wip: run perf tests with swiotlb enabled

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

Author: roypat

tests/framework/microvm.py

@@ -729,6 +729,7 @@ def basic_config(
         rootfs_io_engine=None,
         cpu_template: Optional[str] = None,
         enable_entropy_device=False,
+        swiotlb_size: int = None,
     ):
         """Shortcut for quickly configuring a microVM.
 
@@ -747,10 +748,15 @@ def basic_config(
 
         Reference: file:../../src/vmm/src/vmm_config/boot_source.rs::DEFAULT_KERNEL_CMDLINE
         """
+        mem_config = {}
+        if swiotlb_size is not None:
+            mem_config["initial_swiotlb_size"] = swiotlb_size
+
         self.api.machine_config.put(
             vcpu_count=vcpu_count,
             smt=smt,
             mem_size_mib=mem_size_mib,
+            mem_config=mem_config,
             track_dirty_pages=track_dirty_pages,
             huge_pages=huge_pages,
         )

tests/integration_tests/performance/test_block_ab.py

@@ -4,6 +4,7 @@
 
 import concurrent
 import os
+import platform
 import shutil
 from pathlib import Path
 
@@ -140,22 +141,33 @@ def process_fio_logs(vm, fio_mode, logs_dir, metrics):
 @pytest.mark.parametrize("vcpus", [1, 2], ids=["1vcpu", "2vcpu"])
 @pytest.mark.parametrize("fio_mode", ["randread", "randwrite"])
 @pytest.mark.parametrize("fio_block_size", [4096], ids=["bs4096"])
+@pytest.mark.parametrize("swiotlb_size", [0, 64])
 def test_block_performance(
     microvm_factory,
     guest_kernel_acpi,
     rootfs,
     vcpus,
     fio_mode,
     fio_block_size,
+    swiotlb_size,
     io_engine,
     metrics,
 ):
     """
     Execute block device emulation benchmarking scenarios.
     """
+    if (
+        swiotlb_size
+        and "6.1" not in guest_kernel_acpi
+        or platform.machine() != "aarch64"
+    ):
+        pytest.skip("swiotlb only supported on aarch64/6.1")
+
     vm = microvm_factory.build(guest_kernel_acpi, rootfs, monitor_memory=False)
     vm.spawn(log_level="Info", emit_metrics=True)
-    vm.basic_config(vcpu_count=vcpus, mem_size_mib=GUEST_MEM_MIB)
+    vm.basic_config(
+        vcpu_count=vcpus, mem_size_mib=GUEST_MEM_MIB, swiotlb_size=swiotlb_size
+    )
     vm.add_net_iface()
     # Add a secondary block device for benchmark tests.
     fs = drive_tools.FilesystemFile(