There's mature VirtIO drivers for just about everything already, under the virtio-win umbrella: https://github.com/virtio-win/kvm-guest-drivers-windows

My desktop PC is using libvirt+qemu (on an Arch host. I use Arch, btw) to PCI passthru my RTX 4090 GPU to a Windows guest. I installed the guest initially with emulated SATA for the main drive. Once Windows was up and running, I installed virtio-win and the guest is now using virtIO accelerated drivers for the network interface + main disk. I'm also sharing some filesystems using virtio-fs.