Recording and slides of the post-copy for guest_memfd discussion: https://drive.google.com/corp/drive/folders/1_3bLYrR7oYZ06XvOPY_xZGUApGhq-j3W?resourcekey=0-0C1BYqhodcNvHFIqVwKMTg Key takeaways: - There is no known use case for tying "data invalid" to the guest_memfd inode, i.e. letting each "view" (struct file / struct kvm / VM) control its own behavior is acceptable, and arguably desirable as it provides userspace more flexibility. - If the "data invalid" attribute is tied to a given view, then routing the ioctl() through KVM provides a superset of functionality compared to making a guest_memfd specific ioctl(), e.g. KVM can apply the attribute to any gfn regardless of backing store. - Pursuing a fully generic file-based solution is undesirable as there are a large number of questions that need answers, and there is no known use case beyond KVM to drive those discussions. Feel free to chime in with anything important that I missed.
