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qemu-server/PVE/QMPClient.pm
2013-04-18 08:26:23 +02:00

329 lines
7.2 KiB
Perl
Executable File

package PVE::QMPClient;
use strict;
use PVE::QemuServer;
use IO::Multiplex;
use POSIX qw(EINTR EAGAIN);
use JSON;
use Time::HiRes qw(usleep gettimeofday tv_interval);
use Scalar::Util qw(weaken);
use PVE::IPCC;
use Data::Dumper;
# Qemu Monitor Protocol (QMP) client.
#
# This implementation uses IO::Multiplex (libio-multiplex-perl) and
# allows you to issue qmp commands to different VMs in parallel.
# Note: kvm can onyl handle 1 connection, so we close connections asap
sub new {
my ($class, $eventcb) = @_;
my $mux = new IO::Multiplex;
my $self = bless {
mux => $mux,
fhs => {}, # $vmid => fh
fhs_lookup => {}, # $fh => $vmid
queue => {},
current => {},
errors => {},
}, $class;
$self->{eventcb} = $eventcb if $eventcb;
$mux->set_callback_object($self);
# make sure perl doesn't believe this is a circular reference as we
# delete mux in DESTROY
weaken($mux->{_object});
return $self;
}
# add a single command to the queue for later execution
# with queue_execute()
sub queue_cmd {
my ($self, $vmid, $callback, $execute, %params) = @_;
my $cmd = {};
$cmd->{execute} = $execute;
$cmd->{arguments} = \%params;
$cmd->{callback} = $callback;
push @{$self->{queue}->{$vmid}}, $cmd;
}
# execute a single command
sub cmd {
my ($self, $vmid, $cmd, $timeout) = @_;
my $result;
my $callback = sub {
my ($vmid, $resp) = @_;
$result = $resp->{'return'};
};
die "no command specified" if !($cmd && $cmd->{execute});
$cmd->{callback} = $callback;
$cmd->{arguments} = {} if !defined($cmd->{arguments});
$self->{queue}->{$vmid} = [ $cmd ];
if (!$timeout) {
# hack: monitor sometime blocks
if ($cmd->{execute} eq 'query-migrate') {
$timeout = 60*60; # 1 hour
} elsif ($cmd->{execute} =~ m/^(eject|change)/) {
$timeout = 60; # note: cdrom mount command is slow
} elsif ($cmd->{execute} eq 'savevm-start' ||
$cmd->{execute} eq 'savevm-end' ||
$cmd->{execute} eq 'query-backup' ||
$cmd->{execute} eq 'backup-cancel' ||
$cmd->{execute} eq 'query-savevm' ||
$cmd->{execute} eq 'delete-drive-snapshot' ||
$cmd->{execute} eq 'snapshot-drive' ) {
$timeout = 10*60; # 10 mins ?
} else {
$timeout = 3; # default
}
}
$self->queue_execute($timeout);
my $cmdstr = $cmd->{execute} || '';
die "VM $vmid qmp command '$cmdstr' failed - $self->{errors}->{$vmid}"
if defined($self->{errors}->{$vmid});
return $result;
};
my $cmdid_seq = 0;
my $next_cmdid = sub {
$cmdid_seq++;
return "$$:$cmdid_seq";
};
my $close_connection = sub {
my ($self, $vmid) = @_;
my $fh = $self->{fhs}->{$vmid};
return if !$fh;
delete $self->{fhs}->{$vmid};
delete $self->{fhs_lookup}->{$fh};
$self->{mux}->close($fh);
};
my $open_connection = sub {
my ($self, $vmid, $timeout) = @_;
my $sname = PVE::QemuServer::qmp_socket($vmid);
$timeout = 1 if !$timeout;
my $fh;
my $starttime = [gettimeofday];
my $count = 0;
for (;;) {
$count++;
$fh = IO::Socket::UNIX->new(Peer => $sname, Blocking => 0, Timeout => 1);
last if $fh;
if ($! != EINTR && $! != EAGAIN) {
die "unable to connect to VM $vmid socket - $!\n";
}
my $elapsed = tv_interval($starttime, [gettimeofday]);
if ($elapsed >= $timeout) {
die "unable to connect to VM $vmid socket - timeout after $count retries\n";
}
usleep(100000);
}
$self->{fhs}->{$vmid} = $fh;
$self->{fhs_lookup}->{$fh} = $vmid;
$self->{mux}->add($fh);
