Re: [Qemu-devel] [virtio-dev] [PATCH v3 0/7] Vhost-pci for inter-VM communication

[Maxime Coquelin]

Hi Stefan,

On 12/13/2017 09:08 PM, Stefan Hajnoczi wrote:
> On Wed, Dec 13, 2017 at 3:01 PM, Michael S. Tsirkin <address@hidden> wrote:
> > On Wed, Dec 13, 2017 at 12:35:21PM +0000, Stefan Hajnoczi wrote:
> > > I'm not saying that DPDK should use libvhost-user.  I'm saying that it's
> > > easy to add vfio vhost-pci support (for the PCI adapter I described) to
> > > DPDK.  This patch series would require writing a completely new slave
> > > for vhost-pci because the device interface is so different from
> > > vhost-user.
> >
> > The main question is how appropriate is the vhost user protocol
> > for passing to guests. And I am not sure at this point.
> >
> > Someone should go over vhost user messages and see whether they are safe
> > to pass to guest. If most are then we can try the transparent approach.
> > If most aren't then we can't and might as well use the proposed protocol
> > which at least has code behind it.
>
> I have done that:
...
>   * VHOST_USER_SET_MEM_TABLE
>
>     Set up BARs before sending a VHOST_USER_SET_MEM_TABLE to the guest.

It would require to filter out userspace_addr from the payload not to
leak other QEMU process VAs to the guest.

Maxime