Comment 0 for bug 1774605

PowerPC KVM guest does not emulate L2 and L2 caches for vCPU, it would be good to have them enabled if not any known issues/limitation already with PowerPC.

Host Env:
kernel: 4.17.0-rc7-00045-g0512e0134582
qemu: v2.12.0-923-gc181ddaa17-dirty
#libvirtd -V
libvirtd (libvirt) 4.4.0

Guest Kernel:
# uname -a
Linux atest-guest 4.17.0-rc7-00045-g0512e0134582 #9 SMP Fri Jun 1 02:55:50 EDT 2018 ppc64le ppc64le ppc64le GNU/Linux

Guest:
# lscpu
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 16
On-line CPU(s) list: 0-15
Thread(s) per core: 8
Core(s) per socket: 2
Socket(s): 1
NUMA node(s): 1
Model: 2.1 (pvr 004b 0201)
Model name: POWER8 (architected), altivec supported
Hypervisor vendor: KVM
Virtualization type: para
L1d cache: 64K
L1i cache: 32K
NUMA node0 CPU(s): 0-15

background: x86 enabling cpu L2 cache bydefault and L3 cache on demand for kvm guest
and claims performance improvement as vcpus can be
benefited with lesser `vmexits due to guest send IPIs.` with L3 cache enabled, below was patch for same.

https://git.qemu.org/?p=qemu.git;a=commit;h=14c985cffa6cb177fc01a163d8bcf227c104718c