[Qemu-devel] [PATCH v3 0/8]: Introduce the RunState type

[Qemu-devel] [PATCH v3 0/8]: Introduce the RunState type

[Luiz Capitulino]

It replaces the VMSTOP macros and allows us to drop some global variables.

Additionally, the problem with issuing 'cont' when the VM is in bad state
is addressed and we make the current state available in QMP and HMP.

changelog
---------

v3

o Rebase on top of latest master
o Fix a spice VM change state handler which hasn't been converted
o Turn runstate_get() into runstate_check()
o Rename vm_is_running() to runstate_is_running()
o Other minor renames and log improvements

v2

o Rename the new type from QemuState to RunState
  (also renames related functions)
o Rename the enum values to contain proper word seperation
o Redo patch 'Monitor: Don't allow cont on bad VM state' to not use a global
  variable
o Make the current VM state also available in HMP
o Improve some commit logs a bit

 audio/audio.c      |    2 +-
 cpus.c             |   22 ++++++++--------
 cpus.h             |    1 -
 gdbstub.c          |   34 ++++++++++++------------
 hw/etraxfs_dma.c   |    2 +-
 hw/ide/ahci.c      |    2 +-
 hw/ide/core.c      |    4 +-
 hw/ide/internal.h  |    3 +-
 hw/ide/pci.c       |    2 +-
 hw/kvmclock.c      |    5 ++-
 hw/qxl.c           |    5 ++-
 hw/scsi-disk.c     |    4 +-
 hw/virtio-blk.c    |    5 ++-
 hw/virtio.c        |    4 +-
 hw/watchdog.c      |    2 +-
 kvm-all.c          |    2 +-
 migration.c        |   14 ++++++---
 monitor.c          |   22 +++++++++++----
 qemu-timer.c       |   11 ++++---
 qerror.c           |    4 +++
 qerror.h           |    3 ++
 qmp-commands.hx    |   21 ++++++++++++++-
 savevm.c           |    8 +++---
 sysemu.h           |   40 +++++++++++++++++++---------
 target-i386/kvm.c  |    4 +-
 ui/sdl.c           |    6 ++--
 ui/spice-display.c |    3 +-
 ui/spice-display.h |    4 ++-
 vl.c               |   71 +++++++++++++++++++++++++++++++++++++++++++--------
 xen-all.c          |    8 +++--
 30 files changed, 215 insertions(+), 103 deletions(-)

[Qemu-devel] [PATCH 1/8] Move vm_state_notify() prototype from cpus.h to sysemu.h

[Luiz Capitulino]

It's where all the state handling functions prototypes are located.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 cpus.h   |    1 -
 sysemu.h |    1 +
 2 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/cpus.h b/cpus.h
index f42b54e..5885885 100644
--- a/cpus.h
+++ b/cpus.h
@@ -15,7 +15,6 @@ void cpu_synchronize_all_post_init(void);
 /* vl.c */
 extern int smp_cores;
 extern int smp_threads;
-void vm_state_notify(int running, int reason);
 bool cpu_exec_all(void);
 void set_numa_modes(void);
 void set_cpu_log(const char *optarg);
diff --git a/sysemu.h b/sysemu.h
index 9090457..eb66af5 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -23,6 +23,7 @@ typedef void VMChangeStateHandler(void *opaque, int running, int reason);
 VMChangeStateEntry *qemu_add_vm_change_state_handler(VMChangeStateHandler *cb,
                                                      void *opaque);
 void qemu_del_vm_change_state_handler(VMChangeStateEntry *e);
+void vm_state_notify(int running, int reason);
 
 #define VMSTOP_USER      0
 #define VMSTOP_DEBUG     1
-- 
1.7.7.rc0.72.g4b5ea

[Qemu-devel] [PATCH 2/8] Replace the VMSTOP macros with a proper state type

[Luiz Capitulino]

Today, when notifying a VM state change with vm_state_notify(),
we pass a VMSTOP macro as the 'reason' argument. This is not ideal
because the VMSTOP macros tell why qemu stopped and not exactly
what the current VM state is.

One example to demonstrate this problem is that vm_start() calls
vm_state_notify() with reason=0, which turns out to be VMSTOP_USER.

This commit fixes that by replacing the VMSTOP macros with a proper
state type called RunState.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 audio/audio.c      |    2 +-
 cpus.c             |   12 ++++++------
 gdbstub.c          |   30 +++++++++++++++---------------
 hw/ide/ahci.c      |    2 +-
 hw/ide/core.c      |    4 ++--
 hw/ide/internal.h  |    3 ++-
 hw/ide/pci.c       |    2 +-
 hw/kvmclock.c      |    3 ++-
 hw/qxl.c           |    5 +++--
 hw/scsi-disk.c     |    4 ++--
 hw/virtio-blk.c    |    5 +++--
 hw/virtio.c        |    2 +-
 hw/watchdog.c      |    2 +-
 kvm-all.c          |    2 +-
 migration.c        |    2 +-
 monitor.c          |    4 ++--
 qemu-timer.c       |    3 ++-
 savevm.c           |    4 ++--
 sysemu.h           |   30 +++++++++++++++++-------------
 target-i386/kvm.c  |    2 +-
 ui/spice-display.c |    3 ++-
 ui/spice-display.h |    4 +++-
 vl.c               |   12 ++++++------
 xen-all.c          |    6 ++++--
 24 files changed, 81 insertions(+), 67 deletions(-)

diff --git a/audio/audio.c b/audio/audio.c
index 5649075..50d0d71 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1743,7 +1743,7 @@ static int audio_driver_init (AudioState *s, struct audio_driver *drv)
 }
 
 static void audio_vm_change_state_handler (void *opaque, int running,
-                                           int reason)
+                                           RunState state)
 {
     AudioState *s = opaque;
     HWVoiceOut *hwo = NULL;
diff --git a/cpus.c b/cpus.c
index b163efe..6c1b46a 100644
--- a/cpus.c
+++ b/cpus.c
@@ -118,13 +118,13 @@ int cpu_is_stopped(CPUState *env)
     return !vm_running || env->stopped;
 }
 
-static void do_vm_stop(int reason)
+static void do_vm_stop(RunState state)
 {
     if (vm_running) {
         cpu_disable_ticks();
         vm_running = 0;
         pause_all_vcpus();
-        vm_state_notify(0, reason);
+        vm_state_notify(0, state);
         qemu_aio_flush();
         bdrv_flush_all();
         monitor_protocol_event(QEVENT_STOP, NULL);
@@ -628,9 +628,9 @@ void cpu_stop_current(void)
 {
 }
 
-void vm_stop(int reason)
+void vm_stop(RunState state)
 {
-    do_vm_stop(reason);
+    do_vm_stop(state);
 }
 
 #else /* CONFIG_IOTHREAD */
@@ -1014,7 +1014,7 @@ void cpu_stop_current(void)
     }
 }
 
-void vm_stop(int reason)
+void vm_stop(RunState state)
 {
     if (!qemu_thread_is_self(&io_thread)) {
         qemu_system_vmstop_request(reason);
@@ -1025,7 +1025,7 @@ void vm_stop(int reason)
         cpu_stop_current();
         return;
     }
-    do_vm_stop(reason);
+    do_vm_stop(state);
 }
 
 #endif
diff --git a/gdbstub.c b/gdbstub.c
index 3b87c27..a308a76 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -2267,7 +2267,7 @@ void gdb_set_stop_cpu(CPUState *env)
 }
 
