F #6492: Index PCI passthrough devices with bus

If q35 machine type is detected the slot of the pci device is set to 0
and the bus to pci_id + 1.

Q35 models uses pcie-root-ports to attach PCI devices. Each PCI port is
selected by the bus parameter of the PCI address and it that does not accept a
slot number greater than 0.

Example:

A VM with 2 X710 VFs is defined OpenNebula as:

PCI=[
  ADDRESS="0000:44:0a:0",
  BUS="44",
  CLASS="0200",
  DEVICE="154c",
  DOMAIN="0000",
  FUNCTION="0",
  NUMA_NODE="0",
  PCI_ID="0",
  SHORT_ADDRESS="44:0a.0",
  SLOT="0a",
  VENDOR="8086",
  VM_ADDRESS="01:00.0",
  VM_BUS="0x01",
  VM_DOMAIN="0x0000",
  VM_FUNCTION="0",
  VM_SLOT="0000" ]

PCI=[
  ADDRESS="0000:44:0a:1",
  BUS="44",
  CLASS="0200",
  DEVICE="154c",
  DOMAIN="0000",
  FUNCTION="1",
  NUMA_NODE="0",
  PCI_ID="1",
  SHORT_ADDRESS="44:0a.1",
  SLOT="0a",
  VENDOR="8086",
  VM_ADDRESS="02:00.0",
  VM_BUS="0x02",
  VM_DOMAIN="0x0000",
  VM_FUNCTION="0",
  VM_SLOT="0000" ]

Each PCI VFs is attached to different pcie-root-port, selected with the
VM_BUS parameter:

00:02.0 PCI bridge: Red Hat, Inc. QEMU PCIe Root port
00:02.1 PCI bridge: Red Hat, Inc. QEMU PCIe Root port

The PCI topology is:

-[0000:00]-+-00.0  Intel Corporation 82G33/G31/P35/P31 Express DRAM Controller
           +-01.0  Cirrus Logic GD 5446
           +-02.0-[01]----00.0  Intel Corporation Ethernet Virtual Function 700 Series
           +-02.1-[02]----00.0  Intel Corporation Ethernet Virtual Function 700 Series
           +-02.2-[03-04]----00.0-[04]--
           +-02.3-[05]----00.0  Red Hat, Inc. Virtio network device
           +-02.4-[06]----00.0  Red Hat, Inc. Virtio SCSI
           +-02.5-[07]----00.0  Red Hat, Inc. QEMU XHCI Host Controller
           +-02.6-[08]----00.0  Red Hat, Inc. Virtio console
           +-02.7-[09]----00.0  Red Hat, Inc. Virtio memory balloon
           +-03.0-[0a]--
           +-03.1-[0b]--
           +-03.2-[0c]--
           +-03.3-[0d]--
           +-03.4-[0e]--
           +-03.5-[0f]--
           +-03.6-[10]--
           +-03.7-[11]--
           +-1f.0  Intel Corporation 82801IB (ICH9) LPC Interface Controller
           +-1f.2  Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA Controller [AHCI mode]
           \-1f.3  Intel Corporation 82801I (ICH9 Family) SMBus Controller

include/HostSharePCI.h

@@ -131,6 +131,11 @@ class HostSharePCI : public Template
      *    - VM_FUNCTION: 0
      *    - VM_ADDRESS: BUS:SLOT.0
      *
+     *  When the machine type is q35, SLOT needs to be 0, and devices are attached
+     *  to a different bus. Use param slot_index to select this behavior
+     *    - VM_SLOT: 0
+     *    - VM_BUS: PCI_ID + 1
+     *
      *  Cleans internal attributes:
      *    - NUMA_NODE
      *    - UUID
@@ -139,10 +144,11 @@ class HostSharePCI : public Template
      *  @param pci_device to set the address in
      *  @param default_bus if not set in PCI attribute (PCI_PASSTHROUGH_BUS
      *   in oned.conf)
+     *  @param bus_index when true devices uses slot = 0 and bus = pci_id + 1
      *  @return -1 if wrong bus 0 on success
      */
     static int set_pci_address(VectorAttribute * pci_device, const std::string& dbus,
-            bool clean);
+            bool bus_index, bool clean);
 
 private:
     /**

include/VirtualMachine.h

@@ -345,7 +345,7 @@ class VirtualMachine : public PoolObjectSQL
     {
         VectorAttribute * os = obj_template->get("OS");
 
