[pve-devel] [PATCH RFC container] Add device passthrough

[Filip Schauer]

Signed-off-by: Filip Schauer <f.schauer at proxmox.com>
---
Is it reasonable to add a "dev[n]" argument to the pct.conf, given that
device mount points only allow passing through block devices?

 src/PVE/LXC.pm        | 14 ++++++++++++++
 src/PVE/LXC/Config.pm | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
index c9b5ba7..6090534 100644
--- a/src/PVE/LXC.pm
+++ b/src/PVE/LXC.pm
@@ -639,6 +639,20 @@ sub update_lxc_config {
 	$raw .= "lxc.mount.auto = sys:mixed\n";
     }
 
+    foreach my $k (keys %$conf) {
+	next if $k !~ m/^dev(\d+)$/;
+	my $devpath = $conf->{$k};
+	die "Device $devpath does not exist\n" unless (-e $devpath);
+
+	my ($mode, $rdev) = (stat($devpath))[2, 6];
+	die "Could not find major and minor ids of device $devpath.\n" unless ($mode && $rdev);
+
+	my $major = PVE::Tools::dev_t_major($rdev);
+	my $minor = PVE::Tools::dev_t_minor($rdev);
+	$raw .= "lxc.cgroup2.devices.allow = c $major:$minor rw\n";
+	$raw .= "lxc.mount.entry = $devpath " . substr($devpath, 1) . " none bind,create=file\n";
+    }
+
     # WARNING: DO NOT REMOVE this without making sure that loop device nodes
     # cannot be exposed to the container with r/w access (cgroup perms).
     # When this is enabled mounts will still remain in the monitor's namespace
diff --git a/src/PVE/LXC/Config.pm b/src/PVE/LXC/Config.pm
index 56e1f10..4665ab1 100644
--- a/src/PVE/LXC/Config.pm
+++ b/src/PVE/LXC/Config.pm
@@ -29,6 +29,7 @@ mkdir $lockdir;
 mkdir "/etc/pve/nodes/$nodename/lxc";
 my $MAX_MOUNT_POINTS = 256;
 my $MAX_UNUSED_DISKS = $MAX_MOUNT_POINTS;
+my $MAX_DEVICES = 256;
 
 # BEGIN implemented abstract methods from PVE::AbstractConfig
 
@@ -908,6 +909,37 @@ for (my $i = 0; $i < $MAX_UNUSED_DISKS; $i++) {
     }
 }
 
+PVE::JSONSchema::register_format('pve-lxc-dev-string', \&verify_lxc_dev_string);
+sub verify_lxc_dev_string {
+    my ($dev, $noerr) = @_;
+
+    if ($dev !~ m!^/dev/!) {
+	return undef if $noerr;
+	die "$dev does not start with /dev/\n";
+    }
+
+    return $dev;
+}
+
+my $dev_desc = {
+    dev => {
+	type => 'string',
+	default_key => 1,
+	format => 'pve-lxc-dev-string',
+	format_description => 'Path',
+	description => 'Device to pass through to the container',
+	verbose_description => 'Path to the device to pass through to the container'
+    }
+};
+
+for (my $i = 0; $i < $MAX_DEVICES; $i++) {
+    $confdesc->{"dev$i"} = {
+	optional => 1,
+	type => 'string', format => $dev_desc,
+	description => "Device to pass through to the container",
+    }
+}
+
 sub parse_pct_config {
     my ($filename, $raw, $strict) = @_;
 
-- 
2.39.2