acpi: fix test_net_change_mac_address test

This test is looking for the MMIO address range of virtio-net devices
and then uses it to update the MAC address of the devices by writing
under `/dev/mem`.

The test was using the kernel command line to find the address range.
With ACPI we don't pass this range via kernel command line any more, so
adapt the test to look for this information under /proc/iomem.

Signed-off-by: Babis Chalios <[email protected]>

Author: bchalios

tests/integration_tests/functional/test_net_config_space.py

@@ -21,6 +21,7 @@ def test_net_change_mac_address(uvm_plain_any, change_net_config_space_bin):
     """
 
     test_microvm = uvm_plain_any
+    test_microvm.help.enable_console()
     test_microvm.spawn()
     test_microvm.basic_config(boot_args="ipv6.disable=1")
 
@@ -196,37 +197,110 @@ def _change_guest_if_mac(ssh_connection, guest_if_mac, guest_if_name):
     ssh_connection.run(cmd)
 
 
+def _find_iomem_range(ssh_connection, dev_name):
+    # `/proc/iomem` includes information of the system's MMIO registered
+    # slots. It looks like this:
+    #
+    # ```
+    # ~ cat /proc/iomem
+    # 00000000-00000fff : Reserved
+    # 00001000-0007ffff : System RAM
+    # 00080000-0009ffff : Reserved
+    # 000f0000-000fffff : System ROM
+    # 00100000-0fffffff : System RAM
+    #   01000000-018031d0 : Kernel code
+    #   018031d1-01c863bf : Kernel data
+    #   01df8000-0209ffff : Kernel bss
+    # d0000000-d0000fff : LNRO0005:00
+    #   d0000000-d0000fff : LNRO0005:00
+    # d0001000-d0001fff : LNRO0005:01
+    #   d0001000-d0001fff : LNRO0005:01
+    # ```
+    #
+    # So, to find the address range of a device we just `cat`
+    # its contents and grep for the VirtIO device name, which
+    # with ACPI is "LNRO0005:XY".
+    cmd = f"cat /proc/iomem | grep -m 1 {dev_name}"
+    rc, stdout, stderr = ssh_connection.run(cmd)
+    assert rc == 0, stderr
+
+    # Take range in the form 'start-end' from line. The line looks like this:
+    # d00002000-d0002fff : LNRO0005:02
+    mem_range = stdout.strip().split(" ")[0]
+
+    # Parse range into (start, end) integers
+    tokens = mem_range.split("-")
+    return (int(tokens[0], 16), int(tokens[1], 16))
+
+
+def _get_net_mem_addr_base_x86_acpi(ssh_connection, if_name):
+    """Check for net device memory start address via ACPI info"""
+    # On x86 we define VirtIO devices through ACPI AML bytecode. VirtIO devices
+    # are identified as "LNRO0005" and appear under /sys/devices/platform
+    sys_virtio_mmio_cmdline = "/sys/devices/platform/"
+    cmd = "ls {}"
+    exit_code, stdout, stderr = ssh_connection.run(cmd.format(sys_virtio_mmio_cmdline))
+    assert exit_code == 0, stderr
+    virtio_devs = list(filter(lambda x: "LNRO0005" in x, stdout.strip().split()))
+
+    # For virtio-net LNRO0005 devices, we should have a path like:
+    # /sys/devices/platform/LNRO0005::XY/virtioXY/net which is a directory
+    # that includes a subdirectory `ethZ` which represents the network device
+    # that corresponds to the virtio-net device.
+    cmd = "ls {}/{}/virtio{}/net"
+    for idx, dev in enumerate(virtio_devs):
+        _, guest_if_name, _ = ssh_connection.run(
+            cmd.format(sys_virtio_mmio_cmdline, dev, idx)
+        )
+        if guest_if_name.strip() == if_name:
