From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 9105DA0F84 for ; Fri, 10 Nov 2023 11:44:32 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 768E61E92D for ; Fri, 10 Nov 2023 11:44:32 +0100 (CET) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for ; Fri, 10 Nov 2023 11:44:31 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 15A12478EA for ; Fri, 10 Nov 2023 11:44:31 +0100 (CET) Date: Fri, 10 Nov 2023 11:44:29 +0100 From: Wolfgang Bumiller To: Filip Schauer Cc: pve-devel@lists.proxmox.com Message-ID: References: <20231107134642.110576-1-f.schauer@proxmox.com> <20231107134642.110576-3-f.schauer@proxmox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231107134642.110576-3-f.schauer@proxmox.com> X-SPAM-LEVEL: Spam detection results: 0 AWL 0.102 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record T_SCC_BODY_TEXT_LINE -0.01 - URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [lxc.pm, mount.auto, proxmox.com, config.pm, tools.pm] Subject: Re: [pve-devel] [PATCH v3 container 1/1] Add device passthrough X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Nov 2023 10:44:32 -0000 On Tue, Nov 07, 2023 at 02:46:42PM +0100, Filip Schauer wrote: > Add a dev[n] argument to the container config to pass devices through to > a container. A device can be passed by its path. Additionally the access > mode, uid and gid can be specified through their respective properties. > > Signed-off-by: Filip Schauer > --- > src/PVE/LXC.pm | 29 +++++++++++++- > src/PVE/LXC/Config.pm | 79 +++++++++++++++++++++++++++++++++++++++ > src/PVE/LXC/Tools.pm | 23 +++++++++--- > src/lxc-pve-autodev-hook | 14 ++++++- > src/lxc-pve-prestart-hook | 63 +++++++++++++++++++++++++++++++ > 5 files changed, 201 insertions(+), 7 deletions(-) > > diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm > index 7ec816b..162f093 100644 > --- a/src/PVE/LXC.pm > +++ b/src/PVE/LXC.pm > @@ -5,7 +5,7 @@ use warnings; > > use Cwd qw(); > use Errno qw(ELOOP ENOTDIR EROFS ECONNREFUSED EEXIST); > -use Fcntl qw(O_RDONLY O_WRONLY O_NOFOLLOW O_DIRECTORY); > +use Fcntl qw(O_RDONLY O_WRONLY O_NOFOLLOW O_DIRECTORY :mode); > use File::Path; > use File::Spec; > use IO::Poll qw(POLLIN POLLHUP); > @@ -639,6 +639,33 @@ sub update_lxc_config { > $raw .= "lxc.mount.auto = sys:mixed\n"; > } > > + PVE::LXC::Config->foreach_passthrough_device($conf, sub { > + my ($key, $device) = @_; > + > + die "Path is not defined for passthrough device $key" > + unless (defined($device->{path})); > + > + my $absolute_path = $device->{path}; > + > + die "Device $absolute_path does not exist\n" > + unless (-e $absolute_path); > + > + my ($mode, $rdev) = (stat($absolute_path))[2, 6]; > + > + die "Could not get mode of device $absolute_path\n" > + if $mode !~ /^([\d]+)$/; > + $mode = $1; > + > + die "Could not get device ID of $absolute_path\n" > + if $rdev !~ /^([\d]+)$/; > + $rdev = $1; ^ The above 2 checks don't seem necessary. `stat()` cannot return different types of values there. Just check them for definedness once together. > + > + my $major = PVE::Tools::dev_t_major($rdev); > + my $minor = PVE::Tools::dev_t_minor($rdev); > + my $device_type_char = S_ISBLK($mode) ? 'b' : 'c'; > + $raw .= "lxc.cgroup2.devices.allow = $device_type_char $major:$minor rw\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..b4fa147 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 +909,57 @@ 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@/\.\.?/@ || > + $dev =~ m@/\.\.?$@ || > + $dev !~ m!