Re: [PATCHv4 0/2] kvm: direct msix injection

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 2012-11-21 at 21:26 +0200, Michael S. Tsirkin wrote:
> On Wed, Oct 17, 2012 at 06:05:53PM +0200, Michael S. Tsirkin wrote:
> > We can deliver certain interrupts, notably MSIX,
> > from atomic context.
> > Here's an untested patch to do this (compiled only).
> > 
> > Changes from v2:
> > Don't inject broadcast interrupts directly
> > Changes from v1:
> > Tried to address comments from v1, except unifying
> > with kvm_set_irq: passing flags to it looks too ugly.
> > Added a comment.
> > 
> > Jan, you said you can test this?
> 
> I have tested this with some networking workloads
> and this patchset seems to work fine.
> My setup isn't a good fit for benchmarking device
> assignment though.
> Alex, could you pls verifyu that this solves the
> latency issue that you sometimes observe?
> With this patchset device assignment latency should be
> as fast as vfio.

Yep, that seems to cover the gap.  My environment is too noisy to
declare an absolute winner, but pci-assign and vfio-pci are now very,
very similar under netperf TCP_RR with these patches.  Thanks,

Alex