Linaro generates some minimal openembedded based aarch64 disk images, which are useful for virt testing. There's simple instructions over here for running them with qemu on an x86 host. But with Fedora 21 packages, you can also these images with virt-install + libvirt + qemu.

Finally, import it with virt-install. The command and output are:

$ sudo virt-install
     --name linaro-aarch64 --ram 1024
     --arch aarch64 --cpu cortex-a57
     --disk vexpress64-openembedded_minimal-armv8-gcc-4.9_20141023-693.img
     --boot machine=virt,kernel=Image,kernel_args="root=/dev/vda2 rw rootwait mem=1024M console=ttyAMA0,38400n8"

Starting install...
Creating domain...                                     |    000:00   
Connected to domain linaro-aarch64
Escape character is ^]
[    0.000000] Linux version 3.17.0-1-linaro-vexpress64 (buildslave@x86-64-07) (gcc version 4.8.3 20140401 (prerelease) (crosstool-NG linaro-1.13.1-4.8-2014.04 - Linaro GCC 4.8-2014.04) ) #1ubuntu1~ci+141022120835 SMP PREEMPT Wed Oct 22 12:09:19 UTC 20
[    0.000000] CPU: AArch64 Processor [411fd070] revision 0
[    0.000000] Detected PIPT I-cache on CPU0
[    0.000000] Memory limited to 1024MB
Last login: Wed Nov 19 17:16:22 UTC 2014 on tty1

(Maybe you're wondering, what about fedora images? They are a bit different, since they expect to run with UEFI. I'll blog about that soon once I finish some testing)