kerf init: reconcile the live pool instead of writing the baseline once

.github/workflows/lint_and_test.yml

@@ -37,6 +37,12 @@ jobs:
 
     - name: Install dependencies
       run: |
+        # pylibfdt builds its SWIG wrapper from source, and swig 4.5 dropped
+        # the PyInt_* macros that wrapper still uses. Poetry builds sdists
+        # with "pip --isolated", which ignores PIP_CONSTRAINT, so build
+        # pylibfdt ourselves with a pinned swig and let poetry find it.
+        poetry run python -m pip install "swig<4.5" setuptools setuptools_scm
+        poetry run python -m pip install --no-build-isolation "pylibfdt>=1.7.0,<2"
         poetry install --no-interaction
 
     - name: Analysing the code with pylint

README.md

@@ -127,11 +127,19 @@ Baseline DTB (static)
 
 ### Command Line Interface
 ```bash
-# Initialize resource pool with CPUs (memory parsed from /proc/iomem)
-kerf init --cpus=4-7
+# Initialize resource pool with CPUs and pool memory
+# A plain size lands on the NUMA node of the requested CPUs
+kerf init --cpus=4-7 --memory=2GB
 
-# Initialize with CPUs and devices
-kerf init --cpus=4-31 --devices=enp9s0_dev,nvme0
+# Initialize with CPUs, per-node memory and devices
+kerf init --cpus=4-31 --memory=8GB@0,8GB@1 --devices=enp9s0_dev,nvme0
+
+# Re-run to reshape the live pool; "none" asks for none of a resource
+kerf init --cpus=4-15 --memory=4GB
+kerf init --cpus=4-15 --memory=none
+
+# Hand everything back to the host
+kerf init --cpus=none --memory=none
 
 # Create kernel instance with resource allocation
 kerf create web-server --cpus=4-7 --memory=2GB

examples/bad_system.dts

@@ -14,8 +14,9 @@
     resources {
         cpus = <4 5 6 7 8 9 10 11 12 13 14 15 
                 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31>;
-        memory-base = <0x80000000>;
-        memory-bytes = <0x0 0x380000000>;  // 14GB
+        memory@0 {
+            size = <0x0 0x380000000>;  // 14GB
+        };
 
         devices {
             eth0: ethernet@0 {

examples/baseline.dts

@@ -20,8 +20,9 @@
     resources {
         cpus = <4 5 6 7 8 9 10 11 12 13 14 15 
                 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31>;
-        memory-base = <0x80000000>;
-        memory-bytes = <0x0 0x380000000>;  // 14GB
+        memory@0 {
+            size = <0x0 0x380000000>;  // 14GB
+        };
 
         devices {
             eth0: ethernet@0 {

examples/conflict_example.dts

@@ -13,7 +13,8 @@
 
     resources {
         cpus = <2 3 4 5 6 7 8 9 10 11 12 13 14 15>;
-        memory-base = <0x100000000>;
-        memory-bytes = <0x0 0x300000000>;   // 12GB
+        memory@0 {
+            size = <0x0 0x300000000>;  // 12GB
+        };
     };
 };

examples/edge_computing.dts

@@ -12,8 +12,9 @@
 
     resources {
         cpus = <2 3 4 5 6 7 8 9 10 11 12 13 14 15>;
-        memory-base = <0x200000000>;
-        memory-bytes = <0x0 0x600000000>;   // 24GB
+        memory@0 {
+            size = <0x0 0x600000000>;  // 24GB
+        };
 
         devices {
             eth0: ethernet@0 {

examples/high_performance.dts

@@ -18,8 +18,9 @@
                 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87
                 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103
                 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119>;
-        memory-base = <0x400000000>;
-        memory-bytes = <0x0 0xC00000000>;   // 48GB
+        memory@0 {
+            size = <0x0 0xC00000000>;  // 48GB
+        };
 
         devices {
             eth0: ethernet@0 {

examples/minimal.dts

@@ -12,7 +12,8 @@
 
     resources {
         cpus = <2 3 4 5 6 7>;
-        memory-base = <0x40000000>;
-        memory-bytes = <0x0 0x1C0000000>;   // 7GB
+        memory@0 {
+            size = <0x0 0x1C0000000>;  // 7GB
