Merge remote branch 'qmp/for-stable-0.13' into stable-0.13

10 files changed, 137 insertions, 36 deletions

diff --git a/QMP/README b/QMP/README
index 35a80c73e..d1430b0ab 100644
--- a/QMP/README
+++ b/QMP/README
@@ -7,60 +7,85 @@ Introduction
 The QEMU Monitor Protocol (QMP) allows applications to communicate with
 QEMU's Monitor.
 
-QMP is JSON[1] based and has the following features:
+QMP is JSON[1] based and currently has the following features:
 
 - Lightweight, text-based, easy to parse data format
-- Asynchronous events support 
-- Stability
+- Asynchronous messages support (ie. events)
+- Capabilities Negotiation
 
-For more information, please, refer to the following files:
+For detailed information on QMP's usage, please, refer to the following files:
 
 o qmp-spec.txt      QEMU Monitor Protocol current specification
-o qmp-commands.txt  QMP supported commands
+o qmp-commands.txt  QMP supported commands (auto-generated at build-time)
 o qmp-events.txt    List of available asynchronous events
 
 There are also two simple Python scripts available:
 
-o qmp-shell       A shell
-o vm-info         Show some information about the Virtual Machine
+o qmp-shell  A shell
+o vm-info    Show some information about the Virtual Machine
+
+IMPORTANT: It's strongly recommended to read the 'Stability Considerations'
+section in the qmp-commands.txt file before making any serious use of QMP.
+
 
 [1] http://www.json.org
 
 Usage
 -----
 
-To enable QMP, QEMU has to be started in "control mode". There are
-two ways of doing this, the simplest one is using the the '-qmp'
-command-line option.
+To enable QMP, you need a QEMU monitor instance in "control mode". There are
+two ways of doing this.
+
+The simplest one is using the '-qmp' command-line option. The following
+example makes QMP available on localhost port 4444:
 
-For example:
+  $ qemu [...] -qmp tcp:localhost:4444,server
 
-$ qemu [...] -qmp tcp:localhost:4444,server
+However, in order to have more complex combinations, like multiple monitors,
+the '-mon' command-line option should be used along with the '-chardev' one.
+For instance, the following example creates one user monitor on stdio and one
+QMP monitor on localhost port 4444.
 
-Will start QEMU in control mode, waiting for a client TCP connection
-on localhost port 4444.
+   $ qemu [...] -chardev stdio,id=mon0 -mon chardev=mon0,mode=readline \
+                -chardev socket,id=mon1,host=localhost,port=4444,server \
+                -mon chardev=mon1,mode=control
 
-It is also possible to use the '-mon' command-line option to have
-more complex combinations. Please, refer to the QEMU's manpage for
-more information.
+Please, refer to QEMU's manpage for more information.
 
 Simple Testing
 --------------
 
-To manually test QMP one can connect with telnet and issue commands:
+To manually test QMP one can connect with telnet and issue commands by hand:
 
 $ telnet localhost 4444
 Trying 127.0.0.1...
 Connected to localhost.
 Escape character is '^]'.
-{"QMP": {"version": {"qemu": "0.12.50", "package": ""}, "capabilities": []}}
+{"QMP": {"version": {"qemu": {"micro": 50, "minor": 13, "major": 0}, "package": ""}, "capabilities": []}}
 { "execute": "qmp_capabilities" }
 {"return": {}}
 { "execute": "query-version" }
-{"return": {"qemu": "0.12.50", "package": ""}}
+{"return": {"qemu": {"micro": 50, "minor": 13, "major": 0}, "package": ""}}
+
+Development Process
+-------------------
+
+When changing QMP's interface (by adding new commands, events or modifying
+existing ones) it's mandatory to update the relevant documentation, which is
+one (or more) of the files listed in the 'Introduction' section*.
+
+Also, it's strongly recommended to send the documentation patch first, before
+doing any code change. This is so because:
+
+  1. Avoids the code dictating the interface
+
+  2. Review can improve your interface.  Letting that happen before
+     you implement it can save you work.
+
+* The qmp-commands.txt file is generated from the qemu-monitor.hx one, which
+  is the file that should be edited.
 
