[PATCH qemu-server 4/5] usb: factor out the default usb bus of the tablet

[Dominik Csapak <d.csapak@proxmox.com>]

The bus of the tablet depends on which USB controllers exist, which is
decided in get_usb_controllers. Move the choice next to it, so both can
be adapted together when the controllers change.

No functional change intended.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 src/PVE/QemuServer.pm     | 10 +---------
 src/PVE/QemuServer/USB.pm |  9 +++++++++
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/PVE/QemuServer.pm b/src/PVE/QemuServer.pm
index 39096199..4a67d3a0 100644
--- a/src/PVE/QemuServer.pm
+++ b/src/PVE/QemuServer.pm
@@ -1182,15 +1182,7 @@ sub assert_clipboard_config {
 sub print_tabletdevice_full {
     my ($conf, $arch) = @_;
 
-    my $q35 = PVE::QemuServer::Machine::machine_type_is_q35($conf);
-
-    # we use uhci for old VMs because tablet driver was buggy in older qemu
-    my $usbbus;
-    if ($q35 || $arch eq 'aarch64') {
-        $usbbus = 'ehci';
-    } else {
-        $usbbus = 'uhci';
-    }
+    my $usbbus = PVE::QemuServer::USB::get_default_usb_bus($conf, $arch);
 
     return "usb-tablet,id=tablet,bus=$usbbus.0,port=1";
 }
diff --git a/src/PVE/QemuServer/USB.pm b/src/PVE/QemuServer/USB.pm
index bf2741f6..0ab43614 100644
--- a/src/PVE/QemuServer/USB.pm
+++ b/src/PVE/QemuServer/USB.pm
@@ -119,6 +119,15 @@ my sub assert_usb_index_is_useable {
     return undef;
 }
 
+sub get_default_usb_bus {
+    my ($conf, $arch) = @_;
+
+    my $q35 = PVE::QemuServer::Machine::machine_type_is_q35($conf);
+
+    # we use uhci for old VMs because tablet driver was buggy in older qemu
+    return $q35 || $arch eq 'aarch64' ? 'ehci' : 'uhci';
+}
+
 sub get_usb_controllers {
     my ($conf, $arch, $machine_version) = @_;
 
-- 
2.47.3