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mirror of git://git.proxmox.com/git/qemu-server.git synced 2025-01-06 13:17:56 +03:00
qemu-server/PVE/QMPClient.pm
Fiona Ebner 5674d19810 remove left-over mentions of to-be-dropped, outdated QMP commands
The commands snapshot-drive and delete-drive-snapshot have been unused
by qemu-server since commit eba2b721 ("use qemu's blockdev-snapshot
functions") and are now going to be dropped in our QEMU builds too, so
get rid of these left-overs.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-06-07 19:36:45 +02:00

526 lines
12 KiB
Perl

package PVE::QMPClient;
use strict;
use warnings;
use IO::Multiplex;
use JSON;
use POSIX qw(EINTR EAGAIN);
use Scalar::Util qw(weaken);
use Time::HiRes qw(usleep gettimeofday tv_interval);
use PVE::IPCC;
use PVE::QemuServer::Helpers;
# QEMU Monitor Protocol (QMP) client.
#
# This implementation uses IO::Multiplex (libio-multiplex-perl) and
# allows you to issue qmp and qga commands to different VMs in parallel.
# Note: qemu can only handle 1 connection, so we close connections asap
sub new {
my ($class, $eventcb) = @_;
my $mux = IO::Multiplex->new();
my $self = bless {
mux => $mux,
queue_lookup => {}, # $fh => $queue_info
queue_info => {},
}, $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;
}
# Note: List of special QGA command. Those commands can close the connection
# without sending a response.
my $qga_allow_close_cmds = {
'guest-shutdown' => 1,
'guest-suspend-ram' => 1,
'guest-suspend-disk' => 1,
'guest-suspend-hybrid' => 1,
};
my $push_cmd_to_queue = sub {
my ($self, $vmid, $cmd) = @_;
my $execute = $cmd->{execute} || die "no command name specified";
my $qga = ($execute =~ /^guest\-+/) ? 1 : 0;
my $sname = PVE::QemuServer::Helpers::qmp_socket($vmid, $qga);
$self->{queue_info}->{$sname} = { qga => $qga, vmid => $vmid, sname => $sname, cmds => [] }
if !$self->{queue_info}->{$sname};
push @{$self->{queue_info}->{$sname}->{cmds}}, $cmd;
return $self->{queue_info}->{$sname};
};
# 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_cmd_to_queue($self, $vmid, $cmd);
return;
}
# execute a single command
sub cmd {
my ($self, $vmid, $cmd, $timeout) = @_;
my $result;
my $callback = sub {
my ($vmid, $resp) = @_;
$result = $resp->{'return'};
$result = { error => $resp->{'error'} } if !defined($result) && $resp->{'error'};
};
die "no command specified" if !($cmd && $cmd->{execute});
$cmd->{callback} = $callback;
$cmd->{arguments} = {} if !defined($cmd->{arguments});
my $queue_info = &$push_cmd_to_queue($self, $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 'guest-fsfreeze-freeze') {
# freeze syncs all guest FS, if we kill it it stays in an unfreezable
# locked state with high probability, so use an generous timeout
$timeout = 60*60; # 1 hour
} elsif ($cmd->{execute} eq 'guest-fsfreeze-thaw') {
# While it should return instantly or never (dead locked) for Linux guests,
# the variance for Windows guests can be big. And there might be hook scripts
# that are executed upon thaw, so use 3 minutes to be on the safe side.
$timeout = 3 * 60;
} elsif (
$cmd->{execute} eq 'savevm-start' ||
$cmd->{execute} eq 'savevm-end' ||
$cmd->{execute} eq 'query-backup' ||
$cmd->{execute} eq 'query-block-jobs' ||
$cmd->{execute} eq 'block-job-cancel' ||
$cmd->{execute} eq 'block-job-complete' ||
$cmd->{execute} eq 'backup-cancel' ||
$cmd->{execute} eq 'query-savevm' ||
$cmd->{execute} eq 'guest-fstrim' ||
$cmd->{execute} eq 'guest-shutdown' ||
$cmd->{execute} eq 'blockdev-snapshot-internal-sync' ||
$cmd->{execute} eq 'blockdev-snapshot-delete-internal-sync'
) {
$timeout = 10*60; # 10 mins ?
