From a72acadd08b9135784ef8699bcb65f9edb64735a Mon Sep 17 00:00:00 2001
From: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Date: Sun, 27 Sep 2020 17:43:31 +0800
Subject: [PATCH] hw/arm/boot: Expose the pmem nodes in the DT.

In case of NV-DIMM slots, let's add /pmem DT nodes.
original patch see [1].

rebased by Edmond.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Edmond AK Dantes <edmond.dantes.ak47@outlook.com>

[1] https://patchwork.kernel.org/patch/11174981/
---
 hw/arm/boot.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 hw/arm/virt.c | 13 +++++++++----
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 3e9816af80..3214933c64 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -20,6 +20,7 @@
 #include "hw/boards.h"
 #include "sysemu/reset.h"
 #include "hw/loader.h"
+#include "hw/mem/memory-device.h"
 #include "elf.h"
 #include "sysemu/device_tree.h"
 #include "qemu/config-file.h"
@@ -524,6 +525,44 @@ static void fdt_add_psci_node(void *fdt)
     qemu_fdt_setprop_cell(fdt, "/psci", "migrate", migrate_fn);
 }
 
+static int fdt_add_pmem_node(void *fdt, uint32_t acells, uint32_t scells)
+{
+    MemoryDeviceInfoList *info, *info_list = qmp_memory_device_list();
+    MemoryDeviceInfo *mi;
+    int ret;
+
+    for (info = info_list; info != NULL; info = info->next) {
+        mi = info->value;
+
+        if (mi->type == MEMORY_DEVICE_INFO_KIND_NVDIMM) {
+            PCDIMMDeviceInfo *di = mi->u.nvdimm.data;
+            char *nodename;
+
+            nodename = g_strdup_printf("/pmem@%" PRIx64, di->addr);
+            qemu_fdt_add_subnode(fdt, nodename);
+            qemu_fdt_setprop_string(fdt, nodename, "compatible", "pmem-region");
+            ret = qemu_fdt_setprop_sized_cells(fdt, nodename, "reg", acells,
+                                               di->addr, scells, di->size);
+            /* only set the NUMA ID if it is specified */
+            if (!ret && di->node >= 0) {
+                ret = qemu_fdt_setprop_cell(fdt, nodename, "numa-node-id",
+                                            di->node);
+            }
+
+            g_free(nodename);
+
+            if (ret < 0) {
+                fprintf(stderr, "couldn't add NVDIMM /memory@%"PRIx64" node\n",
+                        di->addr);
+                goto out;
+            }
+        }
+    }
+out:
+    qapi_free_MemoryDeviceInfoList(info_list);
+    return ret;
+}
+
 int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
                  hwaddr addr_limit, AddressSpace *as, MachineState *ms)
 {
@@ -623,6 +662,11 @@ int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
         }
     }
 
+    rc = fdt_add_pmem_node(fdt, acells, scells);
+    if (rc < 0) {
+        fprintf(stderr, "couldn't add pmem memory nodes\n");
+        goto fail;
+    }
     rc = fdt_path_offset(fdt, "/chosen");
     if (rc < 0) {
         qemu_fdt_add_subnode(fdt, "/chosen");
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index ecfee362a1..09eb6c06e4 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2189,9 +2189,12 @@ static void virt_memory_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
     const bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
 
     if (!vms->acpi_dev) {
-        error_setg(errp,
-                   "memory hotplug is not enabled: missing acpi-ged device");
-        return;
+          /* Allow nvdimm DT or cold plug */
+          if (!(is_nvdimm && !dev->hotplugged)) {
+              error_setg(errp,
+                         "memory hotplug is not enabled: missing acpi-ged device");
+              return;
+         }
     }
 
     if (vms->mte) {
@@ -2224,8 +2227,10 @@ static void virt_memory_plug(HotplugHandler *hotplug_dev,
         nvdimm_plug(ms->nvdimms_state);
     }
 
-    hotplug_handler_plug(HOTPLUG_HANDLER(vms->acpi_dev),
+    if (vms->acpi_dev) {
+        hotplug_handler_plug(HOTPLUG_HANDLER(vms->acpi_dev),
                          dev, &error_abort);
+    }
 
 out:
     error_propagate(errp, local_err);
-- 
2.17.1