From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <ian.campbell@citrix.com>
Subject: Re: [PATCH v4 5/6] xen: arm: map child MMIO and IRQs to
 dom0 for PCI bus DT nodes.
Date: Fri, 3 Jul 2015 11:59:01 +0100
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To: Julien Grall <julien.grall@citrix.com>
Cc: julien.grall@linaro.org, tim@xen.org, stefano.stabellini@eu.citrix.com, xen-devel@lists.xen.org
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On Fri, 2015-06-26 at 19:56 +0200, Julien Grall wrote:
> Hi Ian,
> 
> NIT in the title: The final point is not necessary
> 
> On 08/05/2015 13:26, Ian Campbell wrote:
> > +static int map_device_children(struct domain *d,
> > +                               const struct dt_device_node *dev)
> > +{
> > +    bool_t need_mapping = !dt_device_for_passthrough(dev);
> > +    int ret;
> > +
> > +    if ( dt_device_type_is_equal(dev, "pci") )
> > +    {
> > +        DPRINT("Mapping children of %s to guest\n", dt_node_full_name(dev));
> > +
> > +        /*
> > +         * We need to handle IRQs even if !need_mapping in order to
> > +         * setup the domain's permissions on the device's IRQs, such
> > +         * that it can pass them through to other domains.
> > +         */
> > +         ret = dt_for_each_irq_map(dev, &map_interrupt_to_domain, d);
> > +         if ( ret < 0 )
> > +             return ret;
> > +
> > +         if ( need_mapping )
> > +         {
> 
> I forgot to mention in the previous version that we need to give iomem 
> permission to the guest. Otherwise DOM0 won't be able to map the BAR 
> into the guest.

This boils down to a call to iomem_permit_access in the
map_range_to_domain callback and moving the need_mapping check down into
the cb surrouding only the map_mmio_region call but not the
permis_access one, right?