Persisting Guest Memory and Kernel/Device State Safely with pkernfs

Explore the challenges and solutions for hypervisor live updates with device assignment in this Linux Plumbers Conference talk. Delve into the complexities of pausing and serializing running VMs, kexec-ing into a new kernel, and deserializing/resuming VMs while maintaining device assignment functionality. Examine the proposed pkernfs solution, a new in-memory persistent file system designed to store guest memory, userspace memory, and kernel/device memory for IOMMU page tables. Learn about improving the security posture of guest memory, integrating with gmem, and avoiding struct page overhead for guest memory. Witness a demonstration of hypervisor live update with PCI device assignment and gain insights into the kernel memory management aspects of this technology. Understand the relationship between this work and existing projects like QEMU live update patch set, and explore potential applications and implications for virtualization and system management.