test(perf): Do no parameterize restore tests by snapshot_type

Testing DIFF snapshots for the restore test is not an interesting test
permutation, as creating a DIFF vs FULL snapshot only has an impact on
the creation. Before a diff snapshot can be restored, it has to be
rebased, at which point the result is a full snapshot. So the CI tests
related to testing latency of restore with DIFF snapshots do not make
much sense (admittedly, there is one extra valloc call in the KVM
source [1], as dirty-page tracking will be enabled on the load path, but
this hardly warrants an entire new test permutation).

[1]: https://github.com/torvalds/linux/blob/a901a3568fd26ca9c4a82d8bc5ed5b3ed844d451/virt/kvm/kvm_main.c#L1626-L1638

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

tests/integration_tests/performance/test_snapshot_perf.py

@@ -161,12 +161,11 @@ def snapshot_create_producer(
     return value
 
 
-def snapshot_resume_producer(logger, vm_builder, snapshot, snapshot_type, use_ramdisk):
+def snapshot_resume_producer(logger, vm_builder, snapshot, use_ramdisk):
     """Produce results for snapshot resume tests."""
     microvm, metrics_fifo = vm_builder.build_from_snapshot(
         snapshot,
         resume=True,
-        diff_snapshots=snapshot_type == SnapshotType.DIFF,
         use_ramdisk=use_ramdisk,
     )
 
@@ -205,7 +204,6 @@ def test_older_snapshot_resume_latency(
     restore in current version.
     """
     logger = logging.getLogger("old_snapshot_load")
-    snapshot_type = SnapshotType.FULL
     jailer = firecracker_release.jailer()
     fc_version = firecracker_release.base_name()[1:]
     logger.info("Firecracker version: %s", fc_version)
@@ -229,26 +227,21 @@ def test_older_snapshot_resume_latency(
     disks = [vm.rootfs_file]
     # Create a snapshot builder from a microvm.
     snapshot_builder = SnapshotBuilder(vm)
-    snapshot = snapshot_builder.create(
-        disks, rootfs.ssh_key(), snapshot_type, net_ifaces=[iface]
-    )
+    snapshot = snapshot_builder.create(disks, rootfs.ssh_key(), net_ifaces=[iface])
     vm.kill()
 
     st_core.name = "older_snapshot_resume_latency"
     st_core.iterations = SAMPLE_COUNT
     st_core.custom["guest_config"] = microvm_cfg.strip(".json")
     st_core.custom["io_engine"] = io_engine
-    st_core.custom["snapshot_type"] = (
-        "FULL" if snapshot_type == SnapshotType.FULL else "DIFF"
-    )
+    st_core.custom["snapshot_type"] = "FULL"
 
     prod = producer.LambdaProducer(
         func=snapshot_resume_producer,
         func_kwargs={
             "logger": logger,
             "vm_builder": MicrovmBuilder(bin_cloner_path),
             "snapshot": snapshot,
-            "snapshot_type": snapshot_type,
             "use_ramdisk": False,
         },
     )
@@ -363,13 +356,11 @@ def test_snapshot_create_latency(
 
 
 @pytest.mark.parametrize("guest_mem_mib", [256, 512])
-@pytest.mark.parametrize("snapshot_type", [SnapshotType.FULL, SnapshotType.DIFF])
 def test_snapshot_resume_latency(
     microvm_factory,
     guest_kernel,
     rootfs,
     guest_mem_mib,
-    snapshot_type,
     io_engine,
     st_core,
     bin_cloner_path,
@@ -384,7 +375,6 @@ def test_snapshot_resume_latency(
     TODO: Multiple microvm sizes must be tested in the async pipeline.
     """
     logger = logging.getLogger("snapshot_load")
-    diff_snapshots = snapshot_type == SnapshotType.DIFF
     vcpus = 2
     microvm_cfg = f"{vcpus}vcpu_{guest_mem_mib}mb.json"
     vm = microvm_factory.build(guest_kernel, rootfs, monitor_memory=False)
@@ -393,7 +383,6 @@ def test_snapshot_resume_latency(
         vcpu_count=vcpus,
         mem_size_mib=guest_mem_mib,
         use_initrd=True,
-        track_dirty_pages=diff_snapshots,
         rootfs_io_engine=io_engine,
     )
     iface = NetIfaceConfig()
@@ -403,30 +392,26 @@ def test_snapshot_resume_latency(
     exit_code, _, _ = vm.ssh.execute_command("ls")
     assert exit_code == 0
 
-    logger.info("Create %s", snapshot_type)
     # Create a snapshot builder from a microvm.
     snapshot_builder = SnapshotBuilder(vm)
     disks = [vm.rootfs_file]
     snapshot = snapshot_builder.create(
-        disks, rootfs.ssh_key(), snapshot_type, use_ramdisk=True, net_ifaces=[iface]
+        disks, rootfs.ssh_key(), use_ramdisk=True, net_ifaces=[iface]
     )
     vm.kill()
 
     st_core.name = "snapshot_resume_latency"
     st_core.iterations = SAMPLE_COUNT
     st_core.custom["guest_config"] = microvm_cfg.strip(".json")
     st_core.custom["io_engine"] = io_engine
-    st_core.custom["snapshot_type"] = (
-        "FULL" if snapshot_type == SnapshotType.FULL else "DIFF"
-    )
+    st_core.custom["snapshot_type"] = "FULL"
 
     prod = producer.LambdaProducer(
         func=snapshot_resume_producer,
         func_kwargs={
             "logger": logger,
             "vm_builder": MicrovmBuilder(bin_cloner_path),
             "snapshot": snapshot,
-            "snapshot_type": snapshot_type,
             "use_ramdisk": True,
         },
     )