[PATCH qemu-server v4 08/17] cpu flags: improve flags list returned by endpoint

Arthur Bied-Charreton
2026-04-30T16:03:20Z

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 flag to node compatibility is evaluated.

Signed-off-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>
---
src/PVE/API2/Qemu/CPUFlags.pm | 27 +++++++++++++++++++++++----
1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/PVE/API2/Qemu/CPUFlags.pm b/src/PVE/API2/Qemu/CPUFlags.pm
index 672bd2d2..122f0ed9 100644
--- a/src/PVE/API2/Qemu/CPUFlags.pm
+++ b/src/PVE/API2/Qemu/CPUFlags.pm
@@ -6,7 +6,8 @@ use PVE::JSONSchema qw(get_standard_option);
use PVE::RESTHandler;
use PVE::Tools qw(extract_param);

-use PVE::QemuServer::CPUConfig;
+use PVE::QemuServer::Helpers;
+use PVE::QemuServer::CPUFlags;

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 => {
@@ -35,6 +45,14 @@ __PACKAGE__->register_method({
description => {
type => 'string',
description => "Description of the CPU flag.",
+ optional => 1,
+ },
+ '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,
},
},
},
@@ -42,9 +60,10 @@ __PACKAGE__->register_method({
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::CPUConfig::get_supported_cpu_flags($arch);
+ return PVE::QemuServer::CPUFlags::query_available_cpu_flags($accel, 1, $arch);
},
});

--
2.47.3