+            return _find_iomem_range(ssh_connection, dev)[0]
+
+    return None
+
+
+def _get_net_mem_addr_base_x86_cmdline(ssh_connection, if_name):
+    """Check for net device memory start address via command line arguments"""
+    sys_virtio_mmio_cmdline = "/sys/devices/virtio-mmio-cmdline/"
+    cmd = "ls {} | grep virtio-mmio. | sed 's/virtio-mmio.//'"
+    exit_code, stdout, stderr = ssh_connection.run(cmd.format(sys_virtio_mmio_cmdline))
+    assert exit_code == 0, stderr
+    virtio_devs_idx = stdout.strip().split()
+
+    cmd = "cat /proc/cmdline"
+    exit_code, cmd_line, stderr = ssh_connection.run(cmd)
+    assert exit_code == 0, stderr
+    pattern_dev = re.compile("(virtio_mmio.device=4K@0x[0-9a-f]+:[0-9]+)+")
+    pattern_addr = re.compile("virtio_mmio.device=4K@(0x[0-9a-f]+):[0-9]+")
+    devs_addr = []
+    for dev in re.findall(pattern_dev, cmd_line):
+        matched_addr = pattern_addr.search(dev)
+        # The 1st group which matches this pattern
+        # is the device start address. `0` group is
+        # full match
+        addr = matched_addr.group(1)
+        devs_addr.append(addr)
+
+    cmd = "ls {}/virtio-mmio.{}/virtio{}/net"
+    for idx in virtio_devs_idx:
+        _, guest_if_name, _ = ssh_connection.run(
+            cmd.format(sys_virtio_mmio_cmdline, idx, idx)
+        )
+        if guest_if_name.strip() == if_name:
+            return devs_addr[int(idx)]
+
+    return None
+
+
 def _get_net_mem_addr_base(ssh_connection, if_name):
     """Get the net device memory start address."""
     if platform.machine() == "x86_64":
-        sys_virtio_mmio_cmdline = "/sys/devices/virtio-mmio-cmdline/"
-        cmd = "ls {} | grep virtio-mmio. | sed 's/virtio-mmio.//'"
-        exit_code, stdout, _ = ssh_connection.run(cmd.format(sys_virtio_mmio_cmdline))
-        assert exit_code == 0
-        virtio_devs_idx = stdout.split()
-
-        cmd = "cat /proc/cmdline"
-        exit_code, cmd_line, _ = ssh_connection.run(cmd)
-        assert exit_code == 0
-        pattern_dev = re.compile("(virtio_mmio.device=4K@0x[0-9a-f]+:[0-9]+)+")
-        pattern_addr = re.compile("virtio_mmio.device=4K@(0x[0-9a-f]+):[0-9]+")
-        devs_addr = []
-        for dev in re.findall(pattern_dev, cmd_line):
-            matched_addr = pattern_addr.search(dev)
-            # The 1st group which matches this pattern
-            # is the device start address. `0` group is
-            # full match.
-            addr = matched_addr.group(1)
-            devs_addr.append(addr)
-
-        cmd = "ls {}/virtio-mmio.{}/virtio{}/net"
-        for idx in virtio_devs_idx:
-            _, guest_if_name, _ = ssh_connection.run(
-                cmd.format(sys_virtio_mmio_cmdline, idx, idx)
-            )
-            if guest_if_name.strip() == if_name:
-                return devs_addr[int(idx)]
-    elif platform.machine() == "aarch64":
+        acpi_info = _get_net_mem_addr_base_x86_acpi(ssh_connection, if_name)
+        if acpi_info is not None:
+            return acpi_info
+
+        return _get_net_mem_addr_base_x86_cmdline(ssh_connection, if_name)
+
+    if platform.machine() == "aarch64":
         sys_virtio_mmio_cmdline = "/sys/devices/platform"
         cmd = "ls {} | grep .virtio_mmio".format(sys_virtio_mmio_cmdline)
         rc, stdout, _ = ssh_connection.run(cmd)