return $fh;
};
my $check_queue = sub {
my ($self) = @_;
my $running = 0;
foreach my $vmid (keys %{$self->{queue}}) {
my $fh = $self->{fhs}->{$vmid};
next if !$fh;
if ($self->{errors}->{$vmid}) {
&$close_connection($self, $vmid);
next;
}
if ($self->{current}->{$vmid}) { # command running, waiting for response
$running++;
next;
}
if (!scalar(@{$self->{queue}->{$vmid}})) { # no more commands for the VM
&$close_connection($self, $vmid);
next;
}
eval {
my $cmd = $self->{current}->{$vmid} = shift @{$self->{queue}->{$vmid}};
$cmd->{id} = &$next_cmdid();
my $fd = -1;
if ($cmd->{execute} eq 'add-fd' || $cmd->{execute} eq 'getfd') {
$fd = $cmd->{arguments}->{fd};
delete $cmd->{arguments}->{fd};
}
my $qmpcmd = to_json({
execute => $cmd->{execute},
arguments => $cmd->{arguments},
id => $cmd->{id}});
if ($fd >= 0) {
my $ret = PVE::IPCC::sendfd(fileno($fh), $fd, $qmpcmd);
die "sendfd failed" if $ret < 0;
} else {
$self->{mux}->write($fh, $qmpcmd);
}
};
if (my $err = $@) {
$self->{errors}->{$vmid} = $err;
} else {
$running++;
}
}
$self->{mux}->endloop() if !$running;
return $running;
};
# execute all queued command
sub queue_execute {
my ($self, $timeout) = @_;
$timeout = 3 if !$timeout;
$self->{current} = {};
$self->{errors} = {};
# open all necessary connections
foreach my $vmid (keys %{$self->{queue}}) {
next if !scalar(@{$self->{queue}->{$vmid}}); # no commands for the VM
eval {
my $fh = &$open_connection($self, $vmid, $timeout);
my $cmd = { execute => 'qmp_capabilities', arguments => {} };
unshift @{$self->{queue}->{$vmid}}, $cmd;
$self->{mux}->set_timeout($fh, $timeout);
};
if (my $err = $@) {
warn $err;
$self->{errors}->{$vmid} = $err;
}
}
my $running;
for (;;) {
$running = &$check_queue($self);
last if !$running;
$self->{mux}->loop;
}
# make sure we close everything
foreach my $vmid (keys %{$self->{fhs}}) {
&$close_connection($self, $vmid);
}
$self->{queue} = $self->{current} = $self->{fhs} = $self->{fhs_lookup} = {};
}
# mux_input is called when input is available on one of
# the descriptors.
sub mux_input {
my ($self, $mux, $fh, $input) = @_;
return if $$input !~ s/^(.*})\r\n(.*)$/$2/so;
my $raw = $1;
my $vmid = $self->{fhs_lookup}->{$fh};
if (!$vmid) {
warn "internal error - unable to lookup vmid";
return;
}
eval {
my @jsons = split("\n", $raw);
foreach my $json (@jsons) {
my $obj = from_json($json);
next if defined($obj->{QMP}); # skip monitor greeting
if (exists($obj->{error}->{desc})) {
my $desc = $obj->{error}->{desc};
chomp $desc;
die "$desc\n" if $desc !~ m/Connection can not be completed immediately/;
next;
}
if (defined($obj->{event})) {
if (my $eventcb = $self->{eventcb}) {
&$eventcb($obj);
}
next;
}
my $cmdid = $obj->{id};
die "received responsed without command id\n" if !$cmdid;
my $curcmd = $self->{current}->{$vmid};
die "unable to lookup current command for VM $vmid\n" if !$curcmd;
delete $self->{current}->{$vmid};
if ($curcmd->{id} ne $cmdid) {
die "got wrong command id '$cmdid' (expected $curcmd->{id})\n";
}
if (my $callback = $curcmd->{callback}) {
&$callback($vmid, $obj);
}
}
};
if (my $err = $@) {
$self->{errors}->{$vmid} = $err;
}
&$check_queue($self);
}
# This gets called every second to update player info, etc...
sub mux_timeout {
my ($self, $mux, $fh) = @_;
if (my $vmid = $self->{fhs_lookup}->{$fh}) {
$self->{errors}->{$vmid} = "got timeout\n";
}
&$check_queue($self);
}
1;