-        if ( os == 0 )
+        if ( os == nullptr )
         {
             return;
         }
@@ -362,14 +362,28 @@ class VirtualMachine : public PoolObjectSQL
     {
         VectorAttribute * os = obj_template->get("OS");
 
-        if ( os == 0 )
+        if ( os == nullptr )
         {
             return;
         }
 
         os->replace("INITRD", initrd);
     };
 
+    bool test_machine_type(const std::string& machine_type) const
+    {
+        VectorAttribute * os = obj_template->get("OS");
+
+        if ( os == nullptr )
+        {
+            return false;
+        }
+
+        const std::string machine = os->vector_value("MACHINE");
+
+        return machine.find(machine_type) != std::string::npos;
+    }
+
     // ------------------------------------------------------------------------
     // Access to VM locations
     // ------------------------------------------------------------------------

src/host/HostSharePCI.cc

@@ -513,7 +513,7 @@ int HostSharePCI::get_pci_value(const char * name,
 /* ------------------------------------------------------------------------*/
 
 int HostSharePCI::set_pci_address(VectorAttribute * pci_device,
-        const string& dbus, bool clean)
+        const string& dbus, bool bus_index, bool clean)
 {
     string        bus;
     ostringstream oss;
@@ -553,21 +553,28 @@ int HostSharePCI::set_pci_address(VectorAttribute * pci_device,
         return -1;
     }
 
-    oss << showbase << internal << setfill('0') << hex << setw(4) << ibus;
-
-    pci_device->replace("VM_BUS", oss.str());
-
     // --------------------- SLOT (PCI_ID +1) -----------------------
-    oss.str("");
-
     pci_device->vector_value("PCI_ID", slot);
 
     slot = slot + 1;
 
+    if ( bus_index )
+    {
+        ibus = slot;
+        slot = 0;
+    }
+
+    // Set PCI attributes
     oss << showbase << internal << setfill('0') << hex << setw(4) << slot;
 
     pci_device->replace("VM_SLOT", oss.str());
 
+    oss.str("");
+
+    oss << showbase << internal << setfill('0') << hex << setw(4) << ibus;
+
+    pci_device->replace("VM_BUS", oss.str());
+
     // ------------------- ADDRESS (BUS:SLOT.0) ---------------------
     oss.str("");
 

src/vm/VirtualMachine.cc

@@ -3678,7 +3678,8 @@ int VirtualMachine::set_up_attach_nic(VirtualMachineTemplate * tmpl, string& err
 
         nd.get_configuration_attribute("PCI_PASSTHROUGH_BUS", bus);
 
-        if ( HostSharePCI::set_pci_address(_new_nic.get(), bus, false) != 0 )
+        if ( HostSharePCI::set_pci_address(_new_nic.get(), bus,
+                    test_machine_type("q35"), false) != 0 )
         {
             err = "Wrong BUS in PCI attribute";
             return -1;
@@ -3828,7 +3829,8 @@ int VirtualMachine::attach_pci(VectorAttribute * vpci, string& err)
 
     nd.get_configuration_attribute("PCI_PASSTHROUGH_BUS", bus);
 
-    if ( HostSharePCI::set_pci_address(_new_pci.get(), bus, false) != 0 )
+    if ( HostSharePCI::set_pci_address(_new_pci.get(), bus,
+                test_machine_type("q35"), false) != 0 )
     {
         err = "Wrong BUS in PCI attribute";
         return -1;

src/vm/VirtualMachineParser.cc

@@ -381,7 +381,8 @@ int VirtualMachine::parse_pci(string& error_str, Template * tmpl)
             return -1;
         }
 
-        if ( HostSharePCI::set_pci_address(attr, default_bus, true) != 0 )
+        if ( HostSharePCI::set_pci_address(attr, default_bus,
+                    test_machine_type("q35"), true) != 0 )
         {
             error_str = "Wrong BUS in PCI attribute";
             return -1;