[PATCH manager v2] fix #7896: ui: qemu: show effective machine version for Windows guests

[Jakob Klocker <j.klocker@proxmox.com>]

Windows guests without an explicitly pinned machine version still run
with a fixed one: guests created with QEMU 9.1 or newer keep the
version they were created with, older ones fall back to 5.1.

The GUI assumed the 5.1 fallback unconditionally, so guests created
with a newer QEMU were shown a version they are not running. Derive
the version from the QEMU version recorded at creation time instead,
in both the hardware view and the machine edit dialog, and mark it as
implicit so it stays distinguishable from an explicit pin.

The edit dialog also pre-filled the version field with the fallback,
which both suggested a version the guest might not be running and
caused any other change in the dialog to submit that stale value.
Leave the selector at 'latest' instead, so a version can be picked
deliberately, and show the effective version as a read-only field
together with a hint recommending an explicit pin. The advanced
section is expanded so the hint is visible without further
interaction.

Link: https://bugzilla.proxmox.com/show_bug.cgi?id=7896
Signed-off-by: Jakob Klocker <j.klocker@proxmox.com>
---
changes from v1 to v2 (thanks @Dominik):                                                                                                                    
 * consider viommu during machine-version parsing                                                                                                           
 * display viommu when the version is implicit                                                                                                              
 * preserve the current version & note displayed on reset
 
 www/manager6/Utils.js             | 22 ++++++++++++++++
 www/manager6/qemu/HardwareView.js | 27 +++++++++++++++++--
 www/manager6/qemu/MachineEdit.js  | 44 ++++++++++++++++++++++++++++---
 3 files changed, 87 insertions(+), 6 deletions(-)

diff --git a/www/manager6/Utils.js b/www/manager6/Utils.js
index c86a00c5..8b99371d 100644
--- a/www/manager6/Utils.js
+++ b/www/manager6/Utils.js
@@ -1822,6 +1822,28 @@ Ext.define('PVE.Utils', {
             return true;
         },
 
+        qemu_implicit_machine_version: function (machineType, creationQemu, arch) {
+            let baseVersion = '5.1';
+            let m = creationQemu?.match(/^(\d+)\.(\d+)/);
+            if (m) {
+                let major = parseInt(m[1], 10);
+                let minor = parseInt(m[2], 10);
+                if (major > 9 || (major === 9 && minor >= 1)) {
+                    baseVersion = `${major}.${minor}`;
+                }
+            }
+
+            let base;
+            if (machineType === 'q35') {
+                base = 'pc-q35';
+            } else {
+                let defaultMachine = PVE.qemu.Architecture.defaultMachines[arch];
+                base = defaultMachine === 'virt' ? 'virt' : 'pc-i440fx';
+            }
+
+            return `${base}-${baseVersion}`;
+        },
+
         cleanEmptyObjectKeys: function (obj) {
             for (const propName of Object.keys(obj)) {
                 if (obj[propName] === null || obj[propName] === undefined) {
diff --git a/www/manager6/qemu/HardwareView.js b/www/manager6/qemu/HardwareView.js
index e6c02299..f7f4b46f 100644
--- a/www/manager6/qemu/HardwareView.js
+++ b/www/manager6/qemu/HardwareView.js
@@ -197,11 +197,31 @@ Ext.define('PVE.qemu.HardwareView', {
                         me.getObjectValue('arch'),
                         nodename,
                     );
+                    let machineConf = PVE.Parser.parsePropertyString(value, 'type');
+                    let machineType = machineConf.type;
                     if (
                         PVE.Utils.is_windows(ostype) &&
-                        (!value || value === 'pc' || value === 'q35')
+                        (!machineType || machineType === 'pc' || machineType === 'q35')
                     ) {
-                        return value === 'q35' ? 'pc-q35-5.1' : 'pc-i440fx-5.1';
+                        let meta = me.getObjectValue('meta', undefined, pending);
+                        let creationQemu;
+                        if (meta) {
+                            creationQemu = PVE.Parser.parsePropertyString(meta)['creation-qemu'];
+                        }
+
+                        machineType = machineType === 'q35' ? 'q35' : '__default__';
+                        let displayMachine = PVE.Utils.qemu_implicit_machine_version(
+                            machineType,
+                            creationQemu,
+                            arch,
+                        );
+
+                        let displayValue = displayMachine + ' ' + gettext('(implicit)');
+                        if (machineConf.viommu) {
+                            displayValue += ', viommu=' + machineConf.viommu;
+                        }
+
+                        return displayValue;
                     }
                     return PVE.Utils.render_qemu_machine(value, arch);
                 },
@@ -254,6 +274,9 @@ Ext.define('PVE.qemu.HardwareView', {
             ostype: {
                 visible: false,
             },
+            meta: {
+                visible: false,
+            },
             affinity: {
                 visible: false,
             },
diff --git a/www/manager6/qemu/MachineEdit.js b/www/manager6/qemu/MachineEdit.js
index 4b1a9e83..6cf70705 100644
--- a/www/manager6/qemu/MachineEdit.js
+++ b/www/manager6/qemu/MachineEdit.js
@@ -6,6 +6,8 @@ Ext.define('PVE.qemu.MachineInputPanel', {
     viewModel: {
         data: {
             type: '__default__',
+            effectiveVersionLabel: '',
+            implicitVersion: false,
         },
         formulas: {
             q35: (get) => get('type') === 'q35',
@@ -102,10 +104,21 @@ Ext.define('PVE.qemu.MachineInputPanel', {
         }
 