^/dev/! > + ) { > + return undef if $noerr; > + die "$dev is not a valid device path\n"; > + } > + > + return $dev; > +} > + > +my $dev_desc = { > + path => { > + optional => 1, > + 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', > + }, > + mode => { > + optional => 1, > + type => 'integer', > + description => 'Access mode (in octal) to be set on the device node', > + }, > + uid => { > + optional => 1, > + type => 'integer', > + description => 'User ID to be assigned to the device node', > + }, > + gid => { > + optional => 1, > + type => 'integer', > + description => 'Group ID to be assigned to the device node', > + }, > +}; > + > +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, $strict) = @_; > > @@ -1255,6 +1307,21 @@ sub parse_volume { > return; > } > > +sub parse_device { > + my ($class, $device_string, $noerr) = @_; > + > + my $res; > + eval { $res = PVE::JSONSchema::parse_property_string($dev_desc, $device_string) }; > + if ($@) { > + return undef if $noerr; > + die $@; > + } > + > + die "Path has to be defined" unless (defined($res->{path})); > + > + return $res; > +} > + > sub print_volume { > my ($class, $key, $volume) = @_; > > @@ -1762,4 +1829,16 @@ sub get_derived_property { > } > } > > +sub foreach_passthrough_device { > + my ($class, $conf, $func, @param) = @_; > + > + foreach my $key (keys %$conf) { > + next if $key !~ m/^dev(\d+)$/; > + > + my $device = $class->parse_device($conf->{$key}); > + > + $func->($key, $device, @param); > + } > +} > + > 1; > diff --git a/src/PVE/LXC/Tools.pm b/src/PVE/LXC/Tools.pm > index 62cdbc1..c9fb834 100644 > --- a/src/PVE/LXC/Tools.pm > +++ b/src/PVE/LXC/Tools.pm > @@ -81,10 +81,9 @@ sub lxc_hook($$&) { > $code->($ct_name, $common_vars, $namespaces, $args); > } > > -sub for_current_devices($&) { > - my ($vmid, $code) = @_; > +sub for_devices { > + my ($devlist_file, $vmid, $code) = @_; > > - my $devlist_file = "/var/lib/lxc/$vmid/devices"; > my $fd; > > if (! open $fd, '<', $devlist_file) { > @@ -93,8 +92,8 @@ sub for_current_devices($&) { > } > > while (defined(my $line = <$fd>)) { > - if ($line !~ m@^(b):(\d+):(\d+):/dev/(\S+)\s*$@) { > - warn "invalid .pve-devices entry: $line\n"; > + if ($line !~ m@^(b|c):(\d+):(\d+):/dev/(\S+)\s*$@) { > + warn "invalid $devlist_file entry: $line\n"; > next; > } > > @@ -117,6 +116,20 @@ sub for_current_devices($&) { > close $fd; > } > > +sub for_current_devices($&) { > + my ($vmid, $code) = @_; > + > + my $devlist_file = "/var/lib/lxc/$vmid/devices"; > + for_devices($devlist_file, $vmid, $code); > +} > + > +sub for_passthrough_devices($&) { > + my ($vmid, $code) = @_; > + > + my $passthrough_devlist_file = "/var/lib/lxc/$vmid/passthrough_devices"; > + for_devices($passthrough_devlist_file, $vmid, $code); > +} > + > sub cgroup_do_write($$) { > my ($path, $value) = @_; > my $fd; > diff --git a/src/lxc-pve-autodev-hook b/src/lxc-pve-autodev-hook > index 3c45949..cd2b92a 100755 > --- a/src/lxc-pve-autodev-hook > +++ b/src/lxc-pve-autodev-hook > @@ -3,8 +3,9 @@ > use strict; > use warnings; > > -use File::Path; > use File::Basename; > +use File::Path; > +use File::Touch; > > use PVE::LXC::Tools; > use PVE::Tools; > @@ -14,6 +15,17 @@ PVE::LXC::Tools::lxc_hook('autodev', 'lxc', sub { > > my $root = $vars->{ROOTFS_MOUNT}; > > + PVE::LXC::Tools::for_passthrough_devices($vmid, sub { > + my ($type, $major, $minor, $dev) = @_; > + > + my $rel_devpath = "/dev/$dev"; > + my $rel_dir = dirname($rel_devpath); > + File::Path::mkpath("$root/$rel_dir"); > + touch("$root/dev/$dev"); ^ Hint: `touch` is not a syscall. This does an `utimensat()` to update the file mtimes. This isn't really necessary, and an easy way to just create a file and do nothing if it already exists is to just use mknod with S_IFREG for the file type in the mode bits and zero for the device type: PVE::Tools::mknod("$root/dev/$dev", S_IFREG, 0); > + > + PVE::Tools::mount("/var/lib/lxc/$vmid/passthrough/dev/$dev", "$root/dev/$dev", 0, 4096, 0); Don't use magic numbers. Please place the MS_BIND constant in PVE::Tools instead. Also die() if mount fails. > + }); > + > PVE::LXC::Tools::for_current_devices($vmid, sub { > my ($type, $major, $minor, $dev) = @_; > > diff --git a/src/lxc-pve-prestart-hook b/src/lxc-pve-prestart-hook > index 936d0bf..68c7cec 100755 > --- a/src/lxc-pve-prestart-hook > +++ b/src/lxc-pve-prestart-hook > @@ -6,6 +6,7 @@ use strict; > use warnings; > > use Fcntl qw(O_DIRECTORY :mode); > +use File::Basename; > use