现象：错误：无效参数：could not find capabilities for arch=aarch64
解决：
qemu源码编译：（需要指定--cpu=aarch64）
./configure --target-list=arm-softmmu,aarch64-softmmu --enable-kvm --enable-rbd --enable-vnc --prefix=/usr/local --cpu=aarch64
make
make install
最后重启libvirtd服务：systemctl restart libvirtd