-Contact
--------
+Homepage
+--------
 
-http://www.linux-kvm.org/page/MonitorProtocol
-Luiz Fernando N. Capitulino <lcapitulino@redhat.com>
+http://wiki.qemu.org/QMP
diff --git a/arch_init.c b/arch_init.c
index 47bb4b2d8..e0bd18c88 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -104,10 +104,11 @@ static int is_dup_page(uint8_t *page, uint8_t ch)
     return 1;
 }
 
+static RAMBlock *last_block;
+static ram_addr_t last_offset;
+
 static int ram_save_block(QEMUFile *f)
 {
-    static RAMBlock *last_block = NULL;
-    static ram_addr_t last_offset = 0;
     RAMBlock *block = last_block;
     ram_addr_t offset = last_offset;
     ram_addr_t current_addr;
@@ -231,6 +232,8 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
     if (stage == 1) {
         RAMBlock *block;
         bytes_transferred = 0;
+        last_block = NULL;
+        last_offset = 0;
 
         /* Make sure all dirty bits are set */
         QLIST_FOREACH(block, &ram_list.blocks, next) {
diff --git a/buffered_file.c b/buffered_file.c
index a79264f45..1836e7e24 100644
--- a/buffered_file.c
+++ b/buffered_file.c
@@ -230,8 +230,10 @@ static void buffered_rate_tick(void *opaque)
 {
     QEMUFileBuffered *s = opaque;
 
-    if (s->has_error)
+    if (s->has_error) {
+        buffered_close(s);
         return;
+    }
 
     qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
 
diff --git a/migration.c b/migration.c
index 650eb78d2..468d51749 100644
--- a/migration.c
+++ b/migration.c
@@ -67,6 +67,8 @@ void process_incoming_migration(QEMUFile *f)
     qemu_announce_self();
     DPRINTF("successfully loaded vm state\n");
 
+    incoming_expected = false;
+
     if (autostart)
         vm_start();
 }
@@ -314,8 +316,14 @@ ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
     if (ret == -1)
         ret = -(s->get_error(s));
 
-    if (ret == -EAGAIN)
+    if (ret == -EAGAIN) {
         qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s);
+    } else if (ret < 0) {
+        if (s->mon) {
+            monitor_resume(s->mon);
+        }
+        s->state = MIG_STATE_ERROR;
+    }
 
     return ret;
 }
diff --git a/monitor.c b/monitor.c
index 45fd48291..159bbe7db 100644
--- a/monitor.c
+++ b/monitor.c
@@ -669,17 +669,32 @@ help:
 static void do_info_version_print(Monitor *mon, const QObject *data)
 {
     QDict *qdict;
+    QDict *qemu;
 
     qdict = qobject_to_qdict(data);
+    qemu = qdict_get_qdict(qdict, "qemu");
 
-    monitor_printf(mon, "%s%s\n", qdict_get_str(qdict, "qemu"),
-                                  qdict_get_str(qdict, "package"));
+    monitor_printf(mon, "%" PRId64 ".%" PRId64 ".%" PRId64 "%s\n",
+                  qdict_get_int(qemu, "major"),
+                  qdict_get_int(qemu, "minor"),
+                  qdict_get_int(qemu, "micro"),
+                  qdict_get_str(qdict, "package"));
 }
 
 static void do_info_version(Monitor *mon, QObject **ret_data)
 {
-    *ret_data = qobject_from_jsonf("{ 'qemu': %s, 'package': %s }",
-                                   QEMU_VERSION, QEMU_PKGVERSION);
+    const char *version = QEMU_VERSION;
+    int major = 0, minor = 0, micro = 0;
+    char *tmp;
+
+    major = strtol(version, &tmp, 10);
+    tmp++;
+    minor = strtol(tmp, &tmp, 10);
+    tmp++;
+    micro = strtol(tmp, &tmp, 10);
+
+    *ret_data = qobject_from_jsonf("{ 'qemu': { 'major': %d, 'minor': %d, \
+        'micro': %d }, 'package': %s }", major, minor, micro, QEMU_PKGVERSION);
 }
 
 static void do_info_name_print(Monitor *mon, const QObject *data)
@@ -1056,6 +1071,10 @@ static int do_cont(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     struct bdrv_iterate_context context = { mon, 0 };
 
+    if (incoming_expected) {
+        qerror_report(QERR_MIGRATION_EXPECTED);
+        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/qemu-monitor.hx b/qemu-monitor.hx
index 2af3de6c2..5c1da3398 100644
--- a/qemu-monitor.hx
+++ b/qemu-monitor.hx
@@ -35,7 +35,29 @@ information on the Server command and response formats.
 
