Move path_is_scsi to QemuServer/Drive.pm

[qemu-server.git] / PVE / QemuServer / Drive.pm

package PVE::QemuServer::Drive;

use strict;
use warnings;

use Storable qw(dclone);

use IO::File;

use PVE::Storage;
use PVE::JSONSchema qw(get_standard_option);

use base qw(Exporter);

our @EXPORT_OK = qw(
is_valid_drivename
drive_is_cloudinit
drive_is_cdrom
drive_is_read_only
parse_drive
print_drive
path_is_scsi
);

our $QEMU_FORMAT_RE = qr/raw|cow|qcow|qcow2|qed|vmdk|cloop/;

PVE::JSONSchema::register_standard_option('pve-qm-image-format', {
    type => 'string',
    enum => [qw(raw cow qcow qed qcow2 vmdk cloop)],
    description => "The drive's backing file's data format.",
    optional => 1,
});

my $MAX_IDE_DISKS = 4;
my $MAX_SCSI_DISKS = 31;
my $MAX_VIRTIO_DISKS = 16;
our $MAX_SATA_DISKS = 6;
our $MAX_UNUSED_DISKS = 256;

our $drivedesc_hash;
# Schema when disk allocation is possible.
our $drivedesc_hash_with_alloc = {};

my %drivedesc_base = (
    volume => { alias => 'file' },
    file => {
	type => 'string',
	format => 'pve-volume-id-or-qm-path',
	default_key => 1,
	format_description => 'volume',
	description => "The drive's backing volume.",
    },
    media => {
	type => 'string',
	enum => [qw(cdrom disk)],
	description => "The drive's media type.",
	default => 'disk',
	optional => 1
    },
    cyls => {
	type => 'integer',
	description => "Force the drive's physical geometry to have a specific cylinder count.",
	optional => 1
    },
    heads => {
	type => 'integer',
	description => "Force the drive's physical geometry to have a specific head count.",
	optional => 1
    },
    secs => {
	type => 'integer',
	description => "Force the drive's physical geometry to have a specific sector count.",
	optional => 1
    },
    trans => {
	type => 'string',
	enum => [qw(none lba auto)],
	description => "Force disk geometry bios translation mode.",
	optional => 1,
    },
    snapshot => {
	type => 'boolean',
	description => "Controls qemu's snapshot mode feature."
	    . " If activated, changes made to the disk are temporary and will"
	    . " be discarded when the VM is shutdown.",
	optional => 1,
    },
    cache => {
	type => 'string',
	enum => [qw(none writethrough writeback unsafe directsync)],
	description => "The drive's cache mode",
	optional => 1,
    },
    format => get_standard_option('pve-qm-image-format'),
    size => {
	type => 'string',
	format => 'disk-size',
	format_description => 'DiskSize',
	description => "Disk size. This is purely informational and has no effect.",
	optional => 1,
    },
    backup => {
	type => 'boolean',
	description => "Whether the drive should be included when making backups.",
	optional => 1,
    },
    replicate => {
	type => 'boolean',
	description => 'Whether the drive should considered for replication jobs.',
	optional => 1,
	default => 1,
    },
    rerror => {
	type => 'string',
	enum => [qw(ignore report stop)],
	description => 'Read error action.',
	optional => 1,
    },
    werror => {
	type => 'string',
	enum => [qw(enospc ignore report stop)],
	description => 'Write error action.',
	optional => 1,
    },
    aio => {
	type => 'string',
	enum => [qw(native threads io_uring)],
	description => 'AIO type to use.',
	optional => 1,
    },
    discard => {
	type => 'string',
	enum => [qw(ignore on)],
	description => 'Controls whether to pass discard/trim requests to the underlying storage.',
	optional => 1,
    },
    detect_zeroes => {
	type => 'boolean',
	description => 'Controls whether to detect and try to optimize writes of zeroes.',
	optional => 1,
    },
    serial => {
	type => 'string',
	format => 'urlencoded',
	format_description => 'serial',
	maxLength => 20*3, # *3 since it's %xx url enoded
	description => "The drive's reported serial number, url-encoded, up to 20 bytes long.",
	optional => 1,
    },
    shared => {
	type => 'boolean',
	description => 'Mark this locally-managed volume as available on all nodes',
	verbose_description => "Mark this locally-managed volume as available on all nodes.\n\nWARNING: This option does not share the volume automatically, it assumes it is shared already!",
	optional => 1,
	default => 0,
    }
);

