Virtio IRQ problem

[Pavel Davydov <pavel.davydov@hp.com>]

Hello,

I've got the following problem with KVM:

I'm running a proprietary OS under KVM, the OS is neither Linux/Unix, 
nor Windows, and I don't get any IRQs from Virtio device. The Virtio 
device in the system I'm running is a PCI Ethernet device. The device is 
detected correctly, the IRQ line is also identified, its matches with 
the IRQ line number retrieved by running lspci command when Linux is run 
instead of the proprietary system.

When Linux is run on exactly the same virtual machine configuration 
(with the Virtio device), the Virtio device is detected and works 
correctly, there is traffic between the host and the guest.

When the only change in the configuration is that the type of the 
virtual network interface is changed from Virtio to E1000, in both OSes: 
the proprietary OS and Linux, the virtual network interface works correctly.

The question is: what steps is Virtio driver to perform to enable the 
IRQs? (Obviously, Linux driver for Virtio performs these steps, the IRQs 
are generated under Linux VM).

Any hint would be appreciated.

Thank you,
Pavel