test(virtio-mem): add API tests for PATCH

Test that the new PATCH API behaves as expected.
Also updates expected metrics and fixes memory monitor to account for
hotplugging.

Signed-off-by: Riccardo Mancini <[email protected]>

Author: Manciukic

tests/host_tools/fcmetrics.py

@@ -202,6 +202,8 @@ def validate_fc_metrics(metrics):
             "machine_cfg_fails",
             "mmds_count",
             "mmds_fails",
+            "hotplug_memory_count",
+            "hotplug_memory_fails",
         ],
         "put_api_requests": [
             "actions_count",

tests/host_tools/memory.py

@@ -99,7 +99,7 @@ def is_guest_mem_x86(self, size, guest_mem_bytes):
         Checks if a region is a guest memory region based on
         x86_64 physical memory layout
         """
-        return size in (
+        return size >= guest_mem_bytes or size in (
             # memory fits before the first gap
             guest_mem_bytes,
             # guest memory spans at least two regions & memory fits before the second gap
@@ -121,7 +121,7 @@ def is_guest_mem_arch64(self, size, guest_mem_bytes):
         Checks if a region is a guest memory region based on
         ARM64 physical memory layout
         """
-        return size in (
+        return size >= guest_mem_bytes or size in (
             # guest memory fits before the gap
             guest_mem_bytes,
             # guest memory fills the space before the gap

tests/integration_tests/functional/test_api.py

@@ -981,13 +981,14 @@ def test_api_entropy(uvm_plain):
         test_microvm.api.entropy.put()
 
 
-def test_api_memory_hotplug(uvm_plain):
+def test_api_memory_hotplug(uvm_plain_6_1):
     """
     Test hotplug related API commands.
     """
-    test_microvm = uvm_plain
+    test_microvm = uvm_plain_6_1
     test_microvm.spawn()
     test_microvm.basic_config()
+    test_microvm.add_net_iface()
 
     # Adding hotplug memory region should be OK.
     test_microvm.api.memory_hotplug.put(
@@ -1002,6 +1003,10 @@ def test_api_memory_hotplug(uvm_plain):
     with pytest.raises(AssertionError):
         test_microvm.api.memory_hotplug.get()
 
+    # Patch API should be rejected before boot
+    with pytest.raises(RuntimeError, match=NOT_SUPPORTED_BEFORE_START):
+        test_microvm.api.memory_hotplug.patch(requested_size_mib=512)
+
     # Start the microvm
     test_microvm.start()
 
@@ -1013,6 +1018,11 @@ def test_api_memory_hotplug(uvm_plain):
     status = test_microvm.api.memory_hotplug.get().json()
     assert status["total_size_mib"] == 1024
 
+    # Patch API should work after boot
+    test_microvm.api.memory_hotplug.patch(requested_size_mib=512)
+    status = test_microvm.api.memory_hotplug.get().json()
+    assert status["requested_size_mib"] == 512
+
 
 def test_api_balloon(uvm_nano):
     """