Re: [Xen-devel] [PATCH v5 29/30] ARM: vITS: create ITS subnodes for Dom0 DT

[Julien Grall <julien.grall@xxxxxxx>]

On 07/04/17 14:45, Julien Grall wrote:
> On 07/04/17 14:46, Andre Przywara wrote:
> > Hi,
> >
> > On 07/04/17 14:41, Julien Grall wrote:
> > > Hi Andre,
> > >
> > > On 06/04/17 00:19, Andre Przywara wrote:
> > > > Dom0 expects all ITSes in the system to be propagated to be able to
> > > > use MSIs.
> > > > Create Dom0 DT nodes for each hardware ITS, keeping the register frame
> > > > address the same, as the doorbell address that the Dom0 drivers program
> > > > into the BARs has to match the hardware.
> > > >
> > > > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> > > > ---
> > > >  xen/arch/arm/gic-v3-its.c        | 78
> > > > ++++++++++++++++++++++++++++++++++++++++
> > > >  xen/arch/arm/gic-v3.c            |  4 ++-
> > > >  xen/include/asm-arm/gic_v3_its.h | 13 +++++++
> > > >  3 files changed, 94 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
> > > > index a57e63a..a167471 100644
> > > > --- a/xen/arch/arm/gic-v3-its.c
> > > > +++ b/xen/arch/arm/gic-v3-its.c
> > > > @@ -20,6 +20,7 @@
> > > >
> > > >  #include <xen/lib.h>
> > > >  #include <xen/delay.h>
> > > > +#include <xen/libfdt/libfdt.h>
> > > >  #include <xen/mm.h>
> > > >  #include <xen/rbtree.h>
> > > >  #include <xen/sched.h>
> > > > @@ -875,6 +876,83 @@ int gicv3_lpi_change_vcpu(struct domain *d,
> > > > paddr_t vdoorbell,
> > > >      return 0;
> > > >  }
> > > >
> > > > +/*
> > > > + * Create the respective guest DT nodes for a list of host ITSes.
> > > > + * This copies the reg property, so the guest sees the ITS at the
> > > > same address
> > > > + * as the host.
> > > > + * Giving NULL for the its_list will make it use the list of host
> > > > ITSes.
> > > > + */
> > > > +int gicv3_its_make_dt_nodes(struct list_head *its_list,
> > > Why do you have this parameter its_list that you always set to NULL?
> > The idea is to later allow only a subset of ITSes to be mapped into a
> > guest. In this case this function would be called with a specific
> > version of the list.
> > So this feature is basically just in for future DomU support.
> DomU DTS are created by the toolstack and not Xen. So please drop this
> pointless variable.
To complete what I just said, DOM0 will always have a virtual ITS per 
host ITS not matter whether they will be used. So there is really no 
point of that.
Cheers,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel