Re: [Qemu-devel] virtio-blk multiqueue support in qemu.

[Paolo Bonzini]

On 13/07/2015 13:21, Michael S. Tsirkin wrote:
> > Yes, this is already how virtio-scsi multiqueue is implemented.  The
> > speedup is noticeable.  However, for virtio-blk there is a huge
> > consumption of interrupt vectors in the guest, so it doesn't scale to
> > multiple disks as well as virtio-scsi.
>
> Could you elaborate please?  interrupt vector usage is generally
> up to the guest, so whatever the issue is might be fixable by driver
> changes alone.

Yes, but in practice neither Linux nor Windows (AFAIK) are able to share
the same vector across multiple MSIs.

Paolo