my %iothread_fmt = ( iothread => {
	type => 'boolean',
	description => "Whether to use iothreads for this drive",
	optional => 1,
});

my %model_fmt = (
    model => {
	type => 'string',
	format => 'urlencoded',
	format_description => 'model',
	maxLength => 40*3, # *3 since it's %xx url enoded
	description => "The drive's reported model name, url-encoded, up to 40 bytes long.",
	optional => 1,
    },
);

my %queues_fmt = (
    queues => {
	type => 'integer',
	description => "Number of queues.",
	minimum => 2,
	optional => 1
    }
);

my %readonly_fmt = (
    ro => {
	type => 'boolean',
	description => "Whether the drive is read-only.",
	optional => 1,
    },
);

my %scsiblock_fmt = (
    scsiblock => {
	type => 'boolean',
	description => "whether to use scsi-block for full passthrough of host block device\n\nWARNING: can lead to I/O errors in combination with low memory or high memory fragmentation on host",
	optional => 1,
	default => 0,
    },
);

my %ssd_fmt = (
    ssd => {
	type => 'boolean',
	description => "Whether to expose this drive as an SSD, rather than a rotational hard disk.",
	optional => 1,
    },
);

my %wwn_fmt = (
    wwn => {
	type => 'string',
	pattern => qr/^(0x)[0-9a-fA-F]{16}/,
	format_description => 'wwn',
	description => "The drive's worldwide name, encoded as 16 bytes hex string, prefixed by '0x'.",
	optional => 1,
    },
);

my $add_throttle_desc = sub {
    my ($key, $type, $what, $unit, $longunit, $minimum) = @_;
    my $d = {
	type => $type,
	format_description => $unit,
	description => "Maximum $what in $longunit.",
	optional => 1,
    };
    $d->{minimum} = $minimum if defined($minimum);
    $drivedesc_base{$key} = $d;
};
# throughput: (leaky bucket)
$add_throttle_desc->('bps',     'integer', 'r/w speed',   'bps',  'bytes per second');
$add_throttle_desc->('bps_rd',  'integer', 'read speed',  'bps',  'bytes per second');
$add_throttle_desc->('bps_wr',  'integer', 'write speed', 'bps',  'bytes per second');
$add_throttle_desc->('mbps',    'number',  'r/w speed',   'mbps', 'megabytes per second');
$add_throttle_desc->('mbps_rd', 'number',  'read speed',  'mbps', 'megabytes per second');
$add_throttle_desc->('mbps_wr', 'number',  'write speed', 'mbps', 'megabytes per second');
$add_throttle_desc->('iops',    'integer', 'r/w I/O',     'iops', 'operations per second');
$add_throttle_desc->('iops_rd', 'integer', 'read I/O',    'iops', 'operations per second');
$add_throttle_desc->('iops_wr', 'integer', 'write I/O',   'iops', 'operations per second');

# pools: (pool of IO before throttling starts taking effect)
$add_throttle_desc->('mbps_max',    'number',  'unthrottled r/w pool',       'mbps', 'megabytes per second');
$add_throttle_desc->('mbps_rd_max', 'number',  'unthrottled read pool',      'mbps', 'megabytes per second');
$add_throttle_desc->('mbps_wr_max', 'number',  'unthrottled write pool',     'mbps', 'megabytes per second');
$add_throttle_desc->('iops_max',    'integer', 'unthrottled r/w I/O pool',   'iops', 'operations per second');
$add_throttle_desc->('iops_rd_max', 'integer', 'unthrottled read I/O pool',  'iops', 'operations per second');
$add_throttle_desc->('iops_wr_max', 'integer', 'unthrottled write I/O pool', 'iops', 'operations per second');

