Importing VM to Proxmox from AWS EC2
Use the AWSCLI vm-export-import tools to export the EC2 instance into an OVA (making sure to include the metadata), and transfer the OVA to the PVE hypervisor.
Import the VM following steps here https://pve.proxmox.com/wiki/Migration_of_servers_to_Proxmox_VE
It will import a VM without a network interface and without a bootable device. Detach the disk, reattach as virtio, add a network interface, and configure the booting device.
There are some problems with EC2's grub config, so you need to run "update-initramfs -uk all" from a boot repair disk ISO mounted (netboot.xyz works for this). Then run the bootrepair wizard for good measure.
Finally, add a serial port and set the display to use it. A serial port is REQUIRED for the instance to correctly boot.
Might also want to a) set the root password, b) remove the blocking login message from /root/.ssh/authorized_keys, c) enable PasswordAuthentication and RootLogin in sshd_config