[pve-devel] [PATCH v2 qemu-server 2/4] add NBD server unix socket support in vm_start

[Stefan Reiter]

On 17/03/2020 20:56, Mira Limbeck wrote:
> As the NBD server spawned by qemu can only listen on a single socket,
> we're dependent on a version being passed to vm_start that indicates
> which protocol can be used, TCP or Unix, by the source node.
> 
> The change in socket type (TCP to Unix) comes with a different URI. For
> unix sockets it has the form: 'nbd:unix:<path/to/socket>:exportname=<device>'.
> 
> Signed-off-by: Mira Limbeck <m.limbeck at proxmox.com>
> ---
> v2:
>   - added fallback to 0 if nbd_protocol_version is undefined
>   - some cleanup regarding variables only used in one case
> 
>   PVE/QemuServer.pm | 34 ++++++++++++++++++++++++----------
>   1 file changed, 24 insertions(+), 10 deletions(-)
> 
> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
> index 429ec05..2ef8bff 100644
> --- a/PVE/QemuServer.pm
> +++ b/PVE/QemuServer.pm
> @@ -4707,7 +4707,8 @@ sub vmconfig_update_disk {
>   
>   sub vm_start {
>       my ($storecfg, $vmid, $statefile, $skiplock, $migratedfrom, $paused,
> -	$forcemachine, $spice_ticket, $migration_network, $migration_type, $targetstorage, $timeout) = @_;
> +	$forcemachine, $spice_ticket, $migration_network, $migration_type,
> +	$targetstorage, $timeout, $nbd_protocol_version) = @_;
>   
>       PVE::QemuConfig->lock_config($vmid, sub {
>   	my $conf = PVE::QemuConfig->load_config($vmid, $migratedfrom);
> @@ -4985,20 +4986,33 @@ sub vm_start {
>   
>   	#start nbd server for storage migration
>   	if ($targetstorage) {
> -	    my $nodename = nodename();
> -	    my $localip = $get_migration_ip->($migration_network, $nodename);
> -	    my $pfamily = PVE::Tools::get_host_address_family($nodename);
> -	    my $storage_migrate_port = PVE::Tools::next_migrate_port($pfamily);
> -
> -	    mon_cmd($vmid, "nbd-server-start", addr => { type => 'inet', data => { host => "${localip}", port => "${storage_migrate_port}" } } );
> +	    $nbd_protocol_version //= 0;
> +
> +	    my $migrate_storage_uri;
> +	    # nbd_protocol_version > 0 for unix socket support
> +	    if ($nbd_protocol_version > 0 && $migration_type eq 'secure') {
> +		my $socket_path = "/run/qemu-server/$vmid\_nbd.migrate";
> +		mon_cmd($vmid, "nbd-server-start", addr => { type => 'unix', data => { path => $socket_path } } );
> +		$migrate_storage_uri = "nbd:unix:$socket_path";
> +	    } else {
> +		my $nodename = nodename();
> +		my $localip = $get_migration_ip->($migration_network, $nodename);
> +		my $pfamily = PVE::Tools::get_host_address_family($nodename);
> +		my $storage_migrate_port = PVE::Tools::next_migrate_port($pfamily);
>   
> -	    $localip = "[$localip]" if Net::IP::ip_is_ipv6($localip);
> +		mon_cmd($vmid, "nbd-server-start", addr => { type => 'inet', data => { host => "${localip}", port => "${storage_migrate_port}" } } );
> +		$localip = "[$localip]" if Net::IP::ip_is_ipv6($localip);
> +		$migrate_storage_uri = "nbd:${localip}:${storage_migrate_port}";
> +	    }
>   
>   	    foreach my $opt (sort keys %$local_volumes) {
>   		my $drivestr = $local_volumes->{$opt};
>   		mon_cmd($vmid, "nbd-server-add", device => "drive-$opt", writable => JSON::true );
> -		my $migrate_storage_uri = "nbd:${localip}:${storage_migrate_port}:exportname=drive-$opt";
> -		print "storage migration listens on $migrate_storage_uri volume:$drivestr\n";
> +		if ($nbd_protocol_version > 0 && $migration_type eq 'secure') {
> +		    print "storage migration listens on $migrate_storage_uri:exportname=drive-$opt volume:$drivestr\n";
> +		} else {
> +		    print "storage migration listens on $migrate_storage_uri:exportname=drive-$opt volume:$drivestr\n";
> +		}

What's the idea of this if?

>   	    }
>   	}
>   
>