Add usage examples for exposed devices in README

* Add usage examples for exposed devices in README
Added examples for requesting Intel TDX, AMD SEV, and vTPM devices in Kubernetes pods.

* Refactor README for clarity and completeness
Updated README to improve formatting

Author: jimmychiuuuu

README.md

@@ -5,14 +5,17 @@
 
 This is a [Kubernetes][k8s] [device plugin][dp] implementation that enables
 the registration of Confidential Computing devices in a Google Kubernetes
-Engine (GKE) cluster for compute workloads. With the appropriate GKE setup
-and this plugin deployed, your Kubernetes cluster will be able to run jobs
-(e.g., Attestation) that require Confidential Computing devices.
+Engine (GKE) cluster for compute workloads. With the appropriate
+[GKE setup][gke-cc-docs] and this plugin deployed, your Kubernetes cluster
+will be able to run jobs (e.g., Attestation) that require Confidential
+Computing devices.
 
 This plugin supports the following technologies on GKE:
-*   **vTPM / AMD SEV:** Exposes `google.com/cc` resource.
-*   **AMD SEV-SNP:** Exposes `amd.com/sev-snp` resource. Requires AMD SNP machines.
-*   **Intel TDX:** Exposes `intel.com/tdx` resource. Requires Intel TDX machines.
+* **vTPM / AMD SEV:** Exposes `google.com/cc` resource.
+* **AMD SEV-SNP:** Exposes `amd.com/sev-snp` resource. Requires AMD SNP
+    machines.
+* **Intel TDX:** Exposes `intel.com/tdx` resource. Requires Intel TDX
+    machines.
 
 ## Prerequisites
 *   A GKE cluster with node pools configured to support the desired
@@ -31,7 +34,6 @@ node images) are branch-dependent:
 *   Refer to [Confidential VM Supported Configurations][supported-configs]
     for specific version and region availability.
 
-
 ## Deployment
 The device plugin needs to be run on all the nodes that are equipped with
 Confidential Computing devices.  The simplest way to do this is to create a
@@ -52,10 +54,80 @@ or directly pull from the web using
 kubectl create -f https://raw.githubusercontent.com/google/cc-device-plugin/main/manifests/cc-device-plugin.yaml
 ```
 
+## Using the Exposed Devices
+
+To use the devices, request them in your Pod's resource limits. This will cause
+the device plugin to mount the appropriate device node into your container.
+
+**Example: Requesting Intel TDX**
+
+```yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  name: example-tdx-pod
+spec:
+  containers:
+  - name: test-container
+    image: ubuntu # Your application image
+    command: ["/bin/sh", "-c", "ls -l /dev/tdx_guest; sleep 3600"]
+    resources:
+      limits:
+        intel.com/tdx: 1 # Request TDX device
+  nodeSelector:
+    cloud.google.com/gke-confidential-nodes-instance-type: "TDX"
+    cloud.google.com/machine-family: "c3"
+```
+Inside this container, `/dev/tdx_guest` will be available for interacting
+with the Intel Trust Domain.
+
+**Example: Requesting AMD SEV-SNP**
+
+```yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  name: example-sev-snp-pod
+spec:
+  containers:
+  - name: test-container
+    image: ubuntu # Your application image
+    command: ["/bin/sh", "-c", "ls -l /dev/sev-guest; sleep 3600"]
+    resources:
+      limits:
+        amd.com/sev-snp: 1 # Request SEV-SNP device
+  nodeSelector:
+    cloud.google.com/gke-confidential-nodes-instance-type: "SEV_SNP"
+    cloud.google.com/machine-family: "n2d"
+```
+Inside this container, `/dev/sev-guest` will be available for interacting
+with the AMD Secure Processor.
+
+**Example: Requesting vTPM / AMD SEV**
+
+```yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  name: example-vtpm-pod
+spec:
+  containers:
+  - name: test-container
+    image: ubuntu # Your application image
+    command: ["/bin/sh", "-c", "ls -l /dev/tpmrm0; sleep 3600"]
+    resources:
+      limits:
+        google.com/cc: 1 # Request vTPM device
+  nodeSelector:
+    cloud.google.com/gke-confidential-nodes-instance-type: "SEV"
+```
+Inside this container, `/dev/tpmrm0` will be available.
+
 [dp]: https://kubernetes.io/docs/concepts/cluster-administration/device-plugins/
 [k8s]: https://kubernetes.io
 [tpm]: https://cloud.google.com/compute/shielded-vm/docs/shielded-vm#vtpm
 [sevsnp]: https://cloud.google.com/confidential-computing/confidential-vm/docs/confidential-vm-overview#amd_sev-snp
-[tdx]: https://cloud.google.com/blog/products/identity-security/confidential-vms-on-intel-cpus-your-datas-new-intelligent-defense
+[tdx]: https://cloud.google.com/confidential-computing/confidential-vm/docs/confidential-vm-overview#intel_tdx
 [release]: https://us-central1-docker.pkg.dev/gce-confidential-compute/release/cc-device-plugin
 [supported-configs]: https://cloud.google.com/confidential-computing/confidential-vm/docs/supported-configurations
+[gke-cc-docs]: https://cloud.google.com/kubernetes-engine/docs/how-to/confidential-gke-nodes