# burst lengths
$add_throttle_desc->('bps_max_length',     'integer', 'length of I/O bursts',       'seconds', 'seconds', 1);
$add_throttle_desc->('bps_rd_max_length',  'integer', 'length of read I/O bursts',  'seconds', 'seconds', 1);
$add_throttle_desc->('bps_wr_max_length',  'integer', 'length of write I/O bursts', 'seconds', 'seconds', 1);
$add_throttle_desc->('iops_max_length',    'integer', 'length of I/O bursts',       'seconds', 'seconds', 1);
$add_throttle_desc->('iops_rd_max_length', 'integer', 'length of read I/O bursts',  'seconds', 'seconds', 1);
$add_throttle_desc->('iops_wr_max_length', 'integer', 'length of write I/O bursts', 'seconds', 'seconds', 1);

# legacy support
$drivedesc_base{'bps_rd_length'} = { alias => 'bps_rd_max_length' };
$drivedesc_base{'bps_wr_length'} = { alias => 'bps_wr_max_length' };
$drivedesc_base{'iops_rd_length'} = { alias => 'iops_rd_max_length' };
$drivedesc_base{'iops_wr_length'} = { alias => 'iops_wr_max_length' };

my $ide_fmt = {
    %drivedesc_base,
    %model_fmt,
    %ssd_fmt,
    %wwn_fmt,
};
PVE::JSONSchema::register_format("pve-qm-ide", $ide_fmt);

my $idedesc = {
    optional => 1,
    type => 'string', format => $ide_fmt,
    description => "Use volume as IDE hard disk or CD-ROM (n is 0 to " .($MAX_IDE_DISKS - 1) . ").",
};
PVE::JSONSchema::register_standard_option("pve-qm-ide", $idedesc);

my $scsi_fmt = {
    %drivedesc_base,
    %iothread_fmt,
    %queues_fmt,
    %readonly_fmt,
    %scsiblock_fmt,
    %ssd_fmt,
    %wwn_fmt,
};
my $scsidesc = {
    optional => 1,
    type => 'string', format => $scsi_fmt,
    description => "Use volume as SCSI hard disk or CD-ROM (n is 0 to " . ($MAX_SCSI_DISKS - 1) . ").",
};
PVE::JSONSchema::register_standard_option("pve-qm-scsi", $scsidesc);

my $sata_fmt = {
    %drivedesc_base,
    %ssd_fmt,
    %wwn_fmt,
};
my $satadesc = {
    optional => 1,
    type => 'string', format => $sata_fmt,
    description => "Use volume as SATA hard disk or CD-ROM (n is 0 to " . ($MAX_SATA_DISKS - 1). ").",
};
PVE::JSONSchema::register_standard_option("pve-qm-sata", $satadesc);

my $virtio_fmt = {
    %drivedesc_base,
    %iothread_fmt,
    %readonly_fmt,
};
my $virtiodesc = {
    optional => 1,
    type => 'string', format => $virtio_fmt,
    description => "Use volume as VIRTIO hard disk (n is 0 to " . ($MAX_VIRTIO_DISKS - 1) . ").",
};
PVE::JSONSchema::register_standard_option("pve-qm-virtio", $virtiodesc);

my %efitype_fmt = (
    efitype => {
	type => 'string',
	enum => [qw(2m 4m)],
	description => "Size and type of the OVMF EFI vars. '4m' is newer and recommended,"
	    . " and required for Secure Boot. For backwards compatibility, '2m' is used"
	    . " if not otherwise specified. Ignored for VMs with arch=aarch64 (ARM).",
	optional => 1,
	default => '2m',
    },
    'pre-enrolled-keys' => {
	type => 'boolean',
	description => "Use am EFI vars template with distribution-specific and Microsoft Standard"
	    ." keys enrolled, if used with 'efitype=4m'. Note that this will enable Secure Boot by"
	    ." default, though it can still be turned off from within the VM.",
	optional => 1,
	default => 0,
    },
);

my $efidisk_fmt = {
    volume => { alias => 'file' },
    file => {
	type => 'string',
	format => 'pve-volume-id-or-qm-path',
	default_key => 1,
	format_description => 'volume',
	description => "The drive's backing volume.",
    },
    format => get_standard_option('pve-qm-image-format'),
    size => {
	type => 'string',
	format => 'disk-size',
	format_description => 'DiskSize',
	description => "Disk size. This is purely informational and has no effect.",
	optional => 1,
    },
    %efitype_fmt,
};

my $efidisk_desc = {
    optional => 1,
    type => 'string', format => $efidisk_fmt,
    description => "Configure a disk for storing EFI vars.",
};

