[PATCH pve-manager v2 2/3] partially fix #1989: ui: qemu: disk: add qcow2 cache size config

[Erik Fastermann <e.fastermann@proxmox.com>]

Add the option to control the size of the qcow2 cache in the vm disk
create and edit dialogs. This can provide significant performance gains
in some vm configurations.

For a detailed explanation see the QEMU docs [0]. Currently only the
cache-size is configurable in the frontend, either directly or based on
the size of the disk.

[0] https://gitlab.com/qemu-project/qemu/-/blob/master/docs/qcow2-cache.txt

Signed-off-by: Erik Fastermann <e.fastermann@proxmox.com>
---

 changes since v1:
 * simplified qcow2CacheSizeBasedOnDisk usage by binding the value
   (sadly the workaround for isQcow2 is still required)
 * added tooltips for the qcow2 cache options

 www/manager6/Parser.js      |  2 +-
 www/manager6/qemu/HDEdit.js | 73 +++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/www/manager6/Parser.js b/www/manager6/Parser.js
index 36df8e9d..f8d2bdad 100644
--- a/www/manager6/Parser.js
+++ b/www/manager6/Parser.js
@@ -207,7 +207,7 @@ Ext.define('PVE.Parser', {
                 if (!p || p.match(/^\s*$/)) {
                     return undefined; // continue
                 }
-                let match = p.match(/^([a-z_]+)=(\S+)$/);
+                let match = p.match(/^([0-9a-z-]+)=(\S+)$/);
                 if (!match) {
                     if (!p.match(/[=]/)) {
                         res.file = p;
diff --git a/www/manager6/qemu/HDEdit.js b/www/manager6/qemu/HDEdit.js
index 1bb2bfda..fafa0f55 100644
--- a/www/manager6/qemu/HDEdit.js
+++ b/www/manager6/qemu/HDEdit.js
@@ -18,6 +18,8 @@ Ext.define('PVE.qemu.HDInputPanel', {
             isSCSI: false,
             isVirtIO: false,
             isSCSISingle: false,
+            isQcow2: false,
+            qcow2CacheSizeBasedOnDisk: false,
         },
     },
 
@@ -54,6 +56,15 @@ Ext.define('PVE.qemu.HDInputPanel', {
                     vm.set('isSCSISingle', value === 'virtio-scsi-single');
                 },
             },
+            'field[name=diskformat]': {
+                change: 'onDiskFormatChange',
+                // afterrender is needed for setting the initial value
+                afterrender: 'onDiskFormatChange',
+            },
+        },
+
+        onDiskFormatChange: function (field) {
+            this.getViewModel().set('isQcow2', field.getValue() === 'qcow2');
         },
 
         init: function (view) {
@@ -88,6 +99,20 @@ Ext.define('PVE.qemu.HDInputPanel', {
             me.drive.format = values.diskformat;
         }
 
+        if (me.drive?.format === 'qcow2' || me.drive?.file?.endsWith('.qcow2')) {
+            if (values.qcow2CacheSize) {
+                me.drive['qcow2-cache-size'] = values.qcow2CacheSize;
+            } else {
+                delete me.drive['qcow2-cache-size'];
+            }
+        }
+
+        PVE.Utils.propertyStringSet(
+            me.drive,
+            values.qcow2CacheSizeBasedOnDisk,
+            'qcow2-cache-size-based-on-disk',
+        );
+
         PVE.Utils.propertyStringSet(me.drive, !values.backup, 'backup', '0');
         PVE.Utils.propertyStringSet(me.drive, values.noreplicate, 'replicate', 'no');
         PVE.Utils.propertyStringSet(me.drive, values.discard, 'discard', 'on');
@@ -156,6 +181,8 @@ Ext.define('PVE.qemu.HDInputPanel', {
         values.iothread = PVE.Parser.parseBoolean(drive.iothread);
         values.readOnly = PVE.Parser.parseBoolean(drive.ro);
         values.aio = drive.aio || '__default__';
+        values.qcow2CacheSizeBasedOnDisk = drive['qcow2-cache-size-based-on-disk'];
+        values.qcow2CacheSize = drive['qcow2-cache-size'];
 
         values.mbps_rd = drive.mbps_rd;
         values.mbps_wr = drive.mbps_wr;
@@ -167,6 +194,11 @@ Ext.define('PVE.qemu.HDInputPanel', {
         values.iops_wr_max = drive.iops_wr_max;
 
         me.setValues(values);
+
+        me.getViewModel().set(
+            'isQcow2',
+            values.diskformat === 'qcow2' || values.hdimage?.endsWith('.qcow2'),
+        );
     },
 
     setNodename: function (nodename) {
@@ -355,6 +387,47 @@ Ext.define('PVE.qemu.HDInputPanel', {
                     disabled: '{!isVirtIO && !isSCSI}',
                 },
             },
+            {
+                xtype: 'numberfield',
+                name: 'qcow2CacheSize',
+                minValue: 1,
+                fieldLabel: gettext('qcow2 cache') + ' (MiB)',
+                emptyText: gettext('Default cache size'),
+                autoEl: {
+                    tag: 'div',
+                    'data-qtip': gettext(
+                        'Total size of the qcow2 cache in MiB. A larger cache can' +
+                            ' improve I/O performance on large images. Leave empty to' +
+                            ' use the QEMU default (32 MiB L2 cache and 256 KiB' +
+                            ' refcount cache with the default disk settings).',
+                    ),
+                },
+                bind: {
+                    disabled: '{!isQcow2 || qcow2CacheSizeBasedOnDisk}',
+                },
+                listeners: {
+                    disable: (field) => field.setValue(null),
+                },
+            },
+            {
+                xtype: 'proxmoxcheckbox',
+                name: 'qcow2CacheSizeBasedOnDisk',
+                defaultValue: 0,
+                fieldLabel: gettext('qcow2 cache based on disk'),
+                clearOnDisable: true,
+                autoEl: {
+                    tag: 'div',
+                    'data-qtip': gettext(
+                        'Automatically size the qcow2 cache to cover the whole disk.' +
+                            ' Uses roughly 160 KiB of memory per GiB of disk with' +
+                            ' the default disk settings.',
+                    ),
+                },
+                bind: {
+                    value: '{qcow2CacheSizeBasedOnDisk}',
+                    disabled: '{!isQcow2}',
+                },
+            },
         );
 
         advancedColumn2.push(
-- 
2.47.3