Windows 11 support

[rowlap]

Although Windows 10 will be around until 2025, starting to think about upgrades, I saw the following error trying to install Windows 11 on Ganeti:

This PC doesn't currently meet Windows 11 system requirements
Here's why:
X The PC must support TPM 2.0.
X The PC must support Secure Boot.

As I couldn't see any other active discussion, trying to start one here. (TPM was mentioned in #506, but didn't go anywhere.)

[tpaulic]

== Windows 11 install (TPM, UEFI boot) ==

Install TPM
apt install swtpm swtpm-tools

Install UEFI boot support
apt install ovmf

Create an instance in the classic way
Create TPM interface
mkdir /tmp/tpm0
swtpm socket --tpmstate dir=/tmp/tpm0 --tpm2 --ctrl type=unixio,path=/tmp/tpm0/swtpm-sock & sleep 2

Modify the instance to run both UEFI and TPM
gnt-instance modify -H kvm_extra="-device virtio-rng-pci,bus=pci.0,addr=0x1e,max-bytes=1024,period=1000\ -drive if=pflash,format=raw,readonly,file=/usr/share/OVMF/OVMF_CODE_4M.fd -chardev socket,id=chrtpm,path=/tmp/tpm0/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0" instancename

Start the instance and install Windows 11. After the installation, we no longer need the TPM.
Modify the instance and remove TPM but leave UEFI
gnt-instance modify -H kvm_extra="-device virtio-rng-pci,bus=pci.0,addr=0x1e,max-bytes=1024,period=1000\ -drive if=pflash,format=raw,readonly,file=/usr/share/OVMF/OVMF_CODE_4M.fd" instancename