From: Fiona Ebner <f.ebner@proxmox.com>
To: pve-devel@lists.proxmox.com
Subject: [pve-devel] [PATCH qemu-server v3 6/8] snapshot: introduce running-nets-host-mtu property
Date: Thu, 4 Sep 2025 14:40:50 +0200 [thread overview]
Message-ID: <20250904124113.81772-7-f.ebner@proxmox.com> (raw)
In-Reply-To: <20250904124113.81772-1-f.ebner@proxmox.com>
For VirtIO network devices, it is necessary to preserve the values and
presence of the host_mtu setting when restoring a snapshot. See commit
"migration: preserve host_mtu for virtio-net devices" for details.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
New in v3.
src/PVE/API2/Qemu.pm | 1 +
src/PVE/QemuConfig.pm | 6 ++++++
src/PVE/QemuServer.pm | 9 +++++++++
src/PVE/QemuServer/RunState.pm | 3 ++-
4 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/src/PVE/API2/Qemu.pm b/src/PVE/API2/Qemu.pm
index 4770fbf8..ec9f31d8 100644
--- a/src/PVE/API2/Qemu.pm
+++ b/src/PVE/API2/Qemu.pm
@@ -2113,6 +2113,7 @@ my $update_vm_api = sub {
}
push @delete, 'runningmachine' if $conf->{runningmachine};
push @delete, 'runningcpu' if $conf->{runningcpu};
+ push @delete, 'running-nets-host-mtu' if $conf->{'running-nets-host-mtu'};
}
PVE::QemuConfig->check_lock($conf) if !$skiplock;
diff --git a/src/PVE/QemuConfig.pm b/src/PVE/QemuConfig.pm
index 33cac3be..d0844c4c 100644
--- a/src/PVE/QemuConfig.pm
+++ b/src/PVE/QemuConfig.pm
@@ -247,6 +247,8 @@ sub __snapshot_save_vmstate {
or die "cannot obtain PID for VM $vmid!\n";
my $runningcpu = PVE::QemuServer::CPUConfig::get_cpu_from_running_vm($pid);
+ my $nets_host_mtu = PVE::QemuServer::Network::get_nets_host_mtu($vmid, $conf);
+
if (!$suspend) {
$conf = $conf->{snapshots}->{$snapname};
}
@@ -254,6 +256,7 @@ sub __snapshot_save_vmstate {
$conf->{vmstate} = $statefile;
$conf->{runningmachine} = $runningmachine;
$conf->{runningcpu} = $runningcpu;
+ $conf->{'running-nets-host-mtu'} = $nets_host_mtu;
return $statefile;
}
@@ -473,6 +476,8 @@ sub __snapshot_rollback_hook {
# re-initializing its random number generator
$conf->{vmgenid} = PVE::QemuServer::generate_uuid();
}
+
+ $data->{'nets-host-mtu'} = delete($conf->{'running-nets-host-mtu'});
}
return;
@@ -513,6 +518,7 @@ sub __snapshot_rollback_vm_start {
statefile => $vmstate,
forcemachine => $data->{forcemachine},
forcecpu => $data->{forcecpu},
+ 'nets-host-mtu' => $data->{'nets-host-mtu'},
};
PVE::QemuServer::vm_start($storecfg, $vmid, $params);
}
diff --git a/src/PVE/QemuServer.pm b/src/PVE/QemuServer.pm
index 20e26cd5..e312acb6 100644
--- a/src/PVE/QemuServer.pm
+++ b/src/PVE/QemuServer.pm
@@ -635,6 +635,15 @@ EODESCR
pattern => $PVE::QemuServer::CPUConfig::qemu_cmdline_cpu_re,
format_description => 'QEMU -cpu parameter',
},
+ 'running-nets-host-mtu' => {
+ type => 'string',
+ pattern => 'net\d+=\d+(,net\d+=\d+)*',
+ optional => 1,
+ description =>
+ 'List of VirtIO network devices and their effective host_mtu setting. A value of 0'
+ . ' means that the host_mtu parameter is to be avoided for the corresponding device.'
+ . ' This is used internally for snapshots.',
+ },
machine => get_standard_option('pve-qemu-machine'),
arch => {
description => "Virtual processor architecture. Defaults to the host.",
diff --git a/src/PVE/QemuServer/RunState.pm b/src/PVE/QemuServer/RunState.pm
index 05e7fb47..6a5fdbd7 100644
--- a/src/PVE/QemuServer/RunState.pm
+++ b/src/PVE/QemuServer/RunState.pm
@@ -104,7 +104,8 @@ sub vm_suspend {
warn $@ if $@;
PVE::Storage::deactivate_volumes($storecfg, [$vmstate]);
PVE::Storage::vdisk_free($storecfg, $vmstate);
- delete $conf->@{qw(vmstate runningmachine runningcpu)};
+ delete $conf->@{
+ qw(vmstate runningmachine runningcpu running-nets-host-mtu)};
PVE::QemuConfig->write_config($vmid, $conf);
};
warn $@ if $@;
--
2.47.2
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next prev parent reply other threads:[~2025-09-04 12:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-04 12:40 [pve-devel] [PATCH-SERIES qemu-server v3 0/8] virtio-net: fix migration between default/non-default MTUs Fiona Ebner
2025-09-04 12:40 ` [pve-devel] [PATCH qemu-server v3 1/8] virtio-net: fix migration between default/non-default MTUs starting with machine version 10.0+pve1 Fiona Ebner
2025-09-04 12:40 ` [pve-devel] [PATCH qemu-server v3 2/8] api: vm start: introduce nets-host-mtu parameter for migration compat Fiona Ebner
2025-09-04 12:40 ` [pve-devel] [PATCH qemu-server v3 3/8] migration: preserve host_mtu for virtio-net devices Fiona Ebner
2025-09-04 12:40 ` [pve-devel] [PATCH qemu-server v3 4/8] snapshot: save vmstate: avoid using deprecated check_running() function Fiona Ebner
2025-09-04 12:40 ` [pve-devel] [PATCH qemu-server v3 5/8] snapshot: save vmstate: die when PID cannot be obtained Fiona Ebner
2025-09-04 12:40 ` Fiona Ebner [this message]
2025-09-04 12:40 ` [pve-devel] [PATCH qemu-server v3 stable-bookworm 7/8] api: vm start: introduce nets-host-mtu parameter for migration compat Fiona Ebner
2025-09-04 12:40 ` [pve-devel] [PATCH qemu-server v3 stable-bookworm 8/8] migration: preserve host_mtu for virtio-net devices Fiona Ebner
2025-09-04 18:11 ` Thomas Lamprecht
2025-09-05 8:54 ` Fiona Ebner
2025-09-05 9:09 ` Thomas Lamprecht
2025-09-05 9:17 ` Fiona Ebner
2025-09-04 13:06 ` [pve-devel] [PATCH-SERIES qemu-server v3 0/8] virtio-net: fix migration between default/non-default MTUs Fabian Grünbichler
2025-09-04 18:16 ` [pve-devel] applied: " Thomas Lamprecht
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