[pve-devel] [PATCH v2 qemu-server 2/2] remote-migration: add target-cpu param

[Alexandre Derumier <aderumier@odiso.com>]

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

The target vm is restart after the migration

Signed-off-by: Alexandre Derumier <aderumier@odiso.com>
---
 PVE/API2/Qemu.pm   | 18 ++++++++++++++++++
 PVE/CLI/qm.pm      |  6 ++++++
 PVE/QemuMigrate.pm | 25 +++++++++++++++++++++++++
 3 files changed, 49 insertions(+)

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 587bb22..6703c87 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -4460,6 +4460,12 @@ __PACKAGE__->register_method({
 		optional => 1,
 		default => 0,
 	    },
+	    'target-cpu' => {
+		optional => 1,
+		description => "Target Emulated CPU model. For online migration, the storage is live migrate, but the memory migration is skipped and the target vm is restarted.",
+		type => 'string',
+		format => 'pve-vm-cpu-conf',
+	    },
 	    'target-storage' => get_standard_option('pve-targetstorage', {
 		completion => \&PVE::QemuServer::complete_migration_storage,
 		optional => 0,
@@ -4557,11 +4563,14 @@ __PACKAGE__->register_method({
 	raise_param_exc({ 'target-bridge' => "failed to parse bridge map: $@" })
 	    if $@;
 
+	my $target_cpu = extract_param($param, 'target-cpu');
+
 	die "remote migration requires explicit storage mapping!\n"
 	    if $storagemap->{identity};
 
 	$param->{storagemap} = $storagemap;
 	$param->{bridgemap} = $bridgemap;
+	$param->{targetcpu} = $target_cpu;
 	$param->{remote} = {
 	    conn => $conn_args, # re-use fingerprint for tunnel
 	    client => $api_client,
@@ -5604,6 +5613,15 @@ __PACKAGE__->register_method({
 		    PVE::QemuServer::nbd_stop($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($state->{vmid}, 1, 1);
diff --git a/PVE/CLI/qm.pm b/PVE/CLI/qm.pm
index c3c2982..06c74c1 100755
--- a/PVE/CLI/qm.pm
+++ b/PVE/CLI/qm.pm
@@ -189,6 +189,12 @@ __PACKAGE__->register_method({
 		optional => 1,
 		default => 0,
 	    },
+	    'target-cpu' => {
+		optional => 1,
+		description => "Target Emulated CPU model. For online migration, the storage is live migrate, but the memory migration is skipped and the target vm is restarted.",
+		type => 'string',
+		format => 'pve-vm-cpu-conf',
+	    },
 	    'target-storage' => get_standard_option('pve-targetstorage', {
 		completion => \&PVE::QemuServer::complete_migration_storage,
 		optional => 0,
diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
index e182415..04f8053 100644
--- a/PVE/QemuMigrate.pm
+++ b/PVE/QemuMigrate.pm
@@ -731,6 +731,11 @@ sub cleanup_bitmaps {
 sub live_migration {
     my ($self, $vmid, $migrate_uri, $spice_port) = @_;
 
+    if($self->{opts}->{targetcpu}){
+        $self->log('info', "target cpu is different - skip live migration.");
+        return;
+    }
+
     my $conf = $self->{vmconf};
 
     $self->log('info', "starting online/live migration on $migrate_uri");
@@ -995,6 +1000,7 @@ 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}->%*) {
@@ -1354,6 +1360,21 @@ sub phase2 {
     live_migration($self, $vmid, $migrate_uri, $spice_port);
 
     if ($self->{storage_migration}) {
+
+        #freeze source vm io/s if target cpu is different (no livemigration)
+	if ($self->{opts}->{targetcpu}) {
+	    my $agent_running = $self->{conf}->{agent} && PVE::QemuServer::qga_check_running($vmid);
+	    if ($agent_running) {
+		print "freeze filesystem\n";
+		eval { mon_cmd($vmid, "guest-fsfreeze-freeze"); };
+		die $@ if $@;
+	    } else {
+		print "suspend vm\n";
+		eval { PVE::QemuServer::vm_suspend($vmid, 1); };
+		warn $@ if $@;
+	    }
+	}
+
 	# finish block-job with block-job-cancel, to disconnect source VM from NBD
 	# to avoid it trying to re-establish it. We are in blockjob ready state,
 	# thus, this command changes to it to blockjob complete (see qapi docs)
@@ -1608,6 +1629,10 @@ sub phase3_cleanup {
     # clear migrate lock
     if ($tunnel && $tunnel->{version} >= 2) {
 	PVE::Tunnel::write_tunnel($tunnel, 10, "unlock");
+	if ($self->{opts}->{targetcpu}) {
+	    $self->log('info', "target cpu is different - restart target vm.");
+	    PVE::Tunnel::write_tunnel($tunnel, 10, 'restart');
+	}
 
 	PVE::Tunnel::finish_tunnel($tunnel);
     } else {
-- 
2.30.2