+        };
     };
 };

examples/numa_topology.dts

@@ -58,14 +58,31 @@
             };
         };
 
-        memory-base = <0x0 0x800000000>;
-        memory-bytes = <0x0 0x1800000000>;  // 96GB
+        memory@0 {
+            size = <0x0 0x600000000>;  // 24GB
+            numa-node-id = <0>;
+        };
+
+        memory@1 {
+            size = <0x0 0x600000000>;  // 24GB
+            numa-node-id = <1>;
+        };
+
+        memory@2 {
+            size = <0x0 0x600000000>;  // 24GB
+            numa-node-id = <2>;
+        };
+
+        memory@3 {
+            size = <0x0 0x600000000>;  // 24GB
+            numa-node-id = <3>;
+        };
 
         devices {
             eth0: ethernet@0 {
                 compatible = "intel,i40e";
                 pci-id = "0000:01:00.0";
-                numa-node = <0>;
+                numa-node-id = <0>;
                 sriov-vfs = <8>;
                 host-reserved-vf = <0>;
                 available-vfs = <1 2 3 4 5 6 7>;
@@ -74,7 +91,7 @@
             eth1: ethernet@1 {
                 compatible = "intel,i40e";
                 pci-id = "0000:02:00.0";
-                numa-node = <2>;
+                numa-node-id = <2>;
                 sriov-vfs = <8>;
                 host-reserved-vf = <0>;
                 available-vfs = <1 2 3 4 5 6 7>;
@@ -83,7 +100,7 @@
             nvme0: storage@0 {
                 compatible = "nvme";
                 pci-id = "0000:03:00.0";
-                numa-node = <0>;
+                numa-node-id = <0>;
                 namespaces = <4>;
                 host-reserved-ns = <1>;
                 available-ns = <2 3 4>;
@@ -92,7 +109,7 @@
             nvme1: storage@1 {
                 compatible = "nvme";
                 pci-id = "0000:04:00.0";
-                numa-node = <2>;
+                numa-node-id = <2>;
                 namespaces = <4>;
                 host-reserved-ns = <1>;
                 available-ns = <2 3 4>;

examples/simple_numa.dts

@@ -32,8 +32,15 @@
             };
         };
 
-        memory-base = <0x0 0x400000000>;
-        memory-bytes = <0x0 0xC00000000>;  // 48GB
+        memory@0 {
+            size = <0x0 0x600000000>;  // 24GB
+            numa-node-id = <0>;
+        };
+
+        memory@1 {
+            size = <0x0 0x600000000>;  // 24GB
+            numa-node-id = <1>;
+        };
 
         devices {
             eth0: ethernet@0 {

examples/system.dts

@@ -13,8 +13,9 @@
     resources {
         cpus = <4 5 6 7 8 9 10 11 12 13 14 15 
                 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31>;
-        memory-base = <0x80000000>;
-        memory-bytes = <0x0 0x380000000>;  // 14GB
+        memory@0 {
+            size = <0x0 0x380000000>;  // 14GB
+        };
 
         devices {
             eth0: ethernet@0 {

src/kerf/__init__.py

@@ -41,7 +41,7 @@
     get_available_cpus,
     get_allocated_cpus,
     get_allocated_memory_regions,
-    find_available_memory_base,
+    chunk_containing,
     validate_cpu_allocation,
     validate_memory_allocation,
     find_next_instance_id,
@@ -67,7 +67,7 @@
     "get_available_cpus",
     "get_allocated_cpus",
     "get_allocated_memory_regions",
-    "find_available_memory_base",
+    "chunk_containing",
     "validate_cpu_allocation",
     "validate_memory_allocation",
     "find_next_instance_id",

src/kerf/create/main.py

@@ -31,7 +31,6 @@
 from ..resources import (
     validate_cpu_allocation,
     validate_memory_allocation,
-    find_available_memory_base,
     get_available_cpus,
 )
 from ..exceptions import ValidationError, KernelInterfaceError, ResourceError, ParseError
@@ -302,6 +301,12 @@ def parse_memory_spec(memory_spec: str) -> int:
         ) from exc
 
 
+def _placement(instance) -> str:
+    """Name the base only when one was asked for; the kernel picks otherwise."""
