[libvirt] Question about parallel migration connections

[Jim Fehlig]

On 1/10/20 12:16 AM, Peter Krempa wrote:
> On Thu, Jan 09, 2020 at 23:04:19 +0000, Jim Fehlig wrote:
>> Are they supported with tunneled migration? The feature seems limited to native
>> migration, in which case I can send a patch prohibiting parallel migration
>> connections with the tunnel.
> 
> That is true. Libvirt's stream which is used for tunelling the
> connection can carry only one connection and the APIs driving tunelled
> migration allow only one stream in arguments.

So should we check for and reject parallel+tunneled? I don't see any similar 
checks in the migration entry point, but suppose it would look something like 
the below patch (which I can formally send to the list if folks agree to such a 
check).

Regards,
Jim

diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index eb66999f07..a98287551e 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -3011,6 +3011,8 @@ virDomainMigrateVersion3Full(virDomainPtr domain,
          return NULL;
      }

+    VIR_EXCLUSIVE_FLAGS_RET(VIR_MIGRATE_TUNNELLED, VIR_MIGRATE_PARALLEL, NULL);
+
      if (virTypedParamsCopy(&tmp, params, nparams) < 0)
          return NULL;
      params = tmp;