[Qemu-devel] [PATCH v15 1/9] Add migration capabilities

[Orit Wasserman]

Add migration capabilities that can be queried by the management.
The management can query the source QEMU and the destination QEMU in order to
verify both support some migration capability (currently only XBZRLE).
The management can enable a capability for the next migration by using
migrate_set_parameter command.

Signed-off-by: Orit Wasserman <address@hidden>
---
 hmp-commands.hx  |   16 ++++++++++++
 hmp.c            |   64 ++++++++++++++++++++++++++++++++++++++++++++++++
 hmp.h            |    2 +
 migration.c      |   72 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 migration.h      |    2 +
 monitor.c        |    7 +++++
 qapi-schema.json |   53 ++++++++++++++++++++++++++++++++++++++-
 qmp-commands.hx  |   71 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 8 files changed, 280 insertions(+), 7 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index f5d9d91..9245bef 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -861,6 +861,20 @@ Set maximum tolerated downtime (in seconds) for migration.
 ETEXI
 
     {
+        .name       = "migrate_set_parameter",
+        .args_type  = "capability:s,state:b",
+        .params     = "",
+        .help       = "Enable/Disable the usage of a capability for migration",
+        .mhandler.cmd = hmp_migrate_set_parameter,
+    },
+
+STEXI
address@hidden migrate_set_parameter @var{capability} @var{state}
address@hidden migrate_set_parameter
+Enable/Disable the usage of a capability @var{capability} for migration.
+ETEXI
+
+    {
         .name       = "client_migrate_info",
         .args_type  = 
"protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",
         .params     = "protocol hostname port tls-port cert-subject",
@@ -1419,6 +1433,8 @@ show CPU statistics
 show user network stack connection states
 @item info migrate
 show migration status
address@hidden info migration_capabilities
+show migration capabilities
 @item info balloon
 show balloon information
 @item info qtree
diff --git a/hmp.c b/hmp.c
index 4c6d4ae..b0440e6 100644
--- a/hmp.c
+++ b/hmp.c
@@ -131,9 +131,19 @@ void hmp_info_mice(Monitor *mon)
 void hmp_info_migrate(Monitor *mon)
 {
     MigrationInfo *info;
+    MigrationCapabilityInfoList *cap;
 
     info = qmp_query_migrate(NULL);
 
+    if (info->has_capabilities && info->capabilities) {
+        monitor_printf(mon, "capabilities: ");
+        for (cap = info->capabilities; cap; cap = cap->next) {
+            monitor_printf(mon, "%s: %s ",
+                           MigrationCapability_lookup[cap->value->capability],
+                           cap->value->state ? "on" : "off");
+        }
+        monitor_printf(mon, "\n");
+    }
     if (info->has_status) {
         monitor_printf(mon, "Migration status: %s\n", info->status);
     }
@@ -161,6 +171,25 @@ void hmp_info_migrate(Monitor *mon)
     qapi_free_MigrationInfo(info);
 }
 
+void hmp_info_migration_capabilities(Monitor *mon)
+{
+    MigrationCapabilityInfoList *caps_list, *cap;
+
+    caps_list = qmp_query_migration_capabilities(NULL);
+    if (!caps_list) {
+        monitor_printf(mon, "No migration capabilities found\n");
+        return;
+    }
+
+    for (cap = caps_list; cap; cap = cap->next) {
+        monitor_printf(mon, "%s: %s ",
+                       MigrationCapability_lookup[cap->value->capability],
+                       cap->value->state ? "on" : "off");
+    }
+
+    qapi_free_MigrationCapabilityInfoList(caps_list);
+}
+
 void hmp_info_cpus(Monitor *mon)
 {
     CpuInfoList *cpu_list, *cpu;
@@ -735,6 +764,41 @@ void hmp_migrate_set_speed(Monitor *mon, const QDict 
*qdict)
     qmp_migrate_set_speed(value, NULL);
 }
 