+    base = instance.resources.memory_base
+    return f" at {hex(base)}" if base else ""
+
+
 def parse_memory_base(base_spec: str) -> int:
     """
     Parse memory base address specification.
@@ -432,7 +437,8 @@ def dump_overlay_for_debug(
 )
 @click.option(
     "--memory-base",
-    help="Memory base address (hex: 0x80000000 or decimal, auto-assigned if not specified)",
+    help="Memory base address to request (hex: 0x80000000 or decimal). "
+    "Only checked against the pool; the kernel places instance memory itself.",
 )
 @click.option(
     "--devices",
@@ -641,17 +647,11 @@ def create_instance_operation(current):
             # Validate CPU allocation (against baseline and existing instances)
             validate_cpu_allocation(modified, cpu_list)
 
-            # Find memory base if not specified
+            # The kernel places instance memory itself; a base is only ever
+            # a caller's request, so it is all there is to validate.
             if memory_base_addr is None:
-                found_base = find_available_memory_base(modified, memory_bytes)
-                if found_base is None:
-                    raise ResourceError(
-                        f"No available memory region found for {memory_bytes} bytes. "
-                        "Try specifying --memory-base or reduce memory size."
-                    )
-                memory_base_addr = found_base
+                memory_base_addr = 0
             else:
-                # Validate specified memory base
                 validate_memory_allocation(modified, memory_base_addr, memory_bytes)
 
             # Create instance resources with topology settings
@@ -705,7 +705,7 @@ def create_instance_operation(current):
                     click.echo(
                         f"  NUMA Nodes: {', '.join(map(str, instance.resources.numa_nodes))}"
                     )
-                click.echo(f"  Memory: {memory} at {hex(instance.resources.memory_base)}")
+                click.echo(f"  Memory: {memory}{_placement(instance)}")
                 if instance.resources.memory_policy:
                     click.echo(f"  Memory Policy: {instance.resources.memory_policy}")
                 if instance.resources.devices:
@@ -745,7 +745,7 @@ def create_instance_operation(current):
                 if instance.resources.numa_nodes:
                     numa_str = ", ".join(map(str, instance.resources.numa_nodes))
                     click.echo(f"  NUMA Nodes: {numa_str}")
-                click.echo(f"  Memory: {memory} at {hex(instance.resources.memory_base)}")
+                click.echo(f"  Memory: {memory}{_placement(instance)}")
                 if instance.resources.memory_policy:
                     click.echo(f"  Memory Policy: {instance.resources.memory_policy}")
                 if instance.resources.devices:

src/kerf/dtc/extractor.py

@@ -18,6 +18,7 @@
 
 import libfdt
 from ..models import GlobalDeviceTree, Instance
+from ..pool_diff import ANY_NODE
 from .cells import pack_cpu_ids
 
 
@@ -125,9 +126,14 @@ def _add_cpu_properties_sw(self, fdt_sw, cpus):
         fdt_sw.property("cpus", pack_cpu_ids(cpus.available))
 
     def _add_memory_properties_sw(self, fdt_sw, memory):
-        """Add memory properties directly to resources node."""
-        fdt_sw.property_u64("memory-base", memory.memory_pool_base)
-        fdt_sw.property_u64("memory-bytes", memory.memory_pool_bytes)
+        """Add one memory@<idx> request node per requested size (or live chunk)."""
+        entries = list(memory.requested.items()) or [(r.node, r.size) for r in memory.regions]
+        for idx, (node, size) in enumerate(entries):
+            fdt_sw.begin_node(f"memory@{idx}")
+            fdt_sw.property_u64("size", size)
+            if node != ANY_NODE:
