For remote migration, we already check that the config can be parsed on the target. Do the same for intra-cluster migration, to avoid issues like [0] for future new settings, with lines being unexpectedly and relatively silently dropped (there are warnings in the target's system logs).
Unfortunately, before commit "qm: mtunnel: reply when a command is unknown", which is part of the same patch series, when a command is unknown, mtunnel did not reply at all. Therefore, this delays backwards migrations to qemu-server versions less than the next bumped version (at the time of this writing expected to be 9.1.5) by 3 seconds. [0]: https://bugzilla.proxmox.com/show_bug.cgi?id=7341 Signed-off-by: Fiona Ebner <[email protected]> --- Changes in v2: * log when skipping config check For easier testing: # commented out so 'git am' does not apply it O;) # diff --git a/src/PVE/QemuServer.pm b/src/PVE/QemuServer.pm # index 545758dc..b914314e 100644 # --- a/src/PVE/QemuServer.pm # +++ b/src/PVE/QemuServer.pm # @@ -236,6 +236,13 @@ my $spice_enhancements_fmt = { # }; # # my $confdesc = { #+ 'shiny-new' => { #+ type => 'string', #+ enum => ['shiny', 'new'], #+ default => 'shiny', #+ optional => 1, #+ description => "you know you want it", #+ }, # onboot => { # optional => 1, # type => 'boolean', src/PVE/API2/Qemu.pm | 4 +++- src/PVE/QemuMigrate.pm | 27 +++++++++++++++++++++++ src/test/MigrationTest/QemuMigrateMock.pm | 11 ++++++++- 3 files changed, 40 insertions(+), 2 deletions(-) diff --git a/src/PVE/API2/Qemu.pm b/src/PVE/API2/Qemu.pm index 1f0864f5..47466513 100644 --- a/src/PVE/API2/Qemu.pm +++ b/src/PVE/API2/Qemu.pm @@ -5399,7 +5399,9 @@ __PACKAGE__->register_method({ force => { type => 'boolean', description => - "Allow to migrate VMs which use local devices. Only root may use this option.", + "Allow to migrate VMs which use local devices and for intra-cluster migration," + . " configuration options not understood by the target. Only root may use this" + . " option.", optional => 1, }, migration_type => { diff --git a/src/PVE/QemuMigrate.pm b/src/PVE/QemuMigrate.pm index f7ec3227..901fe96d 100644 --- a/src/PVE/QemuMigrate.pm +++ b/src/PVE/QemuMigrate.pm @@ -355,6 +355,33 @@ sub prepare { my $cmd = [@{ $self->{rem_ssh} }, '/bin/true']; eval { $self->cmd_quiet($cmd); }; die "Can't connect to destination address using public key\n" if $@; + + if (!$self->{opts}->{force}) { + # Fork a short-lived tunnel for checking the config. Later, the proper tunnel with SSH + # forwaring info is forked. + my $tunnel = $self->fork_tunnel(); + # Compared to remote migration, which also does volume activation, this only strictly + # parses the config, so no large timeout is needed. Unfortunately, mtunnel did not + # indicate that a command is unknown, but not reply at all, so the timeout must be very + # low right now. + # FIXME PVE 10 - bump timeout, the trade-off between delaying backwards migration and + # giving config check more time should now be in favor of config checking + eval { + my $nodename = PVE::INotify::nodename(); + PVE::Tunnel::write_tunnel($tunnel, 3, "config $vmid $nodename"); + }; + if (my $err = $@) { + chomp($err); + # if there is no reply, assume target did not know the command yet + if ($err =~ m/^no reply to command/) { + $self->log('info', "skipping strict configuration check (target too old?)"); + } else { + die "$err - use --force to migrate regardless\n"; + } + } + eval { PVE::Tunnel::finish_tunnel($tunnel); }; + $self->log('warn', "failed to finish tunnel in prepare() - $@") if $@; + } } return $running; diff --git a/src/test/MigrationTest/QemuMigrateMock.pm b/src/test/MigrationTest/QemuMigrateMock.pm index df8b575a..170634de 100644 --- a/src/test/MigrationTest/QemuMigrateMock.pm +++ b/src/test/MigrationTest/QemuMigrateMock.pm @@ -65,6 +65,10 @@ $tunnel_module->mock( my $vmid = $1; die "resuming wrong VM '$vmid'\n" if $vmid ne $test_vmid; return; + } elsif ($command =~ m/^config (\d+) (\S+)$/) { + my ($vmid, $node) = ($1, $2); + die "check config for wrong VM '$vmid'\n" if $vmid ne $test_vmid; + return; } die "write_tunnel (mocked) - implement me: $command\n"; }, @@ -73,7 +77,12 @@ $tunnel_module->mock( my $qemu_migrate_module = Test::MockModule->new("PVE::QemuMigrate"); $qemu_migrate_module->mock( fork_tunnel => sub { - die "fork_tunnel (mocked) - implement me\n"; # currently no call should lead here + return { + writer => "mocked", + reader => "mocked", + pid => 123456, + version => 1, + }; }, start_remote_tunnel => sub { my ($self, $raddr, $rport, $ruri, $unix_socket_info) = @_; -- 2.47.3