+void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
+{
+    const char *cap = qdict_get_str(qdict, "capability");
+    bool state = qdict_get_bool(qdict, "state");
+    Error *err = NULL;
+    MigrationCapabilityInfoList *params = NULL;
+    int i;
+
+    for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+        if (strcmp(cap, MigrationCapability_lookup[i]) == 0) {
+            if (!params) {
+                params = g_malloc0(sizeof(*params));
+            }
+            params->value = g_malloc0(sizeof(*params->value));
+            params->value->capability = i;
+            params->value->state = state;
+            params->next = NULL;
+            qmp_migrate_set_parameters(params, &err);
+            break;
+        }
+    }
+
+    if (i == MIGRATION_CAPABILITY_MAX) {
+        error_set(&err, QERR_INVALID_PARAMETER, cap);
+    }
+
+    qapi_free_MigrationCapabilityInfoList(params);
+
+    if (err) {
+        monitor_printf(mon, "migrate_set_parameter: %s\n",
+                       error_get_pretty(err));
+        error_free(err);
+    }
+}
+
 void hmp_set_password(Monitor *mon, const QDict *qdict)
 {
     const char *protocol  = qdict_get_str(qdict, "protocol");
diff --git a/hmp.h b/hmp.h
index 79d138d..09ba198 100644
--- a/hmp.h
+++ b/hmp.h
@@ -25,6 +25,7 @@ void hmp_info_uuid(Monitor *mon);
 void hmp_info_chardev(Monitor *mon);
 void hmp_info_mice(Monitor *mon);
 void hmp_info_migrate(Monitor *mon);
+void hmp_info_migration_capabilities(Monitor *mon);
 void hmp_info_cpus(Monitor *mon);
 void hmp_info_block(Monitor *mon);
 void hmp_info_blockstats(Monitor *mon);
@@ -51,6 +52,7 @@ void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict);
 void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
+void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict);
 void hmp_set_password(Monitor *mon, const QDict *qdict);
 void hmp_expire_password(Monitor *mon, const QDict *qdict);
 void hmp_eject(Monitor *mon, const QDict *qdict);
diff --git a/migration.c b/migration.c
index 8db1b43..fd004d7 100644
--- a/migration.c
+++ b/migration.c
@@ -117,12 +117,36 @@ MigrationInfo *qmp_query_migrate(Error **errp)
 {
     MigrationInfo *info = g_malloc0(sizeof(*info));
     MigrationState *s = migrate_get_current();
+    int i;
 
     switch (s->state) {
     case MIG_STATE_SETUP:
-        /* no migration has happened ever */
+        /* no migration has ever happened; show enabled capabilities */
+        for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+            if (!info->has_capabilities) {
+                info->capabilities = g_malloc0(sizeof(*info->capabilities));
+                info->has_capabilities = true;
+            }
+            info->capabilities->value =
+                g_malloc(sizeof(*info->capabilities->value));
+            info->capabilities->value->capability = i;
+            info->capabilities->value->state = s->enabled_capabilities[i];
+            info->capabilities->next = NULL;
+        }
         break;
     case MIG_STATE_ACTIVE:
+        for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+            if (!info->has_capabilities) {
+                info->capabilities = g_malloc0(sizeof(*info->capabilities));
+                info->has_capabilities = true;
+            }
+            info->capabilities->value =
+                g_malloc(sizeof(*info->capabilities->value));
+            info->capabilities->value->capability = i;
+            info->capabilities->value->state = s->enabled_capabilities[i];
+            info->capabilities->next = NULL;
+        }
+
         info->has_status = true;
         info->status = g_strdup("active");
 
@@ -143,6 +167,18 @@ MigrationInfo *qmp_query_migrate(Error **errp)
         }
         break;
     case MIG_STATE_COMPLETED:
+        for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+            if (!info->has_capabilities) {
+                info->capabilities = g_malloc0(sizeof(*info->capabilities));
+                info->has_capabilities = true;
+            }
+            info->capabilities->value =
+                g_malloc(sizeof(*info->capabilities->value));
+            info->capabilities->value->capability = i;
+            info->capabilities->value->state = s->enabled_capabilities[i];
+            info->capabilities->next = NULL;
+        }
+
         info->has_status = true;
         info->status = g_strdup("completed");
 
