Re: [Xen-devel] [PATCH v5 05/11] mm: move modify_identity_mmio to global file and drop __init

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 14.08.17 at 16:28, <roger.pau@xxxxxxxxxx> wrote:
> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -1465,6 +1465,46 @@ int prepare_ring_for_helper(
>      return 0;
>  }
>  
> +#if defined(CONFIG_HAS_PCI)

#ifdef please.

> +int modify_mmio(struct domain *d, gfn_t gfn, mfn_t mfn, unsigned long 
> nr_pages,
> +                bool map)
> +{
> +    int rc;
> +
> +    /*
> +     * ATM this function should only be used by the hardware domain
> +     * because it doesn't support preemption/continuation, and as such
> +     * can take a non-negligible amount of time. Note that it periodically
> +     * calls process_pending_softirqs in order to avoid stalling the system.
> +     */
> +    ASSERT(is_hardware_domain(d));
> +
> +    for ( ; ; )
> +    {
> +        rc = (map ? map_mmio_regions : unmap_mmio_regions)
> +             (d, gfn, nr_pages, mfn);
> +        if ( rc == 0 )
> +            break;
> +        if ( rc < 0 )
> +        {
> +            printk(XENLOG_WARNING
> +                   "Failed to %smap [%" PRI_gfn ", %" PRI_gfn ") -> "
> +                   "[%" PRI_mfn ", %" PRI_mfn ") for d%d: %d\n",
> +                   map ? "" : "un", gfn_x(gfn), gfn_x(gfn_add(gfn, 
> nr_pages)),
> +                   mfn_x(mfn), mfn_x(mfn_add(mfn, nr_pages)), d->domain_id,
> +                   rc);
> +            break;
> +        }
> +        nr_pages -= rc;
> +        mfn = mfn_add(mfn, rc);
> +        gfn = gfn_add(gfn, rc);
> +        process_pending_softirqs();

With the __init dropped, this become questionable: We shouldn't
do this arbitrarily; runtime use should instead force a hypercall
continuation (assuming that's the context it's going to be used in).

Jan


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