cfg2cmd: switch off ACPI hotplug on bridges for q35 VMs

See commit 17858a1695 (hw/acpi/ich9: Set ACPI PCI hot-plug as default
on Q35)[0] in upstream QEMU repository for details about why the change
was made.

As that change affects systemds predictable interface naming[1],
e.g., by going from a previously `ens18` name to `enp6s18`, it may
have rather bad effects for users that did not setup some .link files
to enforce a specific naming by an more stable information like the
NIC's MAC-Address

The alternative would be making the preferred mode of hotplug an
option like `hotplug-mode=<acpi|pcie>`, but it does not seems like
one would like to change that much in the first place...

Note the changes to the tests and especially the tests with q35
machines that did not change.

[0]: https://gitlab.com/qemu-project/qemu/-/commit/17858a1695
[1]: https://www.freedesktop.org/software/systemd/man/systemd.net-naming-scheme.html#Naming

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Acked-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Reviewed-by: Dominik Csapak <d.csapak@proxmox.com>
Tested-by: Dominik Csapak <d.csapak@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 669f4f8d390046b20eb170528e876c4b71e82234..763c41284c1f0a8b64acbced0fe55c5c3ed125dd 100644 (file)
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -2158,6 +2158,31 @@ sub new_meta_info_string {
     );
 }
 
+sub qemu_created_version_fixups {
+    my ($conf, $forcemachine, $kvmver) = @_;
+
+    my $meta = parse_meta_info($conf->{meta}) // {};
+    my $forced_vers = PVE::QemuServer::Machine::extract_version($forcemachine);
+
+    # check if we need to apply some handling for VMs that always use the latest machine version but
+    # had a machine version transition happen that affected HW such that, e.g., an OS config change
+    # would be required (we do not want to pin machine version for non-windows OS type)
+    if (
+       (!defined($conf->{machine}) || $conf->{machine} =~ m/^(?:pc|q35|virt)$/) # non-versioned machine
+       && (!defined($meta->{'creation-qemu'}) || !min_version($meta->{'creation-qemu'}, 6, 1)) # created before 6.1
+       && (!$forced_vers || min_version($forced_vers, 6, 1)) # handle snapshot-rollback/migrations
+       && min_version($kvmver, 6, 1) # only need to apply the change since 6.1
+    ) {
+       my $q35 = PVE::QemuServer::Machine::machine_type_is_q35($conf);
+       if ($q35 && $conf->{ostype} && $conf->{ostype} eq 'l26') {
+           # this changed to default-on in Q 6.1 for q35 machines, it will mess with PCI slot view
+           # and thus with the predictable interface naming of systemd
+           return ['-global', 'ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off'];
+       }
+    }
+    return;
+}
+
 PVE::JSONSchema::register_format('pve-qm-usb-device', \&verify_usb_device);
 sub verify_usb_device {
     my ($value, $noerr) = @_;
@@ -3554,6 +3579,10 @@ sub config_to_command {
        }
     }
 
+    if (defined(my $fixups = qemu_created_version_fixups($conf, $forcemachine, $kvmver))) {
+       push @$cmd, $fixups->@*;
+    }
+
     if ($conf->{vmgenid}) {
        push @$devices, '-device', 'vmgenid,guid='.$conf->{vmgenid};
     }

diff --git a/test/cfg2cmd/q35-linux-hostpci-multifunction.conf.cmd b/test/cfg2cmd/q35-linux-hostpci-multifunction.conf.cmd
index 1f9beda86850a3bb8bc19a8eecf0feb12ae8da2a..d393906924171e4786695a6229c3bb2683bc6949 100644 (file)
--- a/test/cfg2cmd/q35-linux-hostpci-multifunction.conf.cmd
+++ b/test/cfg2cmd/q35-linux-hostpci-multifunction.conf.cmd
@@ -11,6 +11,7 @@
   -smbios 'type=1,uuid=3dd750ce-d910-44d0-9493-525c0be4e687' \
   -drive 'if=pflash,unit=0,format=raw,readonly=on,file=/usr/share/pve-edk2-firmware//OVMF_CODE.fd' \
   -drive 'if=pflash,unit=1,format=qcow2,id=drive-efidisk0,file=/var/lib/vz/images/100/vm-100-disk-1.qcow2' \
+  -global 'ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off' \
   -smp '2,sockets=2,cores=1,maxcpus=2' \
   -nodefaults \
   -boot 'menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg' \

diff --git a/test/cfg2cmd/q35-linux-hostpci.conf.cmd b/test/cfg2cmd/q35-linux-hostpci.conf.cmd
index dd1becef75d759bf657e1986d2d2cb509c93e4d4..5da5c3542b301916d65114512f2df8570e73defa 100644 (file)
--- a/test/cfg2cmd/q35-linux-hostpci.conf.cmd
+++ b/test/cfg2cmd/q35-linux-hostpci.conf.cmd
@@ -11,6 +11,7 @@
   -smbios 'type=1,uuid=3dd750ce-d910-44d0-9493-525c0be4e687' \
   -drive 'if=pflash,unit=0,format=raw,readonly=on,file=/usr/share/pve-edk2-firmware//OVMF_CODE.fd' \
   -drive 'if=pflash,unit=1,format=qcow2,id=drive-efidisk0,file=/var/lib/vz/images/100/vm-100-disk-1.qcow2' \
+  -global 'ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off' \
   -smp '2,sockets=2,cores=1,maxcpus=2' \
   -nodefaults \
   -boot 'menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg' \

diff --git a/test/cfg2cmd/q35-simple.conf.cmd b/test/cfg2cmd/q35-simple.conf.cmd
index 5045caf811bfac6b1b132561f79c54ae512e461b..1c97a890e46c973a101eca2b0b69b201feb361e4 100644 (file)
--- a/test/cfg2cmd/q35-simple.conf.cmd
+++ b/test/cfg2cmd/q35-simple.conf.cmd
@@ -11,6 +11,7 @@
   -smbios 'type=1,uuid=3dd750ce-d910-44d0-9493-525c0be4e687' \
   -drive 'if=pflash,unit=0,format=raw,readonly=on,file=/usr/share/pve-edk2-firmware//OVMF_CODE.fd' \
   -drive 'if=pflash,unit=1,format=qcow2,id=drive-efidisk0,file=/var/lib/vz/images/100/vm-100-disk-1.qcow2' \
+  -global 'ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off' \
   -smp '2,sockets=1,cores=2,maxcpus=2' \
   -nodefaults \
   -boot 'menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg' \