} else {
# NOTE: if you came here as user and want to change this, try using IO-Threads first
# which move out quite some processing of the main thread, leaving more time for QMP
$timeout = 5; # default
}
}
$self->queue_execute($timeout, 2);
die "VM $vmid qmp command '$cmd->{execute}' failed - $queue_info->{error}"
if defined($queue_info->{error});
return $result;
};
my $cmdid_seq = 0;
my $cmdid_seq_qga = 0;
my $next_cmdid = sub {
my ($qga) = @_;
if($qga){
$cmdid_seq_qga++;
return "$$"."0".$cmdid_seq_qga;
} else {
$cmdid_seq++;
return "$$:$cmdid_seq";
}
};
my $lookup_queue_info = sub {
my ($self, $fh, $noerr) = @_;
my $queue_info = $self->{queue_lookup}->{$fh};
if (!$queue_info) {
warn "internal error - unable to lookup queue info" if !$noerr;
return;
}
return $queue_info;
};
my $close_connection = sub {
my ($self, $queue_info) = @_;
if (my $fh = delete $queue_info->{fh}) {
delete $self->{queue_lookup}->{$fh};
$self->{mux}->close($fh);
}
};
my $open_connection = sub {
my ($self, $queue_info, $timeout) = @_;
die "duplicate call to open" if defined($queue_info->{fh});
my $vmid = $queue_info->{vmid};
my $qga = $queue_info->{qga};
my $sname = PVE::QemuServer::Helpers::qmp_socket($vmid, $qga);
$timeout = 1 if !$timeout;
my $fh;
my $starttime = [gettimeofday];
my $count = 0;
my $sotype = $qga ? 'qga' : 'qmp';
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 $sotype socket - $!\n";
}
my $elapsed = tv_interval($starttime, [gettimeofday]);
if ($elapsed >= $timeout) {
die "unable to connect to VM $vmid $sotype socket - timeout after $count retries\n";
}
usleep(100000);
}
$queue_info->{fh} = $fh;
$self->{queue_lookup}->{$fh} = $queue_info;
$self->{mux}->add($fh);
$self->{mux}->set_timeout($fh, $timeout);
return $fh;
};
my $check_queue = sub {
my ($self) = @_;
my $running = 0;
foreach my $sname (keys %{$self->{queue_info}}) {
my $queue_info = $self->{queue_info}->{$sname};
my $fh = $queue_info->{fh};
next if !$fh;
my $qga = $queue_info->{qga};
if ($queue_info->{error}) {
&$close_connection($self, $queue_info);
next;
}
if ($queue_info->{current}) { # command running, waiting for response
$running++;
next;
}
if (!scalar(@{$queue_info->{cmds}})) { # no more commands
&$close_connection($self, $queue_info);
next;
}
eval {
my $cmd = $queue_info->{current} = shift @{$queue_info->{cmds}};
$cmd->{id} = &$next_cmdid($qga);
my $fd = -1;
if ($cmd->{execute} eq 'add-fd' || $cmd->{execute} eq 'getfd') {
$fd = $cmd->{arguments}->{fd};
delete $cmd->{arguments}->{fd};
}
my $qmpcmd;
if ($qga) {
$qmpcmd = to_json({ execute => 'guest-sync-delimited',
arguments => { id => int($cmd->{id})}}) . "\n" .
to_json({ execute => $cmd->{execute}, arguments => $cmd->{arguments}}) . "\n";
} else {
$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 = $@) {
$queue_info->{error} = $err;
} else {
$running++;
}
}
$self->{mux}->endloop() if !$running;
return $running;
};
# execute all queued command
sub queue_execute {
my ($self, $timeout, $noerr) = @_;
$timeout = 3 if !$timeout;
# open all necessary connections
foreach my $sname (keys %{$self->{queue_info}}) {
my $queue_info = $self->{queue_info}->{$sname};
next if !scalar(@{$queue_info->{cmds}}); # no commands
$queue_info->{error} = undef;
$queue_info->{current} = undef;
eval {
&$open_connection($self, $queue_info, $timeout);
if (!$queue_info->{qga}) {
my $cap_cmd = { execute => 'qmp_capabilities', arguments => {} };
unshift @{$queue_info->{cmds}}, $cap_cmd;
}
};
if (my $err = $@) {
$queue_info->{error} = $err;
}
}
my $running;
for (;;) {
$running = &$check_queue($self);
last if !$running;
$self->{mux}->loop;
}
# make sure we close everything
my $errors = '';
foreach my $sname (keys %{$self->{queue_info}}) {
my $queue_info = $self->{queue_info}->{$sname};
&$close_connection($self, $queue_info);
if ($queue_info->{error}) {
if ($noerr) {
warn $queue_info->{error} if $noerr < 2;
} else {
$errors .= $queue_info->{error}
}
}
}
$self->{queue_info} = $self->{queue_lookup} = {};
die $errors if $errors;
}
sub mux_close {
my ($self, $mux, $fh) = @_;
my $queue_info = &$lookup_queue_info($self, $fh, 1);
return if !$queue_info;
$queue_info->{error} = "client closed connection\n"
if !$queue_info->{error};
