[PATCH qemu-server v5 10/21] api: cpu flags: improve flags list returned by endpoint

[Arthur Bied-Charreton <a.bied-charreton@proxmox.com>]

Enhance the cpu-flags endpoint's list of flags by using the new
query_available_cpu_flags utility, which for each flag, additionally
returns a list of nodes supporting it, e.g.:

```
name: 'aes',
'supported-on': ['node1', 'node2'],
description: '...',
```

An `accel` parameter selects the acceleration type, `kvm` (default) or
`tcg` for which the flag-to-node compatibility is evaluated. The now-
unused get_supported_cpu_flags helper is removed.

Signed-off-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>
---
 src/PVE/API2/Qemu/CPUFlags.pm  | 24 +++++++++++++++++++++---
 src/PVE/QemuServer/CPUFlags.pm | 14 --------------
 2 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/src/PVE/API2/Qemu/CPUFlags.pm b/src/PVE/API2/Qemu/CPUFlags.pm
index 4b409a40..873441d9 100644
--- a/src/PVE/API2/Qemu/CPUFlags.pm
+++ b/src/PVE/API2/Qemu/CPUFlags.pm
@@ -7,6 +7,7 @@ use PVE::RESTHandler;
 use PVE::Tools qw(extract_param);
 
 use PVE::QemuServer::CPUFlags;
+use PVE::QemuServer::Helpers;
 
 use base qw(PVE::RESTHandler);
 
@@ -14,13 +15,22 @@ __PACKAGE__->register_method({
     name => 'index',
     path => '',
     method => 'GET',
-    description => 'List of available VM-specific CPU flags.',
+    description =>
+        "List of available VM-specific CPU flags. Returns an empty list for 'aarch64' "
+        . "as no VM-specific flags are defined for it yet.",
     permissions => { user => 'all' },
     parameters => {
         additionalProperties => 0,
         properties => {
             node => get_standard_option('pve-node'),
             arch => get_standard_option('pve-qm-cpu-arch', { optional => 1 }),
+            accel => {
+                description => 'Acceleration type to check node compatibility for.',
+                type => 'string',
+                enum => [qw(kvm tcg)],
+                optional => 1,
+                default => 'kvm',
+            },
         },
     },
     returns => {
@@ -36,15 +46,23 @@ __PACKAGE__->register_method({
                     type => 'string',
                     description => "Description of the CPU flag.",
                 },
+                'supported-on' => {
+                    description =>
+                        'List of nodes supporting the CPU flag with the selected acceleration type ("accel").',
+                    type => 'array',
+                    items => get_standard_option('pve-node'),
+                    optional => 1,
+                },
             },
         },
     },
     code => sub {
         my ($param) = @_;
 
-        my $arch = extract_param($param, 'arch');
+        my $arch = extract_param($param, 'arch') // PVE::QemuServer::Helpers::get_host_arch();
+        my $accel = extract_param($param, 'accel') // 'kvm';
 
-        return PVE::QemuServer::CPUFlags::get_supported_cpu_flags($arch);
+        return PVE::QemuServer::CPUFlags::query_available_cpu_flags($accel, 1, $arch);
     },
 });
 
diff --git a/src/PVE/QemuServer/CPUFlags.pm b/src/PVE/QemuServer/CPUFlags.pm
index 709828d7..09a4ab0b 100644
--- a/src/PVE/QemuServer/CPUFlags.pm
+++ b/src/PVE/QemuServer/CPUFlags.pm
@@ -6,13 +6,11 @@ use Exporter qw(import);
 
 use PVE::Cluster;
 use PVE::File;
-use PVE::QemuServer::Helpers qw(get_host_arch);
 
 our @EXPORT_OK = qw(
     cpu_flag_supported_re
     cpu_flag_any_re
     supported_cpu_flags_names
-    get_supported_cpu_flags
     query_understood_cpu_flags
     normalize_cpu_flag
     query_available_cpu_flags
@@ -168,18 +166,6 @@ sub cpu_flag_any_re() {
     return qr/([+-])([a-zA-Z0-9\-_\.]+)/;
 }
 
-=head3 get_supported_cpu_flags($arch)
-
-Return supported VM-specific CPU flags for $arch. $arch defaults to the host architecture
-if C<undef>.
-
-=cut
-
-sub get_supported_cpu_flags($arch) {
-    $arch = get_host_arch() if !defined($arch);
-    return $supported_vm_specific_cpu_flags_by_arch->{$arch};
-}
-
 sub query_understood_cpu_flags($arch) {
     my $filepath = "$understood_cpu_flag_dir/recognized-CPUID-flags-$arch";
 
-- 
2.47.3