[Qemu-devel] Re: Vhost support

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Feb 21, 2011 at 11:41:39AM +0000, Liu Yu-B13201 wrote:
>  
> 
> > -----Original Message-----
> > From: Michael S. Tsirkin [mailto:mst@redhat.com] 
> > Sent: Monday, February 21, 2011 7:22 PM
> > To: Liu Yu-B13201
> > Cc: qemu-devel@nongnu.org; Yoder Stuart-B08248
> > Subject: Re: Vhost support
> > 
> > On Mon, Feb 21, 2011 at 11:13:33AM +0000, Liu Yu-B13201 wrote:
> > > 
> > > Hello everyone,
> > > 
> > > Does anyone know the status of vhost in upstream qemu?
> > > We would like to try vhost with kvm on powerpc e500v2 platform,
> > > but obviously, powerpc kvm only works with upstream qemu.
> > > 
> > > KVM wike page says it needs to enable CONFIG_PCI_MSI for 
> > guest kernel.
> > > Is MSI a necessary?
> > > 
> > > Thanks,
> > > Yu
> > 
> > At the moment, yes.
> > The issue is not with vhost, it's that irqfd in kvm
> > only works with MSI at the moment.
> > 
> 
> Hi Michael,
> 
> Thanks for your answer.
> But I don't find MSI or irqfd support in upstream qemu.
> Does it mean upstream qemu not support virtio/vhost for now?
> 
> 
> Thanks,
> Yu

Ahm you mean not qemu-kvm?  It does, just slowly by going through
userspace.  You can force vhost bouncing without msi as well, by
setting vhostforce.

-- 
MST