Signed-off-by: Dorjoy Chowdhury <dorjoychy...@gmail.com> --- MAINTAINERS | 1 + docs/system/i386/nitro-enclave.rst | 78 ++++++++++++++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 docs/system/i386/nitro-enclave.rst
diff --git a/MAINTAINERS b/MAINTAINERS index 37411dfffa..ca06473869 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1877,6 +1877,7 @@ F: hw/core/eif.c F: hw/core/eif.h F: hw/i386/nitro_enclave.c F: include/hw/i386/nitro_enclave.h +F: docs/system/i386/nitro-enclave.rst Machine core M: Eduardo Habkost <edua...@habkost.net> diff --git a/docs/system/i386/nitro-enclave.rst b/docs/system/i386/nitro-enclave.rst new file mode 100644 index 0000000000..3fb9e06893 --- /dev/null +++ b/docs/system/i386/nitro-enclave.rst @@ -0,0 +1,78 @@ +'nitro-enclave' virtual machine (``nitro-enclave``) +=================================================== + +``nitro-enclave`` is a machine type which emulates an ``AWS nitro enclave`` +virtual machine. `AWS nitro enclaves`_ is an `Amazon EC2`_ feature that allows +creating isolated execution environments, called enclaves, from Amazon EC2 +instances which are used for processing highly sensitive data. Enclaves have +no persistent storage and no external networking. The enclave VMs are based +on Firecracker microvm with a vhost-vsock device for communication with the +parent EC2 instance that spawned it and a Nitro Secure Module (NSM) device +for cryptographic attestation. The parent instance VM always has CID 3 while +the enclave VM gets a dynamic CID. Enclaves use an EIF (`Enclave Image Format`_) +file which contains the necessary kernel, cmdline and ramdisk(s) to boot. + +In QEMU, ``nitro-enclave`` is a machine type based on ``microvm`` similar to how +``AWS nitro enclaves`` are based on ``Firecracker`` microvm. This is useful for +local testing of EIF files using QEMU instead of running real AWS Nitro Enclaves +which can be difficult for debugging due to its roots in security. The vsock +device emulation is done using vhost-user-vsock which means another process that +can do the userspace emulation, like `vhost-device-vsock`_ from rust-vmm crate, +must be run alongside nitro-enclave for the vsock communication to work. + +``libcbor`` and ``gnutls`` are required dependencies for nitro-enclave machine +support to be added when building QEMU from source. + +.. _AWS nitro enlaves: https://docs.aws.amazon.com/enclaves/latest/user/nitro-enclave.html +.. _Amazon EC2: https://aws.amazon.com/ec2/ +.. _Enclave Image Format: https://github.com/aws/aws-nitro-enclaves-image-format +.. _vhost-device-vsock: https://github.com/rust-vmm/vhost-device/tree/main/vhost-device-vsock + +Using the nitro-enclave machine type +------------------------------ + +Machine-specific options +~~~~~~~~~~~~~~~~~~~~~~~~ + +It supports the following machine-specific options: + +- nitro-enclave.vsock=string (required) (Id of the chardev from '-chardev' option that vhost-user-vsock device will use) +- nitro-enclave.id=string (optional) (Set enclave identifier) +- nitro-enclave.parent-role=string (optional) (Set parent instance IAM role ARN) +- nitro-enclave.parent-id=string (optional) (Set parent instance identifier) + + +Running a nitro-enclave VM +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +First, run `vhost-device-vsock`_ (or a similar tool that supports vhost-user-vsock). +The forward-cid option below with value 1 forwards all connections from the enclave +VM to the host machine and the forward-listen (port numbers separated by '+') is used +for forwarding connections from the host machine to the enclave VM. + + $ vhost-device-vsock \ + --vm guest-cid=4,forward-cid=1,forward-listen=9001+9002,socket=/tmp/vhost4.socket + +Now run the necessary applications on the host machine so that the nitro-enclave VM +applications' vsock communication works. For example, the nitro-enclave VM's init +process connects to CID 3 and sends a single byte hello heartbeat (0xB7) to let the +parent VM know that it booted expecting a heartbeat (0xB7) response. So you must run +a AF_VSOCK server on the host machine that listens on port 9000 and sends the heartbeat +after it receives the heartbeat for enclave VM to boot successfully. You should run all +the applications on the host machine that would typically be running in the parent EC2 +VM for successful communication with the enclave VM. + +Then run the nitro-enclave VM using the following command where ``hello.eif`` is +an EIF file you would use to spawn a real AWS nitro enclave virtual machine: + + $ qemu-system-x86_64 -M nitro-enclave,vsock=c,id=hello-world \ + -kernel hello-world.eif -nographic -m 4G --enable-kvm -cpu host \ + -chardev socket,id=c,path=/tmp/vhost4.socket + +In this example, the nitro-enclave VM has CID 4. If there are applications that +connect to the enclave VM, run them on the host machine after enclave VM starts. +You need to modify the applications to connect to CID 1 (instead of the enclave +VM's CID) and use the forward-listen (e.g., 9001+9002) option of vhost-device-vsock +to forward the ports they connect to. + +.. _vhost-device-vsock: https://github.com/rust-vmm/vhost-device/tree/main/vhost-device-vsock#using-the-vsock-backend -- 2.39.5
