From bd2bc6c0f356e4b974c23f35a17fdc257a579306 Mon Sep 17 00:00:00 2001
From: Gleb Natapov <gleb@redhat.com>
Date: Wed, 1 Jul 2009 14:07:24 +0300
Subject: [PATCH 2/3] provide stop reason on demand

Store VM stop reason and provide it on monitor by demand.

Upstream status: not upstream. Never will be.
BZ: 505999

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Message-ID: <20090701110724.GA27539@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Bugzilla: 505999
RH-Upstream-status: not-applicable
Acked-by: Juan Quintela <quintela@redhat.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Acked-by: Glauber Costa <glommer@redhat.com>
---
 qemu/gdbstub.c        |    3 +++
 qemu/hw/ide.c         |    7 ++++---
 qemu/hw/scsi-disk.c   |    7 ++++---
 qemu/hw/virtio-blk.c  |    7 ++++---
 qemu/migration-exec.c |    1 +
 qemu/migration.c      |    1 +
 qemu/monitor.c        |    8 ++++++++
 qemu/qemu-kvm.c       |    1 +
 qemu/savevm.c         |    3 +++
 qemu/sysemu.h         |    2 ++
 qemu/vl.c             |    2 ++
 11 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/qemu/gdbstub.c b/qemu/gdbstub.c
index 4701382..a9bd058 100644
--- a/qemu/gdbstub.c
+++ b/qemu/gdbstub.c
@@ -1940,6 +1940,7 @@ void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
     gdb_current_syscall_cb = cb;
     s->state = RS_SYSCALL;
 #ifndef CONFIG_USER_ONLY
+    strncpy(vm_stop_reason, "gdbstab", STOP_REASON_LEN);
     vm_stop(EXCP_DEBUG);
 #endif
     s->state = RS_IDLE;
@@ -2014,6 +2015,7 @@ static void gdb_read_byte(GDBState *s, int ch)
     if (vm_running) {
         /* when the CPU is running, we cannot do anything except stop
            it when receiving a char */
+        strncpy(vm_stop_reason, "gdbstab", STOP_REASON_LEN);
         vm_stop(EXCP_INTERRUPT);
     } else
 #endif
@@ -2265,6 +2267,7 @@ static void gdb_chr_event(void *opaque, int event)
 {
     switch (event) {
     case CHR_EVENT_RESET:
+        strncpy(vm_stop_reason, "gdbstab", STOP_REASON_LEN);
         vm_stop(EXCP_INTERRUPT);
         gdb_has_xml = 0;
         break;
diff --git a/qemu/hw/ide.c b/qemu/hw/ide.c
index 6e56b4c..dd56f82 100644
--- a/qemu/hw/ide.c
+++ b/qemu/hw/ide.c
@@ -885,9 +885,10 @@ static int ide_handle_write_error(IDEState *s, int error, int op)
         s->bmdma->ide_if = s;
         s->bmdma->status |= op;
         vm_stop(0);
-        term_printf_async(VMSTOP_ASYNC_EVENT,
-                "VM is stopped due to disk write error: %s: %s\n",
-		bdrv_get_device_name(s->bs), strerror(error));
+	snprintf(vm_stop_reason, STOP_REASON_LEN,
+			"VM is stopped due to disk write error: %s: %s",
+			bdrv_get_device_name(s->bs), strerror(error));
+        term_printf_async(VMSTOP_ASYNC_EVENT, "%s\n", vm_stop_reason);
     } else {
         if (op == BM_STATUS_DMA_RETRY)
             ide_dma_error(s);
diff --git a/qemu/hw/scsi-disk.c b/qemu/hw/scsi-disk.c
index 391066d..e4fc1bb 100644
--- a/qemu/hw/scsi-disk.c
+++ b/qemu/hw/scsi-disk.c
@@ -229,9 +229,10 @@ static int scsi_handle_write_error(SCSIRequest *r, int error)
             || action == BLOCK_ERR_STOP_ANY) {
         r->status |= SCSI_REQ_STATUS_RETRY;
         vm_stop(0);
-        term_printf_async(VMSTOP_ASYNC_EVENT,
-                "VM is stopped due to disk write error: %s: %s\n",
-		bdrv_get_device_name(r->dev->bdrv), strerror(error));
+	snprintf(vm_stop_reason, STOP_REASON_LEN,
+			"VM is stopped due to disk write error: %s: %s",
+			bdrv_get_device_name(r->dev->bdrv), strerror(error));
+        term_printf_async(VMSTOP_ASYNC_EVENT, "%s\n", vm_stop_reason);
     } else {
         scsi_command_complete(r, STATUS_CHECK_CONDITION,
                 SENSE_HARDWARE_ERROR);
diff --git a/qemu/hw/virtio-blk.c b/qemu/hw/virtio-blk.c
index baea65d..ed8575b 100644
--- a/qemu/hw/virtio-blk.c
+++ b/qemu/hw/virtio-blk.c
@@ -66,9 +66,10 @@ static int virtio_blk_handle_write_error(VirtIOBlockReq *req, int error)
         req->next = s->rq;
         s->rq = req;
         vm_stop(0);
-        term_printf_async(VMSTOP_ASYNC_EVENT,
-                "VM is stopped due to disk write error: %s: %s\n",
-		bdrv_get_device_name(req->dev->bs), strerror(error));
+	snprintf(vm_stop_reason, STOP_REASON_LEN,
+			"VM is stopped due to disk write error: %s: %s",
+			bdrv_get_device_name(s->bs), strerror(error));
+        term_printf_async(VMSTOP_ASYNC_EVENT, "%s\n", vm_stop_reason);
     } else {
         virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
     }
diff --git a/qemu/migration-exec.c b/qemu/migration-exec.c
index 5e4108d..6b66344 100644
--- a/qemu/migration-exec.c
+++ b/qemu/migration-exec.c
@@ -132,6 +132,7 @@ int exec_start_incoming_migration(const char *command)
         dprintf("Unable to apply qemu wrapper to popen file\n");
         return -errno;
     }
+    strncpy(vm_stop_reason, "incomming migration", STOP_REASON_LEN);
     vm_stop(0); /* just in case */
     ret = qemu_loadvm_state(f);
     if (ret < 0) {
diff --git a/qemu/migration.c b/qemu/migration.c
index c748444..99512c6 100644
--- a/qemu/migration.c
+++ b/qemu/migration.c
@@ -255,6 +255,7 @@ void migrate_fd_put_ready(void *opaque)
     dprintf("iterate\n");
     if (qemu_savevm_state_iterate(s->file) == 1) {
         dprintf("done iterating\n");
+	strncpy(vm_stop_reason, "migration", STOP_REASON_LEN);
         vm_stop(0);
 
