Add 'IB VF GUID Configuration' design doc

Signed-off-by: amaslennikov <[email protected]>

doc/design/ib-vf-configuration.md

@@ -0,0 +1,72 @@
+---
+title: IB VF GUID Configuration
+authors:
+  - almaslennikov
+reviewers:
+  - SchSeba
+  - adrianchiris
+creation-date: 11-03-2024
+last-updated: 11-03-2024
+---
+
+# IB VF GUID Configuration
+
+## Summary
+Allow SR-IOV Network Operator to use a static configuration file from the host filesystem to assign GUIDs to IB VFs
+
+## Motivation
+We have customers using the SR-IOV operator to create IB VFs, and they need a way to automate GUID assignment,
+so that IB VFs are automatically bound to the required PKeys and no additional manual configuration is needed.
+In this use case, the GUID configuration is static and known in advance.
+Now the GUIDs are assigned by the sriov-network-config-daemon randomly.
+
+### Use Cases
+
+### Goals
+
+* IB GUID configuration can be read from a static json file on the host
+* IB GUID configuration is static and created in advance
+* Static config file is available at the same path on every host
+
+### Non-Goals
+
+* Dynamic GUID allocation is out of scope of this proposal
+
+## Proposal
+
+Mount a configuration file as a part of `/host` hostPath in the config daemon and read it to retrieve the GUID configuration.
+
+### Workflow Description
+
+In the `pkg/host/internal/sriov/sriov.go:configSriovVFDevices` read from the static IB config file
+and assign the GUIDs according to the configuration. Each PF is described by either PCI address
+or the PF GUID and has either a list or a range of VF GUIDs.
+
+### Implementation Details/Notes/Constraints
+
+There can be less VFs created than GUIDs. To persist the dynamic nature of the SR-IOV Network operator,
+it’s proposed not to return an error in this case but assign as many GUIDs as possible.
+To ensure that nothing breaks when users add/remove VFs, the GUID distribution order should always be the same for each individual host.
+
+Example of the config file:
+
+```json
+[
+  {
+    "pci_adress": "<pci_address_1>",
+    "guids": [
+      "02:00:00:00:00:00:00:00",
+      "02:00:00:00:00:00:00:01"
+    ]
+  },
+  {
+    "pf_guid": "<pf_guid_2>",
+    "rangeStart": "02:00:00:00:00:aa:00:02",
+    "rangeEnd": "02:00:00:00:00:aa:00:0a"
+  }
+]
+```
+
+### Test Plan
+
+* Unit tests will be implemented for new logic.