 #ifndef CONFIG_USER_ONLY
-static void gdb_vm_state_change(void *opaque, int running, int reason)
+static void gdb_vm_state_change(void *opaque, int running, RunState state)
 {
     GDBState *s = gdbserver_state;
     CPUState *env = s->c_cpu;
@@ -2278,8 +2278,8 @@ static void gdb_vm_state_change(void *opaque, int running, int reason)
     if (running || s->state == RS_INACTIVE || s->state == RS_SYSCALL) {
         return;
     }
-    switch (reason) {
-    case VMSTOP_DEBUG:
+    switch (state) {
+    case RSTATE_DEBUG:
         if (env->watchpoint_hit) {
             switch (env->watchpoint_hit->flags & BP_MEM_ACCESS) {
             case BP_MEM_READ:
@@ -2302,25 +2302,25 @@ static void gdb_vm_state_change(void *opaque, int running, int reason)
         tb_flush(env);
         ret = GDB_SIGNAL_TRAP;
         break;
-    case VMSTOP_USER:
+    case RSTATE_PAUSED:
         ret = GDB_SIGNAL_INT;
         break;
-    case VMSTOP_SHUTDOWN:
+    case RSTATE_SHUTDOWN:
         ret = GDB_SIGNAL_QUIT;
         break;
-    case VMSTOP_DISKFULL:
+    case RSTATE_IO_ERROR:
         ret = GDB_SIGNAL_IO;
         break;
-    case VMSTOP_WATCHDOG:
+    case RSTATE_WATCHDOG:
         ret = GDB_SIGNAL_ALRM;
         break;
-    case VMSTOP_PANIC:
+    case RSTATE_PANICKED:
         ret = GDB_SIGNAL_ABRT;
         break;
-    case VMSTOP_SAVEVM:
-    case VMSTOP_LOADVM:
+    case RSTATE_SAVEVM:
+    case RSTATE_RESTORE:
         return;
-    case VMSTOP_MIGRATE:
+    case RSTATE_PRE_MIGRATE:
         ret = GDB_SIGNAL_XCPU;
         break;
     default:
@@ -2357,7 +2357,7 @@ 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
-    vm_stop(VMSTOP_DEBUG);
+    vm_stop(RSTATE_DEBUG);
 #endif
     s->state = RS_IDLE;
     va_start(va, fmt);
@@ -2431,7 +2431,7 @@ 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 */
-        vm_stop(VMSTOP_USER);
+        vm_stop(RSTATE_PAUSED);
     } else
 #endif
     {
@@ -2693,7 +2693,7 @@ static void gdb_chr_event(void *opaque, int event)
 {
     switch (event) {
     case CHR_EVENT_OPENED:
-        vm_stop(VMSTOP_USER);
+        vm_stop(RSTATE_PAUSED);
         gdb_has_xml = 0;
         break;
     default:
@@ -2734,7 +2734,7 @@ static int gdb_monitor_write(CharDriverState *chr, const uint8_t *buf, int len)
 static void gdb_sigterm_handler(int signal)
 {
     if (vm_running) {
-        vm_stop(VMSTOP_USER);
+        vm_stop(RSTATE_PAUSED);
     }
 }
 #endif
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index f4fa154..b702a32 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -1105,7 +1105,7 @@ static void ahci_irq_set(void *opaque, int n, int level)
 {
 }
 
-static void ahci_dma_restart_cb(void *opaque, int running, int reason)
+static void ahci_dma_restart_cb(void *opaque, int running, RunState state)
 {
 }
 
diff --git a/hw/ide/core.c b/hw/ide/core.c
index 40abc1e..41f2679 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -526,7 +526,7 @@ static int ide_handle_rw_error(IDEState *s, int error, int op)
         s->bus->dma->ops->set_unit(s->bus->dma, s->unit);
         s->bus->error_status = op;
         bdrv_mon_event(s->bs, BDRV_ACTION_STOP, is_read);
-        vm_stop(VMSTOP_DISKFULL);
+        vm_stop(RSTATE_IO_ERROR);
     } else {
         if (op & BM_STATUS_DMA_RETRY) {
             dma_buf_commit(s, 0);
@@ -1840,7 +1840,7 @@ static int ide_nop_int(IDEDMA *dma, int x)
     return 0;
 }
 
-static void ide_nop_restart(void *opaque, int x, int y)
+static void ide_nop_restart(void *opaque, int x, RunState y)
 {
 }
 
diff --git a/hw/ide/internal.h b/hw/ide/internal.h
index 7f5ef8d..cb2e5f9 100644
--- a/hw/ide/internal.h
+++ b/hw/ide/internal.h
@@ -10,6 +10,7 @@
 #include "block_int.h"
 #include "iorange.h"
 #include "dma.h"
+#include "sysemu.h"
 
 /* debug IDE devices */
 //#define DEBUG_IDE
@@ -379,7 +380,7 @@ typedef void EndTransferFunc(IDEState *);
 typedef void DMAStartFunc(IDEDMA *, IDEState *, BlockDriverCompletionFunc *);
 typedef int DMAFunc(IDEDMA *);
 typedef int DMAIntFunc(IDEDMA *, int);
-typedef void DMARestartFunc(void *, int, int);
+typedef void DMARestartFunc(void *, int, RunState);
 
 struct unreported_events {
     bool eject_request;
diff --git a/hw/ide/pci.c b/hw/ide/pci.c
index d1a14d7..46200a5 100644
--- a/hw/ide/pci.c
+++ b/hw/ide/pci.c
@@ -223,7 +223,7 @@ static void bmdma_restart_bh(void *opaque)
     }
 }
 
-static void bmdma_restart_cb(void *opaque, int running, int reason)
+static void bmdma_restart_cb(void *opaque, int running, RunState state)
 {
     IDEDMA *dma = opaque;
     BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
diff --git a/hw/kvmclock.c b/hw/kvmclock.c
index b73aec4..88961be 100644
--- a/hw/kvmclock.c
+++ b/hw/kvmclock.c
@@ -59,7 +59,8 @@ static int kvmclock_post_load(void *opaque, int version_id)
     return kvm_vm_ioctl(kvm_state, KVM_SET_CLOCK, &data);
 }
 
-static void kvmclock_vm_state_change(void *opaque, int running, int reason)
+static void kvmclock_vm_state_change(void *opaque, int running,
+                                     RunState state)
 {
     KVMClockState *s = opaque;
 
diff --git a/hw/qxl.c b/hw/qxl.c
index 1d9077d..19bfe31 100644
--- a/hw/qxl.c
+++ b/hw/qxl.c
@@ -1458,10 +1458,11 @@ static void qxl_hw_text_update(void *opaque, console_ch_t *chardata)
     }
 }
 
-static void qxl_vm_change_state_handler(void *opaque, int running, int reason)
+static void qxl_vm_change_state_handler(void *opaque, int running,
+                                        RunState state)
 {
     PCIQXLDevice *qxl = opaque;
-    qemu_spice_vm_change_state_handler(&qxl->ssd, running, reason);
+    qemu_spice_vm_change_state_handler(&qxl->ssd, running, state);
 
     if (!running && qxl->mode == QXL_MODE_NATIVE) {
         /* dirty all vram (which holds surfaces) and devram (primary surface)
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 3cc830f..9f451bc 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -192,7 +192,7 @@ static int scsi_handle_rw_error(SCSIDiskReq *r, int error, int type)
         r->status |= SCSI_REQ_STATUS_RETRY | type;
 
         bdrv_mon_event(s->bs, BDRV_ACTION_STOP, is_read);
-        vm_stop(VMSTOP_DISKFULL);
+        vm_stop(RSTATE_IO_ERROR);
     } else {
         switch (error) {
         case ENOMEM:
@@ -309,7 +309,7 @@ static void scsi_dma_restart_bh(void *opaque)
     }
 }
 
-static void scsi_dma_restart_cb(void *opaque, int running, int reason)
+static void scsi_dma_restart_cb(void *opaque, int running, RunState state)
 {
     SCSIDiskState *s = opaque;
 
diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index 2a8ccd0..8a33720 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -77,7 +77,7 @@ static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
         req->next = s->rq;
         s->rq = req;
         bdrv_mon_event(s->bs, BDRV_ACTION_STOP, is_read);
-        vm_stop(VMSTOP_DISKFULL);
+        vm_stop(RSTATE_IO_ERROR);
     } else {
         virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
         bdrv_acct_done(s->bs, &req->acct);
@@ -439,7 +439,8 @@ static void virtio_blk_dma_restart_bh(void *opaque)
     virtio_submit_multiwrite(s->bs, &mrb);
 }
 
-static void virtio_blk_dma_restart_cb(void *opaque, int running, int reason)
+static void virtio_blk_dma_restart_cb(void *opaque, int running,
+                                      RunState state)
 {
     VirtIOBlock *s = opaque;
 
diff --git a/hw/virtio.c b/hw/virtio.c
index 13aa0fa..74ab79e 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -837,7 +837,7 @@ void virtio_cleanup(VirtIODevice *vdev)
     g_free(vdev);
 }
 
-static void virtio_vmstate_change(void *opaque, int running, int reason)
+static void virtio_vmstate_change(void *opaque, int running, RunState state)
 {
     VirtIODevice *vdev = opaque;
     bool backend_run = running && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK);
diff --git a/hw/watchdog.c b/hw/watchdog.c
index 1c900a1..71c6c7d 100644
--- a/hw/watchdog.c
+++ b/hw/watchdog.c
@@ -132,7 +132,7 @@ void watchdog_perform_action(void)
 
     case WDT_PAUSE:             /* same as 'stop' command in monitor */
         watchdog_mon_event("pause");
-        vm_stop(VMSTOP_WATCHDOG);
+        vm_stop(RSTATE_WATCHDOG);
         break;
 
     case WDT_DEBUG:
diff --git a/kvm-all.c b/kvm-all.c
index 0ae2e26..f19e706 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1014,7 +1014,7 @@ int kvm_cpu_exec(CPUState *env)
 
     if (ret < 0) {
         cpu_dump_state(env, stderr, fprintf, CPU_DUMP_CODE);
-        vm_stop(VMSTOP_PANIC);
+        vm_stop(RSTATE_PANICKED);
     }
 
     env->exit_request = 0;
diff --git a/migration.c b/migration.c
index f5959b4..29f1a76 100644
--- a/migration.c
+++ b/migration.c
@@ -374,7 +374,7 @@ void migrate_fd_put_ready(void *opaque)
         int old_vm_running = vm_running;
 
