The KubeVirt provider for HyperShift uses an RHCOS image to boot VMs that will be used as nodes of the hosted clusters.
The OCP release payload image contains a pointer to it but oc-mirror ignores it.

The pull URL of this image can be obtained from the OCP release payload image as:

$ cat release-manifests/0000_50_installer_coreos-bootimages.yaml | yq -r .data.stream | jq -r '.architectures.x86_64.images.kubevirt."digest-ref"'
quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:6ae6015fec8edc8c46248e2f7beba7ef1ce00efe7c050f71f9658043435f7715

    100%

    1. Mirror the OCP release payload image with oc-mirror
    2. Check for the presence of the RHCOS image for the HyperShift KubeVirt provider (cat release-manifests/0000_50_installer_coreos-bootimages.yaml | yq -r .data.stream | jq -r '.architectures.x86_64.images.kubevirt."digest-ref"')
    3.
    

    The RHCOS image used for the HyperShift KubeVirt provider is not present on the internal registry 

    The RHCOS image used for the HyperShift KubeVirt provider got mirrored to the internal registry 

    This is required for the disconnected scenario of HCP with the Kubevirt Provider