Add HOWTO for SRIOV use case

This patch includes document which describe SRIOV usage.

Implements: blueprint kuryr-kubernetes-sriov-support
Change-Id: Ifa663a98ab402753f227b220fe9d817f182514e3
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>

doc/source/installation/index.rst

@@ -42,3 +42,4 @@ This section describes how you can install and configure kuryr-kubernetes
     containerized
     ocp_route
     multi_vif_with_npwg_spec
+    sriov

doc/source/installation/sriov.rst

@@ -0,0 +1,80 @@
+How to configure SR-IOV ports
+=============================
+
+Current approach of SR-IOV relies on sriov-device-plugin [2]_. While
+creating pods with SR-IOV, sriov-device-plugin should be turned on
+on all nodes. To use a SR-IOV port on a baremetal installation the 3
+following steps should be done:
+
+1. Create OpenStack network and subnet for SR-IOV.
+Following steps should be done with admin rights.
+
+.. code-block:: bash
+
+  neutron net-create vlan-sriov-net --shared --provider:physical_network physnet10_4 --provider:network_type vlan --provider:segmentation_id 3501
+  neutron subnet-create vlan-sriov-net 203.0.114.0/24 --name vlan-sriov-subnet --gateway 203.0.114.1
+
+Subnet id <UUID of vlan-sriov-net> will be used later in NetworkAttachmentDefinition.
+
+2. Add sriov section into kuryr.conf.
+
+.. code-block:: ini
+
+  [sriov]
+  physical_device_mappings = physnet1:ens4f0
+  default_physnet_subnets = physnet1:<UUID of vlan-sriov-net>
+
+This mapping is required for ability to find appropriate PF/VF functions at binding phase.
+physnet1 is just an identifier for subnet <UUID of vlan-sriov-net>.
+Such kind of transition is necessary to support many-to-many relation.
+
+3. Prepare NetworkAttachmentDefinition object.
+Apply NetworkAttachmentDefinition with "sriov" driverType inside,
+as described in [1]_.
+
+.. code-block:: yaml
+
+    apiVersion: "k8s.cni.cncf.io/v1"
+    kind: NetworkAttachmentDefinition
+    metadata:
+        name: "sriov-net1"
+        annotations:
+            openstack.org/kuryr-config: '{
+            "subnetId": "UUID of vlan-sriov-net",
+            "driverType": "sriov"
+            }'
+
+
+Then add k8s.v1.cni.cncf.io/networks and request/limits for SR-IOV
+into the pod's yaml.
+
+.. code-block:: yaml
+
+    kind: Pod
+    metadata:
+      name: my-pod
+      namespace: my-namespace
+      annotations:
+        k8s.v1.cni.cncf.io/networks: sriov-net1,sriov-net2
+    spec:
+      containers:
+      - name: containerName
+        image: containerImage
+        imagePullPolicy: IfNotPresent
+        command: ["tail", "-f", "/dev/null"]
+        resources:
+          requests:
+            intel.com/sriov: '2'
+          limits:
+            intel.com/sriov: '2'
+
+
+In the above example two SR-IOV devices will be attached to pod. First one is described
+in sriov-net1 NetworkAttachmentDefinition, second one in sriov-net2. They may have
+different subnetId.
+
+Reference
+---------
+
+.. [1] https://docs.openstack.org/kuryr-kubernetes/latest/specs/rocky/npwg_spec_support.html
+.. [2] https://docs.google.com/document/d/1Ewe9Of84GkP0b2Q2PC0y9RVZNkN2WeVEagX9m99Nrzc