         DPRINTF("done iterating\n");
-        vm_stop(VMSTOP_MIGRATE);
+        vm_stop(RSTATE_PRE_MIGRATE);
 
         if ((qemu_savevm_state_complete(s->mon, s->file)) < 0) {
             if (old_vm_running) {
diff --git a/monitor.c b/monitor.c
index 04f465a..4fb10a0 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1291,7 +1291,7 @@ static void do_singlestep(Monitor *mon, const QDict *qdict)
  */
 static int do_stop(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
-    vm_stop(VMSTOP_USER);
+    vm_stop(RSTATE_PAUSED);
     return 0;
 }
 
@@ -2826,7 +2826,7 @@ static void do_loadvm(Monitor *mon, const QDict *qdict)
     int saved_vm_running  = vm_running;
     const char *name = qdict_get_str(qdict, "name");
 
-    vm_stop(VMSTOP_LOADVM);
+    vm_stop(RSTATE_RESTORE);
 
     if (load_vmstate(name) == 0 && saved_vm_running) {
         vm_start();
diff --git a/qemu-timer.c b/qemu-timer.c
index 19313d3..ea3d2a9 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -1134,7 +1134,8 @@ static void win32_rearm_timer(struct qemu_alarm_timer *t)
 
 #endif /* _WIN32 */
 
-static void alarm_timer_on_change_state_rearm(void *opaque, int running, int reason)
+static void alarm_timer_on_change_state_rearm(void *opaque, int running,
+                                              RunState state)
 {
     if (running)
         qemu_rearm_alarm_timer((struct qemu_alarm_timer *) opaque);
diff --git a/savevm.c b/savevm.c
index b06308b..3ef9643 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1603,7 +1603,7 @@ static int qemu_savevm_state(Monitor *mon, QEMUFile *f)
     int ret;
 
     saved_vm_running = vm_running;
-    vm_stop(VMSTOP_SAVEVM);
+    vm_stop(RSTATE_SAVEVM);
 
     if (qemu_savevm_state_blocked(mon)) {
         ret = -EINVAL;
@@ -1932,7 +1932,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
     }
 
     saved_vm_running = vm_running;
-    vm_stop(VMSTOP_SAVEVM);
+    vm_stop(RSTATE_SAVEVM);
 
     memset(sn, 0, sizeof(*sn));
 
diff --git a/sysemu.h b/sysemu.h
index eb66af5..506862d 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -9,6 +9,20 @@
 #include "notify.h"
 
 /* vl.c */
+
+typedef enum {
+    RSTATE_DEBUG,          /* qemu is running under gdb */
+    RSTATE_PANICKED,       /* paused due to an internal error */
+    RSTATE_IO_ERROR,       /* paused due to an I/O error */
+    RSTATE_PAUSED,         /* paused by the user (ie. the 'stop' command) */
+    RSTATE_PRE_MIGRATE,    /* paused preparing to finish migrate */
+    RSTATE_RESTORE,        /* paused restoring the VM state */
+    RSTATE_RUNNING,        /* qemu is running */
+    RSTATE_SAVEVM,         /* paused saving VM state */
+    RSTATE_SHUTDOWN,       /* guest shut down and -no-shutdown is in use */
+    RSTATE_WATCHDOG        /* watchdog fired and qemu is configured to pause */
+} RunState;
+
 extern const char *bios_name;
 
 extern int vm_running;
@@ -18,28 +32,18 @@ int qemu_uuid_parse(const char *str, uint8_t *uuid);
 #define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
 
 typedef struct vm_change_state_entry VMChangeStateEntry;
-typedef void VMChangeStateHandler(void *opaque, int running, int reason);
+typedef void VMChangeStateHandler(void *opaque, int running, RunState state);
 
 VMChangeStateEntry *qemu_add_vm_change_state_handler(VMChangeStateHandler *cb,
                                                      void *opaque);
 void qemu_del_vm_change_state_handler(VMChangeStateEntry *e);
-void vm_state_notify(int running, int reason);
-
-#define VMSTOP_USER      0
-#define VMSTOP_DEBUG     1
-#define VMSTOP_SHUTDOWN  2
-#define VMSTOP_DISKFULL  3
-#define VMSTOP_WATCHDOG  4
-#define VMSTOP_PANIC     5
-#define VMSTOP_SAVEVM    6
-#define VMSTOP_LOADVM    7
-#define VMSTOP_MIGRATE   8
+void vm_state_notify(int running, RunState state);
 
 #define VMRESET_SILENT   false
 #define VMRESET_REPORT   true
 
 void vm_start(void);
-void vm_stop(int reason);
+void vm_stop(RunState state);
 
 void qemu_system_reset_request(void);
 void qemu_system_shutdown_request(void);
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 1d9b20c..636a958 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -334,7 +334,7 @@ static int kvm_inject_mce_oldstyle(CPUState *env)
     return 0;
 }
 
-static void cpu_update_state(void *opaque, int running, int reason)
+static void cpu_update_state(void *opaque, int running, RunState state)
 {
     CPUState *env = opaque;
 
diff --git a/ui/spice-display.c b/ui/spice-display.c
index 4983963..3e7b48b 100644
--- a/ui/spice-display.c
+++ b/ui/spice-display.c
@@ -255,7 +255,8 @@ void qemu_spice_destroy_host_primary(SimpleSpiceDisplay *ssd)
     qemu_spice_destroy_primary_surface(ssd, 0, QXL_SYNC);
 }
 
-void qemu_spice_vm_change_state_handler(void *opaque, int running, int reason)
+void qemu_spice_vm_change_state_handler(void *opaque, int running,
+                                        RunState state)
 {
     SimpleSpiceDisplay *ssd = opaque;
 
diff --git a/ui/spice-display.h b/ui/spice-display.h
index 1388641..5e52df9 100644
--- a/ui/spice-display.h
+++ b/ui/spice-display.h
@@ -22,6 +22,7 @@
 #include "qemu-thread.h"
 #include "console.h"
 #include "pflib.h"
+#include "sysemu.h"
 
 #define NUM_MEMSLOTS 8
 #define MEMSLOT_GENERATION_BITS 8
@@ -88,7 +89,8 @@ void qemu_spice_destroy_update(SimpleSpiceDisplay *sdpy, SimpleSpiceUpdate *upda
 void qemu_spice_create_host_memslot(SimpleSpiceDisplay *ssd);
 void qemu_spice_create_host_primary(SimpleSpiceDisplay *ssd);
 void qemu_spice_destroy_host_primary(SimpleSpiceDisplay *ssd);
-void qemu_spice_vm_change_state_handler(void *opaque, int running, int reason);
+void qemu_spice_vm_change_state_handler(void *opaque, int running,
+                                        RunState state);
 void qemu_spice_display_init_common(SimpleSpiceDisplay *ssd, DisplayState *ds);
 
 void qemu_spice_display_update(SimpleSpiceDisplay *ssd,
diff --git a/vl.c b/vl.c
index 9cd67a3..f0b56a4 100644
--- a/vl.c
+++ b/vl.c
@@ -1143,14 +1143,14 @@ void qemu_del_vm_change_state_handler(VMChangeStateEntry *e)
     g_free (e);
 }
 
-void vm_state_notify(int running, int reason)
+void vm_state_notify(int running, RunState state)
 {
     VMChangeStateEntry *e;
 
-    trace_vm_state_notify(running, reason);
+    trace_vm_state_notify(running, state);
 
     for (e = vm_change_state_head.lh_first; e; e = e->entries.le_next) {
-        e->cb(e->opaque, running, reason);
+        e->cb(e->opaque, running, state);
     }
 }
 
@@ -1159,7 +1159,7 @@ void vm_start(void)
     if (!vm_running) {
         cpu_enable_ticks();
         vm_running = 1;
-        vm_state_notify(1, 0);
+        vm_state_notify(1, RSTATE_RUNNING);
         resume_all_vcpus();
         monitor_protocol_event(QEVENT_RESUME, NULL);
     }
@@ -1413,13 +1413,13 @@ static void main_loop(void)
 #endif
 
         if (qemu_debug_requested()) {
-            vm_stop(VMSTOP_DEBUG);
+            vm_stop(RSTATE_DEBUG);
         }
         if (qemu_shutdown_requested()) {
             qemu_kill_report();
             monitor_protocol_event(QEVENT_SHUTDOWN, NULL);
             if (no_shutdown) {
-                vm_stop(VMSTOP_SHUTDOWN);
+                vm_stop(RSTATE_SHUTDOWN);
             } else
                 break;
         }
diff --git a/xen-all.c b/xen-all.c
index 84420d8..24aeb83 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -846,7 +846,8 @@ static void xen_main_loop_prepare(XenIOState *state)
 
 /* Initialise Xen */
 
-static void xen_change_state_handler(void *opaque, int running, int reason)
+static void xen_change_state_handler(void *opaque, int running,
+                                     RunState state)
 {
     if (running) {
         /* record state running */
@@ -854,7 +855,8 @@ static void xen_change_state_handler(void *opaque, int running, int reason)
     }
 }
 
-static void xen_hvm_change_state_handler(void *opaque, int running, int reason)
+static void xen_hvm_change_state_handler(void *opaque, int running,
+                                         RunState state)
 {
     XenIOState *state = opaque;
     if (running) {
-- 
1.7.7.rc0.72.g4b5ea

[Qemu-devel] [PATCH 3/8] RunState: Add additional states

[Luiz Capitulino]

Currently, only vm_start() and vm_stop() change the VM state.
That's, the state is only changed when starting or stopping the VM.

This commit adds the runstate_set() function, which makes it possible
to also do state transitions when the VM is stopped or running.

Additional states are also added and the current state is stored.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 cpus.c      |    1 +
 migration.c |    8 +++++++-
 sysemu.h    |   10 +++++++++-
 vl.c        |   20 ++++++++++++++++++++
 4 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/cpus.c b/cpus.c
index 6c1b46a..fc94066 100644
--- a/cpus.c
+++ b/cpus.c
@@ -124,6 +124,7 @@ static void do_vm_stop(RunState state)
         cpu_disable_ticks();
         vm_running = 0;
         pause_all_vcpus();
+        runstate_set(state);
         vm_state_notify(0, state);
         qemu_aio_flush();
         bdrv_flush_all();
diff --git a/migration.c b/migration.c
index 29f1a76..f2499cf 100644
--- a/migration.c
+++ b/migration.c
@@ -72,8 +72,11 @@ void process_incoming_migration(QEMUFile *f)
 
     incoming_expected = false;
 
-    if (autostart)
+    if (autostart) {
         vm_start();
+    } else {
+        runstate_set(RSTATE_PRE_LAUNCH);
+    }
 }
 
 int do_migrate(Monitor *mon, const QDict *qdict, QObject **ret_data)
@@ -390,6 +393,9 @@ void migrate_fd_put_ready(void *opaque)
             }
             state = MIG_STATE_ERROR;
         }
+        if (state == MIG_STATE_COMPLETED) {
+            runstate_set(RSTATE_POST_MIGRATE);
+        }
         s->state = state;
         notifier_list_notify(&migration_state_notifiers, NULL);
     }
diff --git a/sysemu.h b/sysemu.h
index 506862d..865f51a 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -11,16 +11,22 @@
 /* vl.c */
 
 typedef enum {
+    RSTATE_NO_STATE,
     RSTATE_DEBUG,          /* qemu is running under gdb */
+    RSTATE_IN_MIGRATE,     /* paused waiting for an incoming migration */
     RSTATE_PANICKED,       /* paused due to an internal error */
     RSTATE_IO_ERROR,       /* paused due to an I/O error */
     RSTATE_PAUSED,         /* paused by the user (ie. the 'stop' command) */
+    RSTATE_POST_MIGRATE,   /* paused following a successful migration */
+    RSTATE_PRE_LAUNCH,     /* qemu was started with -S and haven't started */
     RSTATE_PRE_MIGRATE,    /* paused preparing to finish migrate */
     RSTATE_RESTORE,        /* paused restoring the VM state */
+    RSTATE_RESTORE_FAILED, /* paused due to a failed attempt to load state */
     RSTATE_RUNNING,        /* qemu is running */
     RSTATE_SAVEVM,         /* paused saving VM state */
     RSTATE_SHUTDOWN,       /* guest shut down and -no-shutdown is in use */
-    RSTATE_WATCHDOG        /* watchdog fired and qemu is configured to pause */
+    RSTATE_WATCHDOG,       /* watchdog fired and qemu is configured to pause */
+    RSTATE_MAX
 } RunState;
 
 extern const char *bios_name;
@@ -31,6 +37,8 @@ extern uint8_t qemu_uuid[];
 int qemu_uuid_parse(const char *str, uint8_t *uuid);
 #define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
 
+bool runstate_check(RunState state);
+void runstate_set(RunState state);
 typedef struct vm_change_state_entry VMChangeStateEntry;
 typedef void VMChangeStateHandler(void *opaque, int running, RunState state);
 
diff --git a/vl.c b/vl.c
index f0b56a4..59f71fc 100644
--- a/vl.c
+++ b/vl.c
@@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
 }
 
 /***********************************************************/
+/* QEMU state */
+
+static RunState current_run_state = RSTATE_NO_STATE;
+
+bool runstate_check(RunState state)
+{
+    return current_run_state == state;
+}
+
+void runstate_set(RunState state)
+{
+    assert(state < RSTATE_MAX);
+    current_run_state = state;
+}
+
+/***********************************************************/
 /* real time host monotonic timer */
 
 /***********************************************************/
@@ -1159,6 +1175,7 @@ void vm_start(void)
     if (!vm_running) {
         cpu_enable_ticks();
         vm_running = 1;
+        runstate_set(RSTATE_RUNNING);
         vm_state_notify(1, RSTATE_RUNNING);
         resume_all_vcpus();
         monitor_protocol_event(QEVENT_RESUME, NULL);
@@ -3378,6 +3395,7 @@ int main(int argc, char **argv, char **envp)
     }
 
     if (incoming) {
+        runstate_set(RSTATE_IN_MIGRATE);
         int ret = qemu_start_incoming_migration(incoming);
         if (ret < 0) {
             fprintf(stderr, "Migration failed. Exit code %s(%d), exiting.\n",
@@ -3386,6 +3404,8 @@ int main(int argc, char **argv, char **envp)
         }
     } else if (autostart) {
         vm_start();
+    } else {
+        runstate_set(RSTATE_PRE_LAUNCH);
     }
 
     os_setup_post();
-- 
1.7.7.rc0.72.g4b5ea

[Qemu-devel] [PATCH 4/8] Drop the incoming_expected global variable

[Luiz Capitulino]

Test against RSTATE_IN_MIGRATE instead.

Please, note that the RSTATE_IN_MIGRATE state is only set when all the
initial VM setup is done, while 'incoming_expected' was set right in
the beginning when parsing command-line options. Shouldn't be a problem
as far as I could check.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 migration.c |    2 --
 monitor.c   |    2 +-
 vl.c        |    2 --
 3 files changed, 1 insertions(+), 5 deletions(-)

diff --git a/migration.c b/migration.c
index f2499cf..a63e2a2 100644
--- a/migration.c
+++ b/migration.c
@@ -70,8 +70,6 @@ void process_incoming_migration(QEMUFile *f)
     qemu_announce_self();
     DPRINTF("successfully loaded vm state\n");
 
-    incoming_expected = false;
-
     if (autostart) {
         vm_start();
     } else {
diff --git a/monitor.c b/monitor.c
index 4fb10a0..4612c89 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1309,7 +1309,7 @@ static int do_cont(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     struct bdrv_iterate_context context = { mon, 0 };
 
-    if (incoming_expected) {
+    if (runstate_check(RSTATE_IN_MIGRATE)) {
         qerror_report(QERR_MIGRATION_EXPECTED);
         return -1;
     }
diff --git a/vl.c b/vl.c
index 59f71fc..e9d57d0 100644
--- a/vl.c
+++ b/vl.c
@@ -185,7 +185,6 @@ int nb_nics;
 NICInfo nd_table[MAX_NICS];
 int vm_running;
 int autostart;
-int incoming_expected; /* Started with -incoming and waiting for incoming */
 static int rtc_utc = 1;
 static int rtc_date_offset = -1; /* -1 means no change */
 QEMUClock *rtc_clock;
@@ -2911,7 +2910,6 @@ int main(int argc, char **argv, char **envp)
                 break;
             case QEMU_OPTION_incoming:
                 incoming = optarg;
-                incoming_expected = true;
                 break;
             case QEMU_OPTION_nodefaults:
                 default_serial = 0;
-- 
1.7.7.rc0.72.g4b5ea

[Qemu-devel] [PATCH 5/8] Drop the vm_running global variable

[Luiz Capitulino]

