[Qemu-devel] [PATCH v4 32/33] pc: ACPI BIOS: reserve SRAT entry for hotplug mem hole

[Igor Mammedov <imammedo@redhat.com>]

Needed for Windows to use hotplugged memory device, otherwise
it complains that server is not configured for memory hotplug.
Tests shows that aftewards it uses dynamically provided
proximity value from _PXM() method if available.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Peter Crosthwaite <peter.crostwaite@xilinx.com>
---
v2:
 - reword comment in build_srat() to make it more clear
 - s/hotplug_as_size/hotplugabble_address_space_size/, requested by mst
 - use property for getting hotplugabble_address_space_size, requested by mst
---
 hw/i386/acpi-build.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 58e7306..c53f0c7 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1199,6 +1199,10 @@ build_srat(GArray *table_data, GArray *linker,
     uint64_t curnode;
     int srat_start, numa_start, slots;
     uint64_t mem_len, mem_base, next_base;
+    PCMachineState *pcms = PC_MACHINE(qdev_get_machine());
+    ram_addr_t hotplugabble_address_space_size =
+        object_property_get_int(OBJECT(pcms), PC_MACHINE_MEMHP_REGION_SIZE,
+                                NULL);
 
     srat_start = table_data->len;
 
@@ -1263,6 +1267,19 @@ build_srat(GArray *table_data, GArray *linker,
         acpi_build_srat_memory(numamem, 0, 0, 0, MEM_AFFINITY_NOFLAGS);
     }
 
+    /*
+     * Entry is required for Windows to enable memory hotplug in OS.
+     * Memory devices may override proximity set by this entry,
+     * providing _PXM method if necessary.
+     */
+    if (hotplugabble_address_space_size) {
+        numamem = acpi_data_push(table_data, sizeof *numamem);
+        acpi_build_srat_memory(numamem, pcms->hotplug_memory_base,
+                               hotplugabble_address_space_size, 0,
+                               MEM_AFFINITY_HOTPLUGGABLE |
+                               MEM_AFFINITY_ENABLED);
+    }
+
     build_header(linker, table_data,
                  (void *)(table_data->data + srat_start),
                  "SRAT",
-- 
1.7.1