[pve-devel] [PATCH v4 qemu-server 2/4] usb: Add USB3 capabilities to Spice USB devices

[Aaron Lauterer]

To not change current behaviour and thus breaking live migration USB3
for a Spice USB device requires Qemu v4.1.

The old behavior was that even though technically it was possible to
the set `usb3=1` setting, it was ignored. The bus was hardcoded to
ehci. If another USB2 device was added or the machine type was set to
Q35 an ehci controller was present and the VM was able to boot.

With this patch the behaviour is changing and the bus is set to xhci if
USB3 is set for the Spice USB device and the VM is running under Qemu
v4.1.

Signed-off-by: Aaron Lauterer <a.lauterer at proxmox.com>
---

I created the new `usb_dev_features` hash which is used to store the
flag if spice is allowed to use usb3 and pass that to the usb module to
avoid cyclic dependencies as suggested by thomas.

 PVE/QemuServer.pm     | 5 ++++-
 PVE/QemuServer/USB.pm | 9 ++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 7128723..78ccf8c 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -3829,7 +3829,10 @@ sub config_to_command {
     }
 
     # usb devices
-    my @usbdevices = PVE::QemuServer::USB::get_usb_devices($conf, $usbdesc->{format}, $MAX_USB_DEVICES);
+    my $usb_dev_features = {};
+    $usb_dev_features->{spice_usb3} = 1 if qemu_machine_feature_enabled($machine_type, $kvmver, 4, 1);
+
+    my @usbdevices = PVE::QemuServer::USB::get_usb_devices($conf, $usbdesc->{format}, $MAX_USB_DEVICES, $usb_dev_features);
     push @$devices, @usbdevices if @usbdevices;
     # serial devices
     for (my $i = 0; $i < $MAX_SERIAL_PORTS; $i++)  {
diff --git a/PVE/QemuServer/USB.pm b/PVE/QemuServer/USB.pm
index 2c09490..d328148 100644
--- a/PVE/QemuServer/USB.pm
+++ b/PVE/QemuServer/USB.pm
@@ -74,7 +74,7 @@ sub get_usb_controllers {
 }
 
 sub get_usb_devices {
-    my ($conf, $format, $max_usb_devices) = @_;
+    my ($conf, $format, $max_usb_devices, $features) = @_;
 
     my $devices = [];
 
@@ -87,9 +87,12 @@ sub get_usb_devices {
 	    my $hostdevice = parse_usb_device($d->{host});
 	    $hostdevice->{usb3} = $d->{usb3};
 	    if ($hostdevice->{spice}) {
-		# usb redir support for spice, currently no usb3
+		# usb redir support for spice
+		my $bus = 'ehci';
+		$bus = 'xhci' if $hostdevice->{usb3} && $features->{spice_usb3};
+
 		push @$devices, '-chardev', "spicevmc,id=usbredirchardev$i,name=usbredir";
-		push @$devices, '-device', "usb-redir,chardev=usbredirchardev$i,id=usbredirdev$i,bus=ehci.0";
+		push @$devices, '-device', "usb-redir,chardev=usbredirchardev$i,id=usbredirdev$i,bus=$bus.0";
 	    } else {
 		push @$devices, '-device', print_usbdevice_full($conf, "usb$i", $hostdevice);
 	    }
-- 
2.20.1