Encrypted and integrity-protected storage for a virtual machine

A computer system, comprising:

• a processor system;
• and
• a computer storage medium that stores computer-executable instructions that are executable by the processor system to at least:
• load a container image as a first filesystem volume for use by a guest operating system (OS) of a virtual machine (VM), including:
• obtaining a root integrity hash that corresponds to the container image from a VM firmware layer that executes in a memory context within the VM isolated from the guest OS;
• determining that data of the container image has a valid integrity state, including validating a first hash tree stored within the container image based on the root integrity hash;
• and
• creating the first filesystem volume as a read-only volume from the container image based on the data of the container image having the valid integrity state;
• load a virtual disk image as a second filesystem volume for use by the guest OS, including:
• generating an ephemeral encryption key, the ephemeral encryption key being stored exclusively within a memory of the VM;
• creating a filesystem on the virtual disk image, creating the filesystem including:
• enabling an encryption feature of the filesystem, the encryption feature of the filesystem being configured to encrypt data written to the filesystem based on the ephemeral encryption key;
• and
• enabling an integrity protection feature of the filesystem, the integrity protection feature being configured to create a writable second hash tree that stores hashes representing data written to the filesystem;
• and
• creating the second filesystem volume as a read-write volume from the filesystem, wherein:
• when a data block is written to the second filesystem volume, the data block is encrypted based on the ephemeral encryption key, and a hash representing the data block is added to the writable second hash tree;
• and
• when the data block is read from the second filesystem volume, the data block is validated using the hash representing the data block;
• create a third filesystem volume as a union of the first filesystem volume and the second filesystem volume, wherein writes to the third filesystem volume are directed to the second filesystem volume;
• and
• expose the third filesystem volume as a system volume for the guest OS.

A computer storage medium that stores computer-executable instructions that are executable by a processor system to at least:

• load a plurality of container images as a first filesystem volume for use by a guest operating system (OS) of a virtual machine (VM), including:
• obtaining a plurality of root integrity hashes, each corresponding to a different container image;
• determining that data of each container image has a valid integrity state, including validating a hash tree stored within each container image based on a corresponding root integrity hash;
• creating a merged filesystem namespace from the plurality of container images;
• and
• creating the first filesystem volume as a read-only volume from the merged filesystem namespace;
• load a virtual disk image as a second filesystem volume for use by the guest OS, including:
• generating an ephemeral encryption key, the ephemeral encryption key being stored exclusively within a memory of the VM;
• creating a filesystem on the virtual disk image, creating the filesystem including:
• enabling an encryption feature of the filesystem, the encryption feature of the filesystem being configured to encrypt data written to the filesystem based on the ephemeral encryption key;
• and
• enabling an integrity protection feature of the filesystem, the integrity protection feature being configured to create a writable second hash tree that stores hashes representing data written to the filesystem;
• and
• creating the second filesystem volume as a read-write volume from the filesystem, wherein:
• when a data block is written to the second filesystem volume, the data block is encrypted based on the ephemeral encryption key, and a hash representing the data block is added to the writable second hash tree;
• and
• when the data block is read from the second filesystem volume, the data block is validated using the hash representing the data block;
• create a third filesystem volume as a union of the first filesystem volume and the second filesystem volume, wherein writes to the third filesystem volume are directed to the second filesystem volume;
• and
• expose the third filesystem volume as a system volume for the guest OS.