+                fdt_sw.property_u32("numa-node-id", node)
+            fdt_sw.end_node()
 
     def _add_devices_section_sw(self, fdt_sw, devices):
         """Add devices section using FdtSw."""
@@ -244,78 +250,6 @@ def _add_device_references_sw(self, fdt_sw, device_references):
 
             fdt_sw.end_node()
 
-    def _add_resources_section(self, parent_offset: int, tree: GlobalDeviceTree):
-        """Add resources section to DTB."""
-        resources_offset = self.fdt.add_subnode(parent_offset, "resources")
-
-        # Add CPU information
-        self._add_cpu_section(resources_offset, tree.hardware.cpus)
-
-        # Add memory information
-        self._add_memory_section(resources_offset, tree.hardware.memory)
-
-        # Add device information
-        self._add_devices_section(resources_offset, tree.hardware.devices)
-
-    def _add_cpu_section(self, parent_offset: int, cpus):
-        """Add CPU section to DTB."""
-        cpus_offset = self.fdt.add_subnode(parent_offset, "cpus")
-        self.fdt.setprop_u32(cpus_offset, "total", cpus.total)
-
-        self.fdt.setprop(cpus_offset, "host-reserved", pack_cpu_ids(cpus.host_reserved))
-        self.fdt.setprop(cpus_offset, "available", pack_cpu_ids(cpus.available))
-
-    def _add_memory_section(self, parent_offset: int, memory):
-        """Add memory section to DTB."""
-        memory_offset = self.fdt.add_subnode(parent_offset, "memory")
-        self.fdt.setprop_u64(memory_offset, "total-bytes", memory.total_bytes)
-        self.fdt.setprop_u64(memory_offset, "host-reserved-bytes", memory.host_reserved_bytes)
-        self.fdt.setprop_u64(memory_offset, "memory-pool-base", memory.memory_pool_base)
-        self.fdt.setprop_u64(memory_offset, "memory-pool-bytes", memory.memory_pool_bytes)
-
-    def _add_devices_section(self, parent_offset: int, devices):
-        """Add devices section to DTB."""
-        devices_offset = self.fdt.add_subnode(parent_offset, "devices")
-
-        for name, device_info in devices.items():
-            device_offset = self.fdt.add_subnode(devices_offset, name)
-            self.fdt.setprop_str(device_offset, "compatible", device_info.compatible)
-
-            if device_info.pci_id:
-                self.fdt.setprop_str(device_offset, "pci-id", device_info.pci_id)
-
-            if device_info.sriov_vfs is not None:
-                self.fdt.setprop_u32(device_offset, "sriov-vfs", device_info.sriov_vfs)
-
-            if device_info.host_reserved_vf is not None:
-                self.fdt.setprop_u32(
-                    device_offset, "host-reserved-vf", device_info.host_reserved_vf
-                )
-
-            if device_info.available_vfs:
-                import struct
-
-                vfs_data = struct.pack(
-                    ">" + "I" * len(device_info.available_vfs), *device_info.available_vfs
-                )
-                self.fdt.setprop(device_offset, "available-vfs", vfs_data)
-
-            if device_info.namespaces is not None:
-                self.fdt.setprop_u32(device_offset, "namespaces", device_info.namespaces)
-
-            if device_info.host_reserved_ns is not None:
-                self.fdt.setprop_u32(
-                    device_offset, "host-reserved-ns", device_info.host_reserved_ns
-                )
-
-            if device_info.available_ns:
-                import struct
-
-                ns_data = struct.pack(
-                    ">" + "I" * len(device_info.available_ns), *device_info.available_ns
-                )
-                self.fdt.setprop(device_offset, "available-ns", ns_data)
-
     def _add_instances_section(self, parent_offset: int, tree: GlobalDeviceTree):
         """Add instances section to DTB."""
         instances_offset = self.fdt.add_subnode(parent_offset, "instances")