PVE::JSONSchema::register_standard_option("pve-qm-efidisk", $efidisk_desc);

my %tpmversion_fmt = (
    version => {
	type => 'string',
	enum => [qw(v1.2 v2.0)],
	description => "The TPM interface version. v2.0 is newer and should be preferred."
	    ." Note that this cannot be changed later on.",
	optional => 1,
	default => 'v2.0',
    },
);
my $tpmstate_fmt = {
    volume => { alias => 'file' },
    file => {
	type => 'string',
	format => 'pve-volume-id-or-qm-path',
	default_key => 1,
	format_description => 'volume',
	description => "The drive's backing volume.",
    },
    size => {
	type => 'string',
	format => 'disk-size',
	format_description => 'DiskSize',
	description => "Disk size. This is purely informational and has no effect.",
	optional => 1,
    },
    %tpmversion_fmt,
};
my $tpmstate_desc = {
    optional => 1,
    type => 'string', format => $tpmstate_fmt,
    description => "Configure a Disk for storing TPM state. The format is fixed to 'raw'.",
};
use constant TPMSTATE_DISK_SIZE => 4 * 1024 * 1024;

my $alldrive_fmt = {
    %drivedesc_base,
    %iothread_fmt,
    %model_fmt,
    %queues_fmt,
    %readonly_fmt,
    %scsiblock_fmt,
    %ssd_fmt,
    %wwn_fmt,
    %tpmversion_fmt,
    %efitype_fmt,
};

my %import_from_fmt = (
    'import-from' => {
	type => 'string',
	format => 'pve-volume-id-or-absolute-path',
	format_description => 'source volume',
	description => "Create a new disk, importing from this source (volume ID or absolute ".
	    "path). When an absolute path is specified, it's up to you to ensure that the source ".
	    "is not actively used by another process during the import!",
	optional => 1,
    },
);

my $alldrive_fmt_with_alloc = {
    %$alldrive_fmt,
    %import_from_fmt,
};

my $unused_fmt = {
    volume => { alias => 'file' },
    file => {
	type => 'string',
	format => 'pve-volume-id',
	default_key => 1,
	format_description => 'volume',
	description => "The drive's backing volume.",
    },
};

my $unuseddesc = {
    optional => 1,
    type => 'string', format => $unused_fmt,
    description => "Reference to unused volumes. This is used internally, and should not be modified manually.",
};

my $with_alloc_desc_cache = {
    unused => $unuseddesc, # Allocation for unused is not supported currently.
};
my $desc_with_alloc = sub {
    my ($type, $desc) = @_;

    return $with_alloc_desc_cache->{$type} if $with_alloc_desc_cache->{$type};

    my $new_desc = dclone($desc);

    $new_desc->{format}->{'import-from'} = $import_from_fmt{'import-from'};

    my $extra_note = '';
    if ($type eq 'efidisk') {
	$extra_note = " Note that SIZE_IN_GiB is ignored here and that the default EFI vars are ".
	    "copied to the volume instead.";
    } elsif ($type eq 'tpmstate') {
	$extra_note = " Note that SIZE_IN_GiB is ignored here and 4 MiB will be used instead.";
    }

    $new_desc->{description} .= " Use the special syntax STORAGE_ID:SIZE_IN_GiB to allocate a new ".
	"volume.${extra_note} Use STORAGE_ID:0 and the 'import-from' parameter to import from an ".
	"existing volume.";

