[pve-devel] [PATCH qemu-server 2/2] migrate: send updated tpmstate volid to target node

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

and update the in-memory config for starting the target VM accordingly.
this possibly breaks migration new -> old iff
- spice is not used (else the explicit ticket wins because it comes
  later)
- a local TPM state volume is used
- that local TPM state volume has a different volume id on the target
  node (switched storage, volname already taken, ..)

because the target node will then mis-interpret the tpmstate0 line as
spice ticket and set it accordingly. if the old tpm state volume ID does
not exist on the target node, migration will fail. if it exists by
chance, it might work albeit with a wrong spice ticket (new because of
this patch) and tpm state volume (pre-existing breakage).

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---

Notes:
    https://forum.proxmox.com/threads/error-live-migrate-a-windows-vm-with-tpm.99906/#post-431345
    
    IMHO this is okay since new->old is always best effort and might fail for
    $reasons. we could extend this to check the broadcasted version on the source
    node once pve-manager requires a new enough qemu-server, and die early there to
    avoid running into the compat issue..
    
    the original compat logic was unfortunate - an "old" source node would only
    ever send an unprefixed spice ticket as first line on STDIN, if the compat
    logic had included a check for that this would be a bit easier..

 PVE/API2/Qemu.pm   |  4 ++++
 PVE/QemuMigrate.pm |  8 ++++++++
 PVE/QemuServer.pm  | 10 +++++++++-
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 8b834bb..6992f6f 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -2319,6 +2319,7 @@ __PACKAGE__->register_method({
 	my $spice_ticket;
 	my $nbd_protocol_version = 0;
 	my $replicated_volumes = {};
+	my $tpmstate_vol;
 	if ($stateuri && ($stateuri eq 'tcp' || $stateuri eq 'unix') && $migratedfrom && ($rpcenv->{type} eq 'cli')) {
 	    while (defined(my $line = <STDIN>)) {
 		chomp $line;
@@ -2328,6 +2329,8 @@ __PACKAGE__->register_method({
 		    $nbd_protocol_version = $1;
 		} elsif ($line =~ m/^replicated_volume: (.*)$/) {
 		    $replicated_volumes->{$1} = 1;
+		} elsif ($line =~ m/^tpmstate0: (.*)$/) {
+		    $tpmstate_vol = $1;
 		} elsif (!$spice_ticket) {
 		    # fallback for old source node
 		    $spice_ticket = $line;
@@ -2369,6 +2372,7 @@ __PACKAGE__->register_method({
 		    storagemap => $storagemap,
 		    nbd_proto_version => $nbd_protocol_version,
 		    replicated_volumes => $replicated_volumes,
+		    tpmstate_vol => $tpmstate_vol,
 		};
 
 		my $params = {
diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
index ae3eaf1..c9bc39d 100644
--- a/PVE/QemuMigrate.pm
+++ b/PVE/QemuMigrate.pm
@@ -870,6 +870,14 @@ sub phase2 {
     # version > 0 for unix socket support
     my $nbd_protocol_version = 1;
     my $input = "nbd_protocol_version: $nbd_protocol_version\n";
+
+    if ($conf->{tpmstate0}) {
+	my $tpmdrive = PVE::QemuServer::parse_drive('tpmstate0', $conf->{tpmstate0});
+	my $tpmvol = $tpmdrive->{file};
+	$input .= "tpmstate0: $self->{volume_map}->{$tpmvol}"
+	    if $self->{volume_map}->{$tpmvol} && $tpmvol ne $self->{volume_map}->{$tpmvol};
+    }
+
     $input .= "spice_ticket: $spice_ticket\n" if $spice_ticket;
 
     my @online_replicated_volumes = $self->filter_local_volumes('online', 1);
diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 76d45a2..45b704d 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -5370,7 +5370,8 @@ sub vm_start {
 #   network => CIDR of migration network
 #   type => secure/insecure - tunnel over encrypted connection or plain-text
 #   nbd_proto_version => int, 0 for TCP, 1 for UNIX
-#   replicated_volumes = which volids should be re-used with bitmaps for nbd migration
+#   replicated_volumes => which volids should be re-used with bitmaps for nbd migration
+#   tpmstate_vol => new volid of tpmstate0, not yet contained in config
 sub vm_start_nolock {
     my ($storecfg, $vmid, $conf, $params, $migrate_opts) = @_;
 
@@ -5395,6 +5396,13 @@ sub vm_start_nolock {
     # this way we can reuse the old ISO with the correct config
     PVE::QemuServer::Cloudinit::generate_cloudinitconfig($conf, $vmid) if !$migratedfrom;
 
+    # override TPM state vol if migrated, conf is out of date still
+    if (my $tpmvol = $migrate_opts->{tpmstate_vol}) {
+        my $parsed = parse_drive("tpmstate0", $conf->{tpmstate0});
+        $parsed->{file} = $tpmvol;
+        $conf->{tpmstate0} = print_drive($parsed);
+    }
+
     my $defaults = load_defaults();
 
     # set environment variable useful inside network script
-- 
2.30.2