[PATCH qemu-server] qemu: viommu: small variable code cleanup

[PATCH qemu-server] qemu: viommu: small variable code cleanup

[Dominik Csapak]

Reusing a variable the way done here reads not very nice and is easily
missable and possibly misunderstood. Instead use a dedicated variable
for the aw-bits additional and directly use that when pushing the
devices to the list.

No functionality change intended.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 src/PVE/QemuServer.pm | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/PVE/QemuServer.pm b/src/PVE/QemuServer.pm
index 63d8c135..d2f569b5 100644
--- a/src/PVE/QemuServer.pm
+++ b/src/PVE/QemuServer.pm
@@ -3777,9 +3777,9 @@ sub config_to_command {
     PVE::QemuServer::Machine::assert_valid_machine_property($machine_conf);
 
     if (my $viommu = $machine_conf->{viommu}) {
-        my $viommu_devstr = '';
+        my $aw_bits = '';
         if ($machine_conf->{'aw-bits'}) {
-            $viommu_devstr .= ",aw-bits=$machine_conf->{'aw-bits'}";
+            $aw_bits .= ",aw-bits=$machine_conf->{'aw-bits'}";
 
             # TODO remove message once this gets properly checked/warned about in QEMU itself.
             print "vIOMMU 'aw-bits' set to $machine_conf->{'aw-bits'}. Sometimes it is necessary to"
@@ -3787,12 +3787,10 @@ sub config_to_command {
         }
 
         if ($viommu eq 'intel') {
-            $viommu_devstr = "intel-iommu,intremap=on,caching-mode=on$viommu_devstr";
-            unshift @$devices, '-device', $viommu_devstr;
+            unshift @$devices, '-device', "intel-iommu,intremap=on,caching-mode=on$aw_bits";
             push @$machineFlags, 'kernel-irqchip=split';
         } elsif ($viommu eq 'virtio') {
-            $viommu_devstr = "virtio-iommu-pci$viommu_devstr";
-            push @$devices, '-device', $viommu_devstr;
+            push @$devices, '-device', "virtio-iommu-pci$aw_bits";
         }
     }
 
-- 
2.47.3

applied: [PATCH qemu-server] qemu: viommu: small variable code cleanup

[Fiona Ebner]

On Mon, 31 Aug 2026 13:25:37 +0200, Dominik Csapak wrote:
> Reusing a variable the way done here reads not very nice and is easily
> missable and possibly misunderstood. Instead use a dedicated variable
> for the aw-bits additional and directly use that when pushing the
> devices to the list.
> 
> No functionality change intended.
> 
> [...]

Applied, thanks! I changed the commit title to be a bit clearer and
avoid the superfluous 'qemu' prefix.

[1/1] code cleanup: cfg2cmd: viommu: avoid unintuitive variable reuse
      commit: 9cba97b4f2d9244ea40ddac5130bc4d147bb1dc3