spapr: Add NVDIMM device support

Add support for NVDIMM devices for sPAPR. Piggyback on existing nvdimm
device interface in QEMU to support virtual NVDIMM devices for Power.
Create the required DT entries for the device (some entries have
dummy values right now).

The patch creates the required DT node and sends a hotplug
interrupt to the guest. Guest is expected to undertake the normal
DR resource add path in response and start issuing PAPR SCM hcalls.

The device support is verified based on the machine version unlike x86.

This is how it can be used ..
Ex :
For coldplug, the device to be added in qemu command line as shown below
-object memory-backend-file,id=memnvdimm0,prealloc=yes,mem-path=/tmp/nvdimm0,share=yes,size=1073872896
-device nvdimm,label-size=128k,uuid=75a3cdd7-6a2f-4791-8d15-fe0a920e8e9e,memdev=memnvdimm0,id=nvdimm0,slot=0

For hotplug, the device to be added from monitor as below
object_add memory-backend-file,id=memnvdimm0,prealloc=yes,mem-path=/tmp/nvdimm0,share=yes,size=1073872896
device_add nvdimm,label-size=128k,uuid=75a3cdd7-6a2f-4791-8d15-fe0a920e8e9e,memdev=memnvdimm0,id=nvdimm0,slot=0

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
               [Early implementation]
Message-Id: <158131058078.2897.12767731856697459923.stgit@lep8c.aus.stglabs.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

2 files changed, 46 insertions, 0 deletions

diff --git a/include/hw/ppc/spapr_drc.h b/include/hw/ppc/spapr_drc.h
index 83f03cc577..df3d958a66 100644
--- a/include/hw/ppc/spapr_drc.h
+++ b/include/hw/ppc/spapr_drc.h
@@ -78,6 +78,13 @@
 #define SPAPR_DRC_PHB(obj) OBJECT_CHECK(SpaprDrc, (obj), \
                                         TYPE_SPAPR_DRC_PHB)
 
+#define TYPE_SPAPR_DRC_PMEM "spapr-drc-pmem"
+#define SPAPR_DRC_PMEM_GET_CLASS(obj) \
+        OBJECT_GET_CLASS(SpaprDrcClass, obj, TYPE_SPAPR_DRC_PMEM)
+#define SPAPR_DRC_PMEM_CLASS(klass) \
+        OBJECT_CLASS_CHECK(SpaprDrcClass, klass, TYPE_SPAPR_DRC_PMEM)
+#define SPAPR_DRC_PMEM(obj) OBJECT_CHECK(SpaprDrc, (obj), \
+                                         TYPE_SPAPR_DRC_PMEM)
 /*
  * Various hotplug types managed by SpaprDrc
  *
@@ -95,6 +102,7 @@ typedef enum {
     SPAPR_DR_CONNECTOR_TYPE_SHIFT_VIO = 3,
     SPAPR_DR_CONNECTOR_TYPE_SHIFT_PCI = 4,
     SPAPR_DR_CONNECTOR_TYPE_SHIFT_LMB = 8,
+    SPAPR_DR_CONNECTOR_TYPE_SHIFT_PMEM = 9,
 } SpaprDrcTypeShift;
 
 typedef enum {
@@ -104,6 +112,7 @@ typedef enum {
     SPAPR_DR_CONNECTOR_TYPE_VIO = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_VIO,
     SPAPR_DR_CONNECTOR_TYPE_PCI = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_PCI,
     SPAPR_DR_CONNECTOR_TYPE_LMB = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_LMB,
+    SPAPR_DR_CONNECTOR_TYPE_PMEM = 1 << SPAPR_DR_CONNECTOR_TYPE_SHIFT_PMEM,
 } SpaprDrcType;
 
 /*
diff --git a/include/hw/ppc/spapr_nvdimm.h b/include/hw/ppc/spapr_nvdimm.h
new file mode 100644
index 0000000000..b3330cc485
--- /dev/null
+++ b/include/hw/ppc/spapr_nvdimm.h
@@ -0,0 +1,37 @@
+/*
+ * QEMU PowerPC PAPR SCM backend definitions
+ *
+ * Copyright (c) 2020, IBM Corporation.
+ *
+ * This code is licensed under the GPL version 2 or later. See the
+ * COPYING file in the top-level directory.
+ */
+
+#ifndef HW_SPAPR_NVDIMM_H
+#define HW_SPAPR_NVDIMM_H
+
+#include "hw/mem/nvdimm.h"
+#include "hw/ppc/spapr.h"
+
+/*
+ * The nvdimm size should be aligned to SCM block size.
+ * The SCM block size should be aligned to SPAPR_MEMORY_BLOCK_SIZE
+ * inorder to have SCM regions not to overlap with dimm memory regions.
+ * The SCM devices can have variable block sizes. For now, fixing the
+ * block size to the minimum value.
+ */
+#define SPAPR_MINIMUM_SCM_BLOCK_SIZE SPAPR_MEMORY_BLOCK_SIZE
+
+/* Have an explicit check for alignment */
+QEMU_BUILD_BUG_ON(SPAPR_MINIMUM_SCM_BLOCK_SIZE % SPAPR_MEMORY_BLOCK_SIZE);
+
+int spapr_pmem_dt_populate(SpaprDrc *drc, SpaprMachineState *spapr,
+                           void *fdt, int *fdt_start_offset, Error **errp);
+int spapr_dt_nvdimm(void *fdt, int parent_offset, NVDIMMDevice *nvdimm);
+void spapr_dt_persistent_memory(void *fdt);
+void spapr_nvdimm_validate_opts(NVDIMMDevice *nvdimm, uint64_t size,
+                                Error **errp);
+void spapr_add_nvdimm(DeviceState *dev, uint64_t slot, Error **errp);
+void spapr_create_nvdimm_dr_connectors(SpaprMachineState *spapr);
+
+#endif