Re: Xen/arm: Virtual ITS command queue handling

[Ian Campbell <ian.campbell@citrix.com>]

On Mon, 2015-06-01 at 15:57 -0700, Manish Jaggi wrote:

> > Anyway, the general shape of this plan seems plausible enough.
> Could you modify the http://xenbits.xen.org/people/ianc/vits/draftC.html(5 vITS to pITS mapping) based on this approach

I'm updating things as I go and feed back will be relected in the next
draft.


> > > -5- domU is booted with a single virtual its node in device tree. Front 
> > > end driver  attaches this its as msi-parent
> > > -6- When domU accesses for ITS are trapped in Xen, using the helper 
> > > function say
> > > get_phys_its_for_guest(guest_id, guest_sbdf, /*[out]*/its_ptr *its)
> > > 
> > > its can be retrieved.
> > > AFAIK this is numa safe.
> > > > > 2) When PCI device is assigned to DomU, how does domU choose
> > > > >      vITS to send commands.  AFAIK, the BDF of assigned device
> > > > >      is different from actual BDF in DomU.
> > > > AIUI this is described in the firmware tables.
> > > > 
> > > > e.g. in DT via the msi-parent phandle on the PCI root complex or
> > > > individual device.
> > > > 
> > > > Is there an assumption here that a single PCI root bridge is associated
> > > > with a single ITS block? Or can different devices on a PCI bus use
> > > > different ITS blocks?
> > > > 
> > > > Ian.
> > > > 
> > > > 
> > > > _______________________________________________
> > > > Xen-devel mailing list
> > > > Xen-devel@lists.xen.org
> > > > http://lists.xen.org/xen-devel
> > 
>