Add new role parameter NovaLibvirtNumPciePorts

Add role parameter NovaLibvirtNumPciePorts which sets `libvirt/num_pcie_ports`
to specify the number of PCIe ports an instance will get.
Libvirt allows a custom number of PCIe ports (pcie-root-port controllers) a
target instance will get. Some will be used by default, rest will be available
for hotplug use. When using the 'q35' machine type, by default, it allows only
a *single* PCIe device to be hotplugged.  And Nova currently sets
'num_pcie_ports' to "0" (which means, it defaults to libvirt's "1"), which is
not sufficient for hotplug use.

Default for NovaLibvirtNumPciePorts is 16.

Change-Id: Ida27b52a091640545aecc982fc1a509fb5107db8
Closes-Bug: #1831701
Depends-On: I16732c9d6013112381cfad999540dd41ec3d7ba3

deployment/nova/nova-compute-container-puppet.yaml

@@ -283,6 +283,17 @@ parameters:
     type: string
     default: 'regionOne'
     description: Keystone region for endpoint
+  NovaLibvirtNumPciePorts:
+    description: >
+      Set `num_pcie_ports` to specify the number of PCIe ports an
+      instance will get.
+      Libvirt allows a custom number of PCIe ports (pcie-root-port controllers) a
+      target instance will get. Some will be used by default, rest will be available
+      for hotplug use.
+    default: 16
+    type: number
+    tags:
+      - role_specific
 
 resources:
 
@@ -344,6 +355,7 @@ resources:
               nfs_share: NovaNfsShare
               nfs_options: NovaNfsOptions
               nfs_vers: NovaNfsVersion
+              nova::compute::libvirt::num_pcie_ports: NovaLibvirtNumPciePorts
             - values: {get_param: [RoleParameters]}
           - values:
               NovaVcpuPinSet: {get_param: NovaVcpuPinSet}
@@ -363,6 +375,7 @@ resources:
               NovaNfsShare: {get_param: NovaNfsShare}
               NovaNfsOptions: {get_param: NovaNfsOptions}
               NovaNfsVersion: {get_param: NovaNfsVersion}
+              NovaLibvirtNumPciePorts: {get_param: NovaLibvirtNumPciePorts}
 
 conditions:
   enable_instance_ha: {equals: [{get_param: EnableInstanceHA}, true]}

releasenotes/notes/nova_libvirt_num_pcie_ports-f904bf0fb9a7b19e.yaml

@@ -0,0 +1,12 @@
+---
+features:
+  - |
+    Add role parameter NovaLibvirtNumPciePorts which sets `libvirt/num_pcie_ports`
+    to specify the number of PCIe ports an instance will get.
+    Libvirt allows a custom number of PCIe ports (pcie-root-port controllers) a
+    target instance will get. Some will be used by default, rest will be available
+    for hotplug use. When using the 'q35' machine type, by default, it allows only
+    a *single* PCIe device to be hotplugged. And Nova currently sets
+    'num_pcie_ports' to "0" (which means, it defaults to libvirt's "1"), which is
+    not sufficient for hotplug use.
+    Default for NovaLibvirtNumPciePorts is 16.