RE: [PATCH 33/37] xen/arm: keep guest still be NUMA unware

[Wei Chen <Wei.Chen@arm.com>]

> -----Original Message-----
> From: Stefano Stabellini <sstabellini@kernel.org>
> Sent: 2021年9月24日 11:19
> To: Wei Chen <Wei.Chen@arm.com>
> Cc: xen-devel@lists.xenproject.org; sstabellini@kernel.org; julien@xen.org;
> Bertrand Marquis <Bertrand.Marquis@arm.com>
> Subject: Re: [PATCH 33/37] xen/arm: keep guest still be NUMA unware
> 
> On Thu, 23 Sep 2021, Wei Chen wrote:
> > The NUMA information provided in the host Device-Tree
> > are only for Xen. For dom0, we want to hide them as they
> > may be different (for now, dom0 is still not aware of NUMA)
> > The CPU and memory nodes are recreated from scratch for the
> > domain. So we already skip the "numa-node-id" property for
> > these two types of nodes.
> >
> > However, some devices like PCIe may have "numa-node-id"
> > property too. We have to skip them as well.
> >
> > Signed-off-by: Wei Chen <wei.chen@arm.com>
> > ---
> >  xen/arch/arm/domain_build.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> > index d233d634c1..6e94922238 100644
> > --- a/xen/arch/arm/domain_build.c
> > +++ b/xen/arch/arm/domain_build.c
> > @@ -737,6 +737,10 @@ static int __init write_properties(struct domain *d,
> struct kernel_info *kinfo,
> >                  continue;
> >          }
> >
> > +        /* Guest is numa unaware in current stage */
> 
> I would say: "Dom0 is currently NUMA unaware"
> 
> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
> 

I will update the code comment in next version.
Thanks!

> 
> > +        if ( dt_property_name_is_equal(prop, "numa-node-id") )
> > +            continue;
> > +
> >          res = fdt_property(kinfo->fdt, prop->name, prop_data, prop_len);
> >
> >          if ( res )
> > @@ -1607,6 +1611,8 @@ static int __init handle_node(struct domain *d,
> struct kernel_info *kinfo,
> >          DT_MATCH_TYPE("memory"),
> >          /* The memory mapped timer is not supported by Xen. */
> >          DT_MATCH_COMPATIBLE("arm,armv7-timer-mem"),
> > +        /* Numa info doesn't need to be exposed to Domain-0 */
> > +        DT_MATCH_COMPATIBLE("numa-distance-map-v1"),
> >          { /* sentinel */ },
> >      };
> >      static const struct dt_device_match timer_matches[] __initconst =
> > --
> > 2.25.1
> >