Use runstate_is_running() instead, which is introduced by this commit.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 cpus.c            |    9 ++++-----
 gdbstub.c         |    4 ++--
 hw/etraxfs_dma.c  |    2 +-
 hw/kvmclock.c     |    2 +-
 hw/virtio.c       |    2 +-
 migration.c       |    2 +-
 monitor.c         |    4 ++--
 qemu-timer.c      |    8 ++++----
 savevm.c          |    4 ++--
 sysemu.h          |    2 +-
 target-i386/kvm.c |    2 +-
 ui/sdl.c          |    6 +++---
 vl.c              |    9 ++++++---
 xen-all.c         |    2 +-
 14 files changed, 30 insertions(+), 28 deletions(-)

diff --git a/cpus.c b/cpus.c
index fc94066..28d4a9c 100644
--- a/cpus.c
+++ b/cpus.c
@@ -115,14 +115,13 @@ void cpu_synchronize_all_post_init(void)
 
 int cpu_is_stopped(CPUState *env)
 {
-    return !vm_running || env->stopped;
+    return !runstate_is_running() || env->stopped;
 }
 
 static void do_vm_stop(RunState state)
 {
-    if (vm_running) {
+    if (runstate_is_running()) {
         cpu_disable_ticks();
-        vm_running = 0;
         pause_all_vcpus();
         runstate_set(state);
         vm_state_notify(0, state);
@@ -137,7 +136,7 @@ static int cpu_can_run(CPUState *env)
     if (env->stop) {
         return 0;
     }
-    if (env->stopped || !vm_running) {
+    if (env->stopped || !runstate_is_running()) {
         return 0;
     }
     return 1;
@@ -148,7 +147,7 @@ static bool cpu_thread_is_idle(CPUState *env)
     if (env->stop || env->queued_work_first) {
         return false;
     }
-    if (env->stopped || !vm_running) {
+    if (env->stopped || !runstate_is_running()) {
         return true;
     }
     if (!env->halted || qemu_cpu_has_work(env) ||
diff --git a/gdbstub.c b/gdbstub.c
index a308a76..ceb39cc 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -2428,7 +2428,7 @@ static void gdb_read_byte(GDBState *s, int ch)
         if (ch != '$')
             return;
     }
-    if (vm_running) {
+    if (runstate_is_running()) {
         /* when the CPU is running, we cannot do anything except stop
            it when receiving a char */
         vm_stop(RSTATE_PAUSED);
@@ -2733,7 +2733,7 @@ static int gdb_monitor_write(CharDriverState *chr, const uint8_t *buf, int len)
 #ifndef _WIN32
 static void gdb_sigterm_handler(int signal)
 {
-    if (vm_running) {
+    if (runstate_is_running()) {
         vm_stop(RSTATE_PAUSED);
     }
 }
diff --git a/hw/etraxfs_dma.c b/hw/etraxfs_dma.c
index e8ad9e6..d3082ac 100644
--- a/hw/etraxfs_dma.c
+++ b/hw/etraxfs_dma.c
@@ -732,7 +732,7 @@ static void DMA_run(void *opaque)
     struct fs_dma_ctrl *etraxfs_dmac = opaque;
     int p = 1;
 
-    if (vm_running)
+    if (runstate_is_running())
         p = etraxfs_dmac_run(etraxfs_dmac);
 
     if (p)
diff --git a/hw/kvmclock.c b/hw/kvmclock.c
index 88961be..5388bc4 100644
--- a/hw/kvmclock.c
+++ b/hw/kvmclock.c
@@ -46,7 +46,7 @@ static void kvmclock_pre_save(void *opaque)
      * it on next vmsave (which would return a different value). Will be reset
      * when the VM is continued.
      */
-    s->clock_valid = !vm_running;
+    s->clock_valid = !runstate_is_running();
 }
 
 static int kvmclock_post_load(void *opaque, int version_id)
diff --git a/hw/virtio.c b/hw/virtio.c
index 74ab79e..c577bbe 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -870,7 +870,7 @@ VirtIODevice *virtio_common_init(const char *name, uint16_t device_id,
     vdev->queue_sel = 0;
     vdev->config_vector = VIRTIO_NO_VECTOR;
     vdev->vq = g_malloc0(sizeof(VirtQueue) * VIRTIO_PCI_QUEUE_MAX);
-    vdev->vm_running = vm_running;
+    vdev->vm_running = runstate_is_running();
     for(i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) {
         vdev->vq[i].vector = VIRTIO_NO_VECTOR;
         vdev->vq[i].vdev = vdev;
diff --git a/migration.c b/migration.c
index a63e2a2..7dd8f4e 100644
--- a/migration.c
+++ b/migration.c
@@ -372,7 +372,7 @@ void migrate_fd_put_ready(void *opaque)
     DPRINTF("iterate\n");
     if (qemu_savevm_state_iterate(s->mon, s->file) == 1) {
         int state;
-        int old_vm_running = vm_running;
+        int old_vm_running = runstate_is_running();
 
         DPRINTF("done iterating\n");
         vm_stop(RSTATE_PRE_MIGRATE);
diff --git a/monitor.c b/monitor.c
index 4612c89..03ffd74 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2630,7 +2630,7 @@ static void do_info_status_print(Monitor *mon, const QObject *data)
 static void do_info_status(Monitor *mon, QObject **ret_data)
 {
     *ret_data = qobject_from_jsonf("{ 'running': %i, 'singlestep': %i }",
-                                    vm_running, singlestep);
+                                    runstate_is_running(), singlestep);
 }
 
 static qemu_acl *find_acl(Monitor *mon, const char *name)
@@ -2823,7 +2823,7 @@ static int do_closefd(Monitor *mon, const QDict *qdict, QObject **ret_data)
 
 static void do_loadvm(Monitor *mon, const QDict *qdict)
 {
-    int saved_vm_running  = vm_running;
+    int saved_vm_running  = runstate_is_running();
     const char *name = qdict_get_str(qdict, "name");
 
     vm_stop(RSTATE_RESTORE);
diff --git a/qemu-timer.c b/qemu-timer.c
index ea3d2a9..290786d 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -246,7 +246,7 @@ static void icount_adjust(void)
     int64_t delta;
     static int64_t last_delta;
     /* If the VM is not running, then do nothing.  */
-    if (!vm_running)
+    if (!runstate_is_running())
         return;
 
     cur_time = cpu_get_clock();
@@ -404,7 +404,7 @@ static void icount_warp_rt(void *opaque)
         return;
     }
 
-    if (vm_running) {
+    if (runstate_is_running()) {
         int64_t clock = qemu_get_clock_ns(rt_clock);
         int64_t warp_delta = clock - vm_clock_warp_start;
         if (use_icount == 1) {
@@ -728,7 +728,7 @@ void qemu_run_all_timers(void)
     }
 
     /* vm time timers */
-    if (vm_running) {
+    if (runstate_is_running()) {
         qemu_run_timers(vm_clock);
     }
 
@@ -1182,7 +1182,7 @@ int qemu_calculate_timeout(void)
 #ifndef CONFIG_IOTHREAD
     int timeout;
 
-    if (!vm_running)
+    if (!runstate_is_running())
         timeout = 5000;
     else {
      /* XXX: use timeout computed from timers */
diff --git a/savevm.c b/savevm.c
index 3ef9643..b5a3f44 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1602,7 +1602,7 @@ static int qemu_savevm_state(Monitor *mon, QEMUFile *f)
     int saved_vm_running;
     int ret;
 
-    saved_vm_running = vm_running;
+    saved_vm_running = runstate_is_running();
     vm_stop(RSTATE_SAVEVM);
 
     if (qemu_savevm_state_blocked(mon)) {
@@ -1931,7 +1931,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
         return;
     }
 
-    saved_vm_running = vm_running;
+    saved_vm_running = runstate_is_running();
     vm_stop(RSTATE_SAVEVM);
 
     memset(sn, 0, sizeof(*sn));
diff --git a/sysemu.h b/sysemu.h
index 865f51a..795525f 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -31,13 +31,13 @@ typedef enum {
 
 extern const char *bios_name;
 
-extern int vm_running;
 extern const char *qemu_name;
 extern uint8_t qemu_uuid[];
 int qemu_uuid_parse(const char *str, uint8_t *uuid);
 #define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
 
 bool runstate_check(RunState state);
+int runstate_is_running(void);
 void runstate_set(RunState state);
 typedef struct vm_change_state_entry VMChangeStateEntry;
 typedef void VMChangeStateHandler(void *opaque, int running, RunState state);
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 636a958..8f963ed 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -1130,7 +1130,7 @@ static int kvm_get_msrs(CPUState *env)
 
     if (!env->tsc_valid) {
         msrs[n++].index = MSR_IA32_TSC;
-        env->tsc_valid = !vm_running;
+        env->tsc_valid = !runstate_is_running();
     }
 
 #ifdef TARGET_X86_64
diff --git a/ui/sdl.c b/ui/sdl.c
index c7aaedf..8cafc44 100644
--- a/ui/sdl.c
+++ b/ui/sdl.c
@@ -409,7 +409,7 @@ static void sdl_update_caption(void)
     char icon_title[1024];
     const char *status = "";
 
-    if (!vm_running)
+    if (!runstate_is_running())
         status = " [Stopped]";
     else if (gui_grab) {
         if (alt_grab)
@@ -853,8 +853,8 @@ static void sdl_refresh(DisplayState *ds)
 {
     SDL_Event ev1, *ev = &ev1;
 
-    if (last_vm_running != vm_running) {
-        last_vm_running = vm_running;
+    if (last_vm_running != runstate_is_running()) {
+        last_vm_running = runstate_is_running();
         sdl_update_caption();
     }
 
diff --git a/vl.c b/vl.c
index e9d57d0..3c7f2bf 100644
--- a/vl.c
+++ b/vl.c
@@ -183,7 +183,6 @@ int mem_prealloc = 0; /* force preallocation of physical target memory */
 #endif
 int nb_nics;
 NICInfo nd_table[MAX_NICS];
-int vm_running;
 int autostart;
 static int rtc_utc = 1;
 static int rtc_date_offset = -1; /* -1 means no change */
@@ -335,6 +334,11 @@ void runstate_set(RunState state)
     current_run_state = state;
 }
 
