diff mbox series

[v2,1/2] migration: enfocre multifd and postcopy preempt to be set before incoming

Message ID 20230530090259.189462-2-wei.w.wang@intel.com (mailing list archive)
State New, archived
Headers show
Series Enfore multifd and postcopy preempt setting | expand

Commit Message

Wang, Wei W May 30, 2023, 9:02 a.m. UTC
qemu_start_incoming_migration needs to check the number of multifd
channels or postcopy ram channels to configure the backlog parameter (i.e.
the maximum length to which the queue of pending connections for sockfd
may grow) of listen(). So enforce the usage of postcopy-preempt and
multifd as below:
- need to use "-incoming defer" on the destination; and
- set_capability and set_parameter need to be done before migrate_incoming

Otherwise, disable the use of the features and report error messages to
remind users to adjust the commands.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
---
 migration/options.c | 36 +++++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

Comments

Peter Xu May 30, 2023, 2:35 p.m. UTC | #1
On Tue, May 30, 2023 at 05:02:58PM +0800, Wei Wang wrote:
> qemu_start_incoming_migration needs to check the number of multifd
> channels or postcopy ram channels to configure the backlog parameter (i.e.
> the maximum length to which the queue of pending connections for sockfd
> may grow) of listen(). So enforce the usage of postcopy-preempt and
> multifd as below:
> - need to use "-incoming defer" on the destination; and
> - set_capability and set_parameter need to be done before migrate_incoming
> 
> Otherwise, disable the use of the features and report error messages to
> remind users to adjust the commands.
> 
> Signed-off-by: Wei Wang <wei.w.wang@intel.com>

Reviewed-by: Peter Xu <peterx@redhat.com>
diff mbox series

Patch

diff --git a/migration/options.c b/migration/options.c
index a560483871..954a39aa6d 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -415,6 +415,11 @@  INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot,
     MIGRATION_CAPABILITY_VALIDATE_UUID,
     MIGRATION_CAPABILITY_ZERO_COPY_SEND);
 
+static bool migrate_incoming_started(void)
+{
+    return !!migration_incoming_get_current()->transport_data;
+}
+
 /**
  * @migration_caps_check - check capability compatibility
  *
@@ -538,6 +543,12 @@  bool migrate_caps_check(bool *old_caps, bool *new_caps, Error **errp)
             error_setg(errp, "Postcopy preempt not compatible with compress");
             return false;
         }
+
+        if (migrate_incoming_started()) {
+            error_setg(errp,
+                       "Postcopy preempt must be set before incoming starts");
+            return false;
+        }
     }
 
     if (new_caps[MIGRATION_CAPABILITY_MULTIFD]) {
@@ -545,6 +556,10 @@  bool migrate_caps_check(bool *old_caps, bool *new_caps, Error **errp)
             error_setg(errp, "Multifd is not compatible with compress");
             return false;
         }
+        if (migrate_incoming_started()) {
+            error_setg(errp, "Multifd must be set before incoming starts");
+            return false;
+        }
     }
 
     return true;
@@ -998,11 +1013,22 @@  bool migrate_params_check(MigrationParameters *params, Error **errp)
 
     /* x_checkpoint_delay is now always positive */
 
-    if (params->has_multifd_channels && (params->multifd_channels < 1)) {
-        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
-                   "multifd_channels",
-                   "a value between 1 and 255");
-        return false;
+    if (params->has_multifd_channels) {
+        if (params->multifd_channels < 1) {
+            error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                       "multifd_channels",
+                       "a value between 1 and 255");
+            return false;
+        }
+        if (migrate_incoming_started()) {
+            MigrationState *ms = migrate_get_current();
+
+            ms->capabilities[MIGRATION_CAPABILITY_MULTIFD] = false;
+            error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                       "multifd_channels",
+                       "must be set before incoming starts");
+            return false;
+        }
     }
 
     if (params->has_multifd_zlib_level &&