From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id C4A4A1FF136 for ; Mon, 23 Feb 2026 17:00:37 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 0D62612EC0; Mon, 23 Feb 2026 17:00:44 +0100 (CET) From: Markus Frank To: pve-devel@lists.proxmox.com Subject: [PATCH qemu-server v2 4/11] virtiofs: add live migration support Date: Mon, 23 Feb 2026 16:40:01 +0100 Message-ID: <20260223155951.468572-5-m.frank@proxmox.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260223155951.468572-1-m.frank@proxmox.com> References: <20260223155951.468572-1-m.frank@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1771862419929 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.007 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: ZXZH7ECNR22YVGK4YE3O7RXCX3H2MCDP X-Message-ID-Hash: ZXZH7ECNR22YVGK4YE3O7RXCX3H2MCDP X-MailFrom: m.frank@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: There are two migration methods with virtiofsd. Virtiofsd in the 'find-paths' migration mode, tries to find the path inside of the shared directory for every filesystem object that must be transferred to the destination. Add two extra parameters that verify file handles and confirm paths. In the 'file-handles' migration mode every filesystem object is converted to a file handle. This migration mode requires the DAC_READ_SEARCH capability. Add a parameter so that migration does not abort if an error occurs. Aborting on error would result in a stopped VM on the destination node. Signed-off-by: Markus Frank --- v2: * fixed broken file-handles migration method by adding '--modcaps=+dac_read_search' to the virtiofsd command as stated in the virtiofsd documentation src/PVE/QemuMigrate/Helpers.pm | 14 +++++++++++--- src/PVE/QemuServer/Virtiofs.pm | 18 ++++++++++++++++++ 2 files changed, 29 insertions(+), 3 deletions(-) diff --git a/src/PVE/QemuMigrate/Helpers.pm b/src/PVE/QemuMigrate/Helpers.pm index 466517da..9b577704 100644 --- a/src/PVE/QemuMigrate/Helpers.pm +++ b/src/PVE/QemuMigrate/Helpers.pm @@ -21,7 +21,6 @@ sub check_non_migratable_resources { if ($state) { push @blockers, "amd-sev" if $conf->{"amd-sev"}; push @blockers, "intel-tdx" if $conf->{"intel-tdx"}; - push @blockers, "virtiofs" if PVE::QemuServer::Virtiofs::virtiofs_enabled($conf); } if (scalar(@blockers) && !$noerr) { @@ -100,8 +99,17 @@ sub check_local_resources { } if ($k =~ m/^virtiofs/) { my $entry = parse_property_string('pve-qm-virtiofs', $conf->{$k}); - $add_missing_mapping->('dir', $k, $entry->{dirid}); - $mapped_res->{$k} = { name => $entry->{dirid} }; + if (my $dirid = $entry->{dirid}) { + $add_missing_mapping->('dir', $k, $dirid); + my $mapped_device = { name => $dirid }; + $mapped_res->{$k} = $mapped_device; + + if ($dir_map->{ids}->{$dirid}->{'live-migration-method'}) { + $mapped_device->{'live-migration'} = 1; + # don't add mapped device with live migration as blocker + next; + } + } } # sockets are safe: they will recreated be on the target side post-migrate next if $k =~ m/^serial/ && ($conf->{$k} eq 'socket'); diff --git a/src/PVE/QemuServer/Virtiofs.pm b/src/PVE/QemuServer/Virtiofs.pm index db4b9c78..1a3db50b 100644 --- a/src/PVE/QemuServer/Virtiofs.pm +++ b/src/PVE/QemuServer/Virtiofs.pm @@ -177,6 +177,9 @@ sub start_virtiofsd { my $dir_cfg = PVE::Mapping::Dir::find_on_current_node($virtiofs->{dirid}); + my $dirid = $virtiofs->{dirid}; + my $dir_properties = PVE::Mapping::Dir::config()->{ids}->{$dirid}; + my $virtiofsd_bin = '/usr/libexec/virtiofsd'; if (!-f $virtiofsd_bin) { die "virtiofsd is not installed. To use virtio-fs, install virtiofsd via apt.\n"; @@ -201,6 +204,21 @@ sub start_virtiofsd { push @$cmd, '--readonly' if $virtiofs->{readonly}; push @$cmd, '--cache=' . $virtiofs->{cache} if $virtiofs->{cache}; push @$cmd, '--inode-file-handles=prefer' if $prefer_inode_fh; + + if (my $method = $dir_properties->{'live-migration-method'}) { + # migration-on-error=abort would result in a stopped VM on the target node + push @$cmd, '--migration-on-error=guest-error'; + if ($method eq 'find-paths') { + push @$cmd, '--migration-mode=find-paths'; + push @$cmd, '--migration-verify-handles'; + push @$cmd, '--migration-confirm-paths'; + } + if ($method eq 'file-handles') { + push @$cmd, '--migration-mode=file-handles'; + push @$cmd, '--modcaps=+dac_read_search'; + } + } + push @$cmd, '--syslog'; exec(@$cmd); } elsif (!defined($pid2)) { -- 2.47.3