    $with_alloc_desc_cache->{$type} = $new_desc;

    return $new_desc;
};

for (my $i = 0; $i < $MAX_IDE_DISKS; $i++)  {
    $drivedesc_hash->{"ide$i"} = $idedesc;
    $drivedesc_hash_with_alloc->{"ide$i"} = $desc_with_alloc->('ide', $idedesc);
}

for (my $i = 0; $i < $MAX_SATA_DISKS; $i++)  {
    $drivedesc_hash->{"sata$i"} = $satadesc;
    $drivedesc_hash_with_alloc->{"sata$i"} = $desc_with_alloc->('sata', $satadesc);
}

for (my $i = 0; $i < $MAX_SCSI_DISKS; $i++)  {
    $drivedesc_hash->{"scsi$i"} = $scsidesc;
    $drivedesc_hash_with_alloc->{"scsi$i"} = $desc_with_alloc->('scsi', $scsidesc);
}

for (my $i = 0; $i < $MAX_VIRTIO_DISKS; $i++)  {
    $drivedesc_hash->{"virtio$i"} = $virtiodesc;
    $drivedesc_hash_with_alloc->{"virtio$i"} = $desc_with_alloc->('virtio', $virtiodesc);
}

$drivedesc_hash->{efidisk0} = $efidisk_desc;
$drivedesc_hash_with_alloc->{efidisk0} = $desc_with_alloc->('efidisk', $efidisk_desc);

$drivedesc_hash->{tpmstate0} = $tpmstate_desc;
$drivedesc_hash_with_alloc->{tpmstate0} = $desc_with_alloc->('tpmstate', $tpmstate_desc);

for (my $i = 0; $i < $MAX_UNUSED_DISKS; $i++) {
    $drivedesc_hash->{"unused$i"} = $unuseddesc;
    $drivedesc_hash_with_alloc->{"unused$i"} = $desc_with_alloc->('unused', $unuseddesc);
}

sub valid_drive_names_for_boot {
    return grep { $_ ne 'efidisk0' && $_ ne 'tpmstate0' } valid_drive_names();
}

sub valid_drive_names {
    # order is important - used to autoselect boot disk
    return ((map { "ide$_" } (0 .. ($MAX_IDE_DISKS - 1))),
            (map { "scsi$_" } (0 .. ($MAX_SCSI_DISKS - 1))),
            (map { "virtio$_" } (0 .. ($MAX_VIRTIO_DISKS - 1))),
            (map { "sata$_" } (0 .. ($MAX_SATA_DISKS - 1))),
            'efidisk0',
            'tpmstate0');
}

sub valid_drive_names_with_unused {
    return (valid_drive_names(), map {"unused$_"} (0 .. ($MAX_UNUSED_DISKS - 1)));
}

sub is_valid_drivename {
    my $dev = shift;

    return defined($drivedesc_hash->{$dev}) && $dev !~ /^unused\d+$/;
}

PVE::JSONSchema::register_format('pve-qm-bootdisk', \&verify_bootdisk);
sub verify_bootdisk {
    my ($value, $noerr) = @_;

    return $value if is_valid_drivename($value);

    return if $noerr;

    die "invalid boot disk '$value'\n";
}

sub drive_is_cloudinit {
    my ($drive) = @_;
    return $drive->{file} =~ m@[:/](?:vm-\d+-)?cloudinit(?:\.$QEMU_FORMAT_RE)?$@;
}

sub drive_is_cdrom {
    my ($drive, $exclude_cloudinit) = @_;

    return 0 if $exclude_cloudinit && drive_is_cloudinit($drive);

    return $drive && $drive->{media} && ($drive->{media} eq 'cdrom');
}

sub drive_is_read_only {
    my ($conf, $drive) = @_;

    return 0 if !PVE::QemuConfig->is_template($conf);

