[PATCH v2 3/3] qom: Link multiple numa nodes to device using a new object

[ankita]

From: Ankit Agrawal <ankita@nvidia.com>

NVIDIA GPU's support MIG (Mult-Instance GPUs) feature [1], which allows
partitioning of the GPU device resources (including device memory) into
several (upto 8) isolated instances. Each of the partitioned memory needs
a dedicated NUMA node to operate. The partitions are not fixed and they
can be created/deleted at runtime.

Unfortunately Linux OS does not provide a means to dynamically create/destroy
NUMA nodes and such feature implementation is not expected to be trivial. The
nodes that OS discovers at the boot time while parsing SRAT remains fixed. So
we utilize the GI Affinity structures that allows association between nodes
and devices. Multiple GI structures per BDF is possible, allowing creation of
multiple nodes by exposing unique PXM in each of these structures.

Introducing a new nvidia-acpi-generic-initiator object, which inherits from
the generic acpi-generic-initiator object to allow a BDF to be associated with
more than 1 nodes.

An admin can provide the range of nodes using numa-node-start and
numa-node-count and link it to a device by providing its id. The following
sample creates 8 nodes and link them to the device dev0:

        -numa node,nodeid=2 \
        -numa node,nodeid=3 \
        -numa node,nodeid=4 \
        -numa node,nodeid=5 \
        -numa node,nodeid=6 \
        -numa node,nodeid=7 \
        -numa node,nodeid=8 \
        -numa node,nodeid=9 \
        -device 
vfio-pci-nohotplug,host=0009:01:00.0,bus=pcie.0,addr=04.0,rombar=0,id=dev0 \
        -object 
nvidia-acpi-generic-initiator,id=gi0,device=dev0,numa-node-start=2,numa-node-count=8
 \

[1] https://www.nvidia.com/en-in/technologies/multi-instance-gpu

Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
---
 hw/acpi/acpi-generic-initiator.c         | 61 ++++++++++++++++++++++++
 include/hw/acpi/acpi-generic-initiator.h | 12 +++++
 qapi/qom.json                            | 24 +++++++++-
 3 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/hw/acpi/acpi-generic-initiator.c b/hw/acpi/acpi-generic-initiator.c
index 1ae79639be..8ef887c3a4 100644
--- a/hw/acpi/acpi-generic-initiator.c
+++ b/hw/acpi/acpi-generic-initiator.c
@@ -150,3 +150,64 @@ void build_srat_generic_initiator(GArray *table_data)
     }
     g_slist_free(list);
 }
+
+static void
+nvidia_acpi_generic_initiator_set_node_start(Object *obj, Visitor *v,
+                                             const char *name, void *opaque,
+                                             Error **errp)
+{
+    AcpiGenericInitiator *gi = ACPI_GENERIC_INITIATOR(obj);
+    uint32_t value;
+
+    if (!visit_type_uint32(v, name, &value, errp)) {
+        return;
+    }
+
+    if (value >= MAX_NODES) {
+        return;
+    }
+
+    gi->node = value;
+}
+
+static void
+nvidia_acpi_generic_initiator_set_node_count(Object *obj, Visitor *v,
+                                             const char *name, void *opaque,
+                                             Error **errp)
+{
+    AcpiGenericInitiator *gi = ACPI_GENERIC_INITIATOR(obj);
+    uint32_t value;
+
+    if (!visit_type_uint32(v, name, &value, errp)) {
+        return;
+    }
+
+    gi->node_count = value;
+}
+
+static void nvidia_acpi_generic_initiator_class_init(ObjectClass *oc, void 
*data)
+{
+    object_class_property_add(oc, 
NVIDIA_ACPI_GENERIC_INITIATOR_NODE_START_PROP,
+                              "uint32", NULL,
+                              nvidia_acpi_generic_initiator_set_node_start,
+                              NULL, NULL);
+    object_class_property_add(oc, 
NVIDIA_ACPI_GENERIC_INITIATOR_NODE_COUNT_PROP,
+                              "uint32", NULL,
+                              nvidia_acpi_generic_initiator_set_node_count,
+                              NULL, NULL);
+}
+
+static const TypeInfo nvidia_acpi_generic_initiator_info = {
+    .parent = TYPE_ACPI_GENERIC_INITIATOR,
+    .name = TYPE_NVIDIA_ACPI_GENERIC_INITIATOR,
+    .instance_size = sizeof(NvidiaAcpiGenericInitiator),
+    .class_size = sizeof(NvidiaAcpiGenericInitiatorClass),
+    .class_init = nvidia_acpi_generic_initiator_class_init,
+};
+
+static void
+nvidia_acpi_generic_initiator_register_types(void)
+{
+    type_register_static(&nvidia_acpi_generic_initiator_info);
+}
+type_init(nvidia_acpi_generic_initiator_register_types);
diff --git a/include/hw/acpi/acpi-generic-initiator.h 
b/include/hw/acpi/acpi-generic-initiator.h
index e8e2670309..3e4cf42064 100644
--- a/include/hw/acpi/acpi-generic-initiator.h
+++ b/include/hw/acpi/acpi-generic-initiator.h
@@ -9,10 +9,14 @@
 #include "qom/object_interfaces.h"
 