File::Path; > use POSIX; > > @@ -118,6 +119,55 @@ PVE::LXC::Tools::lxc_hook('pre-start', 'lxc', sub { > > PVE::LXC::Config->foreach_volume($conf, $setup_mountpoint); > > + # Device passthrough > + my $passthrough_devlist_file = "/var/lib/lxc/$vmid/passthrough_devices"; > + unlink $passthrough_devlist_file; > + my $passthrough_devices = []; > + > + my $passthrough_dir = "/var/lib/lxc/$vmid/passthrough"; > + File::Path::make_path($passthrough_dir); > + PVE::Tools::mount("none", $passthrough_dir, "tmpfs", 0, "size=8k"); ^ checking that `mount` succeeded is particularly important here > + > + my $setup_passthrough_device = sub { > + my ($key, $device) = @_; > + > + my $absolute_path = $device->{path}; > + my ($mode, $rdev) = (stat($absolute_path))[2, 6]; > + > + die "Could not get mode of device $absolute_path\n" > + if $mode !~ /^([\d]+)$/; > + $mode = $1; > + > + die "Could not get device ID of $absolute_path\n" > + if $rdev !~ /^([\d]+)$/; > + $rdev = $1; ^ As above for the 2 checks with the stat() returned values. > + > + my $passthrough_device_path = "$passthrough_dir$absolute_path"; ^ The above concatenation would probably be more readable with `.` instead of quotes ($passthrough_dir . $absolute_path), or with `{}` around the names. > + > + die "passthrough device path is invalid\n" > + if $passthrough_device_path !~ /^([\w\/]+)$/; > + $passthrough_device_path = $1; ^ Why this check? Both portions should be fine - $passthrough_dir is trivial and $absolute_path comes from the parse function after verification (and is already used in `stat()` so definitely contains a valid path we also already used. > + > + File::Path::make_path(dirname($passthrough_device_path)); > + PVE::Tools::mknod($passthrough_device_path, $mode, $rdev); ^ `mknod` should be checked for errors. > + > + # Use chmod because umask could mess with the access mode on mknod > + my $passthrough_mode = 0660; > + $passthrough_mode = oct($device->{mode}) if (defined($device->{mode})); > + chmod $passthrough_mode, $passthrough_device_path; ^ should be checked for errors. > + > + # Set uid and gid of the device node > + my $uid = $rootuid; > + my $gid = $rootgid; > + $uid += $device->{uid} if (defined($device->{uid})); > + $gid += $device->{gid} if (defined($device->{gid})); ^ id mappings can constist of multiple ranges. You get the mapping from `parse_id_maps` (the 1st return value in the line fetching `$root*id`). It's an array of tuples of the form: [ "g" or "u", , , ] Make a helper to map ids using that array (see [1]). $device->{*id} is from the perspective of the container and you want to map from that to the host. [1] https://git.proxmox.com/?p=pve-lxc-syscalld.git;a=blob;f=src/process/id_map.rs;h=d61d489da7af7418908fd8d85f1660c435b7c73e;hb=refs/heads/master#l26 > + chown $uid, $gid, $passthrough_device_path; ^ check for errors > + > + push @$passthrough_devices, $absolute_path; push @$passthrough_devices, [$absolute_path, $mode, $rdev]; to avoid the extra stat below... > + }; > + > + PVE::LXC::Config->foreach_passthrough_device($conf, $setup_passthrough_device); > + > my $lxc_setup = PVE::LXC::Setup->new($conf, $rootdir); > $lxc_setup->pre_start_hook(); > > @@ -140,6 +190,19 @@ PVE::LXC::Tools::lxc_hook('pre-start', 'lxc', sub { > } > PVE::Tools::file_set_contents($devlist_file, $devlist); > } > + > + if (@$passthrough_devices) { > + my $devlist = ''; > + foreach my $dev (@$passthrough_devices) { > + my ($mode, $rdev) = (stat($dev))[2, 6]; > + next if !$mode || !$rdev; ...and then resolve the tuple via: ($dev, my $mode, my $rdev) = @$dev; > + my $major = PVE::Tools::dev_t_major($rdev); > + my $minor = PVE::Tools::dev_t_minor($rdev); > + my $device_type_char = S_ISBLK($mode) ? 'b' : 'c'; > + $devlist .= "$device_type_char:$major:$minor:$dev\n"; > + } > + PVE::Tools::file_set_contents($passthrough_devlist_file, $devlist); > + } > }); > > # Leftover cgroups prevent lxc from starting without any useful information > -- > 2.39.2