[PATCH qemu-server v3 1/2] cpu config: Add 'arch' property to cpu_fmt

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

Preparatory step for adding support for configuring custom CPU types in
the PVE UI.

Add optional property 'arch' (x86_64|aarch64) to cpu_fmt to allow custom
models to indicate which architecture they belong to, default to x86_64
for backwards compatibility.

Add checks to get_cpu_options and validate_cpu_conf to deny illegal
configs early.

Signed-off-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>
---
Changes since v1:
* add checks to validate_cpu_conf + get_cpu_options to fail early on
  misconfigurations
* reuse the pve-qm-cpu-arch standard option for cpu_fmt's arch property
* do not use single quotes for hash keys if not needed
* do not use parentheses for post-ifs

Changes since v2:
* use get_standard_option for getting the pve-qm-cpu-arch standard
  option instead of accessing the arch_desc directly

 src/PVE/QemuServer/CPUConfig.pm | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/PVE/QemuServer/CPUConfig.pm b/src/PVE/QemuServer/CPUConfig.pm
index 32ec4954..a8e146d7 100644
--- a/src/PVE/QemuServer/CPUConfig.pm
+++ b/src/PVE/QemuServer/CPUConfig.pm
@@ -374,6 +374,12 @@ my $cpu_fmt = {
             . " note that doing so will break live migration to CPUs with other values.",
         optional => 1,
     },
+    arch => {
+        %{ PVE::JSONSchema::get_standard_option('pve-qm-cpu-arch') },
+        default => 'x86_64',
+        description => 'The architecture the CPU model belongs to.',
+        optional => 1,
+    },
 };
 
 my $sev_fmt = {
@@ -475,6 +481,13 @@ sub validate_cpu_conf {
     my ($cpu) = @_;
     # required, but can't be forced in schema since it's encoded in section header for custom models
     die "CPU is missing cputype\n" if !$cpu->{cputype};
+
+    if (my $reported_model = $cpu->{'reported-model'}) {
+        my $arch = $cpu->{arch} // $cpu_fmt->{arch}->{default};
+        die "reported model '$reported_model' is not valid for architecture '$arch'\n"
+            if !$cpu_models_by_arch->{$arch}->{$reported_model};
+    }
+
     return $cpu;
 }
 PVE::JSONSchema::register_format('pve-vm-cpu-conf', $cpu_fmt, \&validate_vm_cpu_conf);
@@ -612,6 +625,10 @@ sub get_cpu_models {
 
     my $conf = load_custom_model_conf();
     for my $custom_model (keys %{ $conf->{ids} }) {
+        my $custom_model_arch = $conf->{ids}->{$custom_model}->{arch};
+        $custom_model_arch //= $cpu_fmt->{arch}->{default};
+        next if $custom_model_arch ne $arch;
+
         my $reported_model = $conf->{ids}->{$custom_model}->{'reported-model'};
         $reported_model //= $cpu_fmt->{'reported-model'}->{default};
         my $vendor = $all_cpu_models->{$reported_model};
@@ -854,6 +871,9 @@ sub get_cpu_options {
             $builtin_cpu->{flags} = $model->{'flags'};
         } elsif (is_custom_model($cputype)) {
             $custom_cpu = get_custom_model($cputype);
+            my $custom_cpu_arch = $custom_cpu->{arch} // $cpu_fmt->{arch}->{default};
+            die "custom CPU model has architecture '$custom_cpu_arch', but VM has '$arch'\n"
+                if $custom_cpu_arch ne $arch;
 
             $cputype = $custom_cpu->{'reported-model'} // $cpu_fmt->{'reported-model'}->{default};
             $kvm_off = $custom_cpu->{hidden} if defined($custom_cpu->{hidden});
-- 
2.47.3