[pve-devel] [PATCH v10 qemu-server 1/6] Include "-cpu" parameter with live-migration
Stefan Reiter
s.reiter at proxmox.com
Tue Apr 7 15:56:15 CEST 2020
This is required to support custom CPU models, since the
"cpu-models.conf" file is not versioned, and can be changed while a VM
using a custom model is running. Changing the file in such a state can
lead to a different "-cpu" argument on the receiving side.
This patch fixes this by passing the entire "-cpu" option (extracted
from /proc/.../cmdline) as a "qm start" parameter. Note that this is
only done if the VM to migrate is using a custom model (which we can
check just fine, since the <vmid>.conf *is* versioned with pending
changes), thus not breaking any live-migration directionality.
Signed-off-by: Stefan Reiter <s.reiter at proxmox.com>
---
Changes in v10:
* Introduce and use PVE::QemuServer::CPUConfig::get_cpu_from_running_vm helper
PVE/API2/Qemu.pm | 7 +++++++
PVE/QemuMigrate.pm | 15 +++++++++++++++
PVE/QemuServer.pm | 13 ++++++++++---
PVE/QemuServer/CPUConfig.pm | 14 ++++++++++++++
4 files changed, 46 insertions(+), 3 deletions(-)
diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 6fad972..9e453d2 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -2024,6 +2024,11 @@ __PACKAGE__->register_method({
optional => 1,
},
machine => get_standard_option('pve-qemu-machine'),
+ 'force-cpu' => {
+ description => "Override QEMU's -cpu argument with the given string.",
+ type => 'string',
+ optional => 1,
+ },
targetstorage => {
description => "Target storage for the migration. (Can be '1' to use the same storage id as on the source node.)",
type => 'string',
@@ -2052,6 +2057,7 @@ __PACKAGE__->register_method({
my $timeout = extract_param($param, 'timeout');
my $machine = extract_param($param, 'machine');
+ my $force_cpu = extract_param($param, 'force-cpu');
my $get_root_param = sub {
my $value = extract_param($param, $_[0]);
@@ -2129,6 +2135,7 @@ __PACKAGE__->register_method({
skiplock => $skiplock,
forcemachine => $machine,
timeout => $timeout,
+ forcecpu => $force_cpu,
};
PVE::QemuServer::vm_start($storecfg, $vmid, $params, $migrate_opts);
diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
index e954eca..c12b2b5 100644
--- a/PVE/QemuMigrate.pm
+++ b/PVE/QemuMigrate.pm
@@ -17,6 +17,7 @@ use PVE::ReplicationState;
use PVE::Storage;
use PVE::Tools;
+use PVE::QemuServer::CPUConfig;
use PVE::QemuServer::Drive;
use PVE::QemuServer::Helpers qw(min_version);
use PVE::QemuServer::Machine;
@@ -227,7 +228,17 @@ sub prepare {
$self->{forcemachine} = PVE::QemuServer::Machine::qemu_machine_pxe($vmid, $conf);
+ # To support custom CPU types, we keep QEMU's "-cpu" parameter intact.
+ # Since the parameter itself contains no reference to a custom model,
+ # this makes migration independent of changes to "cpu-models.conf".
+ if ($conf->{cpu}) {
+ my $cpuconf = PVE::QemuServer::CPUConfig::parse_cpu_conf_basic($conf->{cpu});
+ if ($cpuconf && PVE::QemuServer::CPUConfig::is_custom_model($cpuconf->{cputype})) {
+ $self->{forcecpu} = PVE::QemuServer::CPUConfig::get_cpu_from_running_vm($pid);
+ }
+ }
}
+
my $loc_res = PVE::QemuServer::check_local_resources($conf, 1);
if (scalar @$loc_res) {
if ($self->{running} || !$self->{opts}->{force}) {
@@ -664,6 +675,10 @@ sub phase2 {
push @$cmd, '--machine', $self->{forcemachine};
}
+ if ($self->{forcecpu}) {
+ push @$cmd, '--force-cpu', $self->{forcecpu};
+ }
+
if ($self->{online_local_volumes}) {
push @$cmd, '--targetstorage', ($self->{opts}->{targetstorage} // '1');
}
diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 510a995..a0f8429 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -2911,7 +2911,7 @@ sub query_understood_cpu_flags {
}
sub config_to_command {
- my ($storecfg, $vmid, $conf, $defaults, $forcemachine) = @_;
+ my ($storecfg, $vmid, $conf, $defaults, $forcemachine, $forcecpu) = @_;
my $cmd = [];
my $globalFlags = [];
@@ -3317,7 +3317,12 @@ sub config_to_command {
push @$rtcFlags, 'base=localtime';
}
- push @$cmd, get_cpu_options($conf, $arch, $kvm, $kvm_off, $machine_version, $winversion, $gpu_passthrough);
+ if ($forcecpu) {
+ push @$cmd, '-cpu', $forcecpu;
+ } else {
+ push @$cmd, get_cpu_options($conf, $arch, $kvm, $kvm_off,
+ $machine_version, $winversion, $gpu_passthrough);
+ }
PVE::QemuServer::Memory::config($conf, $vmid, $sockets, $cores, $defaults, $hotplug_features, $cmd);
@@ -4800,6 +4805,7 @@ sub vm_start {
# statefile => 'tcp', 'unix' for migration or path/volid for RAM state
# skiplock => 0/1, skip checking for config lock
# forcemachine => to force Qemu machine (rollback/migration)
+# forcecpu => a QEMU '-cpu' argument string to override get_cpu_options
# timeout => in seconds
# paused => start VM in paused state (backup)
# resume => resume from hibernation
@@ -4845,7 +4851,8 @@ sub vm_start_nolock {
print "Resuming suspended VM\n";
}
- my ($cmd, $vollist, $spice_port) = config_to_command($storecfg, $vmid, $conf, $defaults, $forcemachine);
+ my ($cmd, $vollist, $spice_port) = config_to_command($storecfg, $vmid, $conf,
+ $defaults, $forcemachine, $params->{forcecpu});
my $migration_ip;
my $get_migration_ip = sub {
diff --git a/PVE/QemuServer/CPUConfig.pm b/PVE/QemuServer/CPUConfig.pm
index 8a55739..70b96be 100644
--- a/PVE/QemuServer/CPUConfig.pm
+++ b/PVE/QemuServer/CPUConfig.pm
@@ -106,6 +106,8 @@ my @supported_cpu_flags = (
my $cpu_flag_supported_re = qr/([+-])(@{[join('|', @supported_cpu_flags)]})/;
my $cpu_flag_any_re = qr/([+-])([a-zA-Z0-9\-_\.]+)/;
+our $qemu_cmdline_cpu_re = qr/^((?>[+-]?[\w\-_=]+,?)+)$/;
+
my $cpu_fmt = {
cputype => {
description => "Emulated CPU type. Can be default or custom name (custom model names must be prefixed with 'custom-').",
@@ -413,6 +415,18 @@ sub add_hyperv_enlightenments {
}
}
+sub get_cpu_from_running_vm {
+ my ($pid) = @_;
+
+ my $cmdline = PVE::QemuServer::Helpers::parse_cmdline($pid);
+ die "could not read commandline of running machine\n"
+ if !$cmdline->{cpu}->{value};
+
+ # sanitize and untaint value
+ $cmdline->{cpu}->{value} =~ $qemu_cmdline_cpu_re;
+ return $1;
+}
+
__PACKAGE__->register();
__PACKAGE__->init();
--
2.26.0
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