+int runstate_is_running(void)
+{
+    return runstate_check(RSTATE_RUNNING);
+}
+
 /***********************************************************/
 /* real time host monotonic timer */
 
@@ -1171,9 +1175,8 @@ void vm_state_notify(int running, RunState state)
 
 void vm_start(void)
 {
-    if (!vm_running) {
+    if (!runstate_is_running()) {
         cpu_enable_ticks();
-        vm_running = 1;
         runstate_set(RSTATE_RUNNING);
         vm_state_notify(1, RSTATE_RUNNING);
         resume_all_vcpus();
diff --git a/xen-all.c b/xen-all.c
index 24aeb83..8bf48c2 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -736,7 +736,7 @@ static void cpu_handle_ioreq(void *opaque)
          * guest resumes and does a hlt with interrupts disabled which
          * causes Xen to powerdown the domain.
          */
-        if (vm_running) {
+        if (runstate_is_running()) {
             if (qemu_shutdown_requested_get()) {
                 destroy_hvm_domain();
             }
-- 
1.7.7.rc0.72.g4b5ea

[Qemu-devel] [PATCH 6/8] Monitor/QMP: Don't allow cont on bad VM state

[Luiz Capitulino]

We have two states where issuing cont before system_reset can
cause problems: RSTATE_SHUTDOWN (when -no-shutdown is used) and
RSTATE_PANICKED (which only happens with kvm).

This commit fixes that by doing the following when state is
RSTATE_SHUTDOWN or RSTATE_PANICKED:

 1. returning an error to the user/client if cont is issued
 2. automatically transition to RSTATE_PAUSED during system_reset

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 monitor.c |    5 +++++
 qerror.c  |    4 ++++
 qerror.h  |    3 +++
 vl.c      |    4 ++++
 4 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/monitor.c b/monitor.c
index 03ffd74..3468be6 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1312,7 +1312,12 @@ static int do_cont(Monitor *mon, const QDict *qdict, QObject **ret_data)
     if (runstate_check(RSTATE_IN_MIGRATE)) {
         qerror_report(QERR_MIGRATION_EXPECTED);
         return -1;
+    } else if (runstate_check(RSTATE_PANICKED) ||
+               runstate_check(RSTATE_SHUTDOWN)) {
+        qerror_report(QERR_RESET_REQUIRED);
+        return -1;
     }
+
     bdrv_iterate(encrypted_bdrv_it, &context);
     /* only resume the vm if all keys are set and valid */
     if (!context.err) {
diff --git a/qerror.c b/qerror.c
index 3d64b80..c591a54 100644
--- a/qerror.c
+++ b/qerror.c
@@ -194,6 +194,10 @@ static const QErrorStringTable qerror_table[] = {
         .desc      = "QMP input object member '%(member)' is unexpected",
     },
     {
+        .error_fmt = QERR_RESET_REQUIRED,
+        .desc      = "Resetting the Virtual Machine is required",
+    },
+    {
         .error_fmt = QERR_SET_PASSWD_FAILED,
         .desc      = "Could not set password",
     },
diff --git a/qerror.h b/qerror.h
index 8058456..d407001 100644
--- a/qerror.h
+++ b/qerror.h
@@ -163,6 +163,9 @@ QError *qobject_to_qerror(const QObject *obj);
 #define QERR_QMP_EXTRA_MEMBER \
     "{ 'class': 'QMPExtraInputObjectMember', 'data': { 'member': %s } }"
 
+#define QERR_RESET_REQUIRED \
+    "{ 'class': 'ResetRequired', 'data': {} }"
+
 #define QERR_SET_PASSWD_FAILED \
     "{ 'class': 'SetPasswdFailed', 'data': {} }"
 
diff --git a/vl.c b/vl.c
index 3c7f2bf..b535afd 100644
--- a/vl.c
+++ b/vl.c
@@ -1447,6 +1447,10 @@ static void main_loop(void)
             cpu_synchronize_all_states();
             qemu_system_reset(VMRESET_REPORT);
             resume_all_vcpus();
+            if (runstate_check(RSTATE_PANICKED) ||
+                runstate_check(RSTATE_SHUTDOWN)) {
+                runstate_set(RSTATE_PAUSED);
+            }
         }
         if (qemu_powerdown_requested()) {
             monitor_protocol_event(QEVENT_POWERDOWN, NULL);
-- 
1.7.7.rc0.72.g4b5ea

[Qemu-devel] [PATCH 7/8] QMP: query-status: Introduce 'status' key

[Luiz Capitulino]

This new key reports the current VM status to clients. Please, check
the documentation being added in this commit for more details.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 monitor.c       |    3 +--
 qmp-commands.hx |   21 ++++++++++++++++++++-
 sysemu.h        |    1 +
 vl.c            |   24 ++++++++++++++++++++++++
 4 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/monitor.c b/monitor.c
index 3468be6..13ebd2e 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2634,8 +2634,7 @@ static void do_info_status_print(Monitor *mon, const QObject *data)
 
 static void do_info_status(Monitor *mon, QObject **ret_data)
 {
-    *ret_data = qobject_from_jsonf("{ 'running': %i, 'singlestep': %i }",
-                                    runstate_is_running(), singlestep);
+    *ret_data = qobject_from_jsonf("{ 'running': %i, 'singlestep': %i, 'status': %s }", runstate_is_running(), singlestep, runstate_as_string());
 }
 
 static qemu_acl *find_acl(Monitor *mon, const char *name)
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 27cc66e..1fbda8c 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1571,11 +1571,30 @@ Return a json-object with the following information:
 - "running": true if the VM is running, or false if it is paused (json-bool)
 - "singlestep": true if the VM is in single step mode,
                 false otherwise (json-bool)
+- "status": one of the following values (json-string)
+    "debug" - QEMU is running on a debugger
+    "inmigrate" - guest is paused waiting for an incoming migration
+    "internal-error" - An internal error that prevents further guest
+    execution has occurred
+    "io-error" - the last IOP has failed and the device is configured
+    to pause on I/O errors
+    "paused" - guest has been paused via the 'stop' command
+    "postmigrate" - guest is paused following a successful 'migrate'
+    "prelaunch" - QEMU was started with -S and guest has not started
+    "finish-migrate" - guest is paused to finish the migration process
+    "restore-vm" - guest is paused to restore VM state
+    "restore-vm-failed" - guest is paused following a failed attempt to
+    restore the VM state
+    "running" - guest is actively running
+    "save-vm" - guest is paused to save the VM state
+    "shutdown" - guest is shut down (and -no-shutdown is in use)
+    "watchdog" - the watchdog action is configured to pause and
+     has been triggered
 
 Example:
 
 -> { "execute": "query-status" }
-<- { "return": { "running": true, "singlestep": false } }
+<- { "return": { "running": true, "singlestep": false, "status": "running" } }
 
 EQMP
 
diff --git a/sysemu.h b/sysemu.h
index 795525f..7fa28ce 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -38,6 +38,7 @@ int qemu_uuid_parse(const char *str, uint8_t *uuid);
 
 bool runstate_check(RunState state);
 int runstate_is_running(void);
+const char *runstate_as_string(void);
 void runstate_set(RunState state);
 typedef struct vm_change_state_entry VMChangeStateEntry;
 typedef void VMChangeStateHandler(void *opaque, int running, RunState state);
diff --git a/vl.c b/vl.c
index b535afd..986dcea 100644
--- a/vl.c
+++ b/vl.c
@@ -321,6 +321,23 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
 /***********************************************************/
 /* QEMU state */
 
+static const char *const runstate_name_tbl[RSTATE_MAX] = {
+    [RSTATE_DEBUG] = "debug",
+    [RSTATE_IN_MIGRATE] = "incoming-migration",
+    [RSTATE_PANICKED] = "internal-error",
+    [RSTATE_IO_ERROR] = "io-error",
+    [RSTATE_PAUSED] = "paused",
+    [RSTATE_POST_MIGRATE] = "post-migrate",
+    [RSTATE_PRE_LAUNCH] = "prelaunch",
+    [RSTATE_PRE_MIGRATE] = "finish-migrate",
+    [RSTATE_RESTORE] = "restore-vm",
+    [RSTATE_RESTORE_FAILED] = "restore-vm-failed",
+    [RSTATE_RUNNING] = "running",
+    [RSTATE_SAVEVM] = "save-vm",
+    [RSTATE_SHUTDOWN] = "shutdown",
+    [RSTATE_WATCHDOG] = "watchdog",
+};
+
 static RunState current_run_state = RSTATE_NO_STATE;
 
 bool runstate_check(RunState state)
@@ -334,6 +351,13 @@ void runstate_set(RunState state)
     current_run_state = state;
 }
 
+const char *runstate_as_string(void)
+{
+    assert(current_run_state > RSTATE_NO_STATE &&
+           current_run_state < RSTATE_MAX);
+    return runstate_name_tbl[current_run_state];
+}
+
 int runstate_is_running(void)
 {
     return runstate_check(RSTATE_RUNNING);
-- 
1.7.7.rc0.72.g4b5ea

[Qemu-devel] [PATCH 8/8] HMP: info status: Print the VM state

[Luiz Capitulino]

Today our printf format for the "info status" command is:

  VM status: %s

Where the string can be "running", "running (single step mode)" or
"paused".

