On Mon, May 18, 2009 at 12:30:49AM +0300, Avi Kivity wrote: > Michael S. Tsirkin wrote: >> This implements optional MSI-X support in virtio_pci. >> MSI-X is used whenever the host supports at least 2 MSI-X >> vectors: 1 for configuration changes and 1 for virtqueues. >> Per-virtqueue vectors are allocated if enough vectors >> available. > > > I'm not sure I understand how the vq -> msi mapping works. Do we > actually support an arbitrary mapping, or just either linear or n:1? Arbitrary mapping. > I don't mind the driver being limited, but the device interface should > be flexible. We'll want to deal with limited vector availability soon. I agree. The code in qemu lets you specify, for each queue, which MSIX vector you want to use, or a special value if you don't want signalling. You also specify which MSIX vector you want to use for config change notifications, or a special value if you want to e.g. poll. I think that's as flexible as it gets. The API within guest is much simpler, but it does not need to be stable. -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
