[pve-devel] [PATCH qemu-server 4/4] migrate: enable dirty-bitmap migration

[Stefan Reiter <s.reiter@proxmox.com>]

We query QEMU if it's safe before enabling it, as on versions without
the necessary patches it not only would be useless, but can actually
lead to hangs.

PBS state is always migrated, as it's a small amount of data anyway, so
we don't need to set a specific flag for it.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
---
 PVE/QemuServer.pm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 20e284c..a282449 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -4247,6 +4247,8 @@ sub qemu_volume_snapshot_delete {
 sub set_migration_caps {
     my ($vmid) = @_;
 
+    my $qemu_support = eval { mon_cmd($vmid, "query-proxmox-support") };
+
     my $cap_ref = [];
 
     my $enabled_cap = {
@@ -4254,7 +4256,8 @@ sub set_migration_caps {
 	"xbzrle" => 1,
 	"x-rdma-pin-all" => 0,
 	"zero-blocks" => 0,
-	"compress" => 0
+	"compress" => 0,
+	"dirty-bitmaps" => $qemu_support->{'pbs-dirty-bitmap-migration'} ? 1 : 0,
     };
 
     my $supported_capabilities = mon_cmd($vmid, "query-migrate-capabilities");
-- 
2.20.1