Major Changes in microvm.nix

0.5.0 (To be released)

tap interfaces are now multi-queue when running with more than one VCPU. Update your host!
The host module enables Kernel Samepage Merging by default.
qemu can run non-native systems by using its Tiny Code Generator instead of KVM.
SSH deployment scripts are added as config.microvm.deploy.rebuild
qemu gets rid of the q35 machine model entirely as the microvm model supports PCI, USB, and ACPI by now.

cloud-hypervisor replaces rust-hypervisor-firmware with direct kernel+initramfs loading.
The microvm module now optimizes the NixOS configuration for size.
crosvm now supports macvtap interfaces.
The option microvm.qemu.bios has been dropped again for simplicity reasons.

qemu boots fast with the shipped SeaBIOS if after both SATA and the network interface option ROM (iPXE) have been disabled.
microvm.kernelParams always copy boot.kernelParams
firecracker is no longer launched through firectl.
Networking example documentation has been split into multiple scenarios.
Vsock support has been added for Hypervisors that connect them to the Linux host's AF_VSOCK: qemu, crosvm, and kvmtool.
Our packages and overlay include the unstable version of waypipe, featuring Vsock support.
Add support for the old command-line parameter syntax that returned with cloud-hypervisor 36.0.

Stop building a custom kernel by booting the NixOS kernel with an initrd.
New Hypervisor: stratovirt by Huawei
Support fully declarative MicroVMs that are part of the host's NixOS configuration. No Flakes required!
We use squashfs-tools-ng now.
The microvm-console script has been removed because pty console setup was too cumbersome to maintain across all hypervisors.
microvm.storeDiskType defaults to "erofs" now for higher runtime performance.