[Qemu-devel] [PATCH v12 02/13] Add migration capabilites

[Orit Wasserman]

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

Signed-off-by: Orit Wasserman <address@hidden>
---
 hmp-commands.hx  |   16 ++++++++++++++
 hmp.c            |   62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 hmp.h            |    2 +
 migration.c      |   48 ++++++++++++++++++++++++++++++++++++++++-
 migration.h      |    2 +
 monitor.c        |    7 ++++++
 qapi-schema.json |   46 +++++++++++++++++++++++++++++++++++++++-
 qmp-commands.hx  |   48 +++++++++++++++++++++++++++++++++++++++++
 8 files changed, 228 insertions(+), 3 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index f5d9d91..b3051a8 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 the usage of a capability for migration",
+        .mhandler.cmd = hmp_migrate_set_parameter,
+    },
+
+STEXI
address@hidden migrate_set_parameter @var{capabilty} @var{state}
address@hidden migrate_set_parameter
+Enable/Disable the usage of a capability @var{capabilty} 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 2ce8cb9..67d4122 100644
--- a/hmp.c
+++ b/hmp.c
@@ -130,9 +130,18 @@ void hmp_info_mice(Monitor *mon)
 void hmp_info_migrate(Monitor *mon)
 {
     MigrationInfo *info;
+    MigrationCapabilityInfoList *cap;
 
     info = qmp_query_migrate(NULL);
 
+    if (info->has_params && info->params) {
+        monitor_printf(mon, "params: ");
+        for (cap = info->params; cap; cap = cap->next) {
+            monitor_printf(mon, "%s",
+                           MigrationCapability_lookup[cap->value->capability]);
+        }
+        monitor_printf(mon, "\n");
+    }
     if (info->has_status) {
         monitor_printf(mon, "Migration status: %s\n", info->status);
     }
@@ -158,6 +167,24 @@ 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 ",
+                       MigrationCapability_lookup[cap->value->capability]);
+    }
+
+    qapi_free_MigrationCapabilityInfoList(caps_list);
+}
+
 void hmp_info_cpus(Monitor *mon)
 {
     CpuInfoList *cpu_list, *cpu;
@@ -732,6 +759,41 @@ 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 810727f..3b747b6 100644
--- a/migration.c
+++ b/migration.c
@@ -117,10 +117,22 @@ 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 happened ever show enabled capabilities */
+        for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+            if (s->enabled_capabilities[i]) {
+                if (!info->has_params) {
+                    info->params = g_malloc0(sizeof(*info->params));
+                    info->has_params = true;
+                }
+                info->params->value = g_malloc(sizeof(*info->params->value));
+                info->params->value->capability = i;
+                info->params->next = NULL;
+            }
+        }
         break;
     case MIG_STATE_ACTIVE:
         info->has_status = true;
@@ -157,6 +169,33 @@ 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)
@@ -365,12 +404,17 @@ 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;
 
     return s;
diff --git a/migration.h b/migration.h
index 4168883..00d1992 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 {
     int blk;
@@ -37,6 +38,7 @@ struct MigrationState
     int (*write)(MigrationState *s, const void *buff, size_t size);
     void *opaque;
     MigrationParams params;
+    bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
 };
 
 void process_incoming_migration(QEMUFile *f);
diff --git a/monitor.c b/monitor.c
index a3bc2c7..9cfe538 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2541,6 +2541,13 @@ 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 3b6e346..829be0f 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -286,7 +286,7 @@
 ##
 { 'type': 'MigrationInfo',
   'data': {'*status': 'str', '*ram': 'MigrationStats',
-           '*disk': 'MigrationStats'} }
+           '*disk': 'MigrationStats', '*params': ['MigrationCapabilityInfo']} }
 
 ##
 # @query-migrate
@@ -300,6 +300,50 @@
 { 'command': 'query-migrate', 'returns': 'MigrationInfo' }
 
 ##
+# @MigrationCapability
+#
+# Migration capabilities enumaration
+#
+# @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
+#
+# Set the following migration parameters (like xbzrle )
+##
+# Since: 1.2
+##
+{ 'command': 'migrate-set-parameters', 'data': { 'parameters': 
['MigrationCapabilityInfo'] } }
+
+##
 # @MouseInfo:
 #
 # Information about a mouse device.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 2e1a38e..2af4822 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2135,6 +2135,54 @@ EQMP
     },
 
 SQMP
+query-migration-capabilities
+-------
+
+Query migration capabilities
+
+- "xbzrle": xbzrle support
+
+Arguments:
+
+Example:
+
+-> { "execute": "query-migration-capabilities"}
+<- { "return": { "xbzrle" }
+
+EQMP
+
+    {
+        .name       = "query-migration-capabilities",
+        .args_type  = "",
+       .mhandler.cmd_new = qmp_marshal_input_query_migration_capabilities,
+    },
+
+SQMP
+migrate_set_parameters
+-------
+
+Enable migration capabilities
+
+- "xbzrle": xbzrle support
+
+Arguments:
+
+Example:
+
+-> { "execute": "migrate_set_parameters" , "arguments": { "parameters": xbzrle 
on"} }
+
+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