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

[Alexandre Derumier]

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

When defined, only the live storage migration is done,
but instead to transfert memory, we cleanly shutdown source vm
and restart the target vm.
---
 PVE/API2/Qemu.pm   | 18 ++++++++++++++++++
 PVE/CLI/qm.pm      |  6 ++++++
 PVE/QemuMigrate.pm | 20 +++++++++++++++++++-
 3 files changed, 43 insertions(+), 1 deletion(-)

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 09cc1d8..0be4fe1 100644
--- a/PVE/QemuMigrate.pm
+++ b/PVE/QemuMigrate.pm
@@ -782,6 +782,7 @@ 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}->%*) {
@@ -1138,6 +1139,11 @@ sub phase2 {
 	}
     }
 
+    if($self->{opts}->{targetcpu}){
+	$self->log('info', "target cpu is different - skip live migration.");
+	return;
+    }
+
     $self->log('info', "starting online/live migration on $migrate_uri");
     $self->{livemigration} = 1;
 
@@ -1566,7 +1572,15 @@ 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 $shutdown = undef;
+    if ($self->{opts}->{targetcpu}) {
+	$shutdown_timeout = 180;
+	$shutdown = 1;
+	$self->log('info', "target cpu is different - clean shutdown of source vm.");
+    }
+
+    eval { PVE::QemuServer::vm_stop($self->{storecfg}, $vmid, 1, 1, $shutdown_timeout, $shutdown); };
     if (my $err = $@) {
 	$self->log('err', "stopping vm failed - $err");
 	$self->{errors} = 1;
@@ -1600,6 +1614,10 @@ sub phase3_cleanup {
     # clear migrate lock
     if ($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