@@ -166,6 +202,33 @@ MigrationInfo *qmp_query_migrate(Error **errp)
     return info;
 }
 
+MigrationCapabilityInfoList *qmp_query_migration_capabilities(Error **errp)
+{
+    MigrationCapabilityInfoList *caps_list = g_malloc0(sizeof(*caps_list));
+
+    caps_list->value = g_malloc(sizeof(*caps_list->value));
+    caps_list->value->capability = MIGRATION_CAPABILITY_XBZRLE;
+    caps_list->next = NULL;
+
+    return caps_list;
+}
+
+void qmp_migrate_set_parameters(MigrationCapabilityInfoList *params,
+                                Error **errp)
+{
+    MigrationState *s = migrate_get_current();
+    MigrationCapabilityInfoList *cap;
+
+    if (s->state == MIG_STATE_ACTIVE) {
+        error_set(errp, QERR_MIGRATION_ACTIVE);
+        return;
+    }
+
+    for (cap = params; cap; cap = cap->next) {
+        s->enabled_capabilities[cap->value->capability] = cap->value->state;
+    }
+}
+
 /* shared migration helpers */
 
 static int migrate_fd_cleanup(MigrationState *s)
@@ -375,12 +438,17 @@ static MigrationState *migrate_init(const MigrationParams 
*params)
 {
     MigrationState *s = migrate_get_current();
     int64_t bandwidth_limit = s->bandwidth_limit;
+    bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
+
+    memcpy(enabled_capabilities, s->enabled_capabilities,
+           sizeof(enabled_capabilities));
 
     memset(s, 0, sizeof(*s));
     s->bandwidth_limit = bandwidth_limit;
     s->params = *params;
+    memcpy(s->enabled_capabilities, enabled_capabilities,
+           sizeof(enabled_capabilities));
 
-    s->bandwidth_limit = bandwidth_limit;
     s->state = MIG_STATE_SETUP;
     s->total_time = qemu_get_clock_ms(rt_clock);
 
diff --git a/migration.h b/migration.h
index de13004..acc0b94 100644
--- a/migration.h
+++ b/migration.h
@@ -18,6 +18,7 @@
 #include "qemu-common.h"
 #include "notify.h"
 #include "error.h"
+#include "qapi-types.h"
 
 struct MigrationParams {
     bool blk;
@@ -38,6 +39,7 @@ struct MigrationState
     void *opaque;
     MigrationParams params;
     int64_t total_time;
+    bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
 };
 
 void process_incoming_migration(QEMUFile *f);
diff --git a/monitor.c b/monitor.c
index f6107ba..e2be6cd 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2687,6 +2687,13 @@ static mon_cmd_t info_cmds[] = {
         .mhandler.info = hmp_info_migrate,
     },
     {
+        .name       = "migration_capabilities",
+        .args_type  = "",
+        .params     = "",
+        .help       = "show migration capabilities",
+        .mhandler.info = hmp_info_migration_capabilities,
+    },
+    {
         .name       = "balloon",
         .args_type  = "",
         .params     = "",
diff --git a/qapi-schema.json b/qapi-schema.json
index 1ab5dbd..a8408fd 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -288,11 +288,15 @@
 #        status, only returned if status is 'active' and it is a block
 #        migration
 #
-# Since: 0.14.0
+# @capabilities: #optional a list describing all the migration capabilities
+#                state
+#
+# Since: 0.14.0, 'capabilities' since 1.2
 ##
 { 'type': 'MigrationInfo',
   'data': {'*status': 'str', '*ram': 'MigrationStats',
-           '*disk': 'MigrationStats'} }
+           '*disk': 'MigrationStats',
+           '*capabilities': ['MigrationCapabilityInfo']} }
 