    # don't support being marked read-only
    return $drive->{interface} ne 'sata' && $drive->{interface} ne 'ide';
}

# ideX = [volume=]volume-id[,media=d][,cyls=c,heads=h,secs=s[,trans=t]]
#        [,snapshot=on|off][,cache=on|off][,format=f][,backup=yes|no]
#        [,rerror=ignore|report|stop][,werror=enospc|ignore|report|stop]
#        [,aio=native|threads][,discard=ignore|on][,detect_zeroes=on|off]
#        [,iothread=on][,serial=serial][,model=model]

sub parse_drive {
    my ($key, $data, $with_alloc) = @_;

    my ($interface, $index);

    if ($key =~ m/^([^\d]+)(\d+)$/) {
	$interface = $1;
	$index = $2;
    } else {
	return;
    }

    my $desc_hash = $with_alloc ? $drivedesc_hash_with_alloc : $drivedesc_hash;

    if (!defined($desc_hash->{$key})) {
	warn "invalid drive key: $key\n";
	return;
    }

    my $desc = $desc_hash->{$key}->{format};
    my $res = eval { PVE::JSONSchema::parse_property_string($desc, $data) };
    return if !$res;
    $res->{interface} = $interface;
    $res->{index} = $index;

    my $error = 0;
    foreach my $opt (qw(bps bps_rd bps_wr)) {
	if (my $bps = defined(delete $res->{$opt})) {
	    if (defined($res->{"m$opt"})) {
		warn "both $opt and m$opt specified\n";
		++$error;
		next;
	    }
	    $res->{"m$opt"} = sprintf("%.3f", $bps / (1024*1024.0));
	}
    }

    # can't use the schema's 'requires' because of the mbps* => bps* "transforming aliases"
    for my $requirement (
	[mbps_max => 'mbps'],
	[mbps_rd_max => 'mbps_rd'],
	[mbps_wr_max => 'mbps_wr'],
	[miops_max => 'miops'],
	[miops_rd_max => 'miops_rd'],
	[miops_wr_max => 'miops_wr'],
	[bps_max_length => 'mbps_max'],
	[bps_rd_max_length => 'mbps_rd_max'],
	[bps_wr_max_length => 'mbps_wr_max'],
	[iops_max_length => 'iops_max'],
	[iops_rd_max_length => 'iops_rd_max'],
	[iops_wr_max_length => 'iops_wr_max']) {
	my ($option, $requires) = @$requirement;
	if ($res->{$option} && !$res->{$requires}) {
	    warn "$option requires $requires\n";
	    ++$error;
	}
    }

    return if $error;

    return if $res->{mbps_rd} && $res->{mbps};
    return if $res->{mbps_wr} && $res->{mbps};
    return if $res->{iops_rd} && $res->{iops};
    return if $res->{iops_wr} && $res->{iops};

    if ($res->{media} && ($res->{media} eq 'cdrom')) {
	return if $res->{snapshot} || $res->{trans} || $res->{format};
	return if $res->{heads} || $res->{secs} || $res->{cyls};
	return if $res->{interface} eq 'virtio';
    }

    if (my $size = $res->{size}) {
	return if !defined($res->{size} = PVE::JSONSchema::parse_size($size));
    }

    return $res;
}

sub print_drive {
    my ($drive, $with_alloc) = @_;
    my $skip = [ 'index', 'interface' ];
    my $fmt = $with_alloc ? $alldrive_fmt_with_alloc : $alldrive_fmt;
    return PVE::JSONSchema::print_property_string($drive, $fmt, $skip);
}

sub get_bootdisks {
    my ($conf) = @_;

    my $bootcfg;
    $bootcfg = PVE::JSONSchema::parse_property_string('pve-qm-boot', $conf->{boot}) if $conf->{boot};

    if (!defined($bootcfg) || $bootcfg->{legacy}) {
	return [$conf->{bootdisk}] if $conf->{bootdisk};
	return [];
    }

    my @list = PVE::Tools::split_list($bootcfg->{order});
    @list = grep {is_valid_drivename($_)} @list;
    return \@list;
}

sub bootdisk_size {
    my ($storecfg, $conf) = @_;

    my $bootdisks = get_bootdisks($conf);
    return if !@$bootdisks;
    for my $bootdisk (@$bootdisks) {
	next if !is_valid_drivename($bootdisk);
	next if !$conf->{$bootdisk};
	my $drive = parse_drive($bootdisk, $conf->{$bootdisk});
	next if !defined($drive);
	next if drive_is_cdrom($drive);
	my $volid = $drive->{file};
	next if !$volid;
	return $drive->{size};
    }

    return;
}

sub update_disksize {
    my ($drive, $newsize) = @_;

