TD guest boot up slowly with huge resource

Test Environment

• Host/Guest: CentOS Stream release 9
• Host/Guest kernel version: 5.14.0-362.el9s.x86_64
• Architecture: x86
• QEMU flavor: qemu-system-x86_64(/usr/libexec/qemu-kvm)
• QEMU version: qemu-kvm-8.0.0-14.el9s

Bug description When boot TD guest with large memory, for example 64G, it takes about 30 seconds slower than expected

• QEMU command line:

/usr/libexec/qemu-kvm \
     -accel kvm \
     -m 64G -smp 64 \
     -name process=tdxvm,debug-threads=on \
     -cpu host \
     -object tdx-guest,id=tdx \
     -machine q35,hpet=off,kernel_irqchip=split,memory-encryption=tdx,memory-backend=ram1 \
     -object memory-backend-ram,id=ram1,size=64G,private=on \
     -nographic -vga none \
     -chardev stdio,id=mux,mux=on,signal=off -device virtio-serial -device virtconsole,chardev=mux \
     -bios /usr/share/edk2/ovmf/OVMF.inteltdx.fd \
     -serial chardev:mux \
     -nodefaults \
     -device virtio-net-pci,netdev=nic0 -netdev user,id=nic0,hostfwd=tcp::10022-:22 \
     -drive file=/home/tdx/centos9.qcow2,if=none,id=virtio-disk0 \
     -device virtio-blk-pci,drive=virtio-disk0 \