This commit extends it to:

 VM status: %s (%s)

The second string corresponds to the "status" field as returned
by the query-status QMP command and it's only printed if "status"
is not "running" or "paused".

Example:

 VM status: paused (shutdown)

PS: libvirt uses "info status" when using HMP, but the new format
    should not break it.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 monitor.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/monitor.c b/monitor.c
index 13ebd2e..9807005 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2616,6 +2616,7 @@ static int do_inject_nmi(Monitor *mon, const QDict *qdict, QObject **ret_data)
 static void do_info_status_print(Monitor *mon, const QObject *data)
 {
     QDict *qdict;
+    const char *status;
 
     qdict = qobject_to_qdict(data);
 
@@ -2629,6 +2630,11 @@ static void do_info_status_print(Monitor *mon, const QObject *data)
         monitor_printf(mon, "paused");
     }
 
+    status = qdict_get_str(qdict, "status");
+    if (strcmp(status, "paused") && strcmp(status, "running")) {
+        monitor_printf(mon, " (%s)", status);
+    }
+
     monitor_printf(mon, "\n");
 }
 
-- 
1.7.7.rc0.72.g4b5ea

Re: [Qemu-devel] [PATCH 3/8] RunState: Add additional states

[Jan Kiszka]

On 2011-09-01 20:12, Luiz Capitulino wrote:
> Currently, only vm_start() and vm_stop() change the VM state.
> That's, the state is only changed when starting or stopping the VM.
> 
> This commit adds the runstate_set() function, which makes it possible
> to also do state transitions when the VM is stopped or running.
> 
> Additional states are also added and the current state is stored.
> 
> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> ---
>  cpus.c      |    1 +
>  migration.c |    8 +++++++-
>  sysemu.h    |   10 +++++++++-
>  vl.c        |   20 ++++++++++++++++++++
>  4 files changed, 37 insertions(+), 2 deletions(-)
> 

...

> diff --git a/vl.c b/vl.c
> index f0b56a4..59f71fc 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
>  }
>  
>  /***********************************************************/
> +/* QEMU state */
> +
> +static RunState current_run_state = RSTATE_NO_STATE;
> +
> +bool runstate_check(RunState state)
> +{
> +    return current_run_state == state;
> +}
> +
> +void runstate_set(RunState state)
> +{
> +    assert(state < RSTATE_MAX);
> +    current_run_state = state;

I still think this should check for valid state transitions instead of
blindly accepting what the caller passes in.

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux

Re: [Qemu-devel] [PATCH 3/8] RunState: Add additional states

[Luiz Capitulino]

On Thu, 01 Sep 2011 20:30:57 +0200
Jan Kiszka <jan.kiszka@siemens.com> wrote:

> On 2011-09-01 20:12, Luiz Capitulino wrote:
> > Currently, only vm_start() and vm_stop() change the VM state.
> > That's, the state is only changed when starting or stopping the VM.
> > 
> > This commit adds the runstate_set() function, which makes it possible
> > to also do state transitions when the VM is stopped or running.
> > 
> > Additional states are also added and the current state is stored.
> > 
> > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> > ---
> >  cpus.c      |    1 +
> >  migration.c |    8 +++++++-
> >  sysemu.h    |   10 +++++++++-
> >  vl.c        |   20 ++++++++++++++++++++
> >  4 files changed, 37 insertions(+), 2 deletions(-)
> > 
> 
> ...
> 
> > diff --git a/vl.c b/vl.c
> > index f0b56a4..59f71fc 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
> >  }
> >  
> >  /***********************************************************/
> > +/* QEMU state */
> > +
> > +static RunState current_run_state = RSTATE_NO_STATE;
> > +
> > +bool runstate_check(RunState state)
> > +{
> > +    return current_run_state == state;
> > +}
> > +
> > +void runstate_set(RunState state)
> > +{
> > +    assert(state < RSTATE_MAX);
> > +    current_run_state = state;
> 
> I still think this should check for valid state transitions instead of
> blindly accepting what the caller passes in.

I thought your comment where more like a future enhancement than
a request for change.

What to do if the transition is invalid? abort()?

Re: [Qemu-devel] [PATCH 3/8] RunState: Add additional states

[Jan Kiszka]

[-- Attachment #1: Type: text/plain, Size: 1909 bytes --]

On 2011-09-01 20:39, Luiz Capitulino wrote:
> On Thu, 01 Sep 2011 20:30:57 +0200
> Jan Kiszka <jan.kiszka@siemens.com> wrote:
> 
>> On 2011-09-01 20:12, Luiz Capitulino wrote:
>>> Currently, only vm_start() and vm_stop() change the VM state.
>>> That's, the state is only changed when starting or stopping the VM.
>>>
>>> This commit adds the runstate_set() function, which makes it possible
>>> to also do state transitions when the VM is stopped or running.
>>>
>>> Additional states are also added and the current state is stored.
>>>
>>> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
>>> ---
>>>  cpus.c      |    1 +
>>>  migration.c |    8 +++++++-
>>>  sysemu.h    |   10 +++++++++-
>>>  vl.c        |   20 ++++++++++++++++++++
>>>  4 files changed, 37 insertions(+), 2 deletions(-)
>>>
>>
>> ...
>>
>>> diff --git a/vl.c b/vl.c
>>> index f0b56a4..59f71fc 100644
>>> --- a/vl.c
>>> +++ b/vl.c
>>> @@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
>>>  }
>>>  
>>>  /***********************************************************/
>>> +/* QEMU state */
>>> +
>>> +static RunState current_run_state = RSTATE_NO_STATE;
>>> +
>>> +bool runstate_check(RunState state)
>>> +{
>>> +    return current_run_state == state;
>>> +}
>>> +
>>> +void runstate_set(RunState state)
>>> +{
>>> +    assert(state < RSTATE_MAX);
>>> +    current_run_state = state;
>>
>> I still think this should check for valid state transitions instead of
>> blindly accepting what the caller passes in.
> 
> I thought your comment where more like a future enhancement than
> a request for change.

I think we want this now to document at a central place which
transitions are valid and which not. State machines without such checks
break sooner or later, subtly.

> 
> What to do if the transition is invalid? abort()?

Yes.

Jan


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 262 bytes --]

Re: [Qemu-devel] [PATCH 3/8] RunState: Add additional states

[Luiz Capitulino]

On Thu, 01 Sep 2011 22:58:51 +0200
Jan Kiszka <jan.kiszka@web.de> wrote:

> On 2011-09-01 20:39, Luiz Capitulino wrote:
> > On Thu, 01 Sep 2011 20:30:57 +0200
> > Jan Kiszka <jan.kiszka@siemens.com> wrote:
> > 
> >> On 2011-09-01 20:12, Luiz Capitulino wrote:
> >>> Currently, only vm_start() and vm_stop() change the VM state.
> >>> That's, the state is only changed when starting or stopping the VM.
> >>>
> >>> This commit adds the runstate_set() function, which makes it possible
> >>> to also do state transitions when the VM is stopped or running.
> >>>
> >>> Additional states are also added and the current state is stored.
> >>>
> >>> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> >>> ---
> >>>  cpus.c      |    1 +
> >>>  migration.c |    8 +++++++-
> >>>  sysemu.h    |   10 +++++++++-
> >>>  vl.c        |   20 ++++++++++++++++++++
> >>>  4 files changed, 37 insertions(+), 2 deletions(-)
> >>>
> >>
> >> ...
> >>
> >>> diff --git a/vl.c b/vl.c
> >>> index f0b56a4..59f71fc 100644
> >>> --- a/vl.c
> >>> +++ b/vl.c
> >>> @@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
> >>>  }
> >>>  
> >>>  /***********************************************************/
> >>> +/* QEMU state */
> >>> +
> >>> +static RunState current_run_state = RSTATE_NO_STATE;
> >>> +
> >>> +bool runstate_check(RunState state)
> >>> +{
> >>> +    return current_run_state == state;
> >>> +}
> >>> +
> >>> +void runstate_set(RunState state)
> >>> +{
> >>> +    assert(state < RSTATE_MAX);
> >>> +    current_run_state = state;
> >>
> >> I still think this should check for valid state transitions instead of
> >> blindly accepting what the caller passes in.
> > 
> > I thought your comment where more like a future enhancement than
> > a request for change.
> 
> I think we want this now to document at a central place which
> transitions are valid and which not. State machines without such checks
> break sooner or later, subtly.

