[pve-devel] [PATCH v3 qemu-server 2/2] remote-migration: add target-cpu && target-reboot params

[Alexandre Derumier]

This patch add support for remote migration when target
cpu model is different.

target-reboot param need to be defined to allow migration
whens source vm is online.

When defined, only the live storage migration is done,
and instead to transfert memory, we cleanly shutdown source vm
and restart the target vm. (like a virtual reboot between source/dest)
---
 PVE/API2/Qemu.pm   | 28 +++++++++++++++++++++++++++-
 PVE/CLI/qm.pm      | 11 +++++++++++
 PVE/QemuMigrate.pm | 31 +++++++++++++++++++++++++++++--
 3 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 774b0c7..e1cefba 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -4586,6 +4586,17 @@ __PACKAGE__->register_method({
 		optional => 1,
 		default => 0,
 	    },
+	    'target-cpu' => {
+		optional => 1,
+		description => "Target Emulated CPU model. For online migration, this require target-reboot option",
+		type => 'string',
+		format => 'pve-vm-cpu-conf',
+	    },
+	    'target-reboot' => {
+		type => 'boolean',
+		description => "For online migration , don't migrate memory, only storage. Then, the source vm is shutdown and the target vm is restarted.",
+		optional => 1,
+	    },
 	    'target-storage' => get_standard_option('pve-targetstorage', {
 		completion => \&PVE::QemuServer::complete_migration_storage,
 		optional => 0,
@@ -4664,9 +4675,12 @@ __PACKAGE__->register_method({
 	my $is_replicated = $repl_conf->check_for_existing_jobs($source_vmid, 1);
 	die "cannot remote-migrate replicated VM\n" if $is_replicated;
 
+	my $target_cpu = extract_param($param, 'target-cpu');
+	my $target_reboot = extract_param($param, 'target-reboot');
+
 	if (PVE::QemuServer::check_running($source_vmid)) {
 	    die "can't migrate running VM without --online\n" if !$param->{online};
-
+	    die "can't migrate running VM without --target-reboot when target cpu is different" if $target_cpu && !$target_reboot;
 	} else {
 	    warn "VM isn't running. Doing offline migration instead.\n" if $param->{online};
 	    $param->{online} = 0;
@@ -4683,11 +4697,14 @@ __PACKAGE__->register_method({
 	raise_param_exc({ 'target-bridge' => "failed to parse bridge map: $@" })
 	    if $@;
 
+
 	die "remote migration requires explicit storage mapping!\n"
 	    if $storagemap->{identity};
 
 	$param->{storagemap} = $storagemap;
 	$param->{bridgemap} = $bridgemap;
+	$param->{targetcpu} = $target_cpu;
+	$param->{targetreboot} = $target_reboot;
 	$param->{remote} = {
 	    conn => $conn_args, # re-use fingerprint for tunnel
 	    client => $api_client,
@@ -5732,6 +5749,15 @@ __PACKAGE__->register_method({
 		    PVE::QemuServer::nbd_stop($state->{vmid});
 		    return;
 		},
+		'restart' => sub {
+		    PVE::QemuServer::vm_stop(undef, $state->{vmid}, 1, 1);
+		    my $info = PVE::QemuServer::vm_start_nolock(
+			$state->{storecfg},
+			$state->{vmid},
+			$state->{conf},
+		    );
+		    return;
+		},
 		'resume' => sub {
 		    if (PVE::QemuServer::Helpers::vm_running_locally($state->{vmid})) {
 			PVE::QemuServer::vm_resume($state->{vmid}, 1, 1);
diff --git a/PVE/CLI/qm.pm b/PVE/CLI/qm.pm
index b17b4fe..9d89cfe 100755
--- a/PVE/CLI/qm.pm
+++ b/PVE/CLI/qm.pm
@@ -189,6 +189,17 @@ __PACKAGE__->register_method({
 		optional => 1,
 		default => 0,
 	    },
+	    'target-cpu' => {
+		optional => 1,
+		description => "Target Emulated CPU model. For online migration, this require target-reboot option",
+		type => 'string',
+		format => 'pve-vm-cpu-conf',
+	    },
+	    'target-reboot' => {
+		type => 'boolean',
+		description => "For online migration , don't migrate memory, only storage. Then, the source vm is shutdown and the target vm is restarted.",
+		optional => 1,
+	    },
 	    'target-storage' => get_standard_option('pve-targetstorage', {
 		completion => \&PVE::QemuServer::complete_migration_storage,
 		optional => 0,
diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
index 5ea78a7..0eaa73d 100644
--- a/PVE/QemuMigrate.pm
+++ b/PVE/QemuMigrate.pm
@@ -729,6 +729,11 @@ sub cleanup_bitmaps {
 sub live_migration {
     my ($self, $vmid, $migrate_uri, $spice_port) = @_;
 