    return if !defined($newsize);

    my $oldsize = $drive->{size} // 0;

    if ($newsize != $oldsize) {
	$drive->{size} = $newsize;

	my $old_fmt = PVE::JSONSchema::format_size($oldsize);
	my $new_fmt = PVE::JSONSchema::format_size($newsize);

	my $msg = "size of disk '$drive->{file}' updated from $old_fmt to $new_fmt";

	return ($drive, $msg);
    }

    return;
}

sub is_volume_in_use {
    my ($storecfg, $conf, $skip_drive, $volid) = @_;

    my $path = PVE::Storage::path($storecfg, $volid);

    my $scan_config = sub {
	my ($cref) = @_;

	foreach my $key (keys %$cref) {
	    my $value = $cref->{$key};
	    if (is_valid_drivename($key)) {
		next if $skip_drive && $key eq $skip_drive;
		my $drive = parse_drive($key, $value);
		next if !$drive || !$drive->{file} || drive_is_cdrom($drive);
		return 1 if $volid eq $drive->{file};
		if ($drive->{file} =~ m!^/!) {
		    return 1 if $drive->{file} eq $path;
		} else {
		    my ($storeid, $volname) = PVE::Storage::parse_volume_id($drive->{file}, 1);
		    next if !$storeid;
		    my $scfg = PVE::Storage::storage_config($storecfg, $storeid, 1);
		    next if !$scfg;
		    return 1 if $path eq PVE::Storage::path($storecfg, $drive->{file});
		}
	    }
	}

	return 0;
    };

    return 1 if &$scan_config($conf);

    undef $skip_drive;

    for my $snap (values %{$conf->{snapshots}}) {
	return 1 if $scan_config->($snap);
    }

    return 0;
}

sub resolve_first_disk {
    my ($conf, $cdrom) = @_;
    my @disks = valid_drive_names_for_boot();
    foreach my $ds (@disks) {
	next if !$conf->{$ds};
	my $disk = parse_drive($ds, $conf->{$ds});
	next if drive_is_cdrom($disk) xor $cdrom;
	return $ds;
    }
    return;
}

sub scsi_inquiry {
    my($fh, $noerr) = @_;

    my $SG_IO = 0x2285;
    my $SG_GET_VERSION_NUM = 0x2282;

    my $versionbuf = "\x00" x 8;
    my $ret = ioctl($fh, $SG_GET_VERSION_NUM, $versionbuf);
    if (!$ret) {
	die "scsi ioctl SG_GET_VERSION_NUM failoed - $!\n" if !$noerr;
	return;
    }
    my $version = unpack("I", $versionbuf);
    if ($version < 30000) {
	die "scsi generic interface too old\n"  if !$noerr;
	return;
    }

    my $buf = "\x00" x 36;
    my $sensebuf = "\x00" x 8;
    my $cmd = pack("C x3 C x1", 0x12, 36);

    # see /usr/include/scsi/sg.h
    my $sg_io_hdr_t = "i i C C s I P P P I I i P C C C C S S i I I";

    my $packet = pack(
	$sg_io_hdr_t, ord('S'), -3, length($cmd), length($sensebuf), 0, length($buf), $buf, $cmd, $sensebuf, 6000
    );

    $ret = ioctl($fh, $SG_IO, $packet);
    if (!$ret) {
	die "scsi ioctl SG_IO failed - $!\n" if !$noerr;
	return;
    }

    my @res = unpack($sg_io_hdr_t, $packet);
    if ($res[17] || $res[18]) {
	die "scsi ioctl SG_IO status error - $!\n" if !$noerr;
	return;
    }

    my $res = {};
    $res->@{qw(type removable vendor product revision)} = unpack("C C x6 A8 A16 A4", $buf);

    $res->{removable} = $res->{removable} & 128 ? 1 : 0;
    $res->{type} &= 0x1F;

    return $res;
}

sub path_is_scsi {
    my ($path) = @_;

    my $fh = IO::File->new("+<$path") || return;
    my $res = scsi_inquiry($fh, 1);
    close($fh);

    return $res;
}

1;