On 15.12.2023 15:18, Roger Pau Monne wrote:
> Introduce the code to remove regions not to be mapped from the rangeset
> that will be used to setup the IOMMU page tables for the hardware domain.
>
> This change also introduces two new functions: remove_xen_ranges() and
> vpci_subtract_mmcfg() that copy the logic in xen_in_range() and
> vpci_is_mmcfg_address() respectively and remove the ranges that would
> otherwise
> be intercepted by the original functions.
>
> Note that the rangeset is still not populated.
>
> Signed-off-by: Roger Pau Monné <roger....@citrix.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
> @@ -533,6 +541,62 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
> goto commit;
> }
>
> + /* Remove any areas in-use by Xen. */
> + rc = remove_xen_ranges(map);
> + if ( rc )
> + panic("IOMMU failed to remove Xen ranges: %d\n", rc);
> +
> + /* Remove any overlap with the Interrupt Address Range. */
> + rc = rangeset_remove_range(map, 0xfee00, 0xfeeff);
> + if ( rc )
> + panic("IOMMU failed to remove Interrupt Address Range: %d\n",
> + rc);
> +
> + /* If emulating IO-APIC(s) make sure the base address is unmapped. */
> + if ( has_vioapic(d) )
> + {
> + for ( i = 0; i < d->arch.hvm.nr_vioapics; i++ )
> + {
> + rc = rangeset_remove_singleton(map,
> + PFN_DOWN(domain_vioapic(d, i)->base_address));
> + if ( rc )
> + panic("IOMMU failed to remove IO-APIC: %d\n",
> + rc);
> + }
> + }
> +
> + if ( is_pv_domain(d) )
> + {
> + /*
> + * Be consistent with CPU mappings: Dom0 is permitted to establish
> r/o
> + * ones there (also for e.g. HPET in certain cases), so it should
> also
> + * have such established for IOMMUs. Remove any read-only ranges
> here,
> + * since ranges in mmio_ro_ranges are already explicitly mapped below
> + * in read-only mode.
> + */
> + rc = rangeset_report_ranges(mmio_ro_ranges, 0, ~0UL, map_subtract,
> map);
I find it a little odd that you iterate over mmio_ro_ranges twice (once
here, once in what the earlier patch added), but I guess overall it's
easier this way.
Also, nit: Either this line is too long, or ...
> + if ( rc )
> + panic("IOMMU failed to remove read-only regions: %d\n",
> + rc);
... there's no need to wrap lines here.
Jan
