[Qemu-devel] [PATCH v2 07/18] nvdimm: reserve address range for NVDIMM

[Xiao Guangrong <guangrong.xiao@linux.intel.com>]

NVDIMM reserves all the free range above 4G to do:
- Persistent Memory (PMEM) mapping
- implement NVDIMM ACPI device _DSM method

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
---
 hw/i386/pc.c               | 12 ++++++++++--
 hw/mem/nvdimm/pc-nvdimm.c  | 13 +++++++++++++
 include/hw/mem/pc-nvdimm.h |  1 +
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 7661ea9..41af6ea 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -64,6 +64,7 @@
 #include "hw/pci/pci_host.h"
 #include "acpi-build.h"
 #include "hw/mem/pc-dimm.h"
+#include "hw/mem/pc-nvdimm.h"
 #include "qapi/visitor.h"
 #include "qapi-visit.h"
 
@@ -1302,6 +1303,7 @@ FWCfgState *pc_memory_init(MachineState *machine,
     MemoryRegion *ram_below_4g, *ram_above_4g;
     FWCfgState *fw_cfg;
     PCMachineState *pcms = PC_MACHINE(machine);
+    ram_addr_t offset;
 
     assert(machine->ram_size == below_4g_mem_size + above_4g_mem_size);
 
@@ -1339,6 +1341,8 @@ FWCfgState *pc_memory_init(MachineState *machine,
         exit(EXIT_FAILURE);
     }
 
+    offset = 0x100000000ULL + above_4g_mem_size;
+
     /* initialize hotplug memory address space */
     if (guest_info->has_reserved_memory &&
         (machine->ram_size < machine->maxram_size)) {
@@ -1358,8 +1362,7 @@ FWCfgState *pc_memory_init(MachineState *machine,
             exit(EXIT_FAILURE);
         }
 
-        pcms->hotplug_memory.base =
-            ROUND_UP(0x100000000ULL + above_4g_mem_size, 1ULL << 30);
+        pcms->hotplug_memory.base = ROUND_UP(offset, 1ULL << 30);
 
         if (pcms->enforce_aligned_dimm) {
             /* size hotplug region assuming 1G page max alignment per slot */
@@ -1377,8 +1380,13 @@ FWCfgState *pc_memory_init(MachineState *machine,
                            "hotplug-memory", hotplug_mem_size);
         memory_region_add_subregion(system_memory, pcms->hotplug_memory.base,
                                     &pcms->hotplug_memory.mr);
+
+        offset = pcms->hotplug_memory.base + hotplug_mem_size;
     }
 
+     /* all the space left above 4G is reserved for NVDIMM. */
+    pc_nvdimm_reserve_range(offset);
+
     /* Initialize PC system firmware */
     pc_system_firmware_init(rom_memory, guest_info->isapc_ram_fw);
 
diff --git a/hw/mem/nvdimm/pc-nvdimm.c b/hw/mem/nvdimm/pc-nvdimm.c
index a53d235..7a270a8 100644
--- a/hw/mem/nvdimm/pc-nvdimm.c
+++ b/hw/mem/nvdimm/pc-nvdimm.c
@@ -24,6 +24,19 @@
 
 #include "hw/mem/pc-nvdimm.h"
 
+#define PAGE_SIZE      (1UL << 12)
+
+static struct nvdimms_info {
+    ram_addr_t current_addr;
+} nvdimms_info;
+
+/* the address range [offset, ~0ULL) is reserved for NVDIMM. */
+void pc_nvdimm_reserve_range(ram_addr_t offset)
+{
+    offset = ROUND_UP(offset, PAGE_SIZE);
+    nvdimms_info.current_addr = offset;
+}
+
 static char *get_file(Object *obj, Error **errp)
 {
     PCNVDIMMDevice *nvdimm = PC_NVDIMM(obj);
diff --git a/include/hw/mem/pc-nvdimm.h b/include/hw/mem/pc-nvdimm.h
index 51152b8..8601e9b 100644
--- a/include/hw/mem/pc-nvdimm.h
+++ b/include/hw/mem/pc-nvdimm.h
@@ -28,4 +28,5 @@ typedef struct PCNVDIMMDevice {
 #define PC_NVDIMM(obj) \
     OBJECT_CHECK(PCNVDIMMDevice, (obj), TYPE_PC_NVDIMM)
 
+void pc_nvdimm_reserve_range(ram_addr_t offset);
 #endif
-- 
2.4.3