 #define TYPE_ACPI_GENERIC_INITIATOR "acpi-generic-initiator"
+#define TYPE_NVIDIA_ACPI_GENERIC_INITIATOR "nvidia-acpi-generic-initiator"
 
 #define ACPI_GENERIC_INITIATOR_DEVICE_PROP "device"
 #define ACPI_GENERIC_INITIATOR_NODE_PROP "node"
 
+#define NVIDIA_ACPI_GENERIC_INITIATOR_NODE_START_PROP "numa-node-start"
+#define NVIDIA_ACPI_GENERIC_INITIATOR_NODE_COUNT_PROP "numa-node-count"
+
 typedef struct AcpiGenericInitiator {
     /* private */
     Object parent;
@@ -47,6 +51,14 @@ typedef struct PCIDeviceHandle {
     uint64_t res1;
 } PCIDeviceHandle;
 
+typedef struct NvidiaAcpiGenericInitiator {
+    AcpiGenericInitiator parent;
+} NvidiaAcpiGenericInitiator;
+
+typedef struct NvidiaAcpiGenericInitiatorClass {
+        AcpiGenericInitiatorClass parent_class;
+} NvidiaAcpiGenericInitiatorClass;
+
 void build_srat_generic_initiator(GArray *table_data);
 
 #endif
diff --git a/qapi/qom.json b/qapi/qom.json
index 86c87a161c..c29ad1388d 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -793,6 +793,24 @@
 { 'struct': 'AcpiGenericInitiatorProperties',
   'data': { 'device': 'str', 'node': 'uint32' } }
 
+##
+# @NvidiaAcpiGenericInitiatorProperties:
+#
+# Properties for nvidia-acpi-generic-initiator objects.
+#
+# @device: the ID of the device to be associated with the nodes
+#
+# @numa-node-start: the ID of the numa node
+#
+# @numa-node-count: count of the numa nodes assocuated with the device
+#
+# Since: 8.0
+##
+{ 'struct': 'NvidiaAcpiGenericInitiatorProperties',
+  'data': { 'device': 'str',
+            'numa-node-start': 'uint32',
+            'numa-node-count': 'uint32' } }
+
 ##
 # @RngProperties:
 #
@@ -962,7 +980,8 @@
     'tls-cipher-suites',
     { 'name': 'x-remote-object', 'features': [ 'unstable' ] },
     { 'name': 'x-vfio-user-server', 'features': [ 'unstable' ] },
-    'acpi-generic-initiator'
+    'acpi-generic-initiator',
+    'nvidia-acpi-generic-initiator'
   ] }
 
 ##
@@ -1030,7 +1049,8 @@
       'tls-cipher-suites':          'TlsCredsProperties',
       'x-remote-object':            'RemoteObjectProperties',
       'x-vfio-user-server':         'VfioUserServerProperties',
-      'acpi-generic-initiator':     'AcpiGenericInitiatorProperties'
+      'acpi-generic-initiator':     'AcpiGenericInitiatorProperties',
+      'nvidia-acpi-generic-initiator':     
'NvidiaAcpiGenericInitiatorProperties'
   } }
 
 ##
-- 
2.17.1