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

[Paolo Bonzini]

On 09/07/2015 15:29, Michael S. Tsirkin wrote:
> > On the positive side, we do need something similar to the last 3 patches
> > to expose multiqueue to the guest.  But it will require much more work
> > in QEMU to achieve true multiqueue.
> 
> Might this be useful as an intermediate step, e.g. for testing
> guest code?

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.