[pve-devel] [RFC qemu-server 21/22] blockdev: add support for NBD paths

[DERUMIER, Alexandre]

I think I have wrongly dropped  nbd with unix socket  in my last patch
series, but previously it was:


+    } elsif ($path =~ m/^nbd:(\S+):(\d+):exportname=(\S+)$/) {
+	my $server = { type => 'inet', host => $1, port => $2 };
+	$blockdev = { driver => 'nbd', server => $server, export => $3
};
+    } elsif ($path =~ m/^nbd:unix:(\S+):exportname=(\S+)$/) {
+	my $server = { type => 'unix', path => $1 };
+	$blockdev = { driver => 'nbd', server => $server, export => $2
};


-------- Message initial --------
De: Fiona Ebner <f.ebner at proxmox.com>
Répondre à: Proxmox VE development discussion <pve-
devel at lists.proxmox.com>
À: pve-devel at lists.proxmox.com
Objet: [pve-devel] [RFC qemu-server 21/22] blockdev: add support for
NBD paths
Date: 12/06/2025 16:02:52

Co-developed-by: Alexandre Derumier <alexandre.derumier at groupe-
cyllene.com>
Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
---

RFC, because I didn't test it yet.

 PVE/QemuServer/Blockdev.pm | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/PVE/QemuServer/Blockdev.pm b/PVE/QemuServer/Blockdev.pm
index 2d3760f0..839e195a 100644
--- a/PVE/QemuServer/Blockdev.pm
+++ b/PVE/QemuServer/Blockdev.pm
@@ -12,6 +12,15 @@ use PVE::Storage;
 
 use PVE::QemuServer::Drive qw(drive_is_cdrom);
 
+# gives ($host, $port, $export)
+my $NBD_PATH_RE_3 = qr/nbd:(\S+):(\d+):exportname=(\S+)/;
+
+my sub is_nbd {
+    my ($drive) = @_;
+
+    return $drive->{file} =~ $NBD_PATH_RE_3 ? 1 : 0
+}
+
 my sub get_node_name {
     my ($type, $drive_id, $volid, $snap) = @_;
 
@@ -99,7 +108,10 @@ sub generate_file_blockdev {
 
     my $drive_id = PVE::QemuServer::Drive::get_drive_id($drive);
 
-    if ($drive->{file} eq 'cdrom') {
+    if ($drive->{file} =~ m/^$NBD_PATH_RE_3$/) {
+	my $server = { type => 'inet', host => $1, port => $2 };
+	$blockdev = { driver => 'nbd', server => $server, export => $3
};
+    } elsif ($drive->{file} eq 'cdrom') {
 	my $path = PVE::QemuServer::Drive::get_iso_path($storecfg,
$drive->{file});
 	$blockdev = { driver => 'host_cdrom', filename => $path };
     } elsif ($drive->{file} =~ m|^/|) {
@@ -156,6 +168,7 @@ sub generate_format_blockdev {
 
     die "generate_format_blockdev called without volid/path\n" if
!$drive->{file};
     die "generate_format_blockdev called with 'none'\n" if $drive-
>{file} eq 'none';
+    die "generate_format_blockdev called with NBD path\n" if
is_nbd($drive);
 
     my $scfg;
     my $format;
@@ -200,7 +213,9 @@ sub generate_drive_blockdev {
     die "generate_drive_blockdev called with 'none'\n" if $drive-
>{file} eq 'none';
 
     my $child = generate_file_blockdev($storecfg, $drive, $options);
-    $child = generate_format_blockdev($storecfg, $drive, $child,
$options);
+    if (!is_nbd($drive)) {
+	$child = generate_format_blockdev($storecfg, $drive, $child,
$options);
+    }
 
     # this is the top filter entry point, use $drive-drive_id as
nodename
     return {