+    if($self->{opts}->{targetreboot}){
+	$self->log('info', "target reboot - skip live migration.");
+	return;
+    }
+
     my $conf = $self->{vmconf};
 
     $self->log('info', "starting online/live migration on $migrate_uri");
@@ -993,6 +998,7 @@ sub phase1_remote {
     my $remote_conf = PVE::QemuConfig->load_config($vmid);
     PVE::QemuConfig->update_volume_ids($remote_conf, $self->{volume_map});
 
+    $remote_conf->{cpu} = $self->{opts}->{targetcpu};
     my $bridges = map_bridges($remote_conf, $self->{opts}->{bridgemap});
     for my $target (keys $bridges->%*) {
 	for my $nic (keys $bridges->{$target}->%*) {
@@ -1356,7 +1362,14 @@ sub phase2 {
 	# finish block-job with block-job-cancel, to disconnect source VM from NBD
 	# to avoid it trying to re-establish it. We are in blockjob ready state,
 	# thus, this command changes to it to blockjob complete (see qapi docs)
-	eval { PVE::QemuServer::qemu_drive_mirror_monitor($vmid, undef, $self->{storage_migration_jobs}, 'cancel'); };
+	my $finish_cmd = "cancel";
+	if ($self->{opts}->{targetreboot}) {
+	    # no live migration.
+	    # finish block-job with block-job-complete, the source will switch to remote NDB
+	    # then we cleanly stop the source vm at phase3
+	    $finish_cmd = "complete";
+	}
+	eval { PVE::QemuServer::qemu_drive_mirror_monitor($vmid, undef, $self->{storage_migration_jobs}, $finish_cmd); };
 	if (my $err = $@) {
 	    die "Failed to complete storage migration: $err\n";
 	}
@@ -1573,7 +1586,17 @@ sub phase3_cleanup {
     };
 
     # always stop local VM with nocheck, since config is moved already
-    eval { PVE::QemuServer::vm_stop($self->{storecfg}, $vmid, 1, 1); };
+    my $shutdown_timeout = undef;
+    my $shutdown = undef;
+    my $force_stop = undef;
+    if ($self->{opts}->{targetreboot}) {
+	$shutdown_timeout = 180;
+	$shutdown = 1;
+	$force_stop = 1;
+	$self->log('info', "clean shutdown of source vm.");
+    }
+
+    eval { PVE::QemuServer::vm_stop($self->{storecfg}, $vmid, 1, 1, $shutdown_timeout, $shutdown, $force_stop); };
     if (my $err = $@) {
 	$self->log('err', "stopping vm failed - $err");
 	$self->{errors} = 1;
@@ -1607,6 +1630,10 @@ sub phase3_cleanup {
     # clear migrate lock
     if ($tunnel && $tunnel->{version} >= 2) {
 	PVE::Tunnel::write_tunnel($tunnel, 10, "unlock");
+	if ($self->{opts}->{targetreboot}) {
+	    $self->log('info', "restart target vm.");
+	    PVE::Tunnel::write_tunnel($tunnel, 10, 'restart');
+	}
 
 	PVE::Tunnel::finish_tunnel($tunnel);
     } else {
-- 
2.39.2