Ok, I'll do it.

Do you have any suggestion on the preferred way to document it?
Should I use english or try some ascii art?

> 
> > 
> > What to do if the transition is invalid? abort()?
> 
> Yes.
> 
> Jan
> 

Re: [Qemu-devel] [PATCH 3/8] RunState: Add additional states

[Jan Kiszka]

On 2011-09-02 16:28, Luiz Capitulino wrote:
> On Thu, 01 Sep 2011 22:58:51 +0200
> Jan Kiszka <jan.kiszka@web.de> wrote:
> 
>> On 2011-09-01 20:39, Luiz Capitulino wrote:
>>> On Thu, 01 Sep 2011 20:30:57 +0200
>>> Jan Kiszka <jan.kiszka@siemens.com> wrote:
>>>
>>>> On 2011-09-01 20:12, Luiz Capitulino wrote:
>>>>> Currently, only vm_start() and vm_stop() change the VM state.
>>>>> That's, the state is only changed when starting or stopping the VM.
>>>>>
>>>>> This commit adds the runstate_set() function, which makes it possible
>>>>> to also do state transitions when the VM is stopped or running.
>>>>>
>>>>> Additional states are also added and the current state is stored.
>>>>>
>>>>> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
>>>>> ---
>>>>>  cpus.c      |    1 +
>>>>>  migration.c |    8 +++++++-
>>>>>  sysemu.h    |   10 +++++++++-
>>>>>  vl.c        |   20 ++++++++++++++++++++
>>>>>  4 files changed, 37 insertions(+), 2 deletions(-)
>>>>>
>>>>
>>>> ...
>>>>
>>>>> diff --git a/vl.c b/vl.c
>>>>> index f0b56a4..59f71fc 100644
>>>>> --- a/vl.c
>>>>> +++ b/vl.c
>>>>> @@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
>>>>>  }
>>>>>  
>>>>>  /***********************************************************/
>>>>> +/* QEMU state */
>>>>> +
>>>>> +static RunState current_run_state = RSTATE_NO_STATE;
>>>>> +
>>>>> +bool runstate_check(RunState state)
>>>>> +{
>>>>> +    return current_run_state == state;
>>>>> +}
>>>>> +
>>>>> +void runstate_set(RunState state)
>>>>> +{
>>>>> +    assert(state < RSTATE_MAX);
>>>>> +    current_run_state = state;
>>>>
>>>> I still think this should check for valid state transitions instead of
>>>> blindly accepting what the caller passes in.
>>>
>>> I thought your comment where more like a future enhancement than
>>> a request for change.
>>
>> I think we want this now to document at a central place which
>> transitions are valid and which not. State machines without such checks
>> break sooner or later, subtly.
> 
> Ok, I'll do it.
> 
> Do you have any suggestion on the preferred way to document it?
> Should I use english or try some ascii art?

My idea is programmatic:

void runstate_set(RunState new_state)
{
	switch (current_state) {
	case X:
		/* potential comment on why only X->Y or ... is valid */
		if (new_state == Y || ...) {
			break;
		} else {
			abort();
		}

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux

Re: [Qemu-devel] [PATCH 3/8] RunState: Add additional states

[Luiz Capitulino]

On Fri, 02 Sep 2011 16:32:25 +0200
Jan Kiszka <jan.kiszka@siemens.com> wrote:

> On 2011-09-02 16:28, Luiz Capitulino wrote:
> > On Thu, 01 Sep 2011 22:58:51 +0200
> > Jan Kiszka <jan.kiszka@web.de> wrote:
> > 
> >> On 2011-09-01 20:39, Luiz Capitulino wrote:
> >>> On Thu, 01 Sep 2011 20:30:57 +0200
> >>> Jan Kiszka <jan.kiszka@siemens.com> wrote:
> >>>
> >>>> On 2011-09-01 20:12, Luiz Capitulino wrote:
> >>>>> Currently, only vm_start() and vm_stop() change the VM state.
> >>>>> That's, the state is only changed when starting or stopping the VM.
> >>>>>
> >>>>> This commit adds the runstate_set() function, which makes it possible
> >>>>> to also do state transitions when the VM is stopped or running.
> >>>>>
> >>>>> Additional states are also added and the current state is stored.
> >>>>>
> >>>>> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> >>>>> ---
> >>>>>  cpus.c      |    1 +
> >>>>>  migration.c |    8 +++++++-
> >>>>>  sysemu.h    |   10 +++++++++-
> >>>>>  vl.c        |   20 ++++++++++++++++++++
> >>>>>  4 files changed, 37 insertions(+), 2 deletions(-)
> >>>>>
> >>>>
> >>>> ...
> >>>>
> >>>>> diff --git a/vl.c b/vl.c
> >>>>> index f0b56a4..59f71fc 100644
> >>>>> --- a/vl.c
> >>>>> +++ b/vl.c
> >>>>> @@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
> >>>>>  }
> >>>>>  
> >>>>>  /***********************************************************/
> >>>>> +/* QEMU state */
> >>>>> +
> >>>>> +static RunState current_run_state = RSTATE_NO_STATE;
> >>>>> +
> >>>>> +bool runstate_check(RunState state)
> >>>>> +{
> >>>>> +    return current_run_state == state;
> >>>>> +}
> >>>>> +
> >>>>> +void runstate_set(RunState state)
> >>>>> +{
> >>>>> +    assert(state < RSTATE_MAX);
> >>>>> +    current_run_state = state;
> >>>>
> >>>> I still think this should check for valid state transitions instead of
> >>>> blindly accepting what the caller passes in.
> >>>
> >>> I thought your comment where more like a future enhancement than
> >>> a request for change.
> >>
> >> I think we want this now to document at a central place which
> >> transitions are valid and which not. State machines without such checks
> >> break sooner or later, subtly.
> > 
> > Ok, I'll do it.
> > 
> > Do you have any suggestion on the preferred way to document it?
> > Should I use english or try some ascii art?
> 
> My idea is programmatic:
> 
> void runstate_set(RunState new_state)
> {
> 	switch (current_state) {
> 	case X:
> 		/* potential comment on why only X->Y or ... is valid */
> 		if (new_state == Y || ...) {
> 			break;
> 		} else {
> 			abort();
> 		}

Ah, ok. I was thinking in having some fancy graph as documentation,
but let's do the simpler way then.

Re: [Qemu-devel] [PATCH 3/8] RunState: Add additional states

[Luiz Capitulino]

On Fri, 2 Sep 2011 11:28:18 -0300
Luiz Capitulino <lcapitulino@redhat.com> wrote:

> On Thu, 01 Sep 2011 22:58:51 +0200
> Jan Kiszka <jan.kiszka@web.de> wrote:
> 
> > On 2011-09-01 20:39, Luiz Capitulino wrote:
> > > On Thu, 01 Sep 2011 20:30:57 +0200
> > > Jan Kiszka <jan.kiszka@siemens.com> wrote:
> > > 
> > >> On 2011-09-01 20:12, Luiz Capitulino wrote:
> > >>> Currently, only vm_start() and vm_stop() change the VM state.
> > >>> That's, the state is only changed when starting or stopping the VM.
> > >>>
> > >>> This commit adds the runstate_set() function, which makes it possible
> > >>> to also do state transitions when the VM is stopped or running.
> > >>>
> > >>> Additional states are also added and the current state is stored.
> > >>>
> > >>> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> > >>> ---
> > >>>  cpus.c      |    1 +
> > >>>  migration.c |    8 +++++++-
> > >>>  sysemu.h    |   10 +++++++++-
> > >>>  vl.c        |   20 ++++++++++++++++++++
> > >>>  4 files changed, 37 insertions(+), 2 deletions(-)
> > >>>
> > >>
> > >> ...
> > >>
> > >>> diff --git a/vl.c b/vl.c
> > >>> index f0b56a4..59f71fc 100644
> > >>> --- a/vl.c
> > >>> +++ b/vl.c
> > >>> @@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque)
> > >>>  }
> > >>>  
> > >>>  /***********************************************************/
> > >>> +/* QEMU state */
> > >>> +
> > >>> +static RunState current_run_state = RSTATE_NO_STATE;
> > >>> +
> > >>> +bool runstate_check(RunState state)
> > >>> +{
> > >>> +    return current_run_state == state;
> > >>> +}
> > >>> +
> > >>> +void runstate_set(RunState state)
> > >>> +{
> > >>> +    assert(state < RSTATE_MAX);
> > >>> +    current_run_state = state;
> > >>
> > >> I still think this should check for valid state transitions instead of
> > >> blindly accepting what the caller passes in.
> > > 
> > > I thought your comment where more like a future enhancement than
> > > a request for change.
> > 
> > I think we want this now to document at a central place which
> > transitions are valid and which not. State machines without such checks
> > break sooner or later, subtly.
> 
> Ok, I'll do it.

I did it in v4 (just sent). But it wasn't trivial to do and to test, so
a careful review of that patch is very appreciated.