Merge pull request #346 from xcp-ng/abo/test-xen-platform-pci-bar-uc-hvmloader-config

hvmloader: check the cache mode of grant-tables

Author: stormi

tests/xen/test_hvmloader_grant-table.py

@@ -0,0 +1,111 @@
+import pytest
+
+import logging
+import os
+import re
+
+# AMD grant-tables cachability parameter tests.
+# This file contains 2 tests to check if the hvmloader PCI bar fix is applied or not
+# by xenopsd. Tests check the xenopsd configuration and then compare with what is
+# seen inside the VM. If the grant-tables are cached, it means the fix is applied.
+#
+# Requirements:
+# - At least one XCP-ng host (>=8.3)
+# - A Linux VM
+
+def xen_platform_pci_id(vm):
+    pci_path = vm.ssh(['ls', '-d', '/sys/bus/pci/drivers/xen-platform-pci/0000:*'])
+    if pci_path is not None:
+        return os.path.basename(pci_path)
+    pytest.fail("'xen-platform-pci' PCI not found")
+
+def xen_platform_pci_io_address(vm, xen_platform_pci_id):
+    # Find 'xen-platform-pci' IO mem resource address.
+    pci_resource_output = vm.ssh(
+        ['cat', '/sys/devices/pci0000:00/{}/resource'.format(xen_platform_pci_id)])
+
+    # First line is taken by PCI IO port, select 2nd line for IO mem.
+    address_line = pci_resource_output.splitlines()[1].split()
+    start_address = int(address_line[0], 16)
+    return start_address
+
+def mtrr_ranges(vm):
+    # List and check MTRR ranges.
+    return vm.ssh(['cat', '/proc/mtrr']).splitlines()
+
+def are_grant_tables_inside_uncachable_mapping(mtrr_ranges_list, pci_io_address):
+    regexp = r'reg(.*): base=(0x[0-9a-f]*) \(.*\), size=(.*)MB, count=(.*): (.*)'
+
+    for mtrr_range in mtrr_ranges_list:
+        m = re.match(regexp, mtrr_range)
+        base_address = int(m.group(2), 16)
+        size = int(m.group(3)) * 1024 * 1024
+        cache_mode = m.group(5)
+
+        # Check that PCI io memory address is inside MTRR configuration.
+        if pci_io_address >= base_address and \
+                pci_io_address < base_address + size and cache_mode == "uncachable":
+            return True
+    return False
+
+@pytest.mark.usefixtures("host_at_least_8_3")
+@pytest.mark.small_vm
+@pytest.mark.usefixtures("running_unix_vm")
+class TestXenPlatformPciBarUc:
+    @pytest.fixture
+    def host_with_xen_platform_pci_bar_uc_set_to_true(self, host):
+        host.ssh(['echo', 'xen-platform-pci-bar-uc=true', '>', '/etc/xenopsd.conf.d/hvmloader.conf'])
+        host.restart_toolstack(verify=True)
+        yield host
+        host.ssh(['rm', '/etc/xenopsd.conf.d/hvmloader.conf'])
+        host.restart_toolstack(verify=True)
+
+    @pytest.fixture
+    def vm_with_xen_platform_pci_bar_uc_set_to_true(self, host_with_xen_platform_pci_bar_uc_set_to_true, unix_vm):
+        if unix_vm.is_running():
+            unix_vm.shutdown(verify=True)
+        unix_vm.start(on=host_with_xen_platform_pci_bar_uc_set_to_true.uuid)
+        unix_vm.wait_for_vm_running_and_ssh_up()
+        return unix_vm
+
+    @pytest.fixture
+    def host_with_xen_platform_pci_bar_uc_set_to_false(self, host):
+        host.ssh(['echo', 'xen-platform-pci-bar-uc=false', '>', '/etc/xenopsd.conf.d/hvmloader.conf'])
+        host.restart_toolstack(verify=True)
+        yield host
+        host.ssh(['rm', '/etc/xenopsd.conf.d/hvmloader.conf'])
+        host.restart_toolstack(verify=True)
+
+    @pytest.fixture
+    def vm_with_xen_platform_pci_bar_uc_set_to_false(self, host_with_xen_platform_pci_bar_uc_set_to_false, unix_vm):
+        if unix_vm.is_running():
+            unix_vm.shutdown(verify=True)
+        unix_vm.start(on=host_with_xen_platform_pci_bar_uc_set_to_false.uuid)
+        unix_vm.wait_for_vm_running_and_ssh_up()
+        return unix_vm
+
+    # Check the default behavior when 'xen_platform_pci_bar_uc' is true
+    def test_xen_platform_pci_bar_uc_true(self, host_with_xen_platform_pci_bar_uc_set_to_true,
+                                          vm_with_xen_platform_pci_bar_uc_set_to_true):
+        pci_id = xen_platform_pci_id(vm_with_xen_platform_pci_bar_uc_set_to_true)
+        pci_io_address = xen_platform_pci_io_address(vm_with_xen_platform_pci_bar_uc_set_to_true, pci_id)
+        logging.info(f"'xen-platform-pci' PCI IO mem address is 0x{pci_io_address:016X}")
+        mtrr_ranges_list = mtrr_ranges(vm_with_xen_platform_pci_bar_uc_set_to_true)
+
+        if are_grant_tables_inside_uncachable_mapping(mtrr_ranges_list, pci_io_address):
+            logging.info("Grant-tables are inside the 'uncachable' mapping as expected.")
+        else:
+            pytest.fail("Grant_tables are outside of the uncachable MTRR ranges but 'xen-platform-pci-bar-uc' is true")
+
+    # Check the alternate behavior when 'xen_platform_pci_bar_uc' is explicitely set to false
+    def test_xen_platform_pci_bar_uc_false(self, host_with_xen_platform_pci_bar_uc_set_to_false,
+                                           vm_with_xen_platform_pci_bar_uc_set_to_false):
+        pci_id = xen_platform_pci_id(vm_with_xen_platform_pci_bar_uc_set_to_false)
+        pci_io_address = xen_platform_pci_io_address(vm_with_xen_platform_pci_bar_uc_set_to_false, pci_id)
+        logging.info(f"'xen-platform-pci' PCI IO mem address is 0x{pci_io_address:016X}")
+        mtrr_ranges_list = mtrr_ranges(vm_with_xen_platform_pci_bar_uc_set_to_false)
+
+        if are_grant_tables_inside_uncachable_mapping(mtrr_ranges_list, pci_io_address):
+            pytest.fail("Grant-tables are inside of the uncachable MTRR ranges but 'xen-platform-pci-bar-uc' is false.")
+        else:
+            logging.info("Grant-tables are outside of the uncachable MTRR ranges as expected.")