 NOTE: This document is temporary and will be replaced soon.
 
-1. Regular Commands
+1. Stability Considerations
+===========================
+
+The current QMP command set (described in this file) may be useful for a
+number of use cases, however it's limited and several commands have bad
+defined semantics, specially with regard to command completion.
+
+These problems are going to be solved incrementally in the next QEMU releases
+and we're going to establish a deprecation policy for badly defined commands.
+
+If you're planning to adopt QMP, please observe the following:
+
+    1. The deprecation policy will take efect and be documented soon, please
+       check the documentation of each used command as soon as a new release of
+       QEMU is available
+
+    2. DO NOT rely on anything which is not explicit documented
+
+    3. Errors, in special, are not documented. Applications should NOT check
+       for specific errors classes or data (it's strongly recommended to only
+       check for the "error" key)
+
+2. Regular Commands
 ===================
 
 Server's responses in the examples below are always a success response, please
@@ -1592,7 +1614,7 @@ HXCOMM This is required for the QMP documentation layout.
 
 SQMP
 
-2. Query Commands
+3. Query Commands
 =================
 
 EQMP
@@ -1623,13 +1645,25 @@ Show QEMU version.
 
 Return a json-object with the following information:
 
-- "qemu": QEMU's version (json-string)
+- "qemu": A json-object containing three integer values:
+    - "major": QEMU's major version (json-int)
+    - "minor": QEMU's minor version (json-int)
+    - "micro": QEMU's micro version (json-int)
 - "package": package's version (json-string)
 
 Example:
 
 -> { "execute": "query-version" }
-<- { "return": { "qemu": "0.11.50", "package": "" } }
+<- {
+      "return":{
+         "qemu":{
+            "major":0,
+            "minor":11,
+            "micro":5
+         },
+         "package":""
+      }
+   }
 
 EQMP
 
diff --git a/qerror.c b/qerror.c
index 2f6f59061..0af3ab32b 100644
--- a/qerror.c
+++ b/qerror.c
@@ -141,6 +141,10 @@ static const QErrorStringTable qerror_table[] = {
         .desc      = "Using KVM without %(capability), %(feature) unavailable",
     },
     {
+        .error_fmt = QERR_MIGRATION_EXPECTED,
+        .desc      = "An incoming migration is expected before this command can be executed",
+    },
+    {
         .error_fmt = QERR_MISSING_PARAMETER,
         .desc      = "Parameter '%(name)' is missing",
     },
diff --git a/qerror.h b/qerror.h
index 9ad00b4b8..62802ea08 100644
--- a/qerror.h
+++ b/qerror.h
@@ -121,6 +121,9 @@ QError *qobject_to_qerror(const QObject *obj);
 #define QERR_KVM_MISSING_CAP \
     "{ 'class': 'KVMMissingCap', 'data': { 'capability': %s, 'feature': %s } }"
 
+#define QERR_MIGRATION_EXPECTED \
+    "{ 'class': 'MigrationExpected', 'data': {} }"
+
 #define QERR_MISSING_PARAMETER \
     "{ 'class': 'MissingParameter', 'data': { 'name': %s } }"
 
diff --git a/sysemu.h b/sysemu.h
index 9c988bb2a..a1f6466ac 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -99,6 +99,7 @@ typedef enum DisplayType
 } DisplayType;
 
 extern int autostart;
+extern int incoming_expected;
 extern int bios_size;
 
 typedef enum {
diff --git a/vl.c b/vl.c
index ba6ee11ec..c2e7cc1d6 100644
--- a/vl.c
+++ b/vl.c
@@ -182,6 +182,7 @@ 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;
@@ -2557,6 +2558,7 @@ 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;