Allow up to 275 adapters for qemu

See #889 for more details

gns3server/compute/qemu/qemu_vm.py

@@ -23,12 +23,13 @@ order to run a QEMU VM.
 import sys
 import os
 import re
+import math
 import shutil
-import subprocess
 import shlex
 import asyncio
 import socket
 import gns3server
+import subprocess
 
 from gns3server.utils import parse_version
 from .qemu_error import QemuError
@@ -1446,6 +1447,14 @@ class QemuVM(BaseNode):
                 # this is a patched Qemu if version is below 1.1.0
                 patched_qemu = True
 
+        # Each 32 PCI device we need to add a PCI bridge with max 9 bridges
+        pci_devices = 4 + len(self._ethernet_adapters)  # 4 PCI devices are use by default by qemu
+        bridge_id = 0
+        for bridge_id in range(1, math.floor(pci_devices / 32) + 1):
+            network_options.extend(["-device", "i82801b11-bridge,id=dmi_pci_bridge{bridge_id}".format(bridge_id=bridge_id)])
+            network_options.extend(["-device", "pci-bridge,id=pci-bridge{bridge_id},bus=dmi_pci_bridge{bridge_id},chassis_nr=0x1,addr=0x{bridge_id},shpc=off".format(bridge_id=bridge_id)])
+
+        pci_device_id = 4 + bridge_id  # Bridge consume PCI ports
         for adapter_number, adapter in enumerate(self._ethernet_adapters):
             mac = int_to_macaddress(macaddress_to_int(self._mac_address) + adapter_number)
 
@@ -1483,8 +1492,14 @@ class QemuVM(BaseNode):
 
             else:
                 # newer QEMU networking syntax
+                device_string = "{},mac={}".format(self._adapter_type, mac)
+                bridge_id = math.floor(pci_device_id / 32)
+                if bridge_id > 0:
+                    addr = pci_device_id % 32
+                    device_string = "{},bus=pci-bridge{bridge_id},addr=0x{addr:02x}".format(device_string, bridge_id=bridge_id, addr=addr)
+                pci_device_id += 1
                 if nio:
-                    network_options.extend(["-device", "{},mac={},netdev=gns3-{}".format(self._adapter_type, mac, adapter_number)])
+                    network_options.extend(["-device", "{},netdev=gns3-{}".format(device_string, adapter_number)])
                     if isinstance(nio, NIOUDP):
                         network_options.extend(["-netdev", "socket,id=gns3-{},udp={}:{},localaddr={}:{}".format(adapter_number,
                                                                                                                 nio.rhost,
@@ -1494,7 +1509,7 @@ class QemuVM(BaseNode):
                     elif isinstance(nio, NIOTAP):
                         network_options.extend(["-netdev", "tap,id=gns3-{},ifname={},script=no,downscript=no".format(adapter_number, nio.tap_device)])
                 else:
-                    network_options.extend(["-device", "{},mac={}".format(self._adapter_type, mac)])
+                    network_options.extend(["-device", device_string])
 
         return network_options
 

gns3server/schemas/qemu.py

@@ -147,7 +147,7 @@ QEMU_CREATE_SCHEMA = {
             "description": "Number of adapters",
             "type": ["integer", "null"],
             "minimum": 0,
-            "maximum": 32,
+            "maximum": 275,
         },
         "adapter_type": {
             "description": "QEMU adapter type",
@@ -332,7 +332,7 @@ QEMU_UPDATE_SCHEMA = {
             "description": "Number of adapters",
             "type": ["integer", "null"],
             "minimum": 0,
-            "maximum": 32,
+            "maximum": 275,
         },
         "adapter_type": {
             "description": "QEMU adapter type",
@@ -520,7 +520,7 @@ QEMU_OBJECT_SCHEMA = {
             "description": "Number of adapters",
             "type": "integer",
             "minimum": 0,
-            "maximum": 32,
+            "maximum": 275,
         },
         "adapter_type": {
             "description": "QEMU adapter type",

tests/compute/qemu/test_qemu_vm.py

@@ -588,7 +588,7 @@ def test_build_command_two_adapters_mac_address(vm, loop, fake_qemu_binary, port
     vm.adapters = 2
     vm.mac_address = "00:00:ab:0e:0f:09"
     mac_0 = vm._mac_address
-    mac_1 = int_to_macaddress(macaddress_to_int(vm._mac_address))
+    mac_1 = int_to_macaddress(macaddress_to_int(vm._mac_address) + 1)
     assert mac_0[:8] == "00:00:ab"
     with asyncio_patch("asyncio.create_subprocess_exec", return_value=MagicMock()) as process:
         cmd = loop.run_until_complete(asyncio.async(vm._build_command()))
@@ -605,6 +605,37 @@ def test_build_command_two_adapters_mac_address(vm, loop, fake_qemu_binary, port
         assert "e1000,mac={}".format(mac_1) in cmd
 
 
+def test_build_command_large_number_of_adapters(vm, loop, fake_qemu_binary, port_manager):
+    """
+    When we have more than 28 interface we need to add a pci bridge for
+    additionnal interfaces
+    """
+
+    vm.adapters = 100
+    vm.mac_address = "00:00:ab:0e:0f:09"
+    mac_0 = vm._mac_address
+    mac_1 = int_to_macaddress(macaddress_to_int(vm._mac_address) + 1)
+    assert mac_0[:8] == "00:00:ab"
+    with asyncio_patch("asyncio.create_subprocess_exec", return_value=MagicMock()) as process:
+        cmd = loop.run_until_complete(asyncio.async(vm._build_command()))
+
+    assert "e1000,mac={}".format(mac_0) in cmd
+    assert "e1000,mac={}".format(mac_1) in cmd
+    assert "pci-bridge,id=pci-bridge0,bus=dmi_pci_bridge0,chassis_nr=0x1,addr=0x0,shpc=off" not in cmd
+    assert "pci-bridge,id=pci-bridge1,bus=dmi_pci_bridge1,chassis_nr=0x1,addr=0x1,shpc=off" in cmd
+    assert "pci-bridge,id=pci-bridge2,bus=dmi_pci_bridge2,chassis_nr=0x1,addr=0x2,shpc=off" in cmd
+    assert "i82801b11-bridge,id=dmi_pci_bridge1" in cmd
+
+    print(cmd)
+
+    mac_29 = int_to_macaddress(macaddress_to_int(vm._mac_address) + 29)
+    assert "e1000,mac={},bus=pci-bridge1,addr=0x04".format(mac_29) in cmd
+    mac_30 = int_to_macaddress(macaddress_to_int(vm._mac_address) + 30)
+    assert "e1000,mac={},bus=pci-bridge1,addr=0x05".format(mac_30) in cmd
+    mac_74 = int_to_macaddress(macaddress_to_int(vm._mac_address) + 74)
+    assert "e1000,mac={},bus=pci-bridge2,addr=0x11".format(mac_74) in cmd
+
+
 # Windows accept this kind of mistake
 @pytest.mark.skipif(sys.platform.startswith("win"), reason="Not supported on Windows")
 def test_build_command_with_invalid_options(vm, loop, fake_qemu_binary):