6a881 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2599,13 +2599,17 @@ static void do_info_status_print(Monitor *mon, const QObject *data)
         monitor_printf(mon, "paused");
     }
 
+    if (qdict_get_bool(qdict, "panic")) {
+        monitor_printf(mon, " (panic)");
+    }
+
     monitor_printf(mon, "\n");
 }
 
 static void do_info_status(Monitor *mon, QObject **ret_data)
 {
-    *ret_data = qobject_from_jsonf("{ 'running': %i, 'singlestep': %i }",
-                                    vm_running, singlestep);
+    *ret_data = qobject_from_jsonf("{ 'running': %i, 'singlestep': %i, 'panic': %i }",
+                                    vm_running, singlestep, panic);
 }
 
 static qemu_acl *find_acl(Monitor *mon, const char *name)
diff --git a/sysemu.h b/sysemu.h
index a42d83f..8ab0168 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -12,6 +12,7 @@
 extern const char *bios_name;
 
 extern int vm_running;
+extern int panic;
 extern const char *qemu_name;
 extern uint8_t qemu_uuid[];
 int qemu_uuid_parse(const char *str, uint8_t *uuid);
diff --git a/vl.c b/vl.c
index e0191e1..1d9a068 100644
--- a/vl.c
+++ b/vl.c
@@ -185,6 +185,7 @@ int mem_prealloc = 0; /* force preallocation of physical target memory */
 int nb_nics;
 NICInfo nd_table[MAX_NICS];
 int vm_running;
+int panic = 0;
 int autostart;
 int incoming_expected; /* Started with -incoming and waiting for incoming */
 static int rtc_utc = 1;
@@ -1407,6 +1408,7 @@ static void main_loop(void)
             pause_all_vcpus();
             cpu_synchronize_all_states();
             qemu_system_reset();
+            panic = 0;
             resume_all_vcpus();
         }
         if (qemu_powerdown_requested()) {
-- 
1.7.1

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