The virtual PCI model delivers IRQs to the PIC by default and to the
IOAPIC only if the guest operating system selected the IOAPIC with the
'_PIC' ACPI method and if it called the '_PRT' ACPI method afterwards.
When running a guest operating system which uses the IOAPIC, but does
not call these ACPI methods (for example Genode/NOVA), the new
configuration option
<config force_ioapic="yes">
enforces the delivery of PCI IRQs to the IOAPIC.
Fixes#2029
There are currently some issue with the mixing/filtering code of vbox.
So instead of using the audio subsystem to do filtering and mixing we
bypass it to get better audio qualitiy. That means that the device
model of the VM has to use the same sample rate as the Audio_out/in
sessions, however.
Issue #1647.