 ##
 # @query-migrate
@@ -306,6 +310,51 @@
 { 'command': 'query-migrate', 'returns': 'MigrationInfo' }
 
 ##
+# @MigrationCapability
+#
+# Migration capabilities enumeration
+#
+# @xbzrle: current migration supports xbzrle
+#
+# Since: 1.2
+##
+{ 'enum': 'MigrationCapability',
+  'data': ['xbzrle'] }
+
+##
+# @MigrationCapabilityInfo
+#
+# Migration capability information
+#
+# @capability: capability enum
+#
+# Since: 1.2
+##
+{ 'type': 'MigrationCapabilityInfo',
+  'data': { 'capability' : 'MigrationCapability', 'state' : 'bool' } }
+
+##
+# @query-migration-capabilities
+#
+# Returns information about current migration process capabilties.
+#
+# Returns: @MigrationCapabilityInfo list
+#
+# Since: 1.2
+##
+{ 'command': 'query-migration-capabilities', 'returns': 
['MigrationCapabilityInfo'] }
+
+##
+# @migrate_set_parameters
+#
+# Enable/Disable the following migration capabilities (like xbzrle)
+#
+# Since: 1.2
+##
+{ 'command': 'migrate-set-parameters',
+  'data': { 'capabilities': ['MigrationCapabilityInfo'] } }
+
+##
 # @MouseInfo:
 #
 # Information about a mouse device.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 2e1a38e..3ee6e00 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2075,18 +2075,31 @@ The main json-object contains the following:
          - "transferred": amount transferred (json-int)
          - "remaining": amount remaining (json-int)
          - "total": total (json-int)
-
+- "capabilities": migration capabilities state
+         - "xbzrle" : XBZRLE state (json-bool)
 Examples:
 
 1. Before the first migration
 
 -> { "execute": "query-migrate" }
-<- { "return": {} }
+<- { "return": {
+        "capabilities" :  [ { "capability" : "xbzrle", "state" : false } ]
+     }
+   }
 
 2. Migration is done and has succeeded
 
 -> { "execute": "query-migrate" }
-<- { "return": { "status": "completed" } }
+<- { "return": {
+        "status": "completed",
+        "capabilities":  [ { "capability" : "xbzrle", "state" : false } ],
+        "ram":{
+          "transferred":123,
+          "remaining":123,
+          "total":246
+        }
+     }
+   }
 
 3. Migration is done and has failed
 
@@ -2099,6 +2112,7 @@ Examples:
 <- {
       "return":{
          "status":"active",
+         "capabilities":  [ { "capability" : "xbzrle", "state" : false } ],
          "ram":{
             "transferred":123,
             "remaining":123,
@@ -2113,6 +2127,7 @@ Examples:
 <- {
       "return":{
          "status":"active",
+         "capabilities":  [ { "capability" : "xbzrle", "state" : false } ],
          "ram":{
             "total":1057024,
             "remaining":1053304,
@@ -2135,6 +2150,56 @@ EQMP
     },
 
 SQMP
+query-migration-capabilities
+-------
+
+Query migration capabilities
+
+- "xbzrle": xbzrle support
+
+Arguments:
+
+Example:
+
+-> { "execute": "query-migration-capabilities"}
+<- { "return": [ { "capability": "xbzrle", "state": true },
+                 { "capability": "foobar", "state": false } ] }
+
+EQMP
+
+    {
+        .name       = "query-migration-capabilities",
+        .args_type  = "",
+       .mhandler.cmd_new = qmp_marshal_input_query_migration_capabilities,
+    },
+
+SQMP
+migrate_set_parameters
+-------
+
+Enable/Disable migration capabilities
+
+- "xbzrle": xbzrle support
+
+Arguments:
+
+Example:
+
+-> { "execute": "migrate_set_parameters" , "arguments":
+     { "parameters": [ { "capability": "xbzrle", "state": true } ] } }
+
+EQMP
+
+    {
+        .name       = "migrate_set_parameters",
+        .args_type  = "parameters:O",
+       .params     = "capability:s,state:b",
+       .mhandler.cmd_new = qmp_marshal_input_migrate_set_parameters,
+    },
+
+
+
+SQMP
 query-balloon
 -------------
 
-- 
1.7.7.6