I figured out what the problem was. Proxmox no longer uses Grub to boot the system, but rather systemd-boot and the documentation in the above-linked docs haven't been updated. I edited /etc/kernel/cmdline instead, ran proxmox-boot-tool refresh and rebooted and everything worked!
I have an R730XD running Proxmox and I want to pass through a gpu to a VM. Virtualization and SR-IOV are enabled in the BIOS and I've followed the guide on how to enable IOMMU in the proxmox documentation but IOMMU still won't turn on. I tried updating all the firmware since the BIOS was out of date for the E5-2640 v3's I've got installed. How do I enable VT-d?
How do I enable VT-d in my R730XD?