IOMMU/AMD: wire common device reserved memory API

Register common device reserved memory similar to how ivmd= parameter is
handled.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/drivers/passthrough/amd/iommu_acpi.c

@@ -1078,6 +1078,25 @@ static inline bool_t is_ivmd_block(u8 type)
             type == ACPI_IVRS_TYPE_MEMORY_IOMMU);
 }
 
+static int __init cf_check add_one_extra_ivmd(unsigned long start,
+                                              unsigned long nr,
+                                              uint32_t id, void *ctxt)
+{
+    struct acpi_ivrs_memory ivmd = {
+        .header = {
+            .length = sizeof(ivmd),
+            .flags = ACPI_IVMD_UNITY | ACPI_IVMD_READ | ACPI_IVMD_WRITE,
+            .device_id = id,
+            .type = ACPI_IVRS_TYPE_MEMORY_ONE,
+        },
+    };
+
+    ivmd.start_address = pfn_to_paddr(start);
+    ivmd.memory_length = pfn_to_paddr(nr);
+
+    return parse_ivmd_block(&ivmd);
+}
+
 static int __init cf_check parse_ivrs_table(struct acpi_table_header *table)
 {
     const struct acpi_ivrs_header *ivrs_block;
@@ -1121,6 +1140,8 @@ static int __init cf_check parse_ivrs_table(struct acpi_table_header *table)
         AMD_IOMMU_DEBUG("IVMD: %u command line provided entries\n", nr_ivmd);
     for ( i = 0; !error && i < nr_ivmd; ++i )
         error = parse_ivmd_block(user_ivmds + i);
+    if ( !error )
+        error = iommu_get_extra_reserved_device_memory(add_one_extra_ivmd, NULL);
 
     /* Each IO-APIC must have been mentioned in the table. */
     for ( apic = 0; !error && iommu_intremap && apic < nr_ioapics; ++apic )