}
# mux_input is called when input is available on one of the descriptors.
sub mux_input {
my ($self, $mux, $fh, $input) = @_;
my $queue_info = &$lookup_queue_info($self, $fh);
return if !$queue_info;
my $sname = $queue_info->{sname};
my $vmid = $queue_info->{vmid};
my $qga = $queue_info->{qga};
my $curcmd = $queue_info->{current};
die "unable to lookup current command for VM $vmid ($sname)\n" if !$curcmd;
my $raw;
if ($qga) {
return if $$input !~ s/^.*\xff([^\n]+}\r?\n[^\n]+})\r?\n(.*)$/$2/so;
$raw = $1;
} else {
return if $$input !~ s/^(.*})\r?\n(.*)$/$2/so;
$raw = $1;
}
eval {
my @jsons = split("\n", $raw);
if ($qga) {
die "response is not complete" if @jsons != 2 ;
my $obj = from_json($jsons[0]);
my $cmdid = $obj->{'return'};
die "received responsed without command id\n" if !$cmdid;
# skip results fro previous commands
return if $cmdid < $curcmd->{id};
if ($curcmd->{id} ne $cmdid) {
die "got wrong command id '$cmdid' (expected $curcmd->{id})\n";
}
delete $queue_info->{current};
$obj = from_json($jsons[1]);
if (my $callback = $curcmd->{callback}) {
&$callback($vmid, $obj);
}
return;
}
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;
if ($curcmd->{id} ne $cmdid) {
die "got wrong command id '$cmdid' (expected $curcmd->{id})\n";
}
delete $queue_info->{current};
if (my $callback = $curcmd->{callback}) {
&$callback($vmid, $obj);
}
}
};
if (my $err = $@) {
$queue_info->{error} = $err;
}
&$check_queue($self);
}
# This gets called every second to update player info, etc...
sub mux_timeout {
my ($self, $mux, $fh) = @_;
if (my $queue_info = &$lookup_queue_info($self, $fh)) {
$queue_info->{error} = "got timeout\n";
$self->{mux}->inbuffer($fh, ''); # clear to avoid warnings
}
&$check_queue($self);
}
sub mux_eof {
my ($self, $mux, $fh, $input) = @_;
my $queue_info = &$lookup_queue_info($self, $fh);
return if !$queue_info;
my $sname = $queue_info->{sname};
my $vmid = $queue_info->{vmid};
my $qga = $queue_info->{qga};
my $curcmd = $queue_info->{current};
die "unable to lookup current command for VM $vmid ($sname)\n" if !$curcmd;
if ($qga && $qga_allow_close_cmds->{$curcmd->{execute}}) {
return if $$input !~ s/^.*\xff([^\n]+})\r?\n(.*)$/$2/so;
my $raw = $1;
eval {
my $obj = from_json($raw);
my $cmdid = $obj->{'return'};
die "received responsed without command id\n" if !$cmdid;
delete $queue_info->{current};
if (my $callback = $curcmd->{callback}) {
&$callback($vmid, undef);
}
};
if (my $err = $@) {
$queue_info->{error} = $err;
}
&$close_connection($self, $queue_info);
if (scalar(@{$queue_info->{cmds}}) && !$queue_info->{error}) {
$queue_info->{error} = "Got EOF but command queue is not empty.\n";
}
}
}
sub DESTROY {
my ($self) = @_;
foreach my $sname (keys %{$self->{queue_info}}) {
my $queue_info = $self->{queue_info}->{$sname};
$close_connection->($self, $queue_info);
}
}
1;