xen/arm: exclude xen,reg from domU extended regions

When a device is passed through to a dom0less domU, the xen,reg ranges
may overlap with the extended regions. Remove xen,reg from extended
regions.

Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/arch/arm/domain_build.c

@@ -973,6 +973,13 @@ static int __init find_domU_holes(const struct kernel_info *kinfo,
     if ( res )
         goto out;
 
+    if ( kinfo->xen_reg_assigned )
+    {
+        res = rangeset_subtract(mem_holes, kinfo->xen_reg_assigned);
+        if ( res )
+            goto out;
+    }
+
     res = rangeset_report_ranges(mem_holes, 0,
                                  PFN_DOWN((1ULL << p2m_ipa_bits) - 1),
                                  add_ext_regions, ext_regions);

xen/common/device-tree/dom0less-build.c

@@ -146,6 +146,14 @@ static int __init handle_passthrough_prop(struct kernel_info *kinfo,
     int res;
     paddr_t mstart, size, gstart;
 
+    if ( !kinfo->xen_reg_assigned )
+    {
+        kinfo->xen_reg_assigned = rangeset_new(NULL, NULL, 0);
+
+        if ( !kinfo->xen_reg_assigned )
+            return -ENOMEM;
+    }
+
     /* xen,reg specifies where to map the MMIO region */
     cell = (const __be32 *)xen_reg->data;
     len = fdt32_to_cpu(xen_reg->len) / ((address_cells * 2 + size_cells) *
@@ -187,6 +195,11 @@ static int __init handle_passthrough_prop(struct kernel_info *kinfo,
                    mstart, gstart);
             return -EFAULT;
         }
+
+        res = rangeset_add_range(kinfo->xen_reg_assigned, PFN_DOWN(gstart),
+                                 PFN_DOWN(gstart + size - 1));
+        if ( res )
+            return res;
     }
 
     /*
@@ -814,7 +827,11 @@ static int __init construct_domU(struct domain *d,
 
     domain_vcpu_affinity(d, node);
 
-    return alloc_xenstore_params(&kinfo);
+    rc = alloc_xenstore_params(&kinfo);
+
+    rangeset_destroy(kinfo.xen_reg_assigned);
+
+    return rc;
 }
 
 void __init create_domUs(void)

xen/include/xen/fdt-kernel.h

@@ -24,6 +24,7 @@ struct kernel_info {
 #ifdef CONFIG_STATIC_SHM
     struct shared_meminfo shm_mem;
 #endif
+    struct rangeset *xen_reg_assigned;
 
     /* kernel entry point */
     paddr_t entry;