         qemu_aio_flush();
diff --git a/qemu/monitor.c b/qemu/monitor.c
index 072d4b3..1b1c939 100644
--- a/qemu/monitor.c
+++ b/qemu/monitor.c
@@ -610,6 +610,7 @@ static void do_log(const char *items)
 
 static void do_stop(void)
 {
+    strncpy(vm_stop_reason, "monitor command", STOP_REASON_LEN);
     vm_stop(EXCP_INTERRUPT);
 }
 
@@ -1569,6 +1570,11 @@ static void do_info_balloon(void)
         term_printf("balloon: actual=%d\n", (int)(actual >> 20));
 }
 
+static void do_info_stop_reason(void)
+{
+    term_printf("%s\n", vm_stop_reason);
+}
+
 static term_cmd_t term_cmds[] = {
     { "help|?", "s?", do_help,
       "[cmd]", "show the help" },
@@ -1756,6 +1762,8 @@ static term_cmd_t info_cmds[] = {
     { "migrate", "", do_info_migrate, "", "show migration status" },
     { "balloon", "", do_info_balloon,
       "", "show balloon information" },
+    { "stop-reason", "", do_info_stop_reason,
+      "", "show vm stop reason (valid only if vm is stopped)" },
     { NULL, NULL, },
 };
 
diff --git a/qemu/qemu-kvm.c b/qemu/qemu-kvm.c
index 22e4aa5..f11a289 100644
--- a/qemu/qemu-kvm.c
+++ b/qemu/qemu-kvm.c
@@ -606,6 +606,7 @@ int kvm_main_loop(void)
 #ifdef CONFIG_GDBSTUB
 	else if (kvm_debug_cpu_requested) {
 	    gdb_set_stop_cpu(kvm_debug_cpu_requested);
+	    strncpy(vm_stop_reason, "gdbstub", STOP_REASON_LEN);
 	    vm_stop(EXCP_DEBUG);
 	    kvm_debug_cpu_requested = NULL;
 	}
diff --git a/qemu/savevm.c b/qemu/savevm.c
index f3b9707..7089b7d 100644
--- a/qemu/savevm.c
+++ b/qemu/savevm.c
@@ -826,6 +826,7 @@ int qemu_savevm_state(QEMUFile *f)
     int ret;
 
     saved_vm_running = vm_running;
+    strncpy(vm_stop_reason, "savevm", STOP_REASON_LEN);
     vm_stop(0);
 
     bdrv_flush_all();
@@ -1094,6 +1095,7 @@ void do_savevm(const char *name)
     qemu_aio_flush();
 
     saved_vm_running = vm_running;
+    strncpy(vm_stop_reason, "savevm", STOP_REASON_LEN);
     vm_stop(0);
 
     must_delete = 0;
@@ -1190,6 +1192,7 @@ void do_loadvm(const char *name)
     qemu_aio_flush();
 
     saved_vm_running = vm_running;
+    strncpy(vm_stop_reason, "savevm", STOP_REASON_LEN);
     vm_stop(0);
 
     for(i = 0; i <= nb_drives; i++) {
diff --git a/qemu/sysemu.h b/qemu/sysemu.h
index e522a33..b0e4755 100644
--- a/qemu/sysemu.h
+++ b/qemu/sysemu.h
@@ -25,6 +25,8 @@ void qemu_del_vm_stop_handler(VMStopHandler *cb, void *opaque);
 
 void vm_start(void);
 void vm_stop(int reason);
+#define STOP_REASON_LEN 1024
+extern char vm_stop_reason[];
 
 uint64_t ram_bytes_remaining(void);
 uint64_t ram_bytes_transferred(void);
diff --git a/qemu/vl.c b/qemu/vl.c
index 7dd48f0..69d7586 100644
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -3685,6 +3685,8 @@ void vm_start(void)
     }
 }
 
+char vm_stop_reason[STOP_REASON_LEN];
+
 void vm_stop(int reason)
 {
     if (vm_running) {
-- 
1.6.3.rc4.29.g8146