         if (me.isWindows) {
-            if (values.machine === '__default__') {
-                values.version = 'pc-i440fx-5.1';
-            } else if (values.machine === 'q35') {
-                values.version = 'pc-q35-5.1';
+            if (values.machine === '__default__' || values.machine === 'q35') {
+                let effective = PVE.Utils.qemu_implicit_machine_version(
+                    values.machine,
+                    values.creationQemu,
+                    values.arch,
+                );
+                me.getViewModel().set({
+                    effectiveVersionLabel: effective + ' ' + gettext('(implicit)'),
+                    implicitVersion: true,
+                });
+                me.setAdvancedVisible(true);
+                // flush the binding, then re-baseline the reset value to it
+                // otherwise the Reset button reverts to the field's empty initial value
+                me.getViewModel().notify();
+                me.lookup('effectiveVersion').resetOriginalValue();
             }
         }
 
@@ -176,6 +189,24 @@ Ext.define('PVE.qemu.MachineInputPanel', {
                 },
             },
         },
+        {
+            xtype: 'displayfield',
+            fieldLabel: gettext('Current Version'),
+            reference: 'effectiveVersion',
+            bind: {
+                value: '{effectiveVersionLabel}',
+                hidden: '{!implicitVersion}',
+            },
+        },
+        {
+            xtype: 'displayfield',
+            userCls: 'pmx-hint',
+            value: gettext(
+                'No fixed version is set; the version is chosen automatically based on when the VM' +
+                    ' was created. Pinning a specific version is recommended.',
+            ),
+            bind: { hidden: '{!implicitVersion}' },
+        },
         {
             xtype: 'displayfield',
             fieldLabel: gettext('Note'),
@@ -249,6 +280,11 @@ Ext.define('PVE.qemu.MachineEdit', {
                 };
                 values.isWindows = PVE.Utils.is_windows(conf.ostype);
                 values.arch = PVE.qemu.Architecture.getGuestArchitecture(conf.arch, me.nodename);
+                if (conf.meta) {
+                    let meta = PVE.Parser.parsePropertyString(conf.meta);
+                    values.creationQemu = meta['creation-qemu'];
+                }
+
                 me.setValues(values);
             },
         });
-- 
2.47.3